关键词: 乳腺癌, 球囊细胞, ABCG2, RNA干扰, 药物耐受

Abstract: 【Abstract】 Objective To investigate the effect of RNA interference targeting ABCG2 gene on reverse chemotherapy resistance of mamosphere cell of breast cancer..Methods ABCG2-siRNA sequence was designed and inserted into lentiviral vector and virus was packaged,.then a stable ABCG2-silenced MCF-7 mamosphere cell lines was established. The expression level of ABCG2 was detected by Western blot..The proliferation was measured by MTT assay in MCF-7 mamosphere cells after RNA interference..Flow cytometry was performed to assess the cell cycle and apoptotic rate. Results Western Blot showed that ABCG2 was highly expressed in the mamosphere cells,.and the expression decreased concurrently after RNAi silenced ABCG2. MTT showed that inhibition rate of MCF-7 adherent cells was higher than that of MCF-7 mamosphere cells of in the presence of 5-Fu, and the inhibition rate increased as the concentration of 5-FU increased in ABCG2-silenced mamosphere cells. Flow cytometry also showed that most mamosphere cells were in G0/G1 phase, and the number of mamosphere cells in G0/G1 phase and apoptosis were elevated with increasing concentration of 5-Fu or ABCG2 gene blockage. Conclusion ABCG2 protein highly expressed in breast cancer mamosphere cells. The inhibition of ABCG2 gene expression could significantly increase the cell inhibition rate and the apoptosis rate in mamosphere cell, and reverse its resistance to 5-Fu.

Key words: Breast cancer, Mamosphere cell, ABCG2, RNA interference, Drug resistance