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Hemorrhage control system gets expanded approval
Control System
The US Food and Drug Administration has expanded the indication for the iTClamp® Hemorrhage Control System.
It is now approved to provide temporary control of severe bleeding of the neck. The product was already approved for use on the extremities, axilla, inguinal areas, and the scalp.
The iTClamp is a temporary wound closure device designed to control severe bleeding in seconds.
It seals the edges of a wound closed to create a temporary pool of blood under pressure. This forms a stable clot that mitigates further blood
loss until the wound can be surgically repaired.
Each iTClamp measures less than 2 by 2 inches and weighs less than 3 ounces. It requires only minimal training and gross motor skills to use, according to iTraumaCare, the company that makes the product.
“Addressing difficult-to-control hemorrhage in the neck has been a consistent problem with few solutions,” said Dennis Filips, MD, founder and chief medical officer of iTraumaCare.
“This expanded indication for the iTClamp will allow first responders, medical professionals, and tactical and battlefield medics to use the device in even more meaningful ways to improve patient care.” 
Control System
The US Food and Drug Administration has expanded the indication for the iTClamp® Hemorrhage Control System.
It is now approved to provide temporary control of severe bleeding of the neck. The product was already approved for use on the extremities, axilla, inguinal areas, and the scalp.
The iTClamp is a temporary wound closure device designed to control severe bleeding in seconds.
It seals the edges of a wound closed to create a temporary pool of blood under pressure. This forms a stable clot that mitigates further blood
loss until the wound can be surgically repaired.
Each iTClamp measures less than 2 by 2 inches and weighs less than 3 ounces. It requires only minimal training and gross motor skills to use, according to iTraumaCare, the company that makes the product.
“Addressing difficult-to-control hemorrhage in the neck has been a consistent problem with few solutions,” said Dennis Filips, MD, founder and chief medical officer of iTraumaCare.
“This expanded indication for the iTClamp will allow first responders, medical professionals, and tactical and battlefield medics to use the device in even more meaningful ways to improve patient care.”
Control System
The US Food and Drug Administration has expanded the indication for the iTClamp® Hemorrhage Control System.
It is now approved to provide temporary control of severe bleeding of the neck. The product was already approved for use on the extremities, axilla, inguinal areas, and the scalp.
The iTClamp is a temporary wound closure device designed to control severe bleeding in seconds.
It seals the edges of a wound closed to create a temporary pool of blood under pressure. This forms a stable clot that mitigates further blood
loss until the wound can be surgically repaired.
Each iTClamp measures less than 2 by 2 inches and weighs less than 3 ounces. It requires only minimal training and gross motor skills to use, according to iTraumaCare, the company that makes the product.
“Addressing difficult-to-control hemorrhage in the neck has been a consistent problem with few solutions,” said Dennis Filips, MD, founder and chief medical officer of iTraumaCare.
“This expanded indication for the iTClamp will allow first responders, medical professionals, and tactical and battlefield medics to use the device in even more meaningful ways to improve patient care.”
Group creates universal platelets using iPSCs
Credit: Salk Institute
Researchers say they can use induced pluripotent stem cells (iPSCs) to produce large-scale quantities of universal donor platelets.
The team generated megakaryocytes and platelets from iPSCs under feeder-free conditions.
They were able to produce universal platelets by removing a gene essential to expression of the major histocompatibility antigens.
The resulting platelets were functional and behaved like normal human platelets.
The researchers described this method of platelet production, owned by Advanced Cell Technology, Inc., in Stem Cell Reports.
“Unlike other sources of platelets, human induced pluripotent stem cells can be propagated indefinitely, providing a potentially unlimited source of cells for therapeutic purposes,” said Robert Lanza, MD, Chief Scientific Officer at Advanced Cell Technology.
“This study shows that platelets may be produced from [iPSCs] without the need for serum and feeders and, thus, removes potential risks associated with contaminants and pathogens.”
Dr Lanza and his colleagues used a 3-step protocol to differentiate human iPSCs into megakaryocytes and functional platelets in less than 20 days. The method incorporates several discrete intermediate cells, including proprietary hemogenic endothelium-like cells.
The technique allows for long-term storage of megakaryocyte progenitors so they can be available within a few days when needed to produce large quantities of platelets for transfusion.
In addition, by knocking out the β2-microglobulin gene, the researchers were able to generate platelets that are negative for the major histocompatibility antigens.
This suggests the platelets could be transfused into almost any patient, and the method might even prevent platelet refractoriness, according to the researchers.
The team found no major differences in the iPSC platelets and normal human platelets. The iPSC platelets formed aggregates, lamellipodia, and filopodia after activation, just like normal platelets.
Also like normal platelets, the iPSC platelets circulated for at least 8 hours in macrophage-depleted NOD/SCID mice, with a time to reach maximal accumulation of 30 minutes to an hour.
In another murine experiment, iPSC platelets incorporated into a growing thrombus just like normal human platelets, with an average number of 9.0 ± 1.8 platelets per thrombus.
“The platelets generated with our technology are functional and behave like normal human platelets,” Dr Lanza said. “This technology and these results represent an important step towards generating unlimited supplies of universal donor platelets for transfusion.”
Credit: Salk Institute
Researchers say they can use induced pluripotent stem cells (iPSCs) to produce large-scale quantities of universal donor platelets.
The team generated megakaryocytes and platelets from iPSCs under feeder-free conditions.
They were able to produce universal platelets by removing a gene essential to expression of the major histocompatibility antigens.
The resulting platelets were functional and behaved like normal human platelets.
The researchers described this method of platelet production, owned by Advanced Cell Technology, Inc., in Stem Cell Reports.
“Unlike other sources of platelets, human induced pluripotent stem cells can be propagated indefinitely, providing a potentially unlimited source of cells for therapeutic purposes,” said Robert Lanza, MD, Chief Scientific Officer at Advanced Cell Technology.
“This study shows that platelets may be produced from [iPSCs] without the need for serum and feeders and, thus, removes potential risks associated with contaminants and pathogens.”
Dr Lanza and his colleagues used a 3-step protocol to differentiate human iPSCs into megakaryocytes and functional platelets in less than 20 days. The method incorporates several discrete intermediate cells, including proprietary hemogenic endothelium-like cells.
The technique allows for long-term storage of megakaryocyte progenitors so they can be available within a few days when needed to produce large quantities of platelets for transfusion.
In addition, by knocking out the β2-microglobulin gene, the researchers were able to generate platelets that are negative for the major histocompatibility antigens.
This suggests the platelets could be transfused into almost any patient, and the method might even prevent platelet refractoriness, according to the researchers.
The team found no major differences in the iPSC platelets and normal human platelets. The iPSC platelets formed aggregates, lamellipodia, and filopodia after activation, just like normal platelets.
Also like normal platelets, the iPSC platelets circulated for at least 8 hours in macrophage-depleted NOD/SCID mice, with a time to reach maximal accumulation of 30 minutes to an hour.
In another murine experiment, iPSC platelets incorporated into a growing thrombus just like normal human platelets, with an average number of 9.0 ± 1.8 platelets per thrombus.
“The platelets generated with our technology are functional and behave like normal human platelets,” Dr Lanza said. “This technology and these results represent an important step towards generating unlimited supplies of universal donor platelets for transfusion.”
Credit: Salk Institute
Researchers say they can use induced pluripotent stem cells (iPSCs) to produce large-scale quantities of universal donor platelets.
The team generated megakaryocytes and platelets from iPSCs under feeder-free conditions.
They were able to produce universal platelets by removing a gene essential to expression of the major histocompatibility antigens.
The resulting platelets were functional and behaved like normal human platelets.
The researchers described this method of platelet production, owned by Advanced Cell Technology, Inc., in Stem Cell Reports.
“Unlike other sources of platelets, human induced pluripotent stem cells can be propagated indefinitely, providing a potentially unlimited source of cells for therapeutic purposes,” said Robert Lanza, MD, Chief Scientific Officer at Advanced Cell Technology.
“This study shows that platelets may be produced from [iPSCs] without the need for serum and feeders and, thus, removes potential risks associated with contaminants and pathogens.”
Dr Lanza and his colleagues used a 3-step protocol to differentiate human iPSCs into megakaryocytes and functional platelets in less than 20 days. The method incorporates several discrete intermediate cells, including proprietary hemogenic endothelium-like cells.
The technique allows for long-term storage of megakaryocyte progenitors so they can be available within a few days when needed to produce large quantities of platelets for transfusion.
In addition, by knocking out the β2-microglobulin gene, the researchers were able to generate platelets that are negative for the major histocompatibility antigens.
This suggests the platelets could be transfused into almost any patient, and the method might even prevent platelet refractoriness, according to the researchers.
The team found no major differences in the iPSC platelets and normal human platelets. The iPSC platelets formed aggregates, lamellipodia, and filopodia after activation, just like normal platelets.
Also like normal platelets, the iPSC platelets circulated for at least 8 hours in macrophage-depleted NOD/SCID mice, with a time to reach maximal accumulation of 30 minutes to an hour.
In another murine experiment, iPSC platelets incorporated into a growing thrombus just like normal human platelets, with an average number of 9.0 ± 1.8 platelets per thrombus.
“The platelets generated with our technology are functional and behave like normal human platelets,” Dr Lanza said. “This technology and these results represent an important step towards generating unlimited supplies of universal donor platelets for transfusion.”
