| Lung cancer is the highest morbidity and mortality in the world. About 80% of them is non-small cell lung cancer(NSCLC). Because of lacking effective early diagnosis methods, 75% cases were in advanced stage when found. They had lost the opportunity of surgery, thus the chemotherapy had become the important method of curing of NSCLC. The long term survival rate of lung cancer was about 10-15%, the reason is mostly the multi-drug resistence(MDR) towards the tumor cells. MDR is the most important cell defense mechanism of the tumor cells to avoid being attacked from chemotherapeutics. Membrane transport proteins such as P-glycoprotein, multidrug resistance accosiated protein, etc can be active as drugs excavating pump, and lower the concentration of the cell cytotoxic drug and cause MDR. Breast cancer resistance protein is a newly discovered member of the adenosine triphosphate-binding cassette family. It is reported that it had the effect in drug resistance in acute leukemia and breast cancer, but had less in NSCLC. Glutathione s-transferases (GST) are enzymes which related to the deintoxication of the body. GST-Ï€has the closest relationship with the malignant tumor. GST-Ï€ degrades drug through catalysis, and lower the the concentration of the cell cytotoxic drug and cause MDR.Objective To observe the expression of BCRP and GST-Ï€in non-small cell lung cancer and investigate the relationship between the drug sensitivity and expression of BCRP and GST-Ï€in NSCLC.Methods Sixty cases of NSCLC were tested with MTT assay to evaluate their chemoresistance to adriamycin, topotecan, paclitaxel, vincristine and cisplatin.The expression of BCRP and GST-Ï€was examined with immunohistochemical assay.And then the relationship between the expression of two proteins above and the chemoresistance was analysed.Results The percentage of drug resistance of adriamycin, topotecan, paclitaxel, vincristine and cisplatin were 51.7%,53.3%,20%,25% and 53.3% , in NSCLC respectively. Cases of drug resistance of adenocarcinoma were more than those of squamous carcinoma,but there was no significant difference(P>0.05). The expression percentage of BCRP and GST-Ï€was 43.3% and 60% respectively.The expression percentage in adenocarcinoma was higher than in squamous carcinoma, but there was no significant difference(P>0.05).The expression of BCRP was obviously correlated with that of GST-Ï€in NSCLC(P<0.05).The correlation between positive expression of BCRP and GST-Ï€and chemoresistance was significant(P<0.05).Conclusion BCRP and GST-Ï€may co-work to intervene the multi-drug resistance of NSCLC,and they will be one of the indexes of forecasting MDR of NSCLC patients. |
