Abstract: BACKGROUND ＆ AIM: Increased motility is the basis of tumor cell invasion and metastasis. The complicated process modulated by multiplegenes. The expression of motility-related-protein-1(MRP-1), a cell- motility- inhibiting protein was reported to be down －regulated and gave rise to the malignant phenotype associated with invasion and metastasis. But the mechanism was unclear. Focal adhesion kinase, as a key component of integrin-stimulated signal transduction pathways, was also reported as a kinase associated with malignant change of cell and differentiation and invasion. But the reports about the expression of these two proteins in lung cancer and the relationship with clinical parameters and their correlation between each other were inconsistent. We hope to explore the role of MRP-1 and FAK proteins in occurrence, development, invasion and metastasis of lung cancer and their value in predicting its prognosis. The expression levels of MRP-1 and FAK proteins in lung cancer, their relationship with each other and with some clinicopathological parameters. MATERIAL AND METHODS: 89 patients with lung cancer and 10 cases of normal lung tissue and 12 with metastatic cancer were analyzed for their MRP-1 and FAK protein levels using immunobiochemical streptavidin peroxidase method (SP). The χ2 test and Spearman analysis were used. RESULTS: The positive rate of MRP-1 was 100.0％ in normal lung tissue, 41.6％ in lung cancer and 8.3％ in metastatic cancer. The difference was significant(P<0.05) . The expression of FAK was opposite. The positive rate of FAK was weak in normal tissue and elevated to 48.3％ in cancer tissue and to 83.3％ in metastatic cancer. The difference of the above three groups were significant(P<0.05). There was a negative relationship between MRP-1 and FAK. The expression of MRP-1 protein in lung cancers had no relationship with ageor gender of the patients and the macroscopic type of cancer. However it was significantly correlated with histological type, degree of tumor differentiation, clinical stage and whether there was lymphoid metastasis(P<0.05). The expression of FAK protein in lung cancer had no relationship with age or gender of the patients and the macroscopic type and histological type of cancer(P<0.05). But it was significantly correlated with the degree of tumor differentiation, clinical stage and lymphoid metastasis. CONCLUSION: The abnormal expression of MRP-1 and FAK proteins may participate in the invasion and metastasis of lung cancer. Monitoring the expression levels of MRP-1 and FAK proteins probably predict the Malignant progression of lung cancer.

Key words: motility-related-protein-1, focal adhesion kinase, lung cancer, protein expression, invasion, metastasis