Megakaryocytes can control HSCs, team finds
to a megakaryocyte (red)
Credit: Meng Zhao
For the first time, researchers have shown that hematopoietic stem cells (HSCs) can be directly controlled by their own progeny, megakaryocytes.
Preclinical experiments revealed that megakaryocytes maintain HSC quiescence during homeostasis and promote HSC regeneration after chemotherapeutic stress.
The discovery suggests megakaryocytes might be used to treat patients with low blood cell counts and to expand HSCs for transplant.
The researchers described these findings in Nature Medicine.
The team examined the relationship between megakaryocytes and HSCs in mouse bone marrow. And they discovered that, as a terminally differentiated progeny, megakaryocytes regulate HSCs by performing two previously unknown functions.
“Megakaryocytes can directly regulate the amount of hematopoietic stem cells by telling the cells when they need to keep in the quiescent stage and when they need to start proliferating to meet increased demand,” said study author Meng Zhao, PhD, of the Stowers Institute for Medical Research in Kansas City, Missouri.
The researchers found that the protein transforming growth factor B1 (TGF-B1), contained in megakaryocytes, signaled quiescence.
And, when under stress from chemotherapy, megakaryocytes signaled fibroblast growth factor 1 (FGF1), to stimulate HSC proliferation.
“Our findings suggest that megakaryocytes are required for the recovery of hematopoietic stem cells post-chemotherapy,” said Linheng Li, PhD, also of the Stowers Institute.
The discovery could provide insight for using megakaryocyte-derived factors, such as TGF-B1 and FGF1, clinically to facilitate the regeneration of HSCs, he added.
Engineering a megakaryocyte niche that supports the growth of HSCs in culture is the next step for the researchers. They are also investigating whether a megakaryocyte niche can be used to help expand human HSCs in vitro for transplant.
These findings are supported by similar research also reported in Nature Medicine.
to a megakaryocyte (red)
Credit: Meng Zhao
For the first time, researchers have shown that hematopoietic stem cells (HSCs) can be directly controlled by their own progeny, megakaryocytes.
Preclinical experiments revealed that megakaryocytes maintain HSC quiescence during homeostasis and promote HSC regeneration after chemotherapeutic stress.
The discovery suggests megakaryocytes might be used to treat patients with low blood cell counts and to expand HSCs for transplant.
The researchers described these findings in Nature Medicine.
The team examined the relationship between megakaryocytes and HSCs in mouse bone marrow. And they discovered that, as a terminally differentiated progeny, megakaryocytes regulate HSCs by performing two previously unknown functions.
“Megakaryocytes can directly regulate the amount of hematopoietic stem cells by telling the cells when they need to keep in the quiescent stage and when they need to start proliferating to meet increased demand,” said study author Meng Zhao, PhD, of the Stowers Institute for Medical Research in Kansas City, Missouri.
The researchers found that the protein transforming growth factor B1 (TGF-B1), contained in megakaryocytes, signaled quiescence.
And, when under stress from chemotherapy, megakaryocytes signaled fibroblast growth factor 1 (FGF1), to stimulate HSC proliferation.
“Our findings suggest that megakaryocytes are required for the recovery of hematopoietic stem cells post-chemotherapy,” said Linheng Li, PhD, also of the Stowers Institute.
The discovery could provide insight for using megakaryocyte-derived factors, such as TGF-B1 and FGF1, clinically to facilitate the regeneration of HSCs, he added.
Engineering a megakaryocyte niche that supports the growth of HSCs in culture is the next step for the researchers. They are also investigating whether a megakaryocyte niche can be used to help expand human HSCs in vitro for transplant.
These findings are supported by similar research also reported in Nature Medicine.
to a megakaryocyte (red)
Credit: Meng Zhao
For the first time, researchers have shown that hematopoietic stem cells (HSCs) can be directly controlled by their own progeny, megakaryocytes.
Preclinical experiments revealed that megakaryocytes maintain HSC quiescence during homeostasis and promote HSC regeneration after chemotherapeutic stress.
The discovery suggests megakaryocytes might be used to treat patients with low blood cell counts and to expand HSCs for transplant.
The researchers described these findings in Nature Medicine.
The team examined the relationship between megakaryocytes and HSCs in mouse bone marrow. And they discovered that, as a terminally differentiated progeny, megakaryocytes regulate HSCs by performing two previously unknown functions.
“Megakaryocytes can directly regulate the amount of hematopoietic stem cells by telling the cells when they need to keep in the quiescent stage and when they need to start proliferating to meet increased demand,” said study author Meng Zhao, PhD, of the Stowers Institute for Medical Research in Kansas City, Missouri.
The researchers found that the protein transforming growth factor B1 (TGF-B1), contained in megakaryocytes, signaled quiescence.
And, when under stress from chemotherapy, megakaryocytes signaled fibroblast growth factor 1 (FGF1), to stimulate HSC proliferation.
“Our findings suggest that megakaryocytes are required for the recovery of hematopoietic stem cells post-chemotherapy,” said Linheng Li, PhD, also of the Stowers Institute.
The discovery could provide insight for using megakaryocyte-derived factors, such as TGF-B1 and FGF1, clinically to facilitate the regeneration of HSCs, he added.
Engineering a megakaryocyte niche that supports the growth of HSCs in culture is the next step for the researchers. They are also investigating whether a megakaryocyte niche can be used to help expand human HSCs in vitro for transplant.
These findings are supported by similar research also reported in Nature Medicine.
Trio-CES produces higher molecular diagnostic yield
Calvin, who was diagnosed
with Pitt-Hopkins Syndrome
via trio-CES
Credit: Lapidus family
A 3-pronged approach to clinical exome sequencing (CES) can provide a higher diagnostic yield than traditional molecular diagnostic methods, results of a new study suggest.
Investigators found that sequencing a patient’s exome together with his or her parents’—a method known as trio-CES—greatly improved the ability to reach a firm diagnosis in children with suspected genetic conditions.
This research was published in JAMA. It was released to coincide with a presentation at the American Society of Human Genetics Annual Meeting in San Diego.
The researchers performed CES on 814 patients with undiagnosed, suspected genetic conditions between January 2012 and August 2014. Sequencing was conducted as trio-CES or as proband-CES (only the affected individual sequenced) when parental samples were not available.
The team funneled the raw data through an informatics pipeline to identify variants from the standard human genome. Next, they applied a series of filters to the data based on the patient’s family history and other relevant aspects of his or her condition.
The investigators then hunted for all genes and mutations linked by medical literature to the patient’s symptoms. And a multidisciplinary team of experts reviewed the findings to reach a diagnosis.
Overall, 26% of patients (213/814) received a molecular diagnosis, with the causative variant(s) identified in a well-established clinical gene.
There was a significantly higher molecular diagnostic yield from cases performed as trio-CES relative to proband-CES—31% (127/410) and 22% (74/338), respectively.
In cases of developmental delay in children younger than 5 years (n=138), the molecular diagnosis rate was 41% (45/ 109) for trio-CES cases and 9% (2/23) for proband-CES cases.
The typical turnaround time for exome sequencing is less than 8 weeks, though test results have been returned to physicians within 10 days in medically urgent situations.
With preauthorization, many insurance providers cover the cost to sequence a child and both parents. If not, the out-of-pocket fee is about $6650.
“All families deserve a clear diagnosis of their child’s condition,” said study author Wayne Grody, MD, PhD, of the University of California, Los Angeles.
“Exome sequencing plays an important role in identifying the precise cause of a child’s illness. This is immediately useful to families and physicians in understanding how the disease occurred, preventing unnecessary testing, and developing the best strategies to treat it.”
The researchers noted, however, that the clinical implications of their findings should be better understood before trio- or proband-CES are routinely adopted.
Calvin, who was diagnosed
with Pitt-Hopkins Syndrome
via trio-CES
Credit: Lapidus family
A 3-pronged approach to clinical exome sequencing (CES) can provide a higher diagnostic yield than traditional molecular diagnostic methods, results of a new study suggest.
Investigators found that sequencing a patient’s exome together with his or her parents’—a method known as trio-CES—greatly improved the ability to reach a firm diagnosis in children with suspected genetic conditions.
This research was published in JAMA. It was released to coincide with a presentation at the American Society of Human Genetics Annual Meeting in San Diego.
The researchers performed CES on 814 patients with undiagnosed, suspected genetic conditions between January 2012 and August 2014. Sequencing was conducted as trio-CES or as proband-CES (only the affected individual sequenced) when parental samples were not available.
The team funneled the raw data through an informatics pipeline to identify variants from the standard human genome. Next, they applied a series of filters to the data based on the patient’s family history and other relevant aspects of his or her condition.
The investigators then hunted for all genes and mutations linked by medical literature to the patient’s symptoms. And a multidisciplinary team of experts reviewed the findings to reach a diagnosis.
Overall, 26% of patients (213/814) received a molecular diagnosis, with the causative variant(s) identified in a well-established clinical gene.
There was a significantly higher molecular diagnostic yield from cases performed as trio-CES relative to proband-CES—31% (127/410) and 22% (74/338), respectively.
In cases of developmental delay in children younger than 5 years (n=138), the molecular diagnosis rate was 41% (45/ 109) for trio-CES cases and 9% (2/23) for proband-CES cases.
