Posted on Apr 01, 2009, 10 a.m.
By gary clark
Researchers from the National Institutes of Health have identified that an enzyme gene once believed to be an oncogene actually suppresses tumor growth in melanoma.
In a study conducted by the National Institutes of Health, researchers examined a bank of tumor and blood samples collected from 70 patients with an aggressive form of melanoma, the deadliest type of skin cancer. They discovered that six percent of those patients had mutations in MMP-8, an enzyme once thought to be an oncogene, which when mutated or expressed at high levels helps turn a normal cell into a cancer cell.
They took their study to the laboratory, injecting mice with cells expressing normal MMP-8. Those mice did not develop skin ulcers, one of the key measures of cancer aggression in melanoma. On the other hand, those mice injected with cells expressing mutated MMP-8 went on to develop ulcerations and tumors in their lungs.
As a result of the study, the researchers found that MMP-8, which is one of the most often mutated genes that code for matrix metalloproteinase (MMP) enzymes, actually serves as a tumor suppressor gene. As researchers noted, MMP enzymes play a key role in remodeling skin after a sunburn, cut or other wound. It has long been believed that the MMP gene family increases the risk of cancer, in particular breast, colon and melanoma cancers.
"The study suggests that a better approach may be to look for drugs that restore or increase MMP-8 function or for drugs that block only those MMPs that are truly oncogenes," the researchers note. Their findings were recently published in the British journal, Nature Genetics.
News Release: Gene found to suppress skin cancer www.news.xinhuanet.com March 30, 2009