Abstract: Multi-drug resistance (MDR) of breast cancer is a key factor of breast cancer treatment failure. MicroRNA (miRNA) is a class of endogenous expressed, small, single-stranded RNA molecules, and regulate the expression of genes at post-transcriptional level by combining with target message RNA. MiRNA participate in the mechanisms of drug resistance of breast cancer, and are feasible therapeutic targets for the treatment of drug resistance in breast cancer. Finding and studying miRNA related with drug resistance of breast cancer as well as their mechanisms have become a current research hotspot.

Key words: MicroRNAs, Breast neoplasms, Drug resistance