Two Studies Make Promising Advances in Prostate Cancer Research

September 10, 2009 06:00 PM
by Denis Cummings
Two recently released studies have moved science closer to discovering the cause of prostate cancer; one strengthened the link between prostate cancer and a virus, while the other discovered a stem cell in the prostate.

Prostate Cancer Link to XMRV Virus

In a study published in this week’s Proceedings of the National Academy of Sciences, researchers at the University of Utah and Columbia University have found strong evidence to support the link between prostate cancer and the retrovirus XMRV (Xenotropic murine leukemia virus). XMRV was seen in 27 percent of the 200 cancerous prostates studied; the virus is seen in just 6 percent of non-cancerous prostates.

XMRV was linked to prostate cancer when it was discovered in 2006, but the latest study linked it specifically to an aggressive form of the cancer. XMRV is also known to cause leukemia and other tumors.

The research may help scientists identify a key trigger for prostate cancer and help them construct treatments. HealthDay reporter Ed Edelson writes that finding XMRV in patients will help doctors distinguish “the minority of virulent, life-threatening cancers from the majority of tumors which grow so slowly that ‘watchful waiting’ may be enough.”

Furthermore, the findings raise hope of creating a vaccine for the disease. “In the future, if it turns out to be true, then we could speculate about the possibility of vaccination to protect against prostate cancer, similar to the approach now used to prevent cervical cancer,” said Dr. Chris Parker of the Institute of Cancer Research to the BBC.

New Stem Cell Discovered in Prostate

A second study, published online Sept. 9 in the journal Nature, discovered a potentially new source of prostate cancer: stem cells, named CARNs, located in the luminal layer of the prostate, the layer that makes secretions. Previously, stem cells had only been discovered in the basal layer, which support the luminal layer.

“Since prostate cancers are filled exclusively with cells that have features of luminal cells, it has been unclear how cancer might arise from basal cells,” says a Columbia University press release. “The new study may resolve this conundrum.”

Researchers found that CARNs “gave rise to prostate cancers” when the tumor-suppressing gene PTEN becomes inactive. PTEN is known to become mutated in prostate cancers.

The discovery was made while examining adult mice, and studies of human prostates will be necessary before conclusions can be reached. “It is unclear whether CARNs exist in the normal human prostate and if human prostate cancers can originate from these CARN,” writes Michael Smith of MedPage Today.

The discovery could potentially change the way late-stage prostate cancer is treated. “Importantly, this new stem cell does not rely on androgens—the male sex hormones that control prostate growth—to survive and grow,” said Dr. Helen Rippon, head of research management at Britain’s Prostate Cancer Charity, in a statement. “This may give a clue as to why prostate cancer often becomes resistant to treatments designed to regulate these androgens in the later stages of the disease”

Reference: Prostate Cancer

Prostate cancer is one of the most prevalent cancers in men. FindingDulcinea’s Web Guide to Prostate Cancer provides information on the disease, including symptoms and diagnosis, prevention and support groups.

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