The present study aimed to investigate the effect of the long noncoding RNA cancer susceptibility candidate 9 (CASC9) on doxorubicin (DOX)-resistant breast cancer and to reveal the potential underlying mechanisms. The expression of CASC9 in breast cancer tissues and cell lines, in addition to drug-resistant breast cancer cells (MCF-7/DOX), was detected by reverse transcription-quantitative polymerase chain reaction. Subsequently, MCF-7/DOX cells were transfected with the silencing vector pS-C ASC9, containing enhancer of zeste homolog 2(EZH2), ...
