Abstract: Objective To detect the expression of ABCG4 mRNA and protein in non-small cell lung cancer （NSCLC）， and to analyze the relationship between the expression and pathological types， drug resistance of NSCLC cells.
MethodsImmunohistochemical staining， RTPCR and Western blotting were used to detect the expression of ABCG4 mRNA and protein in NSCLC tissues. MTT assay was used to detect the sensitivity of NSCLC cells to chemotherapeutic drugs， and the relationship between drug sensitivity and the expression of ABCG4 mRNA and protein was analyzed. Results The positive expression of ABCG4 protein was mainly located in the cell membrane and cytoplasm. The positive expression rate of ABCG protein in NSCLC was 73.9（68/92）, but was not expressed in 30 cases of adjacent non tumorous lung tissues. The positive expression rate of ABCG4 protein in lung squamous cell carcinoma and lung adenocarcinoma was 67.3% and 81.4％ without statistical diference（P＞0.05）. The drug sensitivity of cyclophosphamide， gemcitabine， doxorubicin， paclitaxel and cisplatin in NSCLC tissues was related to the positive expression of ABCG4 protein in the corresponding tissues（rs＞0.3， P＜0.05）. Except for paclitaxel， drug sensitivity of cyclophosphamide， gemcitabine， doxorubicin and cisplatin in NSCLC tissues was related to the expression of ABCG4 mRNA in the corresponding tissues （P＜0.05）. Conclusion The ABCG4 mRNA and protein are overexpressed in squamous cell lung cancer and adenocarcinoma. The expression of ABCG4 mRNA and protein may be related to chemoresistance in NSCLC， which provides experimental basis for further study on ABCG4 chemoresistance and its mechanism in NSCLC.