Ectopic expression of CNN2 of colon cancer promotes cell migration

BACKGROUND: Calponin is an actin filament-associated regulatory protein originally identified in smooth muscle cells. Three homologous have been identified in vertebrate species, but little functional characterization of potential activities in cancer has been performed. In this study, we determined the levels of CNN2 in colon cancer cell lines and determined the effects of this protein by increasing expression. METHODS: We used IHC and RT-PCR to measure CNN2 expression in colon cancer tissues and normal tissues and found increased expression levels in cancer tissues. We used viral vectors to decrease the level of CNN2 in the SW480 colon cancer cell line and found that silencing of CNN2 inhibited cell invasion. We detected potential protein interactions in signal pathways by western bolt analysis. To confirm the effect of CNN2 on cell invasion, we increased CNN2 expression in the SW620 cell line and observed increased invasion increased expression levels of associated proteins. RESULTS: High-expression levels of CNN2 were detected in cancer tissues. Silencing CNN2 inhibited cell invasion, down-regulated N-cadherin (N-CA) and C-myc proteins, and up-regulated E-cadherin (E-CA), suggesting that CNN2 promotes colon cancer cell invasion. Increasing CNN2 levels in the SW620 cell line showed the opposite results. CONCLUSIONS: CNN2 may act to promote colon cancer.