Objective:To examine the expressions of osteopontin (OPN),αvβ3 and Pim-1 in non-small cell lung cancer (NSCLC),and investigate their potential pathogenic roles in the development of NSCLC.Methods:Immunohistochemistry was used to examine the expressions of OPN,αvβ3 and Pim-1 in cohort (136cases) of NSCLC samples and their adjacent normal lung tissue specimens.Statistical analysis was performed to evaluate the relationships among expressions of OPN,αvβ3 and Pim-1 and their associations with patients clinicopathological parameters.Results:The expressions of OPN and Pim-1 were predominantly observed in cytoplasm.The expression of αvβ3was mostly detected in cytoplasm and/or membrane.In NSCLC samples,the positive rates of OPN,αvβ3 and Pim-1 expressions were 68.4％ (93/136),77.2％ (105/136) and 57.4％ (78/136),respectively.In normal lung tissues,in contrast,the positive rates of OPN,αvβ3 and Pim-1 were 24.0％ (12/50),26.0％ (13/50) and 16.0％ (8/50),respectively.There were significant differences of the positive expression rates of OPN,αvβ3 and Pim-1 between NSCLCs samples and normal lung tissues (P＜0.01).In addition,the positive expression of OPN,αvβ3 and Pim-1 in NSCLCs samples was significantly associated with increased pathological grade,lymph node metastasis and advanced clinical stage (P＜0.01),and they were independent of other clinicopathological parameters (P＞O.05).Furthermore,a significantly positive correlation between the expression of OPN and αvβ3 (r=0.38,P＜O.01),OPN and Pim-1 (r=0.37,P＜0.01),or αvβ3 and Pim-1 (r=0.20,P＜0.05) was evaluated in our NSCLC cohort.Conclusion:OPN,αvβ33 and Pim-1 proteins are frequently overexpressed in NSCLC,and they may play important roles in the development and/or progression of NSCLC.