Study On Inhibitory Effects Of Tetrandrine Derivatives On Human Triple-negative Breast Cancer MDA-MB-231 Cells And Its Possible Mechanism

Objective: To investigate the effects of tetrandrine derivatives HL-42 and HL-49 on the proliferation,colony formation and apoptosis of human triple-negative breast cancer MDA-MB-231 cells and to explore the possible molecular mechanism and to explore the effects of HL-49 in combination with three chemotherapeutic agents on the proliferation in human triple-negative breast cancer MDA-MB-231 cells.Methods: After MDA-MB-231 cells were treated with different concentrations of HL-42 or HL-49,the cell proliferation was detected by MTT assay,and the colony-forming ability was evaluated by colony-forming assay.After MDA-MB-231 cells were treated with 2 and 10 ?mol/L HL-42 or HL-49 for 24 h,the apoptosis rate was detected by FCM,and the expression levels of Bloom's syndrome helicase(BLM),breast cancer susceptibility gene1(BRCA1)and homologous recombination repair molecule Rad51 mRNAs and proteins were measured by semi-quantitative RT-PCR and Western blotting,respectively.MTT method was used to detect the combined effect on cell proliferation.Results: The proliferation of MDA-MB-231 cells was inhibited after treatment with 1.25-10 ?mol/L HL-42 or HL-49 for 24-72 h,in a concentration and time-dependent manner(all P<0.05).The half maximal inhibitory concentration(IC50)of HL-42 in MDA-MB-231 cells after treatment for 24,48 and 72 h were(8.27±0.27)?mol/L,(3.92±0.39)?mol/L and(2.72±0.14)?mol/L,respectively;the corresponding IC50 values of HL-49 were(5.30±0.45)?mol/L,(3.19±0.32)?mol/L and(1.64±0.12)?mol/L,respectively;while the IC50 values of tetrandrine(as the positive drug)were(23.61±2.02)?mol/L,(14.85±0.56)?mol/L and(12.39±0.92)?mol/L,respectively;the IC50 values of cisplatin(as the positive drug)were(61.96±3.83)?mol/L,(29.08±4.11)?mol/L and(16.19±2.53)?mol/L,respectively.The colony-forming ability of MDA-MB-231 cells was suppressed after treatment with 0.2,0.5,1 and 5 ?mol/L HL-42 or HL-49(all P<0.001).The apoptosis of MDA-MB-231 cells was induced by 2 and 10 ?mol/L HL-42 or HL-49,in a concentration-dependent manner(all P<0.05).The expression levels of Rad51 mRNA and protein in MDA-MB-231 cells were not changed after treatment with 2 ?mol/L HL-42 for 24 h(both P>0.05),But which were significantly decreased after treatment with 10 ?mol/L HL-42 for 24 h(both P<0.05).While the expression levels of BLM and BRCA1 mRNAs and proteins in MDA-MB-231 cells were not changed after treatment with 2 and 10 ?mol/L HL-42 for 24 h(all P>0.05).The expression levels of BRCA1 mRNA and protein in MDA-MB-231 cells were not changed after treatment with 2 ?mol/L HL-49 for 24 h(both P>0.05),but which were significantly decreased after treatment with 10 ?mol/L HL-49 for 24 h(both P<0.01).The expression levels of BLM and Rad51 mRNAs and proteins in MDA-MB-231 cells treated with 2 and 10 ?mol/L HL-49 for 24 h were decreased(all P<0.01).The inhibitory effect of HL-49 combined with cisplatin(DDP),adriamycin(ADM)and paclitaxel(TAX)on MDA-MB-231 cells was higher than that of the single drug administration group(all P<0.05).Conclusion: Tetrandrine derivatives HL-42 and HL-49 can inhibit the proliferation of human triple-negative breast cancer MDA-MB-231 cells,and induced apoptosis.The mechanism may be related to the partial block of cellular DNA repair pathway by HL-42 and HL-49.HL-49 had a synergistic effect with cisplatin(DDP),adriamycin(ADM)and paclitaxel(TAX).