BTG2 overexpression increases the radiosensitivity of breast cancer cells in vitro and in vivo.

Antiproliferative gene B-cell translocation gene, member 2 (BTG2) is a member of the BTG/TOB antiproliferative gene family. In this study, we investigated the effect of BTG2 gene overexpression on the radiosensitivity of breast cancer cells in vitro and in vivo. Results show that in human breast cancer cell line MCF-7 stably overexpressing BTG2 gene, cell sensitivity to ionizing radiation increased. The MCF-7-BTG2 cells were more susceptible to radiation-caused apoptosis with decreased cyclin B1, cyclin D1, Ku70, FEN-1, and XRCC1 protein expression as well as increased BAX protein expression. The findings indicate for the first time that BTG2 can improve the radiosensitivity of breast cancer cells by affecting cell cycle distribution, enhancing radiation-induced apoptosis, and inhibiting DNA repair-related protein expression.