PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Protein abundant in cancerous cells causes DNA 'supercoiling'

Specialized protein maintains genome stability by maintaining DNA structure, but may also facilitate cancer cells by changing the very shape of DNA

2013-03-11
(Press-News.org) A team of USC scientists has identified a protein that can change DNA topology, making DNA twist up into a so-called "supercoil."

The finding provides new insight about the role of the protein—known as mini-chromosome maintenance (MCM)—in cancer cells, which have high levels of MCM.

Think about twisting one end of a rubber band while holding the other end still. After a few turns, it forms a neatly twisted rope. But if you keep on turning, the twisted band will twist back upon itself into an increasingly coiled-up knot. Similarly, a DNA molecule can be twisted and coiled to varying extents to form different "supercoiled" structures.

Chromosomal DNA forms different supercoiled structures to enable a number of important processes. It turns on or off some genes, while tuning up or down other genes. The study suggests that an overabundance of MCM in a cell may allow certain genes to be overexpressed, and tune down or turn off other important genes, causing the cell to grow out of control and become cancerous.

Chromosomal DNA structure is very important for regulating gene expression of a cell, and thus the physiological status of the cell. Changing DNA topology is one effective way of controlling chromosomal DNA structure. The discovery of MCM's ability to change DNA topology offers a totally new perspective to MCM's role in gene regulation and cancer," said Xiaojiang Chen, professor of molecular biology at the USC Dornsife College of Letters, Arts and Sciences, and corresponding author of the study.

Chen worked with fellow USC professor Susan Forsburg and USC graduate students Ian M. Slaymaker, Yang Fu and Nimna Ranatunga; as well as Daniel B. Toso and Z. Hong Zhou of UCLA and Aaron Brewster of UC Berkeley. Their study was published online by Nucleic Acids Research on Jan. 29.

Chen and his team found that MCM proteins form a filament that looks much like a wide tube, through which the DNA strand spirals its way along the inner tube wall. Inside of the tube is a wide spiral path that has a strong positive electrical charge.

"Such a striking feature is unusual," said Chen. Who is also a member of the USC Norris Cancer Center. "When you see that, you know it must have a special function." Indeed, it turns out that the positively charged spiral path attracts and binds to the DNA strand, which has a negatively charged phosphate backbone.

Holding the DNA tightly to the spiral path inside the helical filament tube causes the DNA double-helix to change structure, creating supercoils. Future research by the team will explore how the DNA topology changes caused by MCM impacts cancer cell formation as well as its utility in cancer therapy.

###This research was funded by the National Institutes of Health, grant numbers GM080338, AI055926, GM071940 and GM059321.


ELSE PRESS RELEASES FROM THIS DATE:

No increase in risk of death for patients with well-controlled HIV, reports AIDS journal

2013-03-11
Philadelphia, Pa. (March 11, 2013) – For HIV-infected patients whose disease is well-controlled by modern treatment, the risk of death is not significantly higher than in the general population, according to a study published in AIDS, official journal of the International AIDS Society. AIDS is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health. The study suggests that patients with undetectable viral loads and near-normal levels of immune cells on state-of-the art antiretroviral therapy (ART) can expect to have about the same risk of death as ...

Combination therapy provides similar clinical benefit as single drug treatment in MS

2013-03-11
People with multiple sclerosis (MS) who were treated with combination therapy did not see significant clinical benefit over those treated with single drug therapy, but combination therapy did reduce the development of new lesions, according to an international research team led by The Mount Sinai Medical Center. The findings, part of the largest-ever MS trial sponsored by the National Institutes of Health, are published in the March 11 issue of Annals of Neurology. In the Phase III CombiRx trial, researchers led by Fred Lublin, MD, of The Mount Sinai Medical Center, sought ...

Older adults benefit from home-based DVD exercise program

Older adults benefit from home-based DVD exercise program
2013-03-11
CHAMPAIGN, Ill. — Fitness DVDs are a multimillion-dollar business, and those targeting adults over the age of 55 are a major part of the market. With names like "Boomers on the Move," "Stronger Seniors" and "Ageless Yoga," the programs promise much, but few have ever been rigorously tested. "There are tons of DVDs out there, 20 percent of them are purchased by older adults, and with few exceptions there is no evidence that they work," said University of Illinois kinesiology and community health professor Edward McAuley, who led a new study testing the efficacy of a home-based ...

Tiny piece of RNA keeps 'clock' running in earliest stages of life

2013-03-11
COLUMBUS, Ohio – New research shows that a tiny piece of RNA has an essential role in ensuring that embryonic tissue segments form properly. The study, conducted in chicken embryos, determined that this piece of RNA regulates cyclical gene activity that defines the timing of the formation of tissue segments that later become muscle and vertebrae. Genes involved in this activity are turned on and off in an oscillating pattern that matches the formation of each tissue segment. If the timing of these genes' activity doesn't remain tightly regulated, the tissue either won't ...

