AIM: To investigate the effects of KAI1/CD82 on biological behavior of colorectal carcinoma cells. METHODS: KAI1 cDNA was transfected into highly malignant colorectal carcinoma cell line, LoVo, which had low level of endogenous KAI1 expression, and established stable transfectant clones with high KAI1/CD82 expression. The cell-cell adhesion, cell aggregation, cell-matrix adhesion and cell invasion assay were performed to determine whether KAI1 transfectant could have an effect on proliferation, adhesion and tumor metastasis in comparison with the control transfectant cells. RESULTS: KAI1 expression did not alter in vitro cell proliferation. But the KAI1 transfectant cells exhibited significantly increased homotypic cell-cell adhesion and cell aggregation in comparison with the control transfectant cells(P<0.05). Furthermore, KAI1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in KAI1-transfected LoVo cells. The data indicated that KAI1 expression significantly suppressed the metastatic potential of KAI1-transfected LoVo cells. CONCLUSION: Our results suggest that KAI1 might function as a negative regulator of colorectal carcinoma metastasis.
AIM: To investigate the effects of KAI1/CD82 on biological behavior of colorectal carcinoma cells. METHODS:KAI1 cDNA was transfected into highly malignant colorectal carcinoma cell line, LoVo, which had low level of endogenous KAI1 expression, and established stable transfectant clones with high KAI1/CD82 expression. The cell-cell adhesion, cell aggregation, cell-matrix adhesion and cell invasion assay were performed to determine whether KAI1 transfectant could have an effect on proliferation, adhesion and tumor metastasis in comparison with the control transfectant cells. RESULTS:KAI1 expression did not alter in vitro cell proliferation. But the KAI1 transfectant cells exhibited significantly increased homotypic cell-cell adhesion and cell aggregation in comparison with the control transfectant cells(P<0.05). Furthermore, KAI1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in KAI1-transfected LoVo cells. The data indicated that KAI1 expression significantly suppressed the metastatic potential of KAI1-transfected LoVo cells. CONCLUSION: Our results suggest that KAI1 might function as a negative regulator of colorectal carcinoma metastasis.