Cancer treatment potential discovered in gene repair mechanism

Case Western Reserve researchers have identified a two-pronged therapeutic approach that shows great potential for weakening and then defeating cancer cells.

The team's complex mix of genetic and biochemical experiments unearthed a way to increase the presence of a tumor-suppressing protein which, in turn, gives it the strength to direct cancer cells toward a path that leads to their destruction.

If the laboratory findings are supported by tests in animal models, the breakthrough could hold the promise of increasing the effectiveness of radiation and chemotherapy in shrinking or even eliminating tumors. The key is to build up a "good" protein -- p53-binding protein 1 (53BP1) -- so that it weakens the cancer cells, leaving them more susceptible to existing cancer-fighting measures.

"Our discovery one day could lead to a gene therapy where extra amounts of 53BP1 will be generated to make cancer cells more vulnerable to cancer treatment," said senior author Youwei Zhang, PhD, assistant professor of pharmacology, Case Western Reserve University School of Medicine, and member of the Case Comprehensive Cancer Center. "Alternatively, we could design molecules to increase levels of 53BP1 in cancers with the same cancer-killing end result."

The cornerstone of the research involves DNA repair -- more specifically, double-stand DNA repair. During his study, Zhang and fellow investigators discovered a previously unidentified function of a known gene, UbcH7, in regulating DNA double-strand break repair. Specifically, they found that depleting UbcH7 led to a dramatic increase in the level of the 53BP1 protein.