BACKGROUNDRecent researches have manifested that down-regulation of KAI1 relates to metastasis in various tumors, but its association with non-small cell lung cancer (NSCLC) and the mechanism for its down-regulation are not clear. The aim of this study is to investigate the expression of KAI1 in NSCLC and its relationship with clinicopathological characteristics and mutant P53 protein.

METHODSThe expression of KAI1/CD82 and mutant P53 protein was detected in 48 cases of NSCLC tissues by Western blot, and KAI1 mRNA was detected by RT-PCR method, with 20 cases of pulmonary benign disease tissues and normal lung tissues as control..

RESULTSThe positive rate of KAI1 mRNA was 52% in lung cancer group and 90% in control group, respectively (P < 0.01), KAI1/CD82 was 48% and 85% respectively (P < 0.01), and mutant P53 protein was 65% and 5% respectively (P < 0.01). The positive rate of KAI1 mRNA, KAI1/CD82 and mutant P53 protein closely related to the tumor stages, cell differentiation and lymph node metastasis status (P < 0.05 or P < 0.01). The expression of KAI1/CD82 highly related to KAI1 mRNA (P < 0.01) and mutant P53 protein (P < 0.05), while expression of KAI1 mRNA did not relate to mutant P53 protein expression (P > 0.05).

CONCLUSIONSThe down-regulation of KAI1 may relate to carcinogenesis, development and metastasis of NSCLC. Its reduction may occur mainly at transcriptional level and correlate with p53 in NSCLC. KAI1 and p53 might be helpful to predict the potential metastasis of NSCLC.