Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
Scientists reveal how DNA damage leads to cancer and hereditary diseases

Scientists reveal how DNA damage leads to cancer and hereditary diseases

Scientists revealed how DNA damage influences mutations. Turned out that its contribution to mutagenesis was underestimated and many of the inheritance mutations are caused not by errors in DNA doubling, but by damage to this fragile molecule. The study was conducted by an international research group and published in Nature Genetics.

Unfortunately, the reasons for mutations in normal cells not exposed to ultraviolet, smoke or other external mutagens are understudied. According to the most popular beliefs, the vast majority of mutations result from inaccurate DNA copying before each cell division. These assumptions were supported by correlation between the risk of cancer and the number of cell divisions. Another argument for this was that the divisions number that each sperm cell passes before its final formation is proportional to the age of the man. For example, the sperm of an 18-year-old man undergoes about 100 doublings before it becomes “mature”, while for a 50-year-old man this number is around 800. With each doubling, the number of errors in the DNA increases leading to accumulation of mutations in the sperm.

“We decided to look at this problem from a different perspective and evaluated the contribution of the DNA damage to the accumulation of mutations”, comments Vladimir Seplyarskiy one of the authors from the Institute for Information Transmission Problems RAS and Harvard Medical School, USA. “We looked how the cell repair system works. Since it works only on the DNA strand from which genes are read, we looked at what types of mutations occur in these areas unexpectedly rarely, and thus were able to estimate the number of mutations that are caused by DNA damage.”

Next, scientists looked at what happens to damaged DNA during cell division. They compared mutations on both leading and lagging doubling chains of DNA. It turned out that mutations associated with DNA damage occur more often on the lagging chain. This is true both for mutations caused by known mutagens during the development of a cancer tumor (for example, as a result of exposure to tobacco smoke in lung cancer, ultraviolet radiation in melanoma, and aristolochic acid in liver cancer), and for mutations inherited. Thus, it turned out that many of the inheritance mutations are caused not by errors in DNA doubling, but by damage to this fragile molecule.

The result obtained by computer analysis was tested experimentally. Scientists also tried to answer the question: if so many mutations are caused by DNA damage, why is the number of accumulated mutations related to the number of cell doublings? The experiments were conducted in collaboration with scientists from the Karolinska Institute, Sweden. The cell line was irradiated with ultraviolet light, and in one case cell division was artificially delayed for two days, while the second cell samples divided normally. It turned out that a slight delay reduced the mutagenic effect of ultraviolet radiation by 30 times. Therefore, DNA damage turns into mutations only if they occurred shortly before the cell division. These results suggest that mutations leading to cancers might be caused by mutagens only in actively dividing cells. Such a hypothesis gives a completely different interpretation of the relationship between the number of cell divisions and the number of accumulated mutations.

“I have long been looking for the cause of mutations in the germ line. It has been suggested that mutations inherited from the father are a consequence of replication inaccuracies. In this work, we statistically showed that DNA damage also plays a significant role. Unfortunately, the assessment of the contribution of such damage to mutagenesis, which we have received now, is clearly underestimated, and we are looking for new approaches to clarify it,” summarizes Vladimir Seplyarskiy.

The study of how hereditary mutations arise has not only theoretical importance. Understanding the mechanisms of mutagenesis helps to estimate the likelihood, and even partly to predict, mutations that lead to cancer and hereditary diseases. In the long run, it might become possible to prevent this diseases.

Source:

http://www.akson.science/

Tagged with:

About author

Related Articles