Expression And Significance Of Osteopontin In Non-small Cell Lung Cancer

ObjectiveIn this study,OPN gene was targeted by RNA interference to observe the changes of biological behavior of non-small cell lung cancer cell line H1703 after OPN gene overexpression and that of A549,SK-MES-1 after OPN gene silencing,and to explore the related mechanisms,so as to provide experimental basis for the clinical treatment of non-small cell lung cancer.MethodsThe expression of OPN in 28 cases of stage Ⅰ/Ⅱ NSCLC and 73 cases of stage Ⅲ/ⅣNSCLC was detected by immunohistochemistry and real-time fluorescence quantitative PCR and the correlation between OPN expression and clinicopathological parameters was analyzed.Western blotting was used to detect the expression of OPN in lung cancer cell lines A549,SK-MES-1,H1703 and immortalized human bronchial epithelial cells 16HBE.RNA interference was used to down-regulate the expression of OPN in A549 and SK-MES-1 cell lines and overexpress the OPN in H1703 cell lines.MTT colorimetry and Transwell invasion test were used to detect the invasiveness and sensitivity to cisplatin of each cell line.Western blotting was used to detect the expression of LDHA in A549 and SK-MES-1 cell lines after RNA interference,and to observe the effect of lactate on the sensitivity of A549 and SK-MES-1 cell lines to cisplatin.Results1.The expression of OPN in lung cancer tissues was significantly higher than that in normal tissues,and was related to the metastatic status,differentiation degree and sensitivity to cisplatin of NSCLC.There was no significant correlation between OPN expression and age,sex,pathological type and smoking history.2.Compared with immortalized human bronchial epithelial cell line 16HBE,Western blotting showed that OPN expression was significantly increased in A549,SK-MES-1 and H1703 cell lines;OPN RNAi lentiviral vector was successfully constructed.Western blotting showed that OPN protein expression was significantly inhibited in A549 and SK-MES-1 cell lines and was significantly enhanced in H1703 line.3.MTT assay showed that the proliferation of A549 and SK-MES-1 cell lines decreased and their sensitivity to cisplatin increased after OPN knockdown,while the proliferation of H1703 cell lines increased and it’s sensitivity to cisplatin decreased.Transwell assay showed that OPN knockdown inhibited the migration and invasion of A549 and SK-MES-1 cell lines.4.The expression of OPN mRNA and protein was significantly correlated with LDHA.Lactate decreased the sensitivity of A549 and SK-MES-1 cells to cisplatin.Conclusion1.The expression of OPN in non-small cell lung cancer tissues is significantly increased,and is related to the metastasis,differentiation and cisplatin sensitivity of non-small cell lung cancer.2.Overexpression of OPN gene can effectively enhance the proliferation of H1703 cell line and reduce its sensitivity to cisplatin.Downregulation of OPN gene can effectively inhibit the migration and invasion of A549 and SK-MES-1 cell lines and increase their sensitivity to cisplatin.3.The expression of OPN was significantly correlated with LDHA.OPN could affect the sensitivity of A549 and SK-MES-1 cells to cisplatin by regulating LDHA.