Experiment Of Chemosensitivity And Study Of Mechanism Of Drug Resistance Of Non-small Cell Lung Cancer

Objective To investigate the chemoresistance of non-small cell lung cancer (NSCLC) and the expression of correlative protein and genes which can lead to multidrug resistance(MDR) we explore the relation between chmoresistance and the expression of mdrl, MRP, LRP, GST-J1 and c-erbB-2 in NSCLC respectively,and define the function of the five kinds of genes in multidrug resistance mechanisms. Method 91 cases of NSCLC were tasted with MTT assay to evaluate their chemoresistance.The chemotherapy drugs include cyclophamide, adriamycin and cisplatin+fluorouracil.The expression of the 5 kinds of genes above were examined with immunohistochemical assay. Result 1. 1. The percentage of drug resistance of cyclophamide, adriamycin and cisplatin+ fluorouracil were 58.2%, 56.0% and 46.2%, respectively. There are 27 cases resisting all three medications, while there are 19 cases sensitizing all three medications. The multidrug resistance was not associated with histological types and degree of differentiation of NSCLC .2.The expression percentage of P-gp, MRP, LRP, GST- and c-erbB-2 in NSCLC were 58.2%,73.6%,53.8%,64.8% and 51.6% respectively.There is not significant difference in the expression of P-gp, MRP, LRP, GST-7C and c-erbB-2 between human adeoncarcinoma and sequamous cell carcinoma(p>0.05) .3.The correlation between the positive expression of P-gp, MRP, LRP , GST- and c-erbB-2 and thedegrees of chemoresistance to the three kinds of agents were significantly respectively(p<0.05),and the degree of chemoresistance to the three kinds of agents among the different degrees of expressions of p-gp, MRP, LRP, GST- and c-erbB-2 are significantly different respectively(p<0.05). Conclusions 1.There are certain degrees of intrinsic resistance in different kinds of chemotherapeutic agents in NSCLC.2.The intrinsic multidrug resistance mechanisms may be of the co-effect of these five genes(mdrl gene, MRP gene, LRP gene , GST- gene and c-erbB-2 gene).3.The in vitro chemosensitivity is feasible and necessary to predict the chemosensitivity of NSCLC ,and it has clinical value on determining the individualized chemotherapy and effective chemotherapy and on avoiding inefficacy chemotherapy which can finally raise the reta of cure and improve the living quality of patients.