Scientists Reveal Mechanism that Regulates Cancer-causing Genes.

Scientists have discovered how reactive oxygen species (a type of stress signal) regulate a cancer inducing protein. They believe this insight into protein dynamics within human cells could help with treating cancer through development of cancer-specific targeting drugs. Doctoral student D. Kemble and Prof. Gongqiu Sun of University of Rhode Island have provided a mechanism that describes how Src and Fibroblast Growth Factor Receptor protein families’ tyrosine kinases sense and respond to oxidation.
The Src enzyme has been previously recognised as a cancer-causing gene. It is a regulator of cell function, controlling the cell lifecycle including metabolism, division and death. Src is usually inactive unless undergoing the processes. If the Src regulator is disrupted, Src activity may become continuous turning the normal cell into a cancer cell. This disrupting factor is reactive oxygen species. Reactive oxygen species are by-products of oxygen-based metabolism and are produced during growth stimulation in cells, and they regulate other cellular processes. Accumulating data shows that reactive oxygen species can directly regulate the function of Src function and therefore indirectly control many cellular processes.
The URI researchers took a systematic approach, examined all the potential mechanisms and identified the Src sensor that responds to the ROS regulation. They also discovered this sensor was shared by several similar enzymes. According to Prof. Sun "Src function is under the control of several different mechanisms; each one needs to fit in with the others to form a seamless regulatory system."
Further study is underway into how these mechanisms work together to control Src function in cells.

Their results were published online March 9 in the Proceedings of the National Academy of Sciences.


Todd McLeish. “Mechanism That Regulates Cancer-Causing Gene, Revealed By URI Scientists.”
University of Rhode Island. Medical News Today. (28th March 2009)
http://www.medicalnewstoday.com/articles/144015.php

David J. Kemble and Gongqin Sun. Direct and specific inactivation of protein tyrosine kinases in the Src and FGFR families by reversible cysteine oxidation. Proceedings of the National Academy of Sciences. (9th March 2009)
http://www.pnas.org/content/early/2009/03/06/0806117106.abstract?sid=7d6cc3cf-fc2b-4be2-8045-1147af26e28c