Relationship between drug sensitivity and expression of drug resistance genes in lung cancer

Abstract

Objective To study the relationship between the expression of drug resistance genes (MRP1,P-gp,GST-π,and Topo Ⅱ) and the results of drug sensitivity test.Methods The drug sensitivity was measured by MTT colorimetric method.The drug resistance genes MRP1,P-gp,GST-π,and Topo Ⅱ were detected by immunohistochemistry.Results The expression percentages of MRP1,P-gp,GST-π,and Topo Ⅱ genes in lung cancer were 72.5 ％,67.5 ％,57.5 ％,50.0 ％.There was no significant difference in the expression of MRP1,P-gp,GST-π,and Topo Ⅱ between human adencarcinoma and sequamous cell carcinoma (P ＞0.05),but there was significant difference in the expression of P-gp and GST-π between human adencarcinoma or sequamous carcinoma cell and small cell lung cancer (P ＜0.05).There was positive correlation between the expression of P-gp and GST-π and the degrees of chemoresistance to cisplatin,gemcitabine,vinorelbine and paclitaxel (P ＜ 0.05),but there was no correlation with iphspamide drug tolerance (P ＞0.05).There was positive correlation between the expression of MRP1 and the degrees of chemoresistance to cisplatin,gemcitabine,and vinorelbine (P ＜0.05),but there was no correlation with drug tolerance of paclitaxel and iphspamide (P ＞ 0.05).Conclusions The high expression of MRP1,P-gp,GST-π and the low expression of Topo Ⅱ commonly mediate and partipate in the drug resistance mechanism of lung cancer,and have correlation with the chemotherapy drug resistance. Key words: Lung cancinoma; Drug sensitivity; Drug resistance gene