[Expression of KAI1, MRP-1, and FAK proteins in lung cancer detected by high-density tissue microarray]

The genesis, development, invasion, and metastasis of tumor are closely correlate with alterations of multi-genes. At present, the roles of Kang-ai-1 (KAI1), motility-related protein-1 (MRP-1), and focal adhesion kinase (FAK) in lung cancer have seldom been reported. This study was designed to investigate the roles of KAI1, MRP-1, and FAK in tumorigenesis and development of lung cancer, and their values in diagnosis and predicting the prognosis of lung cancer.

The expression of KAI1, MRP-1, and FAK proteins in a high-density tissue microarray containing 240 spots were detected by SP immunohistochemistry.

The positive rates of KAI1 and MRP-1 were significantly lower in primary lung cancer than in normal lung tissue (25.9% vs. 100%, 42.6% vs. 100%, P<0.05). The positive rate of FAK was significantly higher in primary lung cancer than in normal lung tissue (44.4% vs. 10.0%, P<0.05). The expression of KAI1, FAK, and MRP-1 in primary lung cancer had no correlation with age and gender of the patients, and macroscopic and histological type of tumor, but had correlations with tumor differentiation, clinical stage, and lymph node metastasis. In addition, the expression of MRP-1 had correlation with histological type of tumor; the positive rate of MRP-1 was significantly lower in small cell lung cancer than in non-small cell lung cancer (0 vs. 50.0%, P<0.05). KAI1 expression was negatively correlated to FAK expression (rs=-0.458, P<0.05); MRP-1 expression was positively correlated with KAI1 expression (rs=0.535, P<0.05), and negatively correlated with FAK expression (rs=-0.438, P<0.05).

The abnormal expression of KAI1, MRP-1, and FAK proteins are related to invasion and metastasis of lung cancer. Combined detection of the 3 proteins may be useful in predicting the development and prognosis of lung cancer.