Effect Of TMP On Multidrug Resistance Reversal And P-gp Expression In Human Bladder Tumor T24/ADM Cells

Bladder tumor is urogenital system frequent malignant tumor.At present,therapeutic tools of bladder tumor are the operation,chemotherapy,radiotherapy and immunization adjunctive therapy.After the operation,making chemistries drug pour into the bladde is important method to cure bladder tumor.However,after the chemotherapy,bladder tumor has 40%～80%recurrence rate.Tumor cell drug resistance is the failure cause.When tumor cells appear drug resistance to a kind of antitumor drug,to other antitumor drug of distinct constructionand and affecting distinct target site produce drug resistance,the phenomenon called multidrug resistance(MDR).Reported,TMP could partially reverse the resistance to ADM in human breast cancer MCF-7/ADM cell line.The drug-resistance to ADM in SPCA-1/ADM cells can be reversed by non-cell toxic concentrantion of TMP.etc.to elevate tumor chemotherapy curative effect. TMP is essential component of alkaloid.In this study,we aimed to explore the possibility of using TMP for the purpose of MDR reversal,and to investigate the mechanism of action.Part one To establish multi-drug resistant bladder tumor T24 cell lines and to assess their resistant characteristics.Objective:To establish multi-drug resistant bladder tumor T24 cell lines and to assess their resistant characteristics.Methods:Human bladder tumor cell line T24 was induced to multidrug resistance cell line T24/ADM by intermittent administration of high dose ADM.Morphologic studies were performed with optical microscopy;the expression of MDR gene was assessed by RT-PCR.Result prove.,the multidrug resistance characteristics was evaluated by MTT assay; P-gp expression was determined by flow cytometry.Results:Six months were taken to establish drug resistant cell linesT24/ADM.T24/ADM has drug resistance characteristics to ADM.and its IC₅₀ of ADM was 16.3 times higher than that of T24.P-gp overexpression of T24/ADM,the analysis of variance showed that exist between the groups was significant statistical significance of differences.P＜0.01 among all groups there are significant differences.Conclusion To establish multidrug resistant bladder tumor T24/ADM cell lines and T24/ADM is a human multidrug-resistant cell line.Part two Effect of TMP on multidrug resistance reversal and P-gp expression in human bladder tumor T24/ADMObjective:To investigate the effect of TMP on multidrug resistance reversal and P-glycop rotein(P-gp) expression in human bladder tumor T24/ADMMethods:Use Adlumidin to irradiate T24/ADM cell.The drug sensitivity and resistant characteristics of T24/ADM cells were detected by MTT assay.P-gp expression was determined by flow cytometryResults:The IC50 value of TMP in T24/ADM cell line was significantly decreased by the non-cytotoxic dose(320μg/ml) or low-cytotoxic dose(1250μg/ml) of TMP(P＜0.01) and the resistance reversing effect was 1.25-folds,2.26-folds respectively compared with the IC50 value of ADM in T24/ADM cells.The intracellular ADM concent ration in T24/ADM cells were significantly elevated by TMP at the same dose.P-gp expression from(91.25±0.40)%to (70.11±1.65)%and(51.36±1.25)%respectively.The analysis of variance showed that exist between the groups was significant statistical significance of differences.P＜0.01 among all groups there are significant differences.Conclusion:TMP could partially reverse the resistance to ADM in bladder tumor T24/ ADM cell line.Which reversal mechanism may be related to inhibiting P-gp expression in T24/ADM cells.