Tuesday, 21 October 2014

Loss of Y chromosome associated with higher mortality and cancer in men




Y chromosome


Age-related loss of the Y chromosome (LOY) from blood cells, a frequent occurrence among elderly men, is associated with elevated risk of various cancers and earlier death, according to research presented at the American Society of Human Genetics (ASHG) 2014 Annual Meeting in San Diego.


This finding could help explain why men tend to have a shorter life span and higher rates of sex-unspecific cancers than women, who do not have a Y chromosome, said Lars Forsberg, PhD, lead author of the study and a geneticist at Uppsala University in Sweden.


LOY, which occurs occasionally as a given man's blood cells replicate – and thus takes place inconsistently throughout the body – was first reported nearly 50 years ago and remains largely unexplained in both its causes and effects. Recent advances in genetic technology have allowed researchers to use a to detect when only a small fraction of a man's blood cells have undergone LOY.


Dr. Forsberg and colleagues studied blood samples from 1,153 aged 70 to 84 years, who were followed clinically for up to 40 years. They found that men whose samples showed LOY in a significant fraction of their blood cells lived an average of 5.5 years less than men whose blood was not affected by LOY. In addition, having undergone LOY significantly increased the men's risk of dying from cancer during the course of the study. These associations remained statistically significant when results were adjusted for men's age and other .


"Many people think the Y chromosome only contains genes involved in sex determination and sperm production," said Jan Dumanski, MD, PhD, co-author on the study and a professor at Uppsala University. "In fact, these genes have other important functions, such as possibly playing a role in preventing tumors." When LOY takes place, Y chromosome genes are not expressed, and this tumor prevention would be reduced.


Interestingly, LOY in blood cells is associated with many different cancers, including those outside of the blood system. This may be because Y chromosome genes enable blood cells to assist with immunosurveillance, the process by which the immune system detects and kills to prevent cancer.


"Our hypothesis is that LOY disrupts the immunosurveillance normally conducted by blood cells, allowing tumors to grow unchecked and develop into cancer," Dr. Forsberg said.


These findings suggest a new approach to early detection of cancer risk in men: a blood test to assess LOY. "LOY is not very dangerous in a small fraction of , but becomes increasingly predictive of cancer as more cells lose their Y chromosome," Dr. Forsberg explained. "This takes years, so you'd have a window of time to do something to reduce your risk."


The researchers are currently exploring LOY in more detail, including the effects of various lifestyle factors and other health conditions. They are also examining the frequency and consequences of LOY in different types of cells and throughout the life course.



More information: Forsberg L et al. (2014 Oct 21). Abstract: Mosaic loss of chromosome Y (LOY) in blood cells is associated with shorter survival and higher risk of cancer in men. Presented at American Society of Human Genetics 2014 Annual Meeting. San Diego, Calif.


Medical Xpress on facebook

Related Stories


Loss of Y chromosome can explain shorter life expectancy and higher cancer risk for men


Apr 28, 2014



It is generally well known that men have an overall shorter life expectancy compared to women. A recent study, led by Uppsala University researchers, shows a correlation between a loss of the Y chromosome ...



Many older people have mutations linked to leukemia, lymphoma in their blood cells


Oct 19, 2014



At least 2 percent of people over age 40 and 5 percent of people over 70 have mutations linked to leukemia and lymphoma in their blood cells, according to new research at Washington University School of Medicine ...



New blood test determines whether you have or are likely to get cancer


Sep 30, 2014



A new research report published in the October 2014 issue of The FASEB Journal may make the early detection of cancer as easy as a simple blood test. This test, called the "lymphocyte genome sensitivity" (LGS) test, could ...



Women with high blood pressure get different treatment to men


Oct 14, 2014



Women who are treated for high blood pressure are not given the same medication as men, nor do they hit the treatment targets as often, reveals a thesis from the University of Gothenburg.



Children's genes affect their mothers' risk of rheumatoid arthritis


Oct 19, 2014



A child's genetic makeup may contribute to his or her mother's risk of rheumatoid arthritis, possibly explaining why women are at higher risk of developing the disease than men. This research will be presented Tuesday, October ...



Recommended for you


New research software automates DNA analysis


20 hours ago



At the core of medical research is problem-solving, which is exactly what two PhD scientists did when they set out to eliminate a common, time-consuming task performed in research laboratories around the world.





Genetic variant protects some Latina women from breast cancer


Oct 20, 2014



An international research collaboration led by UC San Francisco researchers has identified a genetic variant common in Latina women that protects against breast cancer.





Metabolic genetics research paves way to treating diabetes and obesity


Oct 19, 2014



Breaking down complex conditions such as Type 2 Diabetes and obesity into the specific metabolic proteins and processes that underlie them offers a new approach to studying the genetics of these diseases and ...



Scientists identify mutation associated with cleft palate in humans and dogs


Oct 19, 2014



Scientists studying birth defects in humans and purebred dogs have identified an association between cleft lip and cleft palate – conditions that occur when the lip and mouth fail to form properly during pregnancy – and ...



Gene duplications associated with autism evolved recently in human history


Oct 19, 2014



Human geneticists have discovered that a region of the genome associated with autism contains genetic variation that evolved in the last 250,000 years, after the divergence of humans from ancient hominids, and likely plays ...



Whole exome sequencing closer to becoming 'new family history'


Oct 19, 2014



Approximately one-fourth of the 3,386 patients whose DNA was submitted for clinical whole exome testing received a diagnosis related to a known genetic disease, often ending a long search for answers for them and their parents, ...



