Integrin α3 expression as a prognostic factor in colon cancer: Association with MRP‐1/CD9 and KAI1/CD82

Publisher Website
Google Scholar
Abstract
Recently, we established that a murine monoclonal antibody (MAb) MH8‐4 inhibits the motility of the colon cancer cell line RPMI4788 and that it recognizes integrin α3. In addition, we have also cloned the motility‐related protein‐1 (MRP‐1)/cluster of differentiation 9 (CD9) as a metastasis suppressor molecule. We investigated integrin α3 expression in 114 resected colon cancers using immunohistochemistry and reverse transcription‐polymerase chain reaction (RT‐PCR) to evaluate whether these experimental results are of relevance in the prognosis of actual colon cancers. Furthermore, we investigated the correlation of integrin α3 with MRP‐1/CD9 and KAI1/CD82. Sixty patients (52.6%) were evaluated as integrin α3‐positive and 54 patients (47.4%) as integrin α3‐negative. Integrin α3 expression was associated with tumor status, lymph node status and pathologic stage. The overall and disease‐free survival rates for patients whose tumors were positive for integrin α3 were significantly higher than for those with integrin α3‐negative tumors (p< 0.001 andp< 0.001, respectively). This same tendency was observed in node‐negative patients (p= 0.007 andp= 0.001, respectively). Integrin α3 was found to be the significant prognostic factor in a multivariate analysis using the Cox proportional hazards model (p= 0.036). A correlation was found between integrin α3 with MRP‐1/CD9 and KAI1/CD82 for stage I tumors. However, no correlation was found in stage III tumors. Our data seem to suggest that low expression of integrin α3 is a useful indicator of a poor prognosis for colon cancer patients and that colon cancer progresses following collapse of the complex formed by integrin α3 with MRP‐1/CD9 and KAI1/CD82.