October 13, 2005
Enzyme complex thought to promote cancer development can also help prevent itTopics: Medicine
[The image shows prostate cancer cells stained for EZH2 protein (left) and DNA microarray data (right). Red squares identify genes that are active in metastatic prostate cancer, while green squares indicate genes that are repressed (Photo: Vasudeva Mahavisno - UM)]
Good basic science detective work by researchers at The University of Texas M. D. Anderson Cancer Center, has solved the puzzle of the "inconsistent biomarker" and, in the process, may have discovered an agent that can suppress cancer development. Researchers report in the Oct. 14 issue of Science, that the biomarker in question - an enzyme known as EZH2 - leads a duplicitous life. In its "native" state, the enzyme acts as a suppressor for cancer cell growth that works to inhibit cancer development. But when it is phosphorylated (when a phosphate group is added to the molecule), it turns vicious and acts to promote oncogenesis(the formation and development of tumors).
(...) The researchers found the two forms of EZH2 after they identified the "switch" that leads to its phosphorylation - the well-known culprit Akt, an enzyme that has already been associated with cancer development.Their findings are important for a number of different reasons...
(...) The findings explain not only why high levels of EZH2 (when bound to its partner proteins, such as EED) have been shown to identify people who have an aggressive, metastatic form of breast or prostate cancer, but also why elevated levels of EED appear to offer protective effects against virulent lymphoma.
(...) This has become a big riddle to cancer researchers who want to be able to use EZH2 as a marker upon which to base aggressive treatment," says the study's lead author, Mien-Chie Hung, Ph.D., chair of the Department of Molecular and Cellular Oncology. "We now know there are two different forms of EZH2. The phosphorylated one enhances oncogenesis, whereas the nonphosphorylated EZH2 works to inhibit cell growth."
Cross posted to New Hope Blog
Posted by Richard at October 13, 2005 9:56 PM
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