The typical turnaround time for exome sequencing is less than 8 weeks, though test results have been returned to physicians within 10 days in medically urgent situations.
With preauthorization, many insurance providers cover the cost to sequence a child and both parents. If not, the out-of-pocket fee is about $6650.
“All families deserve a clear diagnosis of their child’s condition,” said study author Wayne Grody, MD, PhD, of the University of California, Los Angeles.
“Exome sequencing plays an important role in identifying the precise cause of a child’s illness. This is immediately useful to families and physicians in understanding how the disease occurred, preventing unnecessary testing, and developing the best strategies to treat it.”
The researchers noted, however, that the clinical implications of their findings should be better understood before trio- or proband-CES are routinely adopted.
Calvin, who was diagnosed
with Pitt-Hopkins Syndrome
via trio-CES
Credit: Lapidus family
A 3-pronged approach to clinical exome sequencing (CES) can provide a higher diagnostic yield than traditional molecular diagnostic methods, results of a new study suggest.
Investigators found that sequencing a patient’s exome together with his or her parents’—a method known as trio-CES—greatly improved the ability to reach a firm diagnosis in children with suspected genetic conditions.
This research was published in JAMA. It was released to coincide with a presentation at the American Society of Human Genetics Annual Meeting in San Diego.
The researchers performed CES on 814 patients with undiagnosed, suspected genetic conditions between January 2012 and August 2014. Sequencing was conducted as trio-CES or as proband-CES (only the affected individual sequenced) when parental samples were not available.
The team funneled the raw data through an informatics pipeline to identify variants from the standard human genome. Next, they applied a series of filters to the data based on the patient’s family history and other relevant aspects of his or her condition.
The investigators then hunted for all genes and mutations linked by medical literature to the patient’s symptoms. And a multidisciplinary team of experts reviewed the findings to reach a diagnosis.
Overall, 26% of patients (213/814) received a molecular diagnosis, with the causative variant(s) identified in a well-established clinical gene.
There was a significantly higher molecular diagnostic yield from cases performed as trio-CES relative to proband-CES—31% (127/410) and 22% (74/338), respectively.
In cases of developmental delay in children younger than 5 years (n=138), the molecular diagnosis rate was 41% (45/ 109) for trio-CES cases and 9% (2/23) for proband-CES cases.
The typical turnaround time for exome sequencing is less than 8 weeks, though test results have been returned to physicians within 10 days in medically urgent situations.
With preauthorization, many insurance providers cover the cost to sequence a child and both parents. If not, the out-of-pocket fee is about $6650.
“All families deserve a clear diagnosis of their child’s condition,” said study author Wayne Grody, MD, PhD, of the University of California, Los Angeles.
“Exome sequencing plays an important role in identifying the precise cause of a child’s illness. This is immediately useful to families and physicians in understanding how the disease occurred, preventing unnecessary testing, and developing the best strategies to treat it.”
The researchers noted, however, that the clinical implications of their findings should be better understood before trio- or proband-CES are routinely adopted.
Exome sequencing shows potential as diagnostic tool
Credit: Graham Colm
In a large study, whole-exome sequencing provided 25% of patients with a diagnosis related to a known genetic disease, giving young
patients and their parents some long-sought answers.
The technology was able to detect a number of rare genetic events and new mutations contributing to disease.
Among the medically actionable findings were mutations related to Fanconi anemia, erythrocytosis, hemolytic anemia, and von Willebrand disease.
“The findings in this report, I believe, will forever change the future practice of pediatrics and medicine as a whole,” said study author James R. Lupski, MD, PhD, of the Baylor College of Medicine in Houston.
“It is just a matter of time before genomics moves up on the physician’s list of things to do and is ordered before formulating a differential diagnosis. It will be the new ‘family history’ that, better yet, gets you both the important variants inherited from each parent and the new mutations that contribute to disease susceptibility.”
This research was published in JAMA and is set to be presented on October 21 at the American Society of Human Genetics Annual Meeting in San Diego.
The researchers had previously conducted a pilot study of whole-exome sequencing that included 250 patients and revealed a 25% molecular diagnostic rate.
This current study included 2000 patients (88% pediatric) with clinical whole-exome sequencing analyzed between June 2012 and August 2014. The majority of patients—87.8%—had neurological disorders or a developmental delay, and 12.2% had non-neurological disorders.
The researchers collected peripheral blood, tissue, or extracted DNA samples from patients and their parents. The team sequenced patients’ DNA and compared those results to the normal reference. Any disease-associated mutations were then compared with the parent’s DNA to determine if the child inherited it from one or both parents.
In all, 504 patients (25.2%) received a molecular diagnosis, and 58% of the diagnostic mutations had not previously been reported. Two hundred and eighty patients had a single mutation that caused disease, 181 were autosomal recessive, 65 were X-linked, and 1 was presumed inherited through the mitochondria.
In 5 cases, the patient inherited 2 copies of the mutated gene from the same parent. Of the dominant mutations, 208 were de novo mutations not inherited from either parent, 32 were inherited, and 40 were not determined because parental samples were not available.
Among the de novo mutations, 5 demonstrated mosaicism, which suggested the mutation occurred after fertilization.
The researchers found 708 presumptive causative variant alleles in the 504 cases. Almost 30% of the diagnoses occurred in disease genes only identified by researchers in the last 3 years. In 65 cases, there was no available genetic test other than whole-exome sequencing to find the mutated gene at the time the test was ordered.
Twenty-three patients (about 5%) had mutations in 2 different genes, which could account for various aspects of the patient’s medical condition.
“Doctors generally try to find one diagnosis that explains all the issues a patient may have,” said study author Christine Eng, MD, of the Baylor College of Medicine.
“We have found that, in some cases, a patient may have a blended phenotype of 2 different conditions. That patients may have 2 different rare genetic diseases to explain their condition was an unexpected finding prior to the use of whole-exome sequencing.”
In the 2000 cases, incidental findings of medically actionable results that could result in early diagnosis, screening, or treatment were found in 92 patients. Three patients had more than 1 finding.
“Clinical exome sequencing can assist diagnosis in a wide range of disorders that are diagnostic dilemmas,” Dr Lupski said. “Rare variants and Mendelian disease are important contributors to disease populations. This is in sharp contrast to the thinking of population geneticists, who investigate how common variants contribute to disease susceptibility.”
“We find ‘rare variants’ in aggregate actually contribute to disease susceptibility in a big way. The individual diseases may be rare, but there are thousands of such diseases and many more being defined through genomics.”
Credit: Graham Colm
In a large study, whole-exome sequencing provided 25% of patients with a diagnosis related to a known genetic disease, giving young
patients and their parents some long-sought answers.
The technology was able to detect a number of rare genetic events and new mutations contributing to disease.
Among the medically actionable findings were mutations related to Fanconi anemia, erythrocytosis, hemolytic anemia, and von Willebrand disease.
“The findings in this report, I believe, will forever change the future practice of pediatrics and medicine as a whole,” said study author James R. Lupski, MD, PhD, of the Baylor College of Medicine in Houston.
“It is just a matter of time before genomics moves up on the physician’s list of things to do and is ordered before formulating a differential diagnosis. It will be the new ‘family history’ that, better yet, gets you both the important variants inherited from each parent and the new mutations that contribute to disease susceptibility.”
This research was published in JAMA and is set to be presented on October 21 at the American Society of Human Genetics Annual Meeting in San Diego.
The researchers had previously conducted a pilot study of whole-exome sequencing that included 250 patients and revealed a 25% molecular diagnostic rate.
This current study included 2000 patients (88% pediatric) with clinical whole-exome sequencing analyzed between June 2012 and August 2014. The majority of patients—87.8%—had neurological disorders or a developmental delay, and 12.2% had non-neurological disorders.
The researchers collected peripheral blood, tissue, or extracted DNA samples from patients and their parents. The team sequenced patients’ DNA and compared those results to the normal reference. Any disease-associated mutations were then compared with the parent’s DNA to determine if the child inherited it from one or both parents.
In all, 504 patients (25.2%) received a molecular diagnosis, and 58% of the diagnostic mutations had not previously been reported. Two hundred and eighty patients had a single mutation that caused disease, 181 were autosomal recessive, 65 were X-linked, and 1 was presumed inherited through the mitochondria.
In 5 cases, the patient inherited 2 copies of the mutated gene from the same parent. Of the dominant mutations, 208 were de novo mutations not inherited from either parent, 32 were inherited, and 40 were not determined because parental samples were not available.
Among the de novo mutations, 5 demonstrated mosaicism, which suggested the mutation occurred after fertilization.
The researchers found 708 presumptive causative variant alleles in the 504 cases. Almost 30% of the diagnoses occurred in disease genes only identified by researchers in the last 3 years. In 65 cases, there was no available genetic test other than whole-exome sequencing to find the mutated gene at the time the test was ordered.
Twenty-three patients (about 5%) had mutations in 2 different genes, which could account for various aspects of the patient’s medical condition.
“Doctors generally try to find one diagnosis that explains all the issues a patient may have,” said study author Christine Eng, MD, of the Baylor College of Medicine.
“We have found that, in some cases, a patient may have a blended phenotype of 2 different conditions. That patients may have 2 different rare genetic diseases to explain their condition was an unexpected finding prior to the use of whole-exome sequencing.”
