Tumor-Suppressing Gene Determines Drug Effectiveness

Researchers studying how best to use chemotherapy to treat breast cancer have found that the tumor-suppressing gene pRb2/p130 is critical in determining how effective a particular drug therapy will be.

They reported in the June 5, 2003, issue of Oncogene that in estrogen receptor-positive and estrogen receptor-negative mammary cell lines of women who have been affected with breast cancer, pRb2/p130 binds with the estrogen receptor gene alpha and sends out signals to engage or recruit a specific subset of molecules.

"These key molecules together are recruited by pRb2/p130 onto the receptor gene alpha, which when expressed on mammary cell lines makes the breast tumors more responsive to treatment,” explained first author Dr. Antonio Giordano, director of the Sbarro Institute for Cancer Research and Molecular Medicine at Temple University (Philadelphia, PA, USA).

In estrogen receptor-negative cell lines, the signal from pRb2/p130 is damaged or mutated, and the gene recruits a different sequence of molecules, which cause Rb2 to silence the expression of the estrogen receptor and block drug therapies from being successful against the cancer cells.

"There is a lack of success in therapies because the drug does not recognize the tumor cells anymore,” said Dr. Giordano. "It cannot distinguish between the good cells and the bad cells.”






Related Links:
Temple University