User comments








Y chromosome


Age-related loss of the Y chromosome (LOY) from blood cells, a frequent occurrence among elderly men, is associated with elevated risk of various cancers and earlier death, according to research presented at the American Society of Human Genetics (ASHG) 2014 Annual Meeting in San Diego.


This finding could help explain why men tend to have a shorter life span and higher rates of sex-unspecific cancers than women, who do not have a Y chromosome, said Lars Forsberg, PhD, lead author of the study and a geneticist at Uppsala University in Sweden.


LOY, which occurs occasionally as a given man's blood cells replicate – and thus takes place inconsistently throughout the body – was first reported nearly 50 years ago and remains largely unexplained in both its causes and effects. Recent advances in genetic technology have allowed researchers to use a to detect when only a small fraction of a man's blood cells have undergone LOY.


Dr. Forsberg and colleagues studied blood samples from 1,153 aged 70 to 84 years, who were followed clinically for up to 40 years. They found that men whose samples showed LOY in a significant fraction of their blood cells lived an average of 5.5 years less than men whose blood was not affected by LOY. In addition, having undergone LOY significantly increased the men's risk of dying from cancer during the course of the study. These associations remained statistically significant when results were adjusted for men's age and other .


"Many people think the Y chromosome only contains genes involved in sex determination and sperm production," said Jan Dumanski, MD, PhD, co-author on the study and a professor at Uppsala University. "In fact, these genes have other important functions, such as possibly playing a role in preventing tumors." When LOY takes place, Y chromosome genes are not expressed, and this tumor prevention would be reduced.


Interestingly, LOY in blood cells is associated with many different cancers, including those outside of the blood system. This may be because Y chromosome genes enable blood cells to assist with immunosurveillance, the process by which the immune system detects and kills to prevent cancer.


"Our hypothesis is that LOY disrupts the immunosurveillance normally conducted by blood cells, allowing tumors to grow unchecked and develop into cancer," Dr. Forsberg said.


These findings suggest a new approach to early detection of cancer risk in men: a blood test to assess LOY. "LOY is not very dangerous in a small fraction of , but becomes increasingly predictive of cancer as more cells lose their Y chromosome," Dr. Forsberg explained. "This takes years, so you'd have a window of time to do something to reduce your risk."


The researchers are currently exploring LOY in more detail, including the effects of various lifestyle factors and other health conditions. They are also examining the frequency and consequences of LOY in different types of cells and throughout the life course.



More information: Forsberg L et al. (2014 Oct 21). Abstract: Mosaic loss of chromosome Y (LOY) in blood cells is associated with shorter survival and higher risk of cancer in men. Presented at American Society of Human Genetics 2014 Annual Meeting. San Diego, Calif.


Medical Xpress on facebook

Related Stories


Loss of Y chromosome can explain shorter life expectancy and higher cancer risk for men


Apr 28, 2014



It is generally well known that men have an overall shorter life expectancy compared to women. A recent study, led by Uppsala University researchers, shows a correlation between a loss of the Y chromosome ...



Many older people have mutations linked to leukemia, lymphoma in their blood cells


Oct 19, 2014



At least 2 percent of people over age 40 and 5 percent of people over 70 have mutations linked to leukemia and lymphoma in their blood cells, according to new research at Washington University School of Medicine ...



New blood test determines whether you have or are likely to get cancer


Sep 30, 2014



A new research report published in the October 2014 issue of The FASEB Journal may make the early detection of cancer as easy as a simple blood test. This test, called the "lymphocyte genome sensitivity" (LGS) test, could ...



Women with high blood pressure get different treatment to men


Oct 14, 2014



Women who are treated for high blood pressure are not given the same medication as men, nor do they hit the treatment targets as often, reveals a thesis from the University of Gothenburg.



Children's genes affect their mothers' risk of rheumatoid arthritis


Oct 19, 2014



A child's genetic makeup may contribute to his or her mother's risk of rheumatoid arthritis, possibly explaining why women are at higher risk of developing the disease than men. This research will be presented Tuesday, October ...



Recommended for you


New research software automates DNA analysis


20 hours ago



At the core of medical research is problem-solving, which is exactly what two PhD scientists did when they set out to eliminate a common, time-consuming task performed in research laboratories around the world.





Genetic variant protects some Latina women from breast cancer


Oct 20, 2014



An international research collaboration led by UC San Francisco researchers has identified a genetic variant common in Latina women that protects against breast cancer.





Metabolic genetics research paves way to treating diabetes and obesity


Oct 19, 2014



Breaking down complex conditions such as Type 2 Diabetes and obesity into the specific metabolic proteins and processes that underlie them offers a new approach to studying the genetics of these diseases and ...



Scientists identify mutation associated with cleft palate in humans and dogs


Oct 19, 2014



Scientists studying birth defects in humans and purebred dogs have identified an association between cleft lip and cleft palate – conditions that occur when the lip and mouth fail to form properly during pregnancy – and ...



Gene duplications associated with autism evolved recently in human history


Oct 19, 2014



Human geneticists have discovered that a region of the genome associated with autism contains genetic variation that evolved in the last 250,000 years, after the divergence of humans from ancient hominids, and likely plays ...



Whole exome sequencing closer to becoming 'new family history'


Oct 19, 2014



Approximately one-fourth of the 3,386 patients whose DNA was submitted for clinical whole exome testing received a diagnosis related to a known genetic disease, often ending a long search for answers for them and their parents, ...



User comments








Categories:

0 comments:

Post a Comment