In the 2000 cases, incidental findings of medically actionable results that could result in early diagnosis, screening, or treatment were found in 92 patients. Three patients had more than 1 finding.
“Clinical exome sequencing can assist diagnosis in a wide range of disorders that are diagnostic dilemmas,” Dr Lupski said. “Rare variants and Mendelian disease are important contributors to disease populations. This is in sharp contrast to the thinking of population geneticists, who investigate how common variants contribute to disease susceptibility.”
“We find ‘rare variants’ in aggregate actually contribute to disease susceptibility in a big way. The individual diseases may be rare, but there are thousands of such diseases and many more being defined through genomics.”
Credit: Graham Colm
In a large study, whole-exome sequencing provided 25% of patients with a diagnosis related to a known genetic disease, giving young
patients and their parents some long-sought answers.
The technology was able to detect a number of rare genetic events and new mutations contributing to disease.
Among the medically actionable findings were mutations related to Fanconi anemia, erythrocytosis, hemolytic anemia, and von Willebrand disease.
“The findings in this report, I believe, will forever change the future practice of pediatrics and medicine as a whole,” said study author James R. Lupski, MD, PhD, of the Baylor College of Medicine in Houston.
“It is just a matter of time before genomics moves up on the physician’s list of things to do and is ordered before formulating a differential diagnosis. It will be the new ‘family history’ that, better yet, gets you both the important variants inherited from each parent and the new mutations that contribute to disease susceptibility.”
This research was published in JAMA and is set to be presented on October 21 at the American Society of Human Genetics Annual Meeting in San Diego.
The researchers had previously conducted a pilot study of whole-exome sequencing that included 250 patients and revealed a 25% molecular diagnostic rate.
This current study included 2000 patients (88% pediatric) with clinical whole-exome sequencing analyzed between June 2012 and August 2014. The majority of patients—87.8%—had neurological disorders or a developmental delay, and 12.2% had non-neurological disorders.
The researchers collected peripheral blood, tissue, or extracted DNA samples from patients and their parents. The team sequenced patients’ DNA and compared those results to the normal reference. Any disease-associated mutations were then compared with the parent’s DNA to determine if the child inherited it from one or both parents.
In all, 504 patients (25.2%) received a molecular diagnosis, and 58% of the diagnostic mutations had not previously been reported. Two hundred and eighty patients had a single mutation that caused disease, 181 were autosomal recessive, 65 were X-linked, and 1 was presumed inherited through the mitochondria.
In 5 cases, the patient inherited 2 copies of the mutated gene from the same parent. Of the dominant mutations, 208 were de novo mutations not inherited from either parent, 32 were inherited, and 40 were not determined because parental samples were not available.
Among the de novo mutations, 5 demonstrated mosaicism, which suggested the mutation occurred after fertilization.
The researchers found 708 presumptive causative variant alleles in the 504 cases. Almost 30% of the diagnoses occurred in disease genes only identified by researchers in the last 3 years. In 65 cases, there was no available genetic test other than whole-exome sequencing to find the mutated gene at the time the test was ordered.
Twenty-three patients (about 5%) had mutations in 2 different genes, which could account for various aspects of the patient’s medical condition.
“Doctors generally try to find one diagnosis that explains all the issues a patient may have,” said study author Christine Eng, MD, of the Baylor College of Medicine.
“We have found that, in some cases, a patient may have a blended phenotype of 2 different conditions. That patients may have 2 different rare genetic diseases to explain their condition was an unexpected finding prior to the use of whole-exome sequencing.”
In the 2000 cases, incidental findings of medically actionable results that could result in early diagnosis, screening, or treatment were found in 92 patients. Three patients had more than 1 finding.
“Clinical exome sequencing can assist diagnosis in a wide range of disorders that are diagnostic dilemmas,” Dr Lupski said. “Rare variants and Mendelian disease are important contributors to disease populations. This is in sharp contrast to the thinking of population geneticists, who investigate how common variants contribute to disease susceptibility.”
“We find ‘rare variants’ in aggregate actually contribute to disease susceptibility in a big way. The individual diseases may be rare, but there are thousands of such diseases and many more being defined through genomics.”
Ibrutinib gets EU approval for CLL, MCL
Credit: Steven Harbour
The European Commission has granted marketing approval for the Bruton’s tyrosine kinase inhibitor ibrutinib (Imbruvica) in the European Union (EU).
The drug is now approved to treat adult patients with relapsed or refractory mantle cell lymphoma (MCL), adults with chronic lymphocytic leukemia (CLL) who have received at least one prior therapy, and first-line CLL patients who have 17p deletion or TP53 mutation and are unsuitable for chemotherapy.
In the EU and all other countries except the US, ibrutinib is marketed by Janssen Pharmaceutical Companies. In the US, the drug is being jointly developed and commercialized by Pharmacyclics and Janssen Biotech, Inc.
The EU approval of ibrutinib was based on data from a phase 2 study (PCYC-1104) in patients with MCL, the phase 3 RESONATE trial (PCYC-1112-CA) in CLL and small lymphocytic lymphoma (SLL), and a phase 1b/2 study (PCYC-1102) in CLL/SLL.
PCYC-1104: Ibrutinib in MCL
Results of this trial were presented at ASH 2012 and published in NEJM in 2013. The NEJM data included 111 patients who received ibrutinib at 560 mg daily in continuous, 28-day cycles until disease progression.
The overall response rate was 68%, with a complete response rate of 21% and a partial response rate of 47%. With an estimated median follow-up of 15.3 months, the estimated median response duration was 17.5 months.
The estimated progression-free survival was 13.9 months, and the overall survival was not reached. The estimated rate of overall survival was 58% at 18 months.
Common nonhematologic adverse events included diarrhea (50%), fatigue (41%), nausea (31%), peripheral edema (28%), dyspnea (27%), constipation (25%), upper respiratory tract infection (23%), vomiting (23%), and decreased appetite (21%). The most common grade 3, 4, or 5 infection was pneumonia (6%).
Grade 3 and 4 hematologic adverse events included neutropenia (16%), thrombocytopenia (11%), and anemia (10%). Grade 3 bleeding events occurred in 5 patients.
RESONATE: Ibrutinib in CLL/SLL
Results of the RESONATE trial were reported at EHA 2014 and published in NEJM in July. This trial was stopped early after an interim analysis showed that ibrutinib-treated patients experienced a 78% reduction in the risk of disease progression or death.
The trial included 391 patients with relapsed or refractory CLL or SLL who were randomized to receive ibrutinib (n=195) or ofatumumab (n=196). Patients in the ofatumumab arm were allowed to cross over to ibrutinib if they progressed (n=57). The median time on study was 9.4 months.
The best overall response rate was higher in the ibrutinib arm than the ofatumumab arm, at 78% and 11%, respectively. And ibrutinib significantly prolonged progression-free survival. The median was 8.1 months in the ofatumumab arm and was not reached in the ibrutinib arm (P<0.0001).
Ibrutinib significantly prolonged overall survival as well. The median overall survival was not reached in either arm, but the hazard ratio was 0.434 (P=0.0049).
Adverse events occurred in 99% of patients in the ibrutinib arm and 98% of those in the ofatumumab arm. Grade 3/4 events occurred in 51% and 39% of patients, respectively.
Atrial fibrillation, bleeding-related events, diarrhea, and arthralgia were more common in the ibrutinib arm. Infusion-related reactions, peripheral sensory neuropathy, urticaria, night sweats, and pruritus were more common in the ofatumumab arm.
PCYC-1102: Ibrutinib in CLL/SLL
Results of this phase 1b/2 trial were published in The Lancet Oncology in January. The trial enrolled 29 patients with previously untreated CLL and 2 with SLL.
They received 28-day cycles of once-daily ibrutinib at 420 mg or 840 mg. The 840 mg dose was discontinued after enrollment had begun because the doses showed comparable activity.
After a median follow-up of 22.1 months, 71% of patients achieved an objective response. Four patients (13%) had a complete response. The median time to response was 1.9 months.
Study investigators did not establish whether ibrutinib confers improvements in survival or disease-related symptoms.
Common adverse events included diarrhea (68%), nausea (48%), fatigue (32%), peripheral edema (29%), hypertension (29%), dizziness (26%), dyspepsia (26%), upper respiratory tract infection (26%), arthralgia (23%), constipation (23%), urinary tract infection (23%), and vomiting (23%).
Grade 3 adverse events included diarrhea (13%), fatigue (3%), hypertension (6%), dizziness (3%), urinary tract infection (3%), headache (3%), back pain (3%), and neutropenia (3%). One patient (3%) had grade 4 thrombocytopenia.
Credit: Steven Harbour
The European Commission has granted marketing approval for the Bruton’s tyrosine kinase inhibitor ibrutinib (Imbruvica) in the European Union (EU).
The drug is now approved to treat adult patients with relapsed or refractory mantle cell lymphoma (MCL), adults with chronic lymphocytic leukemia (CLL) who have received at least one prior therapy, and first-line CLL patients who have 17p deletion or TP53 mutation and are unsuitable for chemotherapy.
In the EU and all other countries except the US, ibrutinib is marketed by Janssen Pharmaceutical Companies. In the US, the drug is being jointly developed and commercialized by Pharmacyclics and Janssen Biotech, Inc.