International conference to tackle climate-change threats to agriculture

2013-03-11
Scientists and policymakers from around the world will gather March 20-22 at the University of California, Davis, to grapple with the threats of climate change for global agriculture and recommend science-based actions to slow its effects while meeting the world's need for food, livelihood and sustainability. The Climate-Smart Agriculture Global Science Conference, planned in coordination with the World Bank, builds on a 2011 international meeting on this theme in the Netherlands. "Climate change, which brings severe weather events and more subtle but equally menacing ...

Fluoride in drinking water cuts tooth decay in adults

2013-03-11
A new study conducted by researchers at the University of North Carolina at Chapel Hill and the University of Adelaide, Australia, has produced the strongest evidence yet that fluoride in drinking water provides dental health benefits to adults, even those who had not received fluoridated drinking water as children. In the first population-level study of its kind, the study shows that fluoridated drinking water prevents tooth decay for all adults regardless of age, and whether or not they consumed fluoridated water during childhood. Led by UNC School of Dentistry faculty ...

Nonprofits a major source of employment growth globally

2013-03-11
A new report from the Johns Hopkins Institute for Policy Studies reveals that nonprofit organizations are major employers and major sources of employment growth in countries throughout the world. The report draws on new data generated by statistical offices in 16 countries that have implemented a new United Nations Handbook on Nonprofit Institutions. This Handbook calls on national statistical offices to report on the economic scale and composition of nonprofit organizations in their countries for the first time. Key findings to date from implementation of this Handbook, ...

A new drug reduces heart damage

2013-03-11
This press release is available in French. A single dose of an investigational anti-inflammatory drug called inclacumab considerably reduces damage to heart muscle during angioplasty (the opening of a blocked artery), according to a recent international clinical trial spearheaded by Dr. Jean-Claude Tardif, Director of the Research Centre at the Montreal Heart Institute, affiliated with the University of Montreal. Presented today in San Francisco at the prestigious American cardiology conference, these findings show great promise. "Inclacumab could indeed become an ...

Significant reduction in temperature and vegetation seasonality over northern latitudes

2013-03-11
An international team of authors from 17 institutions in seven countries, including the Woods Hole Research Center, published a study in the journal Nature Climate Change on the 10 March 2013 (10.1038/NCLIMATE1836: http://www.nature.com/nclimate). The study shows that, as the cover of snow and ice in the northern latitudes has diminished in recent years, the temperature over the northern land mass has increased at different rates during the four seasons, causing a reduction in temperature and vegetation seasonality in this area. The temperature and vegetation at northern ...

Can hormone help treat multiple sclerosis long-term?

2013-03-11
SAN DIEGO – A new study suggests that treatment with adrenocorticotropic hormone (ACTH) may be helpful for people whose multiple sclerosis (MS) is not well-controlled through their regular treatment. The study was released today and will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego, March 16 to 23, 2013. The study involved 23 people with MS who were taking beta-interferon treatment and had at least one relapse or brain scan showing new disease activity within the previous year. They were considered to have "breakthrough" MS, which ...

LAST 30 PRESS RELEASES:

High exposure to everyday chemicals linked to asthma risk in children

How can brands address growing consumer scepticism?

New paradigm of quantum information technology revealed through light-matter interaction!

MSU researchers find trees acclimate to changing temperatures

World's first visual grading system developed to combat microplastic fashion pollution

Teenage truancy rates rise in English-speaking countries

Cholesterol is not the only lipid involved in trans fat-driven cardiovascular disease

Study: How can low-dose ketamine, a ‘lifesaving’ drug for major depression, alleviate symptoms within hours? UB research reveals how

New nasal vaccine shows promise in curbing whooping cough spread

Smarter blood tests from MSU researchers deliver faster diagnoses, improved outcomes

Q&A: A new medical AI model can help spot systemic disease by looking at a range of image types

For low-risk pregnancies, planned home births just as safe as birth center births, study shows

Leaner large language models could enable efficient local use on phones and laptops

‘Map of Life’ team wins $2 million prize for innovative rainforest tracking

Rise in pancreatic cancer cases among young adults may be overdiagnosis

New study: Short-lived soda tax reinforces alternative presumptions on tax impacts on consumer behaviors

Fewer than 1 in 5 know the 988 suicide lifeline

Semaglutide eligibility across all current indications for US adults

Can podcasts create healthier habits?

Zerlasiran—A small-interfering RNA targeting lipoprotein(a)

Anti-obesity drugs, lifestyle interventions show cardiovascular benefits beyond weight loss

Oral muvalaplin for lowering of lipoprotein(a)

Revealing the hidden costs of what we eat

New therapies at Kennedy Krieger offer effective treatment for managing Tourette syndrome

American soil losing more nutrients for crops due to heavier rainstorms, study shows

With new imaging approach, ADA Forsyth scientists closely analyze microbial adhesive interactions

Global antibiotic consumption has increased by more than 21 percent since 2016

New study shows how social bonds help tool-using monkeys learn new skills

Modeling and analysis reveals technological, environmental challenges to increasing water recovery from desalination

Navy’s Airborne Scientific Development Squadron welcomes new commander

[Press-News.org] Protein abundant in cancerous cells causes DNA 'supercoiling'
Specialized protein maintains genome stability by maintaining DNA structure, but may also facilitate cancer cells by changing the very shape of DNA