miR-34a Reverses Doxorubicin Resistance in Breast Cancer

Abstract

Chemotherapy is effectively used for treating breast cancer, but the problem of tumor resistance to chemotherapy drugs has been plaguing scientists. Our study investigated miR-34a?s effect on the sensitivity of drug-resistant strains to chemotherapeutic drugs using doxorubicin-resistant strains of breast cancer cells. Cell survival rate was detected by MTT assay. The doxorubicin-resistant strain rMCF-7 was obtained. The cell scratching method and CCK-8 method were used to detect cell migration and proliferation.Western Blot was performed for measuring SIRT1, p-AKT, AKT, p-mTOR and mTOR level. miR-34a significantly reduced the survival rate o doxorubicin-resistant breast cancer cell line rMCF-7 and significantly enhanced doxorubicin?s effect on inhibiting cell proliferation and cell migration. Compared with the doxorubicin group alone, miR-34a and doxorubicin combination group significantly downregulated SIRT1, p-AKT/AKT and p-mTOR/mTOR related proteins in rMCF-7 cells. miR-34a can reverse the resistance of doxorubicin in breast cancer in vitro and the mechanism may be through inhibition of SIRT and AKT signaling.