The EU approval of ibrutinib was based on data from a phase 2 study (PCYC-1104) in patients with MCL, the phase 3 RESONATE trial (PCYC-1112-CA) in CLL and small lymphocytic lymphoma (SLL), and a phase 1b/2 study (PCYC-1102) in CLL/SLL.
PCYC-1104: Ibrutinib in MCL
Results of this trial were presented at ASH 2012 and published in NEJM in 2013. The NEJM data included 111 patients who received ibrutinib at 560 mg daily in continuous, 28-day cycles until disease progression.
The overall response rate was 68%, with a complete response rate of 21% and a partial response rate of 47%. With an estimated median follow-up of 15.3 months, the estimated median response duration was 17.5 months.
The estimated progression-free survival was 13.9 months, and the overall survival was not reached. The estimated rate of overall survival was 58% at 18 months.
Common nonhematologic adverse events included diarrhea (50%), fatigue (41%), nausea (31%), peripheral edema (28%), dyspnea (27%), constipation (25%), upper respiratory tract infection (23%), vomiting (23%), and decreased appetite (21%). The most common grade 3, 4, or 5 infection was pneumonia (6%).
Grade 3 and 4 hematologic adverse events included neutropenia (16%), thrombocytopenia (11%), and anemia (10%). Grade 3 bleeding events occurred in 5 patients.
RESONATE: Ibrutinib in CLL/SLL
Results of the RESONATE trial were reported at EHA 2014 and published in NEJM in July. This trial was stopped early after an interim analysis showed that ibrutinib-treated patients experienced a 78% reduction in the risk of disease progression or death.
The trial included 391 patients with relapsed or refractory CLL or SLL who were randomized to receive ibrutinib (n=195) or ofatumumab (n=196). Patients in the ofatumumab arm were allowed to cross over to ibrutinib if they progressed (n=57). The median time on study was 9.4 months.
The best overall response rate was higher in the ibrutinib arm than the ofatumumab arm, at 78% and 11%, respectively. And ibrutinib significantly prolonged progression-free survival. The median was 8.1 months in the ofatumumab arm and was not reached in the ibrutinib arm (P<0.0001).
Ibrutinib significantly prolonged overall survival as well. The median overall survival was not reached in either arm, but the hazard ratio was 0.434 (P=0.0049).
Adverse events occurred in 99% of patients in the ibrutinib arm and 98% of those in the ofatumumab arm. Grade 3/4 events occurred in 51% and 39% of patients, respectively.
Atrial fibrillation, bleeding-related events, diarrhea, and arthralgia were more common in the ibrutinib arm. Infusion-related reactions, peripheral sensory neuropathy, urticaria, night sweats, and pruritus were more common in the ofatumumab arm.
PCYC-1102: Ibrutinib in CLL/SLL
Results of this phase 1b/2 trial were published in The Lancet Oncology in January. The trial enrolled 29 patients with previously untreated CLL and 2 with SLL.
They received 28-day cycles of once-daily ibrutinib at 420 mg or 840 mg. The 840 mg dose was discontinued after enrollment had begun because the doses showed comparable activity.
After a median follow-up of 22.1 months, 71% of patients achieved an objective response. Four patients (13%) had a complete response. The median time to response was 1.9 months.
Study investigators did not establish whether ibrutinib confers improvements in survival or disease-related symptoms.
Common adverse events included diarrhea (68%), nausea (48%), fatigue (32%), peripheral edema (29%), hypertension (29%), dizziness (26%), dyspepsia (26%), upper respiratory tract infection (26%), arthralgia (23%), constipation (23%), urinary tract infection (23%), and vomiting (23%).
Grade 3 adverse events included diarrhea (13%), fatigue (3%), hypertension (6%), dizziness (3%), urinary tract infection (3%), headache (3%), back pain (3%), and neutropenia (3%). One patient (3%) had grade 4 thrombocytopenia.
Credit: Steven Harbour
The European Commission has granted marketing approval for the Bruton’s tyrosine kinase inhibitor ibrutinib (Imbruvica) in the European Union (EU).
The drug is now approved to treat adult patients with relapsed or refractory mantle cell lymphoma (MCL), adults with chronic lymphocytic leukemia (CLL) who have received at least one prior therapy, and first-line CLL patients who have 17p deletion or TP53 mutation and are unsuitable for chemotherapy.
In the EU and all other countries except the US, ibrutinib is marketed by Janssen Pharmaceutical Companies. In the US, the drug is being jointly developed and commercialized by Pharmacyclics and Janssen Biotech, Inc.
The EU approval of ibrutinib was based on data from a phase 2 study (PCYC-1104) in patients with MCL, the phase 3 RESONATE trial (PCYC-1112-CA) in CLL and small lymphocytic lymphoma (SLL), and a phase 1b/2 study (PCYC-1102) in CLL/SLL.
PCYC-1104: Ibrutinib in MCL
Results of this trial were presented at ASH 2012 and published in NEJM in 2013. The NEJM data included 111 patients who received ibrutinib at 560 mg daily in continuous, 28-day cycles until disease progression.
The overall response rate was 68%, with a complete response rate of 21% and a partial response rate of 47%. With an estimated median follow-up of 15.3 months, the estimated median response duration was 17.5 months.
The estimated progression-free survival was 13.9 months, and the overall survival was not reached. The estimated rate of overall survival was 58% at 18 months.
Common nonhematologic adverse events included diarrhea (50%), fatigue (41%), nausea (31%), peripheral edema (28%), dyspnea (27%), constipation (25%), upper respiratory tract infection (23%), vomiting (23%), and decreased appetite (21%). The most common grade 3, 4, or 5 infection was pneumonia (6%).
Grade 3 and 4 hematologic adverse events included neutropenia (16%), thrombocytopenia (11%), and anemia (10%). Grade 3 bleeding events occurred in 5 patients.
RESONATE: Ibrutinib in CLL/SLL
Results of the RESONATE trial were reported at EHA 2014 and published in NEJM in July. This trial was stopped early after an interim analysis showed that ibrutinib-treated patients experienced a 78% reduction in the risk of disease progression or death.
The trial included 391 patients with relapsed or refractory CLL or SLL who were randomized to receive ibrutinib (n=195) or ofatumumab (n=196). Patients in the ofatumumab arm were allowed to cross over to ibrutinib if they progressed (n=57). The median time on study was 9.4 months.
The best overall response rate was higher in the ibrutinib arm than the ofatumumab arm, at 78% and 11%, respectively. And ibrutinib significantly prolonged progression-free survival. The median was 8.1 months in the ofatumumab arm and was not reached in the ibrutinib arm (P<0.0001).
Ibrutinib significantly prolonged overall survival as well. The median overall survival was not reached in either arm, but the hazard ratio was 0.434 (P=0.0049).
Adverse events occurred in 99% of patients in the ibrutinib arm and 98% of those in the ofatumumab arm. Grade 3/4 events occurred in 51% and 39% of patients, respectively.
Atrial fibrillation, bleeding-related events, diarrhea, and arthralgia were more common in the ibrutinib arm. Infusion-related reactions, peripheral sensory neuropathy, urticaria, night sweats, and pruritus were more common in the ofatumumab arm.
PCYC-1102: Ibrutinib in CLL/SLL
Results of this phase 1b/2 trial were published in The Lancet Oncology in January. The trial enrolled 29 patients with previously untreated CLL and 2 with SLL.
They received 28-day cycles of once-daily ibrutinib at 420 mg or 840 mg. The 840 mg dose was discontinued after enrollment had begun because the doses showed comparable activity.
After a median follow-up of 22.1 months, 71% of patients achieved an objective response. Four patients (13%) had a complete response. The median time to response was 1.9 months.
Study investigators did not establish whether ibrutinib confers improvements in survival or disease-related symptoms.
Common adverse events included diarrhea (68%), nausea (48%), fatigue (32%), peripheral edema (29%), hypertension (29%), dizziness (26%), dyspepsia (26%), upper respiratory tract infection (26%), arthralgia (23%), constipation (23%), urinary tract infection (23%), and vomiting (23%).
Grade 3 adverse events included diarrhea (13%), fatigue (3%), hypertension (6%), dizziness (3%), urinary tract infection (3%), headache (3%), back pain (3%), and neutropenia (3%). One patient (3%) had grade 4 thrombocytopenia.
Blocking STAT3 in NK cells to fight leukemia
Credit: Bjorn Onfelt/Dan Davis
Inhibiting STAT3 in natural killer (NK) cells can kill leukemia in two ways, according to research published in Blood.
In mouse models lacking STAT3, NK cells were still able to develop normally, and the loss of STAT3 prompted an increase in antileukemic activity.
Mice whose NK cells lacked STAT3 showed a reduction in tumor growth and an increase in survival compared to controls.
Similar results were observed in mouse models of melanoma.
“We were expecting the loss of STAT3 to make the NK cells less efficient,” said study author Dagmar Gotthardt, of the University of Veterinary Medicine, Vienna (Vetmeduni Vienna).
“Instead, it makes them even more potent killers. Inhibiting STAT3 could thus help cancer patients in two ways: both stopping the cancer cells from dividing and helping the patients’ NK cells to fight them more efficiently.”
Researchers are already attempting to develop STAT3 inhibitors for cancer therapy, but their effect on NK cells was not known.
So Gotthardt and her colleagues assessed the function of STAT3 in NK cells using Stat3Δ/ΔNcr1-iCreTg mice, whose NK cells lack STAT3.
