Navigation Links
Study reveals one reason brain tumors are more common in men
Date:8/1/2014

New research at Washington University School of Medicine in St. Louis helps explain why brain tumors occur more often in males and frequently are more harmful than similar tumors in females. For example, glioblastomas, the most common malignant brain tumors, are diagnosed twice as often in males, who suffer greater cognitive impairments than females and do not survive as long.

The researchers found that retinoblastoma protein (RB), a protein known to reduce cancer risk, is significantly less active in male brain cells than in female brain cells.

The study appears Aug. 1 in The Journal of Clinical Investigation.

"This is the first time anyone ever has identified a sex-linked difference that affects tumor risk and is intrinsic to cells, and that's very exciting," said senior author Joshua Rubin, MD, PhD. "These results suggest we need to go back and look at multiple pathways linked to cancer, checking for sex differences. Sex-based distinctions at the level of the cell may not only influence cancer risk but also the effectiveness of treatments."

Rubin noted that RB is the target of drugs now being evaluated in clinical trials. Trial organizers hope the drugs trigger the protein's anti-tumor effects and help cancer patients survive longer.

"In clinical trials, we typically examine data from male and female patients together, and that could be masking positive or negative responses that are limited to one sex," said Rubin, who is an associate professor of pediatrics, neurology and anatomy and neurobiology. "At the very least, we should think about analyzing data for males and females separately in clinical trials."

Scientists have identified many sex-linked diseases that either occur at different rates in males and females or cause different symptoms based on sex. These distinctions often are linked to sex hormones, which create and maintain many but not all of the biological differences between the sexes.

However, Rubin and his colleagues knew that sex hormones could not account for the differences in brain tumor risk.

"Male brain tumor risk remains higher throughout life despite major age-linked shifts in sex hormone production in males and females," he said. "If the sex hormones were causing this effect, we'd see major changes in the relative rates of brain tumors in males and females at puberty. But they don't happen then or later in life when menopause changes female sex hormone production."

Rubin used a cell model of glioblastoma to prove it is easier to make male brain cells become tumors. After a series of genetic alterations and exposure to a growth factor, male brain cells became cancerous faster and more often than female brain cells.

In experiments designed to identify the reasons for the differences in the male and female cells, the team evaluated three genes to see if they were naturally less active in male brain cells. The genes they studied neurofibromin, p53 and RB normally suppress cell division and cell survival. They are mutated and disabled in many cancers.

The scientists found RB was more likely to be inactivated in male brain cells than in female brain cells. When they disabled the RB protein in female brain cells, the cells were equally susceptible to becoming cancers.

"There are other types of tumors that occur at different rates based on sex, such as some liver cancers, which occur more often in males," Rubin said. "Knowing more about why cancer rates differ between males and females will help us understand basic mechanisms in cancer, seek more effective therapies and perform more informative clinical trials."


'/>"/>

Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
Source:Eurekalert  

Related medicine news :

1. Despite Recent Study, Abington Health Expert Encourages Breastfeeding
2. Hairdo Trumps Exercise for Many Black Women, Study Finds
3. 1 in 4 U.S. Kids Underestimate Their Weight, Study Finds
4. Burnout Common Among Transplant Surgeons, Study Reveals
5. Infection Prevention and Control Market to Post about 7.5% CAGR through 2018, States Infiniti Research in Its Study Published at MarketPublishers.com
6. Cold Sore Virus Active Without Symptoms, Study Finds
7. Benefits of E-Cigarettes May Outweigh Harms, Study Finds
8. Make Kids Weight Loss a Family Affair, Study Suggests
9. Study: Telephone support program beneficial for caregivers of those with dementia
10. Dieting at Young Age Often Backfires, Study Says
11. Study Finds Common Blood Protein May Predict Mesothelioma Survival, Reports Surviving Mesothelioma
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study reveals one reason brain tumors are more common in men
(Date:5/28/2017)... ... May 28, 2017 , ... Starting in May, patients at The ... Rate Variability (HRV) diagnostic test. , Nerve-Express, originally designed for the Navy in the ... state of a patient’s autonomic nervous system (ANS). The ANS controls all the ...
(Date:5/28/2017)... , ... May 28, 2017 , ... ... (PPOA), is proud to announce that Sheldon K. Cho, MD, has joined its ... management, a specialty that concentrates on minimally invasive techniques to treat and manage ...
(Date:5/27/2017)... , ... May 27, 2017 , ... Hate visiting the dentist? You should go twice ... to take care of your teeth at home. Here are some dental tips to help ... Keep a small toothbrush in your work desk or a locker at school for a ...
(Date:5/27/2017)... ... 27, 2017 , ... Most us are familiar with the sound of occasional ... the Osteoarthritis Initiative shows that certain people who experience consistent joint popping, grating ... give doctors the opportunity to treat patients before the problem becomes pronounced, potentially hedging ...
(Date:5/26/2017)... ... May 26, 2017 , ... Leading CEOs from biotech, pharmaceutical, ... and 31st at The Four Seasons Hotel Boston. , The Boston CEO ... offering exclusive access to key decision makers who influence deal making and investment. ...
Breaking Medicine News(10 mins):
(Date:5/4/2017)...  A recent study published in the American ... as a means of disinfection anesthesia workstations ... on anesthesia workstations. In the study, UVC disinfection ... equipment surfaces contaminated with three (3) organisms commonly ... further validates the body of literature supporting Tru-D," ...
(Date:5/4/2017)...  A new tight-tolerance microextrusion medical tubing product ... is being launched by Natvar, a Tekni-Plex company. ... recent years to service a wide variety of ... expensive materials such as glass and fluoropolymers have ... their ability to consistently hold tolerances. This is ...
(Date:5/3/2017)... 3, 2017  Getinge, a leading global provider ... enhancement and cost efficiency within healthcare and life ... contemporary practice demonstrating that intra-aortic balloon counterpulsation (IABC) ... ill patients. The single-center, retrospective, observational study showed ... MEGA ® 50cc intra-aortic balloon (IAB) in ...
Breaking Medicine Technology: