Mutation and expression of the metastasis suppressor gene KAI1 in esophageal squamous cell carcinoma

BACKGROUND. KAI1/CD82, a tumor metastasis suppressor gene, is correlated in versely with the progression and invasion of several tumors. It also has be en reported that the KAI1 gene is related to the tumor suppressor gene p53. This study was performed to clarify the correlation between KAI1/CD82 expr ession and clinicopathologic characteristics and p53 expression in patients with esophageal squamous cell carcinoma (ESCC). The authors also investiga ted mutation of the KAI1 gene coding region to determine whether this may r educe KAI1 expression in ESCC. METHODS. Using immunohistochemistry with anti-KAI1 polyclonal antibody and monoclonal antibody against p53, KAI1/CD82 and p53 expression were detected in 55 patients with ESCC who had undergone surgery. The authors examined t he KAI1 gene mutation in 22 patients with ESCC by polymerase chain reaction -single strand conformation polymorphism (PCR-SSCP) analysis and DNA sequen cing. RESULTS. KAI1/CD82 expression was positive in 36 of 55 patients (65.5%). Th ere was a significant inverse correlation between KAI1/CD82 expression and regional lymph node metastasis (P = 0.0045), distant metastasis (P = 0.0092 ), the number of lymph node metastases (P = 0.0019), and pathologic stage ( P = 0.0046). The survival rates of KAlI/CD82 negative patients were poorer than those of positive patients (P = 0.024). The correlation between KAI1 p ositive and p53 positive tumors was not statistically significant. None of the 22 patients with ESCC showed mutation of the KAI1 gene by PCR-SSCP. In one patient, there was polymorphism in the SSCP assay and DNA sequencing. CONCLUSIONS. The authors demonstrated immunohistochemically that the expres sion of KAI1 protein appeared to be correlated with lymph node metastasis. Mutation does not seem to be a mechanism for dysregulation of the KAI1 prot ein in ESCC. (C) 2000 American Cancer Society.