HMGA1 interacts with β-catenin to positively regulate Wnt/β-catenin signaling in colorectal cancer cells.

The high mobility group A1 (HMGA1) protein plays an important role in numerous biological processes, such as embryogenesis, cell proliferation, differentiation, apoptosis and carcinogenesis. Wnt/β-catenin signaling pathway plays a key role in development and cancer. Although previous reports have shown HMGA1 protein level can be induced by Wnt/β-catenin signaling pathway, however, the specific mechanism of HMGA1 on regulating Wnt/β-catenin signaling remains unclear. Here, we reported that HMGA1 interacted with β-catenin by using coimmunoprecipitation approach with exogenous and endogenous protein samples. HMGA1 positively regulated Wnt/β-catenin signaling, as determined by that HMGA1 increased the TOP-FLASH activity in a dose-dependent manner and β-catenin downstream target gene expression. Moreover, HMGA1 induced proliferation of colorectal cancer cells. Mechanistically, HMGA1 increased the β-catenin-TCF4 complex formation. Importantly, there was a correlation between HMGA1 and β-catenin expression in human colorectal cancer tissues. In summary, HMGA1 positively regulates Wnt/β-catenin signaling through interacting with β-catenin, which leads to increase the β-catenin-TCF4 complex formation. This suggests that targeting HMGA1 may be a useful therapeutic option in clinical application.