The team discovered that NK cells lacking STAT3 still develop and mature normally, but they do have alterations in the kinetics of interferon-γ production. In addition, there is a consistent increase in levels of perforin, granzyme B, and DNAM-1 in the absence of STAT3.
The investigators also found the loss of STAT3 in NK cells improved tumor surveillance against leukemia.
They injected v-abl1 leukemic cell lines into Stat3fl/fl and Stat3Δ/ΔNcr1-iCreTg mice. After 12 days, the Stat3fl/fl mice had large tumors, but there was “a pronounced reduction of tumor mass” in the Stat3Δ/ΔNcr1-iCreTg mice.
The researchers then injected 2 individually derived leukemic cell lines into Stat3fl/fl and Stat3Δ/ΔNcr1-iCreTg mice. And the results were similar to those of the previous experiment. Stat3Δ/ΔNcr1-iCreTg mice survived significantly longer than Stat3fl/fl mice (P=0.0002).
Next, the investigators injected newborn mice with a replication-incompetent ecotropic retrovirus encoding for v-abl, as this model more closely mimics the development of human disease.
Again, there was a significant difference in survival between Stat3fl/fl mice and Stat3Δ/ΔNcr1-iCreTg mice (P=0.007). All Stat3fl/fl mice died, but 20% of Stat3Δ/ΔNcr1-iCreTg mice were still alive at 150 days post-injection, and their disease latency was significantly delayed.
The researchers also found that loss of STAT3 in NK cells led to an increase in killing activity against melanoma cells. They said the decrease in metastasis caused by melanoma cells was especially dramatic and confirmed that NK cells lacking STAT3 are extremely efficient killers of tumor cells.
Credit: Bjorn Onfelt/Dan Davis
Inhibiting STAT3 in natural killer (NK) cells can kill leukemia in two ways, according to research published in Blood.
In mouse models lacking STAT3, NK cells were still able to develop normally, and the loss of STAT3 prompted an increase in antileukemic activity.
Mice whose NK cells lacked STAT3 showed a reduction in tumor growth and an increase in survival compared to controls.
Similar results were observed in mouse models of melanoma.
“We were expecting the loss of STAT3 to make the NK cells less efficient,” said study author Dagmar Gotthardt, of the University of Veterinary Medicine, Vienna (Vetmeduni Vienna).
“Instead, it makes them even more potent killers. Inhibiting STAT3 could thus help cancer patients in two ways: both stopping the cancer cells from dividing and helping the patients’ NK cells to fight them more efficiently.”
Researchers are already attempting to develop STAT3 inhibitors for cancer therapy, but their effect on NK cells was not known.
So Gotthardt and her colleagues assessed the function of STAT3 in NK cells using Stat3Δ/ΔNcr1-iCreTg mice, whose NK cells lack STAT3.
The team discovered that NK cells lacking STAT3 still develop and mature normally, but they do have alterations in the kinetics of interferon-γ production. In addition, there is a consistent increase in levels of perforin, granzyme B, and DNAM-1 in the absence of STAT3.
The investigators also found the loss of STAT3 in NK cells improved tumor surveillance against leukemia.
They injected v-abl1 leukemic cell lines into Stat3fl/fl and Stat3Δ/ΔNcr1-iCreTg mice. After 12 days, the Stat3fl/fl mice had large tumors, but there was “a pronounced reduction of tumor mass” in the Stat3Δ/ΔNcr1-iCreTg mice.
The researchers then injected 2 individually derived leukemic cell lines into Stat3fl/fl and Stat3Δ/ΔNcr1-iCreTg mice. And the results were similar to those of the previous experiment. Stat3Δ/ΔNcr1-iCreTg mice survived significantly longer than Stat3fl/fl mice (P=0.0002).
Next, the investigators injected newborn mice with a replication-incompetent ecotropic retrovirus encoding for v-abl, as this model more closely mimics the development of human disease.
Again, there was a significant difference in survival between Stat3fl/fl mice and Stat3Δ/ΔNcr1-iCreTg mice (P=0.007). All Stat3fl/fl mice died, but 20% of Stat3Δ/ΔNcr1-iCreTg mice were still alive at 150 days post-injection, and their disease latency was significantly delayed.
The researchers also found that loss of STAT3 in NK cells led to an increase in killing activity against melanoma cells. They said the decrease in metastasis caused by melanoma cells was especially dramatic and confirmed that NK cells lacking STAT3 are extremely efficient killers of tumor cells.
Credit: Bjorn Onfelt/Dan Davis
Inhibiting STAT3 in natural killer (NK) cells can kill leukemia in two ways, according to research published in Blood.
In mouse models lacking STAT3, NK cells were still able to develop normally, and the loss of STAT3 prompted an increase in antileukemic activity.
Mice whose NK cells lacked STAT3 showed a reduction in tumor growth and an increase in survival compared to controls.
Similar results were observed in mouse models of melanoma.
“We were expecting the loss of STAT3 to make the NK cells less efficient,” said study author Dagmar Gotthardt, of the University of Veterinary Medicine, Vienna (Vetmeduni Vienna).
“Instead, it makes them even more potent killers. Inhibiting STAT3 could thus help cancer patients in two ways: both stopping the cancer cells from dividing and helping the patients’ NK cells to fight them more efficiently.”
Researchers are already attempting to develop STAT3 inhibitors for cancer therapy, but their effect on NK cells was not known.
So Gotthardt and her colleagues assessed the function of STAT3 in NK cells using Stat3Δ/ΔNcr1-iCreTg mice, whose NK cells lack STAT3.
The team discovered that NK cells lacking STAT3 still develop and mature normally, but they do have alterations in the kinetics of interferon-γ production. In addition, there is a consistent increase in levels of perforin, granzyme B, and DNAM-1 in the absence of STAT3.
The investigators also found the loss of STAT3 in NK cells improved tumor surveillance against leukemia.
They injected v-abl1 leukemic cell lines into Stat3fl/fl and Stat3Δ/ΔNcr1-iCreTg mice. After 12 days, the Stat3fl/fl mice had large tumors, but there was “a pronounced reduction of tumor mass” in the Stat3Δ/ΔNcr1-iCreTg mice.
The researchers then injected 2 individually derived leukemic cell lines into Stat3fl/fl and Stat3Δ/ΔNcr1-iCreTg mice. And the results were similar to those of the previous experiment. Stat3Δ/ΔNcr1-iCreTg mice survived significantly longer than Stat3fl/fl mice (P=0.0002).
Next, the investigators injected newborn mice with a replication-incompetent ecotropic retrovirus encoding for v-abl, as this model more closely mimics the development of human disease.
Again, there was a significant difference in survival between Stat3fl/fl mice and Stat3Δ/ΔNcr1-iCreTg mice (P=0.007). All Stat3fl/fl mice died, but 20% of Stat3Δ/ΔNcr1-iCreTg mice were still alive at 150 days post-injection, and their disease latency was significantly delayed.
The researchers also found that loss of STAT3 in NK cells led to an increase in killing activity against melanoma cells. They said the decrease in metastasis caused by melanoma cells was especially dramatic and confirmed that NK cells lacking STAT3 are extremely efficient killers of tumor cells.
Stem cells can help form blood vessels
A novel technique can jump-start the creation of blood vessels, researchers have reported in Nature Biotechnology.
The team used human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) to create endothelial colony-forming cells (ECFCs).
These lab-generated ECFCs successfully produced human blood vessels in mice and restored blood flow to damaged retinas and limbs, without posing a risk of teratoma formation.
ECFCs can lose their ability to proliferate into new blood vessels as patients age or develop diseases such as peripheral arterial disease, said Mervin C. Yoder Jr, MD, of the Indiana University School of Medicine in Indianapolis.
He and his colleagues theorized that injecting patients with “younger,” more “enthusiastic” ECFCs might jump-start the process of creating new blood vessels. Such cells are difficult to find in adults but are common in umbilical cord blood.
With that in mind, the researchers developed a novel method to mature hiPSCs or hESCs into cells with the characteristics of ECFCs found in cord blood.
Both hiPSC-ECFCs and hESC-ECFCs exhibited properties of cord blood-derived ECFCs, including a homogenous monolayer with a cobblestone appearance and high clonal proliferative potential.
In addition, hiPSC-ECFCs and hESC-ECFCs formed capillary structures when cultured on Matrigel, and they generated in vivo inosculated vessels when implanted in immune-deficient mice.
In other murine experiments, hiPSC-ECFCs contributed to vascular repair of experimentally induced ischemic limbs and injured retinas. The cells’ effects were similar to those observed with cord blood-derived ECFCs and superior to effects observed with endothelial cells isolated using other published protocols.
Furthermore, hiPSC-ECFCs did not transition to nonendothelial cells over prolonged culture, and they could expand to more than 1 trillion endothelial cells in less than 3 months.
“This is one of the first studies using induced pluripotent stem cells that has been able to produce new cells in clinically relevant numbers, enough to enable a clinical trial,” Dr Yoder said.
He added that one of the next steps for this research is reaching an agreement with a facility approved to produce cells for use in human testing.
A novel technique can jump-start the creation of blood vessels, researchers have reported in Nature Biotechnology.
The team used human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) to create endothelial colony-forming cells (ECFCs).
