Scientists reveal mechanism that regulates cancer-causing gene

Mar 26, 2009

Two University of Rhode Island scientists have revealed how a cancer causing protein is regulated by reactive oxygen species (ROS) -- a type of stress signal. Their findings provide new insight into how this protein normally behaves in human cells and may help in the design of drugs targeting specific cancers.

Doctoral student David J. Kemble and Professor Gongqin Sun in the URI Department of Cell and Molecular Biology are the first to provide a biochemical mechanism describing how certain protein tyrosine kinases sense and respond to oxidation. This sensing system was found to uniquely apply to two families of proteins implicated in numerous cancers: the Src and Fibroblast Growth Factor Receptor families of tyrosine kinases.

Their results were published online March 9 in the .

Src was the first enzyme identified as a cancer-causing gene in the early 1900's. For years scientists have been studying how the enzymes are expressed in - what do they do and what controls them.

According to Kemble and Sun, Src is a master regulator of cell function, controlling , division, and death. In normal cells, the function of Src is turned off, and it is turned on only when certain stimulatory signals activate it. When the regulatory mechanisms that control Src activity are disrupted, Src may be turned on all the time, which turns the into a cancer cell. Thus, it is crucial to understand how Src function is controlled.

Reactive oxygen species have long been viewed as damaging byproducts of oxygen-based metabolism. However, it is now recognized that ROS are produced when the cells are under growth stimulation, and they in turn regulate other cellular events.
Accumulating evidence indicates that ROS can directly regulate the function of Src function, and thus indirectly control many . Yet how Src responds to this regulation has remained elusive.

The URI scientists took a systematic approach, examined all the potential mechanisms, and identified the sensor that enables Src to respond to ROS regulation. They further found that the sensor is also present in several other similar enzymes, mostly in the FGFR family.

"Our results were surprising at first, given that the results contradict some reports in the literature," Kemble said. "But there was always a very clear answer to each question we asked. It was both unusual and exciting to see things progress as smoothly as it did."

According to Sun, this mechanism of regulation represents just a small piece of the large puzzle of how Src is controlled in the cells. "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." Sun said.

Source: University of Rhode Island (news : web)

Explore further: New cancer drug target involving lipid chemical messengers

add to favorites email to friend print save as pdf

Related Stories

Notorious cancer gene may work by destroying messenger

Mar 19, 2007

A new study suggests how a notorious cancer gene may contribute to tumor growth.The insight emerged from a long-running study of a protein called PMR1, the key player in an unusual mechanism that cells use to quickly stop ...

Deactivating a cancer growth promoter

Sep 25, 2008

Three enzymes called phosphatases that shut down a molecule called SRC-3 (steroid receptor coactivator 3) could provide a new pathway for fighting cancer, particularly tumors of the breast and prostate, said researchers at ...

An Achilles heel in cancer cells

Dec 08, 2008

A protein that shields tumor cells from cell death and exerts resistance to chemotherapy has an Achilles heel, a vulnerability that can be exploited to target and kill the very tumor cells it usually protects, researchers ...

New discovery raises doubts about current bladder treatment

Mar 25, 2009

Researchers at the University of Virginia Health System have found that one of the genes commonly thought to promote the growth and spread of some types of cancers is in fact beneficial in bladder cancer - a major discovery ...

Recommended for you

User comments : 0