The enhancing effect of curcumin on the sensitivity of cisplatin-resistance human ovarian cancer cell line COC1/DDP to cisplatin

Objective To investigate the association of curcumin use with the sensitivity of cisplatin-resistant ovarian cancer line COC1/DDP to cisplatin.Methods The effects of curcumin alone,cisplatin alone,or a combined therapy with both agents on the proliferation and apoptosis in cisplatin-resistant cells COC1/DDP were determined by MTT assay and TUNEL.The expressions of apoptosis-associated genes Bcl-2 and Smac were detected using RT-PCR.Results Coadministration of cisplatin at concentrations of 1.25 to 5 μg/mL with curcumin markedly decreased the survival rate of COC1/DDP(P0.05);and the most significant deline in the rate occurred after the use of 2.5 μg/mL of cisplatin combined with 20 μmol/L of curcumin.As compared with cisplatin or curcumin alone,the combination therapy evidently increased the apoptotic rate,downregulated the expression of Bcl-2 mRNA,and upregulated that of Smac mRNA(P0.05 for all comparisons).Conclusions Curcumin can inhibit the growth of COC1/DDP and enhance the sensitivity of the cells to cisplatin,whose mechanism may be associated with the upregulation of Smac and downregulation of Bcl-2.