洛贝林逆转胃癌细胞SGC7901/VCR多药耐药的作用

目的:探讨哌啶类生物碱洛贝林(Lobeline)能否逆转人胃癌多药耐药细胞株SGC7901/VCR的多药耐药,并进一步探讨洛贝林逆转其多药耐药的机制,评估其有效性.方法:以人胃癌多药耐药细胞株SGC7901/VCR为研究对象,用四氮唑蓝(MTT)法分别测定在无和有洛贝林(细胞无毒浓度10 mol/L)作用下多药耐药细胞株SGC7901/VCR对VCR及5-Fu的半数生长抑制率,并由此求其耐药逆转的倍数;RT-PCR分别检测在无和不同终浓度洛贝林(5、10、20、50、100 mol/L)作用下多药耐药细胞株SGC7901/VCR的多药耐药基因MDR1 mRNA表达情况;Western blot分别检测在无和不同终浓度洛贝林(5、10、20、50、100 mol/L)作用下多药耐药细胞株SGC7901/VCR的P-gp蛋白表达.结果:在洛贝林无毒作用浓度(10 mol/L)作用下,多药耐药细胞株SGC7901/VCR对化疗药的敏感性增加,VCR对耐药细胞株的IC50由原来的16.55 g/L±0.13 g/L变成7.27g/L±0.65 g/L,逆转指数约为2.28;5-Fu对耐药细胞株的IC50由原来的11.01 g/L±0.43 g/L变成9.53 g/L±0.79 g/L,逆转指数约为1.16;RT-PCR检测示多药耐药细胞株SGC7901/VCR呈现MDR1 mRNA高度表达,随洛贝林终作用浓度的增大,MDR1 mRNA表达逐渐下降,各组间差距有统计学意义(P<0.05);Western blot检测表明多药耐药细胞株SGC7901/VCR高度表达P-gp蛋白,随洛贝林作用终浓度依次增加P-gp蛋白表达依次减弱,组间呈浓度依赖性,差别有统计学意义(P<0.05).结论:无细胞毒作用浓度的洛贝林可以逆转胃癌多药耐药细胞株SGC7901/VCR的多药耐药,增强VCR和5-Fu的化疗敏感性.洛贝林对SGC7901/VCR细胞多药耐药的逆转可能机制为抑制P-gp蛋白的表达.

Lobelin reverses multidrug resistance of human gastric carcinoma cell line SGC7901/VCR

AIM: To investigate the reversal effects of lobeline on multidrug resistance(MDR) of human gastric carcinoma cell line SGC7901/VCR,and to explore the possible mechanisms involved.METHODS: The human gastric carcinoma cell line SGC7901/VCR that had multidrug resistant phenotype was used in this study.MTT assay was used to determine the IC 50 of VCR and 5-Fu for non-treated SGC7901/VCR cells and SGC7901/VCR cells treated with non-toxic concentration of lobeline(10 mol/L).RT-PCR was used to detect MDR1 mRNA expression in nontreated SGC7901/VCR cells and SGC7901/VCR cells treated with different final concentrations(5,10,20,50,100 mol/L) of lobeline.Western blot was used to determine intracellular P-gp protein expression.RESULTS: Treatment with 10 mol/L lobeline increased the chemotherapy sensitivity of SGC7901/VCR cells,and the IC 50 of VCR declined from 16.55 g/L ± 0.13 g/L to 7.27 g/L ± 0.65 g/L,with a reversion index of 2.28.The IC 50 of 5-Fu declined from 11.01 g/L ± 0.43 g/L to 9.53 g/L ± 0.79 g/L,and the reversion index is 1.16.RT-PCR analysis demonstrated that SGC7901/ VCR cells highly expressed MDR1 mRNA,and lobeline decreased MDR1 mRNA expression in a concentration-dependent manner(P < 0.05).Western blot analysis indicated that SGC7901/ VCR cells highly expressed P-glycoprotein,and lobeline decreased P-glycoprotein expression in a concentration-dependent manner(P < 0.05).CONCLUSION: Lobeline can reverse the multidrug resistance of SGC7901/VCR cell line and increase chemotherapy sensitivity of SGC7901/ VCR cell line to VCR and 5-Fu possibly via mechanism associated with inhibiting the expression of P-glycoprotein.