Aberrant promoter DNA methylation inhibits bone morphogenetic protein 2 expression and contributes to drug resistance in breast cancer.

Bone morphogenetic protein 2 (BMP2) is a growth factor that is involved in the development and progression of various types of cancer. However, the epigenetic regulation of the expression of BMP2 and the association between BMP2 expression and drug resistance in breast cancer remains to be elucidated. The present study reported that the expression of BMP2 was significantly decreased in primary breast cancer samples and the MCF­7/ADR breast cancer mulitdrug resistance cell line, which was closely associated with its promoter DNA methylation status. The expression of BMP2 in MCF­7/ADR cells markedly increased when treated with 5­Aza­2'­deoxycytidine. Knockdown of BMP2 by specific small interfering RNA enhanced the chemoresistance of the MCF­7 breast cancer cell line. These findings indicated that epigenetic silencing of BMP2 in breast cancer may be involved in breast cancer progression and drug resistance, and provided a novel prognostic marker and therapeutic strategy for breast cancer.