汉防己甲素对人胰腺癌耐药细胞株SW1990-GEM多药耐药性的逆转机制

Reversal Mechanism of Tetradrine on Multi-Drug Resistance in Human Pancreatic Carcinoma Cell Line SW1990-GEM

目的探讨汉防己甲素(Tet)对人胰腺癌吉西他滨(Gem)耐药细胞株SW1990-GEM耐药逆转作用及其可能的机制。方法应用免疫细胞化学法检测SW1990-GEM细胞多药耐药(MDR)1基因编码的P-糖蛋白(P-gp)表达;应用四甲基偶氮唑蓝(MTT)法检测不同浓度Tet对SW1990-GEM细胞的增殖抑制效应,并计算半数抑制浓度(IC50)及耐药逆转倍数。应用流式细胞仪检测无毒剂量Tet对SW1990-GEM细胞内罗丹明123(Rh123)蓄积情况的影响;Western-blot检测Tet应用前后SW1990-GEM细胞P-gp的表达。结果 P-gp在SW1990-GEM细胞较SW1990细胞高表达;无毒剂量Tet通过增加SW1990-GEM细胞内化疗药物蓄积发挥耐药逆转作用;SW1990-GEM细胞对Gem的耐药指数为217.91,加入Tet(1.5mg/L)后耐药指数为24.32,其逆转倍数为8.96;SW1990-GEM细胞在应用Tet前后P-gp表达无明显变化。结论 Tet通过增加肿瘤细胞内化疗药物浓度逆转SW1990-GEM细胞多药耐药性从而增强化疗药物抗肿瘤作用,其逆转机制与抑制P-gp功能有关,而对P-gp表达无影响。

Objective To investigate the reversal effects of tetradrine （Tet） on human pancreatic carcinoma muhidrng resistance cell line SW1990-GEM, and the mechanism thereof, Methods Immunocytochemistry was used to test the expression of P-glycoprotein （P-gp） coded by the multidrng resistance-1 gene of SW1990-GEM cells. The inhibitory effects of Tet on the proliferation of SW1990-GEM cells were evaluated by MTT assay. The median inhibitory concentration or ICS0 and resistance reversac multiples were calculated. The effects of non-toxic doses of TET on Rhodamin123 （Rh123） accumulation in SW1990-GEM cells were analyzed by flow cytometry. The expression of P-gp was detected by Western blot before and after treatment of Tet in SW1990-GEM cells. Results The expression of P-gp was higher in SW1990- GEM cells than that of SW1990 cells, The non-toxic doses of Tet played the resistance reversal effect by increasing the accumulation of the intracellular chemotherapy drugs in SW1990-GEM cells. The resistance index of SW1990-GEM cells to Gem was 217.91. After 1.5 mg/L Tet was added, the resistance index was 24.32. The reversal folds were 8.96. There was no significant difference in the expression level of P-gp before and after Tet treatment in SW1990-GEM cells. Conclusion Tet significantly reversed multidrug resistance of SW1990-GEM ceils to enhance the accumulation of chemotherapeutical drug in cells and increase its antitumor function.This mechanism may relate with the inhibited transport function of P-gp, but it did not alter the protein expression level of P-gp.