[The expression and significance of RKIP in lung squamous cell carcinoma tissues].

BACKGROUND AND OBJECTIVE Raf kinase inhibitory protein (RKIP) belongs to the phosphatidylethanolamine binding protein (PEBP) family. RKIP is an endogenous inhibitor of the Raf-1-MEK1/2-ERK1/2 signaling pathway, NFkappaB signaling pathway and G protein coupled receptors signaling pathway. The aim of this study is to explore the expression of RKIP in lung squamous cell carcinoma, and the relationship between RKIP expression and clinical pathology of lung squamous cell carcinoma. METHODS The expression of RKIP mRNA was detected in 56 lung squamous cell carcinoma tissues and adjacent cancer tissues by RT-PCR. The expression level of RKIP protein was detected by Western blot. The positive rates of RKIP expression in cancer tissues and adjacent cancer tissues were analyzed. RESULTS RKIP mRNA positive expression rate in cancer tissues was significantly lower than that in adjacent cancer tissues (P < 0.05). The positive rate of RKIP mRNA expression in the cancer tissues with lymph node metastasis was significantly lower than that without lymph node metastasis (P < 0.05). RKIP mRNA expression has no remarkable correlation with age, sex, tumor differentiation and size (P > 0.05). RKIP protein expression in the cancer tissues was significantly lower than that in adjacent cancer tissues (P < 0.05). CONCLUSIONS The deficiency of RKIP expression is positively correlated with carcinogenesis and invasion metastasis of lung squamous cell carcinoma.