University of Texas Medical Branch at Galveston researchers have found a surprising connection between a key DNA-repair process and a cellular signaling network linked to aging, heart disease, cancer and other chronic conditions. The discovery promises to open up an important new area of research one that could ultimately yield novel treatments for a wide variety of diseases.
"This is a totally new concept it goes against current dogma about the role of DNA repair," said UTMB professor Istvan Boldogh, senior author of a paper on the work now online in the Journal of Biological Chemistry. "We couldn't believe it ourselves, but the data convinced us."
Boldogh and his colleagues came up with the idea of a link between DNA repair and cellular signaling after a close examination of the relationship between DNA damage and cell death produced unexpected results. Conventional DNA-repair dogma holds that a cell's lifespan is determined by the amount of accumulated DNA damage it suffers the overall corruption of genetic information stored in sequences of molecules called bases, which form the "rungs" of the DNA double helix. The cells used in Boldogh's study were especially vulnerable to damage because they lacked a key enzyme that repairs the DNA base guanine. According to dogma, this should have shortened the cells' lives; instead, they actually lived longer than expected. This made Boldogh wonder if another factor was involved in reducing the lifespan of normal cells.
"We proposed the hypothesis that instead of the accumulation of damaged guanine in DNA causing ill effects, what is significant is the release of a DNA-repair byproduct that somehow activates processes that shorten the lifespan of cells," Boldogh said.
The researchers knew just where to look to find this hypothetical repair byproduct. The majority of DNA damage is caused by ubiquitous reactive oxygen species, very chemically active molecules created as
|Contact: Jim Kelly|
University of Texas Medical Branch at Galveston