TDP-43 induces EMT and promotes hepatocellular carcinoma metastasis via activating Wnt/β-catenin signaling pathway

The trans-activation response DNA-binding protein of 43 kDa (TDP-43) is a nuclear protein that has been shown to be involved in the growth and metastasis of breast cancer, neuroblastoma, and melanoma. However, the effect of TDP-43 on hepatocellular carcinoma (HCC) metastasis remains unclear. Here, we demonstrated that TDP-43 was highly upregulated in both clinical samples and cell lines of HCC. Moreover, knockdown and overexpression of TDP-43 efficiently affected the proliferation and metastasis of HCC cells as well as the expression of some proteins associated with epithelial-mesenchymal transition (EMT) and Wnt/beta-catenin signaling pathway. Furthermore, activation of the Wnt/beta-catenin pathway by LiCI restored the effect of TDP-43 knockdown on EMT and HCC cells, whereas inhibition of the Wnt/beta-catenin pathway by XAV939 negated the effect of TDP-43 overexpression. Importantly, we found that TDP-43 protein could interact with GSK3 beta mRNA and regulate the level of GSK3 beta protein translation. Taken together, our findings suggest that TDP-43 may activate the Wnt/beta-catenin pathway by targeting the inhibition of GSK3 beta protein translation, thus inducing the proliferation and metastasis of HCC cells, which supports its potential value as a therapeutic target for the treatment of metastatic HCC.