These lab-generated ECFCs successfully produced human blood vessels in mice and restored blood flow to damaged retinas and limbs, without posing a risk of teratoma formation.
ECFCs can lose their ability to proliferate into new blood vessels as patients age or develop diseases such as peripheral arterial disease, said Mervin C. Yoder Jr, MD, of the Indiana University School of Medicine in Indianapolis.
He and his colleagues theorized that injecting patients with “younger,” more “enthusiastic” ECFCs might jump-start the process of creating new blood vessels. Such cells are difficult to find in adults but are common in umbilical cord blood.
With that in mind, the researchers developed a novel method to mature hiPSCs or hESCs into cells with the characteristics of ECFCs found in cord blood.
Both hiPSC-ECFCs and hESC-ECFCs exhibited properties of cord blood-derived ECFCs, including a homogenous monolayer with a cobblestone appearance and high clonal proliferative potential.
In addition, hiPSC-ECFCs and hESC-ECFCs formed capillary structures when cultured on Matrigel, and they generated in vivo inosculated vessels when implanted in immune-deficient mice.
In other murine experiments, hiPSC-ECFCs contributed to vascular repair of experimentally induced ischemic limbs and injured retinas. The cells’ effects were similar to those observed with cord blood-derived ECFCs and superior to effects observed with endothelial cells isolated using other published protocols.
Furthermore, hiPSC-ECFCs did not transition to nonendothelial cells over prolonged culture, and they could expand to more than 1 trillion endothelial cells in less than 3 months.
“This is one of the first studies using induced pluripotent stem cells that has been able to produce new cells in clinically relevant numbers, enough to enable a clinical trial,” Dr Yoder said.
He added that one of the next steps for this research is reaching an agreement with a facility approved to produce cells for use in human testing.
A novel technique can jump-start the creation of blood vessels, researchers have reported in Nature Biotechnology.
The team used human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) to create endothelial colony-forming cells (ECFCs).
These lab-generated ECFCs successfully produced human blood vessels in mice and restored blood flow to damaged retinas and limbs, without posing a risk of teratoma formation.
ECFCs can lose their ability to proliferate into new blood vessels as patients age or develop diseases such as peripheral arterial disease, said Mervin C. Yoder Jr, MD, of the Indiana University School of Medicine in Indianapolis.
He and his colleagues theorized that injecting patients with “younger,” more “enthusiastic” ECFCs might jump-start the process of creating new blood vessels. Such cells are difficult to find in adults but are common in umbilical cord blood.
With that in mind, the researchers developed a novel method to mature hiPSCs or hESCs into cells with the characteristics of ECFCs found in cord blood.
Both hiPSC-ECFCs and hESC-ECFCs exhibited properties of cord blood-derived ECFCs, including a homogenous monolayer with a cobblestone appearance and high clonal proliferative potential.
In addition, hiPSC-ECFCs and hESC-ECFCs formed capillary structures when cultured on Matrigel, and they generated in vivo inosculated vessels when implanted in immune-deficient mice.
In other murine experiments, hiPSC-ECFCs contributed to vascular repair of experimentally induced ischemic limbs and injured retinas. The cells’ effects were similar to those observed with cord blood-derived ECFCs and superior to effects observed with endothelial cells isolated using other published protocols.
Furthermore, hiPSC-ECFCs did not transition to nonendothelial cells over prolonged culture, and they could expand to more than 1 trillion endothelial cells in less than 3 months.
“This is one of the first studies using induced pluripotent stem cells that has been able to produce new cells in clinically relevant numbers, enough to enable a clinical trial,” Dr Yoder said.
He added that one of the next steps for this research is reaching an agreement with a facility approved to produce cells for use in human testing.
Invention allows for precise gene control
Credit: NIGMS
A new way to control genes may provide a better understanding of cancers and aid the development of new therapies.
The key to the method is an invention called SunTag, a series of molecular hooks for hanging multiple copies of biologically active molecules onto a single protein scaffold used to target genes or other molecules.
Compared to molecules assembled without these hooks, those incorporating SunTag can greatly amplify biological activity.
SunTag was developed by researchers in the lab of Ron Vale, PhD, of the University of California, San Francisco (UCSF), and described in two papers published in Cell.
In one paper, the authors recount how they used SunTag to greatly amplify the light-emitting signal from the green fluorescent protein commonly used to label molecules within cells.
In another paper, the researchers explain how they used SunTag to supercharge a variation of a biochemical approach known as CRISPR.
CRISPR is a technique that emerged a few years ago as a way to edit DNA anywhere within the genome.
The UCSF researchers adapted CRISPR to activate genes or interfere with their activity in a reversible way without altering DNA. The team believes this capability might make previous methods for probing poorly understood cellular functions obsolete.
“With these techniques, we can fine-tune the activity of genes within cells, and this has broad implications for the reprogramming of cells,” said Jonathan Weissman, PhD, also of UCSF.
Scientists previously reported ways to activate or interfere with genes using CRISPR, but Dr Vale said these methods were inefficient, especially for activating genes.
“It depends on the gene, but this new approach appears to amplify gene-switching by as much as 50-fold,” he said. “It’s a much more robust way of activating genes.”
CRISPR with SunTag sheds light on cancers
CRISPR is a natural system that bacteria use to defend themselves against viruses. The basis for CRISPR applications in the lab is a protein called Cas9, a chassis into which scientists can insert any specific RNA partner molecule.
The selected RNA serves as an adaptor that determines the target anywhere within the genome. The researchers attached SunTag to this chassis, enabling one Cas9 to recruit many copies of a protein to a specific DNA sequence.
The adaptation of SunTag for CRISPR activation makes it possible to systematically probe the biological roles of all genes within the genome in a single experiment, the team said.
They used CRISPR activation to identify a number of tumor suppressor genes that inhibit the growth of cancer cells. In future studies, they plan to use CRISPR activation to reveal mechanisms by which cancer cells develop resistance to anticancer drugs, a process that typically involves gene activation.
Will RNA interference become obsolete?
CRISPR interference has the potential to render RNA interference obsolete, according to Dr Weissman.
Unlike conventional RNA interference techniques, CRISPR interference allows any number of individual genes to be silenced at the same time. In addition, there is little risk of turning off untargeted genes the way RNA interference techniques do.
RNA interference blocks the messenger RNA that drives protein protection based on the blueprint contained within a gene’s DNA sequence. By preventing protein production, RNA interference may be used to get around the problem of difficult-to-target proteins, a frequent challenge in drug development.
But CRISPR interference acts one step earlier in the cell’s protein-manufacturing process.
“The horse has already left the barn with RNA interference, in the sense that the RNA message already has been transcribed from DNA,” Dr Weissman said. “With CRISPR interference, we can prevent the message from being written.”
Credit: NIGMS
A new way to control genes may provide a better understanding of cancers and aid the development of new therapies.
The key to the method is an invention called SunTag, a series of molecular hooks for hanging multiple copies of biologically active molecules onto a single protein scaffold used to target genes or other molecules.
Compared to molecules assembled without these hooks, those incorporating SunTag can greatly amplify biological activity.
SunTag was developed by researchers in the lab of Ron Vale, PhD, of the University of California, San Francisco (UCSF), and described in two papers published in Cell.
In one paper, the authors recount how they used SunTag to greatly amplify the light-emitting signal from the green fluorescent protein commonly used to label molecules within cells.
In another paper, the researchers explain how they used SunTag to supercharge a variation of a biochemical approach known as CRISPR.
CRISPR is a technique that emerged a few years ago as a way to edit DNA anywhere within the genome.
The UCSF researchers adapted CRISPR to activate genes or interfere with their activity in a reversible way without altering DNA. The team believes this capability might make previous methods for probing poorly understood cellular functions obsolete.
“With these techniques, we can fine-tune the activity of genes within cells, and this has broad implications for the reprogramming of cells,” said Jonathan Weissman, PhD, also of UCSF.
Scientists previously reported ways to activate or interfere with genes using CRISPR, but Dr Vale said these methods were inefficient, especially for activating genes.
“It depends on the gene, but this new approach appears to amplify gene-switching by as much as 50-fold,” he said. “It’s a much more robust way of activating genes.”
CRISPR with SunTag sheds light on cancers
CRISPR is a natural system that bacteria use to defend themselves against viruses. The basis for CRISPR applications in the lab is a protein called Cas9, a chassis into which scientists can insert any specific RNA partner molecule.
The selected RNA serves as an adaptor that determines the target anywhere within the genome. The researchers attached SunTag to this chassis, enabling one Cas9 to recruit many copies of a protein to a specific DNA sequence.
The adaptation of SunTag for CRISPR activation makes it possible to systematically probe the biological roles of all genes within the genome in a single experiment, the team said.
They used CRISPR activation to identify a number of tumor suppressor genes that inhibit the growth of cancer cells. In future studies, they plan to use CRISPR activation to reveal mechanisms by which cancer cells develop resistance to anticancer drugs, a process that typically involves gene activation.
Will RNA interference become obsolete?
CRISPR interference has the potential to render RNA interference obsolete, according to Dr Weissman.
Unlike conventional RNA interference techniques, CRISPR interference allows any number of individual genes to be silenced at the same time. In addition, there is little risk of turning off untargeted genes the way RNA interference techniques do.
