ABSTRACT
Objective:To explore the changes of chemotherapy sensitivity of breast cancer MCF-7/ADM cells after Hiwi gene targeting silence, and to illuminate the role of Hiwi gene in resistant mechanism of breast cancer MCF-7/ADM cells.Methods:The MCF-7/ADM cells were transfected with Hiwi control,siRNA1 Hiwi gene and siRNA2 Hiwi gene as Hiwi control group, Hiwi siRNA1 group and Hiwi siRNA2 group.The expression levels of Hiwi gene mRNA and protein in breast cancer MCF-7/ADM cells were detected by Real-time PCR and Western blotting methods to judge the transfection rates in various groups.After transfection,the breast cancer MCF-7/ADM cells in various groups were treated with the different concentrations(0,0.1,0.5 and 1.0 mg·L-1) of adriamycin, and the cell resistant sensitivities were detected by MTT method.Results:Compared with control group(0 mg·L-1 adriamycin), the expression levels of Hiwi gene mRNA and protein inMCF-7/ADM cells in Hiwi siRNA1 and Hiwi siRNA2 groups were significantly decreased (P<0.01).Compared with control group, the survival rates of Cells in Hiwi siRNA1 and Hiwi siRNA2 groups were significantly decreased after treated with different concentrations of adriamycin,and the survival rates in Hiwi siRNA1 and Hiwi siRNA2 groups were significantly decreased(P<0.01);they were (48.15±6.28)% and (41.73±6.17)% when the concentration of adriamycin was 1 mg·L-1,and the sensitivities to the adriamycinwere obviously enhanced(P<0.01).Conclusion:The target silencing Hiwi genes in MCF-7/ADM cells is efficient.The sensitivity of MCF-7/ADM cells to adriamycin restores after Hiwi gene silencing.
ABSTRACT
Objective One of the major obstacle to the successful treatment of cancer in clinic is the drug-resistance phenotype.In this study,the effect of realgar(REA) on the induction of apoptosis and the reversal of drug resistance were investigated. Methods Human breast cancer line MCF-7 and its adriamycin(ADM) resistant counterpart MCF-7/ADM cells were used in this study.15mg/L REA and 25mg/L REA were selected as non-cytotoxic dose and low-cytotoxic to MCF-7/ADM cells respectively by MTT assay.Then,they were adopted to affect the growth of MCF-7/ADM cells. MTT assay was used to analyze the effect of REA on drug sensitivity to ADM.The cells apoptosis was detected by transmission electron microscope and flow cytornetry.The expressions of anti-apoptosis protein Bcl-2 were detected by flow cytometry.Finally,the intracellular accumulation of ADM in MCF-7/ADM cells was detected by fluorescent-spectrophotometry. Results REA reversed the drug-resistance of ADM in MCF-7/ADM cells with dose-dependent relationship.When 15mg/L REA or 25mg/L REA was added into the culture,the 50% inhibitory concentration(IC_(50)) of ADM in MCF-7/ADM cells was reduced from 30.4mg/L to 13.2mg/L and 10.8mg/L(P