Mechanism Of Curcumin Sensitizes Cisplatin-resistant Chordoma Cells

ObjectiveTo observe the effect of curcumin on the apoptosis of cisplatin-resistantChordoma cells, and explore its potential mechanism.MethodsChordoma cell line CM-319was cultured in vitro, and was divided into4groupsaccording to protocol:（1）control (0.1%DMSO);(2) cisplatin group (0-40mg/L);(3)curcumin group (0-40μmol/L);(4) cisplatin with curcumin group. After treatment, thelargest action concentrations of curcumin and cisplatin were screened by Lactatedehydrogenase experiment；proliferation of CM-319cells was detected by WST-8assay; Cell cycle and apoptosis were determined by flow cytometry; expressions ofMDR1and MRP1mRNA were measured by real-time quantitative PCR;expressions of HIF-1α in the nucleus and P-gp、MRP1in the cytoplasm wereexamined by Western blot.Results(1) Lactate dehydrogenase release experiment showed that0-30mg/L of cisplatin hadno obvious influence on CM-319cells (P>0.05). When CM-319cells were culturedwith30mg/L cisplatin and different concentrations of curcumin for24hours, thelargest joint dose of curcumin was30μmol/L.(2) WST-8results showed that30μmol/L curcumin per se could slightly inhibitCM-319cells growth. While when they combined together, the proliferation ofCM-319cells was reduced significantly.(3) Real-time quantitative PCR results showed that the expression of MDR1mRNA in CM-19cells was very low, and curcumin and (or) cisplatin did not affect itsexpression. MRP1was significantly expressed in CM-319cells, and its mRNAlevels could be both reduced by curcumin and (or) cisplatin.(4) Western blot results showed that there was almost no P-gp protein expression inCM-319cells. By contrast, MRP1expression was higher. HIF-1alpha showedcertain expression in the nucleus. Treated with curcumin or cisplatin couldeffectively reduce the intracellular MRP1protein content, at the same time, theycould also reduce the content of HIF-1alpha in the nucleus. When curcumincombined with cisplatin, MRP1and HIF-1alpha expression level were furtherreduced.(5) Flow cytometry results showed that cells in the S phase of the control group’sshared of22.65%, G1phase was54.30%, G2phase23.05%, the apoptosis was2.91%. Curcumin combined with cisplatin effected cells, the S, G1and G2phaseaccounted for5.47%,87.23%and7.34%, respectively. The apoptosis was25.28%.ConclusionsCurcumin suppressed the growth of Chordoma cells through sensitizingcisplation on CM-319.