RNA interference blocks the messenger RNA that drives protein protection based on the blueprint contained within a gene’s DNA sequence. By preventing protein production, RNA interference may be used to get around the problem of difficult-to-target proteins, a frequent challenge in drug development.
But CRISPR interference acts one step earlier in the cell’s protein-manufacturing process.
“The horse has already left the barn with RNA interference, in the sense that the RNA message already has been transcribed from DNA,” Dr Weissman said. “With CRISPR interference, we can prevent the message from being written.”
Credit: NIGMS
A new way to control genes may provide a better understanding of cancers and aid the development of new therapies.
The key to the method is an invention called SunTag, a series of molecular hooks for hanging multiple copies of biologically active molecules onto a single protein scaffold used to target genes or other molecules.
Compared to molecules assembled without these hooks, those incorporating SunTag can greatly amplify biological activity.
SunTag was developed by researchers in the lab of Ron Vale, PhD, of the University of California, San Francisco (UCSF), and described in two papers published in Cell.
In one paper, the authors recount how they used SunTag to greatly amplify the light-emitting signal from the green fluorescent protein commonly used to label molecules within cells.
In another paper, the researchers explain how they used SunTag to supercharge a variation of a biochemical approach known as CRISPR.
CRISPR is a technique that emerged a few years ago as a way to edit DNA anywhere within the genome.
The UCSF researchers adapted CRISPR to activate genes or interfere with their activity in a reversible way without altering DNA. The team believes this capability might make previous methods for probing poorly understood cellular functions obsolete.
“With these techniques, we can fine-tune the activity of genes within cells, and this has broad implications for the reprogramming of cells,” said Jonathan Weissman, PhD, also of UCSF.
Scientists previously reported ways to activate or interfere with genes using CRISPR, but Dr Vale said these methods were inefficient, especially for activating genes.
“It depends on the gene, but this new approach appears to amplify gene-switching by as much as 50-fold,” he said. “It’s a much more robust way of activating genes.”
CRISPR with SunTag sheds light on cancers
CRISPR is a natural system that bacteria use to defend themselves against viruses. The basis for CRISPR applications in the lab is a protein called Cas9, a chassis into which scientists can insert any specific RNA partner molecule.
The selected RNA serves as an adaptor that determines the target anywhere within the genome. The researchers attached SunTag to this chassis, enabling one Cas9 to recruit many copies of a protein to a specific DNA sequence.
The adaptation of SunTag for CRISPR activation makes it possible to systematically probe the biological roles of all genes within the genome in a single experiment, the team said.
They used CRISPR activation to identify a number of tumor suppressor genes that inhibit the growth of cancer cells. In future studies, they plan to use CRISPR activation to reveal mechanisms by which cancer cells develop resistance to anticancer drugs, a process that typically involves gene activation.
Will RNA interference become obsolete?
CRISPR interference has the potential to render RNA interference obsolete, according to Dr Weissman.
Unlike conventional RNA interference techniques, CRISPR interference allows any number of individual genes to be silenced at the same time. In addition, there is little risk of turning off untargeted genes the way RNA interference techniques do.
RNA interference blocks the messenger RNA that drives protein protection based on the blueprint contained within a gene’s DNA sequence. By preventing protein production, RNA interference may be used to get around the problem of difficult-to-target proteins, a frequent challenge in drug development.
But CRISPR interference acts one step earlier in the cell’s protein-manufacturing process.
“The horse has already left the barn with RNA interference, in the sense that the RNA message already has been transcribed from DNA,” Dr Weissman said. “With CRISPR interference, we can prevent the message from being written.”
‘Nano-cocoons’ offer targeted drug delivery
Photo courtesy of the Gu lab
Biomedical engineers have developed a drug delivery system in which cancer cells are “tricked” into absorbing nanoscale “cocoons” before
they unleash anticancer drugs.
Each cocoon is made of a deoxyribonuclease (DNase)-degradable DNA nanoclew embedded with an acid-responsive DNase I nanocapsule.
A cancer cell’s acidic environment prompts the DNase to degrade the cocoon and release the drug encapsulated in the endolysosomal compartment.
The engineers described the creation of these nano-cocoons and in vitro experiments testing the delivery of doxorubicin in the Journal of the American Chemical Society.
“This drug delivery system is DNA-based, which means it is biocompatible and less toxic to patients than systems that use synthetic materials,” said study author Zhen Gu, PhD, of the University of North Carolina Chapel Hill.
“This technique also specifically targets cancer cells, can carry a large drug load, and releases the drugs very quickly once inside the cancer cell.”
“In addition, because we used self-assembling DNA techniques, it is relatively easy to manufacture,” added Wujin Sun, a PhD student in Dr Gu’s lab.
Each nano-cocoon is made of a single strand of DNA that self-assembles into a structure measuring 150 nanometers across.
The core of the nano-cocoon contains the anticancer drug doxorubicin and DNase. The DNase, an enzyme that would normally dismantle the DNA cocoon, is contained by a thin polymer coating.
The surface of the nano-cocoon is studded with folic acid ligands. When the nano-cocoon encounters a cancer cell, the ligands bind the nano-cocoon to receptors on the surface of the cell, causing the cell to engulf the nano-cocoon.
Once the cocoon is inside the cancer cell, the cell’s acidic environment destroys the polymer sheath containing the DNase. The DNase then slices through the DNA cocoon, spilling doxorubicin into the cancer cell and killing it.
“We’re preparing to launch preclinical testing now,” Dr Gu said. “We’re very excited about this system and think it holds promise for delivering a variety of drugs targeting cancer and other diseases.”
Photo courtesy of the Gu lab
Biomedical engineers have developed a drug delivery system in which cancer cells are “tricked” into absorbing nanoscale “cocoons” before
they unleash anticancer drugs.
Each cocoon is made of a deoxyribonuclease (DNase)-degradable DNA nanoclew embedded with an acid-responsive DNase I nanocapsule.
A cancer cell’s acidic environment prompts the DNase to degrade the cocoon and release the drug encapsulated in the endolysosomal compartment.
The engineers described the creation of these nano-cocoons and in vitro experiments testing the delivery of doxorubicin in the Journal of the American Chemical Society.
“This drug delivery system is DNA-based, which means it is biocompatible and less toxic to patients than systems that use synthetic materials,” said study author Zhen Gu, PhD, of the University of North Carolina Chapel Hill.
“This technique also specifically targets cancer cells, can carry a large drug load, and releases the drugs very quickly once inside the cancer cell.”
“In addition, because we used self-assembling DNA techniques, it is relatively easy to manufacture,” added Wujin Sun, a PhD student in Dr Gu’s lab.
Each nano-cocoon is made of a single strand of DNA that self-assembles into a structure measuring 150 nanometers across.
The core of the nano-cocoon contains the anticancer drug doxorubicin and DNase. The DNase, an enzyme that would normally dismantle the DNA cocoon, is contained by a thin polymer coating.
The surface of the nano-cocoon is studded with folic acid ligands. When the nano-cocoon encounters a cancer cell, the ligands bind the nano-cocoon to receptors on the surface of the cell, causing the cell to engulf the nano-cocoon.
Once the cocoon is inside the cancer cell, the cell’s acidic environment destroys the polymer sheath containing the DNase. The DNase then slices through the DNA cocoon, spilling doxorubicin into the cancer cell and killing it.
“We’re preparing to launch preclinical testing now,” Dr Gu said. “We’re very excited about this system and think it holds promise for delivering a variety of drugs targeting cancer and other diseases.”
Photo courtesy of the Gu lab
Biomedical engineers have developed a drug delivery system in which cancer cells are “tricked” into absorbing nanoscale “cocoons” before
they unleash anticancer drugs.
Each cocoon is made of a deoxyribonuclease (DNase)-degradable DNA nanoclew embedded with an acid-responsive DNase I nanocapsule.
A cancer cell’s acidic environment prompts the DNase to degrade the cocoon and release the drug encapsulated in the endolysosomal compartment.
The engineers described the creation of these nano-cocoons and in vitro experiments testing the delivery of doxorubicin in the Journal of the American Chemical Society.
“This drug delivery system is DNA-based, which means it is biocompatible and less toxic to patients than systems that use synthetic materials,” said study author Zhen Gu, PhD, of the University of North Carolina Chapel Hill.
“This technique also specifically targets cancer cells, can carry a large drug load, and releases the drugs very quickly once inside the cancer cell.”
“In addition, because we used self-assembling DNA techniques, it is relatively easy to manufacture,” added Wujin Sun, a PhD student in Dr Gu’s lab.
Each nano-cocoon is made of a single strand of DNA that self-assembles into a structure measuring 150 nanometers across.
The core of the nano-cocoon contains the anticancer drug doxorubicin and DNase. The DNase, an enzyme that would normally dismantle the DNA cocoon, is contained by a thin polymer coating.
The surface of the nano-cocoon is studded with folic acid ligands. When the nano-cocoon encounters a cancer cell, the ligands bind the nano-cocoon to receptors on the surface of the cell, causing the cell to engulf the nano-cocoon.
Once the cocoon is inside the cancer cell, the cell’s acidic environment destroys the polymer sheath containing the DNase. The DNase then slices through the DNA cocoon, spilling doxorubicin into the cancer cell and killing it.
“We’re preparing to launch preclinical testing now,” Dr Gu said. “We’re very excited about this system and think it holds promise for delivering a variety of drugs targeting cancer and other diseases.”