Understanding Skin Cancer
(Ivanhoe Newswire) – A case of mistaken identity may ultimately end up benefiting people with the most deadly form of skin cancer.
National Institutes of Health researchers have found a genetic mutation originally tagged as an ontogeny (responsible for promoting the growth of cancer by activating growth-promoting signals) is really a tumor suppressor gene. When scientists target oncogenes, they attempt to curtail their activity so cancers can’t grow. When they target tumor suppressor genes, they try to boost their activity to help cancers from forming.
The gene in question is one of many that codes for metalloproteinase (MMP) enzymes. The mutated form of MMP-8 was thought to be an oncogene but new work in the laboratory has shown it is really a tumor suppressor gene instead. About a quarter of the human melanoma samples tested had some type of MMP mutation, with MMP-8 showing up in more than 6 percent.
The lab tests were confirmed by tests in mice. When researchers injected mice with cells containing the normal form of MMP-8 they did not develop skin ulcers that can lead to melanoma. When they injected them with the mutated form, they did develop these ulcers and also were more likely to have cancers that spread to their lungs.
The researchers note this study reinforces the theory cancer is a diverse condition. “We often talk about cancer as though it is one disease, and cancers do have many common denominators,” study author Yardena Samuels, Ph.D., was quoted as saying. “But when we look at the DNA level, we see that different cancers have different genetic profiles, and so do different patients who have the same cancer.”
SOURCE: Nature Genetics, published online March 29, 2009