EXPRESSIONS OF P-gp,GST-II AND TOPO-II IN LUNG CANCER AND THEIR RELATIONSHIP WITH Ki-67

Objective To explore the expression of products of multidrug resistance(MDR) gene-P-glycoprotein(P-gp),glutathione S epoxide transferase Ⅱ(GST-Ⅱ) and DNA topoisomerase(TOPO-Ⅱ)-in human lung cancer and their correlation with Ki-67. Methods The expressions of P-gp,GST-Ⅱ,TOPO-Ⅱand Ki-67 in 63 cases of lung cancer were detected by immunohistochemical method. Results The positive rates of P-gp,GST-Ⅱ,TOPO-Ⅱand Ki-67 were 61.9%,63.5%,77.8% and 39.7%,respectively.The expressions of P-gp,GST-Ⅱ,and Ki-67 were correlated with the histological typing and differentiation of the cancer(χ2=6.733-22.532,P0.01).The expression rate of TOPO-Ⅱin squamous cell carcinoma and small cell cancer was significantly higher than that in adenocarcinoma(χ2=8.259,4.189;P0.01,0.05).The coexpression rate of more than one MDR gene products was 90.5%,which was apparently higher than the expression of single gene product such as P-gp and TOPO-Ⅱ(χ2=59.660,P0.01).The expressions of P-gp and GST-Ⅱ were not obviously associated with that of Ki-67(P0.05),but that of TOPO-Ⅱwas positively correlated with Ki-67(r=0.380,P0.01) Conclusion Different levels of expressions of P-gp,GST-Ⅱ,and TOPO-Ⅱcan be seen in different-type lung cancer,in pattern of co-expression.Their expressions play an important role in lung cancer resistant to chemotherapy.Hence co-detection of the expressions conduces to assessment of chemotherapeutic efficacy and prediction of prognosis.