Resistance of CD133 + subset to chemotherapy drugs and its expressions of apoptosis genes in gastric cancer / 国际外科学杂志

ABSTRACT

Objective To study the resistances of CDl33 + subset purified from gastric cancer cell line to chemotherapy drugs and the mechanism of this resistance regarding to the mRNA expressions of both Bcl-2 and BAX in relation to the relative apoptotic genes.Methods CD133 + subset and CD133-subset were purified from KATOⅢ cell linc by magnetic activated cell sorting.The proliferating ability of these two subsets resistantnt to 5-FU,Cisplatin(DDP,PDD) and Etoposide was checked and compared by CCK-8 test.The apoptotic changes of these two subsets regarding to the expression of mRNA of both Bcl-2 and BAX were also analized by RT-PCR.Results In CD133 + subset,the contant percentage of CD133 + expression rate was 90％ via analysis of flow cytometye.Twelve hours after treatment of5-FU,DDP and VP-16,the cells in both CD133 + subgroup and CD133-subgroup would gradually start to change in apoptotic morphology.The growth inhibiting rate by CCK-8 measurement for 5-FU,DDP and VP-16 groups in CD133 + subgroup was significantly lower than that in CD133-subgroup.The data under different treatment respectively was,5-FU(30.56 ± 1.99) ％-(88.60 ± 1.95) ％ vs (32.81 ± 2.67) ％-(95.73±2.12)％,P=0.045,cisplatin(45.89 ±3.64)％-(81.20 ± 1.18)％ vs (50.21 ±3.22)％-(90.46±1.89)％,P=0.043,VP-16(37.21 ±3.80)％-(78.49 ±3.22)％ vs (35.55 ±3.23)％-(89.32 ±-3.54) ％,P =0.048).After treatment of these three kind of anti-tumour drugs,the expression level of Bcl-2 mR-NA decreased significantly and the expression level of BAX mRNA increased significantly in both CD133 + subgroup and CD133-subgroup.However,these changing ranges of Bcl-2 mRNA and BAX mRNA were more obvious in CD133 + subgroup in comparison with those in CD133-subgroup.Conclusions In some degree,resistent potentiality of CD133 + cells to 5-FU,DDP and VP-16 has been identified,which may probably be due to the up-regulation of the expression of BAX and down-regulation of the expression of Bcl-2.