Testosterone may contribute to colon cancer tumor growth
2014-12-10
(Press-News.org) COLUMBIA, Mo. - Previous cancer research has revealed that women are less likely than men to suffer from non-sex specific cancers such as cancer of the colon, pancreas and stomach. Scientists theorized that perhaps this trend was due to a protecting effect created by female hormones, such as estrogen, that help prevent tumors from forming. Now, researchers at the University of Missouri have found evidence suggesting that the male hormone testosterone may actually be a contributing factor in the formation of colon cancer tumors.
In his study, James Amos-Landgraf, an assistant professor of veterinary pathobiology in the MU College of Veterinary Medicine, observed normal levels of naturally occurring colon cancer in a group of male rats. He then removed testosterone from those rats and colon cancer rates decreased dramatically. After reintroducing testosterone, the colon cancer rates returned to normal.
"Previously, scientists believed that female hormones may have lent some sort of protection against tumor susceptibility," Amos-Landgraf said. "However, by showing that removing testosterone from rats leads to a drastic decrease in colon cancer susceptibility, it appears that male hormones may actually contribute to colon tumor growth rather than female hormones being protective."
Amos-Landgraf also points to higher rates of colon cancer in post-menopausal women as potential evidence to support testosterone as a contributing agent to tumor growth.
"All women have some level of testosterone in their bodies naturally, but those levels typically are much lower than estrogen and other female hormones," Amos-Landgraf said. "Once women experience menopause and their female hormone levels decrease, their testosterone levels become relatively higher. This corresponds to the time when they begin to experience higher rates of colon cancer and could be a sign of a relationship between testosterone levels and colon tumor growth."
Amos-Landgraf says he plans to continue his research by investigating the genetic traits that are responsible for the difference in susceptibility to cancer between men and women.
INFORMATION:
This study was published in the Proceedings of the National Academy of Sciences and was funded by two grants from the National Institutes of Health (Grants R01 CA63677 and R01 CA125591) and support from the American Cancer Society and University of Missouri.
ELSE PRESS RELEASES FROM THIS DATE:
2014-12-10
Ants: Ever since agriculture evolved ca 10.000 years ago, plants have been artificially selected to become the fast growing and highly productive varieties we know today. However, humans were not the first to see merit in cultivating their own food, as ants have been doing this for 50 million years. A lineage of South-American ants collect leaves and recycle their own feces to manure a fungus garden for food. New research shows that these ants have an evolutionary history of improvement of their fungal crops.
A joint effort by researchers at the Universities of Copenhagen ...
2014-12-10
ANN ARBOR, Mich. - Urinary tract infections can occur with no apparent cause, and as effectiveness of antibiotics fades, treating them is also becoming less predictable.
University of Michigan Medical School researchers have identified bacterial genes that help the infections spread, providing a potential new target for treating UTIs, a global public health concern mostly affecting women. UTIs lead to lost work time, emergency room visits and health care spending of $3.5 billion in the United States.
The research findings, published in this week's Proceedings of the ...
2014-12-10
A new study by Robert Stahelin, an adjunct associate professor of chemistry and biochemistry at the University of Notre Dame and an associate professor at the Indiana University School of Medicine-South Bend, as well as a member of Notre Dame's Eck Institute for Global Health, investigates how the most abundant protein that composes the Ebola virus, VP 40, mediates replication of a new viral particle.
"In brief, the Ebola virus has just seven proteins that encode in its genome," Stahelin said. "VP40 is critical to the formation of a new viral particle and it does this ...
2014-12-10
Ads can communicate their main message in as little as a tenth of a second, helped by color, according to a new study published in Marketing Science, a publication of the Institute for Operations Research and the Management Sciences (INFORMS).
The Buffer Effect: The Role of Color When Advertising Exposures Are Brief and Blurred is by Michel Wedel, Pepsico Chaired Professor of Marketing at the Robert H. Smith School of Business of the University of Maryland and Rik Pieters, Professor of Marketing at the Tilburg School of Economics and Management of the University of Tilburg ...
2014-12-10
A sex-changing fish called California sheephead (Semicossyphus pulcher) plays a vital role in the food web of kelp forests along the Pacific coast. Commonly found in the waters from Baja California to Point Conception -- although they can sometimes be found as far north as Monterey Bay -- sheephead feed on sea urchins, whose grazing habits can wreak havoc on community composition in kelp forests.
A new study by UC Santa Barbara research biologist Jenn Caselle uses data from three decades of research to document differential exploitation and recovery of sheephead populations ...
2014-12-10
Recent research from the University of Alberta reveals that contrary to current scientific knowledge, there's no atmospheric lead pollution in the province's oil sands region.
William Shotyk, a soil and water scientist who specializes in heavy metal pollution, examined sphagnum moss from 21 separate peat bogs in three locations around the oil sands area, near open pit mines and processing facilities.
After measuring the heavy metal content in the moss samples in his ultra-clean lab at the University of Alberta, Shotyk, based in the Faculty of Agricultural, Life and ...
2014-12-10
A University of Colorado Cancer Center study being presented at the San Antonio Breast Cancer Symposium shows that triple negative breast cancer cells process tryptophan to promote survival while traveling through the body in order to seed new tumor sites.
"I'm not saying that people with metastatic breast cancer shouldn't eat turkey during the holidays, but triple-negative breast cancer appears to have found a way to process tryptophan more quickly, equipping cancer cells to survive while in circulation, which allows them to metastasize," says Thomas Rogers, the paper's ...
2014-12-10
DALLAS - Dec. 10, 2014 - UT Southwestern Medical Center microbiologists have identified key bacteria in the gut whose resources are hijacked to spread harmful foodborne E. coli infections and other intestinal illnesses.
Though many E. coli bacteria are harmless and critical to gut health, some E. coli species are harmful and can be spread through contaminated food and water, causing diarrhea and other intestinal illnesses. Among them is enterohemorrhagic E. coli or EHEC, one of the most common foodborne pathogens linked with outbreaks featured in the news, including ...
2014-12-10
An anomaly spotted at the Large Hadron Collider has prompted scientists to reconsider a mathematical description of the underlying physics. By considering two forces that are distinct in everyday life but unified under extreme conditions like those within the collider and just after the birth of the universe, they have simplified one description of the interactions of elementary particles. Their new version makes specific predictions about events that future experiments at the LHC and other colliders should observe and could help to reveal "new physics," particles or processes ...
2014-12-10
BERKELEY -- Future fitness trackers could soon add blood-oxygen levels to the list of vital signs measured with new technology developed by engineers at the University of California, Berkeley.
"There are various pulse oximeters already on the market that measure pulse rate and blood-oxygen saturation levels, but those devices use rigid conventional electronics, and they are usually fixed to the fingers or earlobe," said Ana Arias, an associate professor of electrical engineering and computer sciences and head of the UC Berkeley team that is developing a new organic optoelectronic ...
LAST 30 PRESS RELEASES:
[Press-News.org] Testosterone may contribute to colon cancer tumor growth
