Knockdown of RRM2 gene by siRNA inhibits human breast cancer cell proliferation,migration and tumor growth in nude mice

AIM: To explore the effect of ribonucleotide reductase M2 (RRM2) gene knockdown by siRNA on the proliferation and migration of human breast cancer MCF-7 cells and the tumor growth in BALB/c nude mice. METHODS: The mRNA and protein expression leves of RRM2 in human breast cancer cell line MCF-7 and human normal breast cell line MCF-10A were determined by real-time PCR and Western blotting. siRNA-RRM2 was constructed and transfected into MCF-7 cells at different time points and different concentrations. The silencing efficiency of RRM2 gene was detected by real-time PCR. The cell proliferation was measured by CCK-8 assay. The migration was observed using Transwell cell migration system. The effect of siRNA-RRM2 on the tumor growth was determined in nude mice. RESULTS: The mRNA and protein levels of RRM2 were higher in MCF-7 cells than those in MCF-10A cells. siRNA-RRM2 down-regulated the expression of RRM2 in MCF-7 cells in a time-and concentration-dependent manner. The results of CCK-8 assay showed that siRNA-RRM2 inhibited the proliferation ability of MCF-7 cells, but not that of MCF-10A cells. The results of Transwell assay indicated that siRNA-RRM2 inhibited the migration ability of MCF-7 cells. siRNA-RRM2 also inhibited the tumor growth in nude mice. CONCLUSION: RRM2 overexpression is associated with the breast cancer proliferation and migration. Suppression of RRM2 function is a potential therapeutic strategy for treating breast cancer.