肿瘤干细胞在人结肠癌细胞株HT29耐奥沙利铂中的作用探讨

Role of cancer stem cells in the acquired resistance to Oxaliplatin of human colon cancer cell line HT29

目的探讨肿瘤干细胞(cancer stem cell,CSC)在人结肠癌细胞株HT29对奥沙利铂(L-OHP)产生获得性耐药中的作用。方法采用浓度递增法诱导产生人结肠癌耐奥沙利铂细胞株HT29/L-OHP。采用As2O3逆转HT29/L-OHP的耐药性。采用MTT法检测As2O3逆转前后HT29/L-OHP的增殖能力和对L-OHP的敏感性。采用实时荧光定量PCR检测As2O3逆转前后HT29/L-OHP中Sox-2、miR-200c和let-7的表达。结果①在L-OHP(12μmol/L)的作用下,HT29/L-OHP的增殖能力显著高于HT29(P<0.01),但是同未经L-OHP作用的HT29相比差异无统计学意义(P>0.05)。HT29和HT29/L-OHP对L-OHP的IC50分别为12.1μmol/L和138.4μmol/L,耐药指数为11.44。②0.20 mg/L的As2O3预处理后,降低了HT29/L-OHP对L-OHP的耐药性,逆转倍数为3.76,相对逆转效率为80.4%。③相对于HT29,HT29/L-OHP中Sox-2的表达显著增加[(0.072±0.038)比(0.019±0.010)](P<0.01),而miR-200c和let-7的表达显著下降[(0.262±0.136)比(0.726±0.289),(0.213±0.145)比(0.642±0.268)](P<0.05)。④As2O3处理后,相对于未处理前,HT29/L-OHP中Sox-2的表达显著降低[(0.032±0.012)比(0.072±0.038)](P<0.05),而miR-200c和let-7的表达显著升高[分别为(0.367±0.256)比(0.262±0.136),(0.3869±0.253)比(0.213±0.145)](P<0.05)。结论 CSC有可能是人结肠癌细胞株HT29产生L-OHP耐药的机制之一。

Objective To investigate the role of cancer stem cells （CSC） in the acquired resistance to Oxaliplatin （L-OHP） of human colon cancer cell line HT29. Methods L-OHP-resistant human colon cancer cell line HT29 （HT29/L-OHP） was established in vitro by exposure to increased L-OHP concentration in cell culture medium. As203 was used to reverse the resistance of HT29/L-OHP. The proliferation and sensitivity to L-OHP of HT29/L-OHP before and after treatment of As203 were tested using MTT assay. Real-time PCR was used to determine the expression of Sox-2, miR-200c and let-7 in HT29/L-OHP before and after treatment of As2O3. Results①In the effects of L-OHP （12 μmol/L）, the growth rate of HT29/L-OHP was higher than that of HT29 （P 〈 0.01）. It was also indicated that HT29/L-OHP treated by L-OHP expressed similar proliferation to that of HT29 in the absence of L-OI-IP （P 〉 0.05）. The IC50 of HT29 and HT29/L-OHP to L-OHP was 12.1 μmol/L and 138.4 μmol/L, the resistance index was 11.44. ②As2O3 （0.20 mg/L） decreased the resistance of HT29/L-OHP to L-OHP, with reversed multiples and relative reversed efficiency of 3.76 and 80.4% respectively. ③Compared with HT29, HT29/L-OHP showed increased expression of Sox-2 [（0.072±0.038） vs （0.019±0.010）] （P 〈 0.01） and decreased expression of miR-200c and let-7 [（0.262±0.136） vs （0.726±0.289）, （0.213±0.145） vs （0.642±0.268） respectively] （P 〈 0.05）. （±）Compared with HT29/L-OHP without treatment of As203, after treatment of As203, the expression of Sox-2 decreased [（0.032±0.012） vs （0.072±0.038）] （P 〈 0.05） and the expression of miR-200c and let-7 increased [（0.367±0.256） vs （0.262±0.136）, （0.3869±0.253） vs （0.213±0.145） respectively] （P 〈 0.05）. Conclusion CSC is a possible mechanism responsible for the acquired resistance of HT29/L-OHP to L-OHP.