蛇床子素逆转人膀胱肿瘤T24／ADM细胞耐药作用及其机制

目的研究蛇床子素（osthole,OST）对T24／ADM细胞多药耐药的逆转及对P-gP表达、功能的影响。方法采用MTT法筛选OST对T24／ADM细胞无毒或低毒浓度,以筛选出的浓度作为耐药逆转的实验浓度。分别利用MTF法分别检测阿霉素（adriamycin,ADM）、氟尿嘧啶（fluorouracil,Fu）及顺铂（cisplatin,DDP）对细胞株T24和T24／ADM以及OST处理后的T24／ADM细胞的半数抑制浓度IC50。用流式细胞仪测定OST对T24／ADM细胞上P-gP表达的影响。结果浓度17Ixmol／LOST对T24／ADM无明显细胞毒性,T24／ADM对ADM、FU和DDP均有不同程度的。耐药,耐药倍数分别为18．86、5．09、3．28,使用17μmol／LOST处理后T24／ADM对上述ADM、Fu和DDP的敏感性均有不同程度的提高,ADM对耐药细胞株的IC蜘由（0．962±0．017）μxg／mL降至（0．364±0．031）μg／mL,逆转指数为2．64;FU对耐药细胞株的IC。由（0．723±0．003）μg／mL降至（0．463±0．021）μxg／mL,逆转指数为1．56;DDP对耐药细胞株的IC50由（0．664±0．007）μg／mL降至（0．587±0．016）μg／mL,逆转指数为1．13,使T24／ADM细胞内P-gP蛋白表达明显下降,下降了16．32％（P〈0．05）。结论蛇床子素在体外能部分逆转T24／ADM的耐药性,逆转机制可能是通过抑制P—gP蛋白表达实现的。

Reversal effect and mechanism of osthole on the multidrug-resistance of human bladder cancer cells T24/ADM

Objective To study the reversal of osthole on the role of drug resistance T24/ADM cells.Methods The low or no cytotoxicity concentration of OST for T24/ADM cells by MTT,and take these concentrations as the experimental concentrations.The inhibition rate of ADM,FU,DDP without and with no cytotoxicity concentration of OST to T24 and T24/ADM cells were evaluated With MTT assay.The IC50 of different agents was counted.The concentrations of P-gp in T24/ADM cells with and without OST were measured by flow cytometey(FCM).Results Osthol at the concentration of 17 μmol/L had no significant cytoxicity to T24/ADM cells.T24/ADM cells were resistant to ADM,FU and DDP and the resistance index was 18.86,5.09,3.28 respectively.The sensitivity of T24/ADM to ADM,FU and DDP was significantly increased by osthol in the concentration of 20 μmol/L.The inhibitive concentration 50 (IC50) of ADM declined from (0.962±0.017) μg/mL to (0.364±0.031) μg/mL with a reversion index of 2.64.The IC50 of Fu declined from (0.723±0.003) μg/mL to (0.463±0.021) μg/mL with a reversion index of 1.56.The IC50 of DDP declined from (0.664±0.007) μg/mL to (0.587±0.016) μg/mL with a reversion index of 1.13.FCM results indicated that the positive expression rate of P-gP dropped (P < 0.05).Conclusion Osthole had the reversal effect on T24/ADM cell resistance,the mechanism of reversion is related with down regulation of expression of P-gp.