Kindlin-2-miR-1258-TCF4 feedback loop promotes hepatocellular carcinoma invasion and metastasis

Background Upregulated Kindlin-2 expression in hepatocellular carcinoma (HCC) correlates with metastasis and poor prognosis. In this study, we investigated the molecular mechanism of Kindlin-2 in HCC. Methods Kindlin-2 downstream pathways were explored through microRNA sequencing. The Kindlin-2-miR-1258-TCF4 axis was verified using bisulfite sequencing, a luciferase reporter assay, quantitative real-time PCR, and rescue assays. Binding of TCF4 to the Kindlin-2 promoter was confirmed by promoter activity analysis and chromatin immunoprecipitation. Results MiRNA sequencing identified miR-1258 as a downstream effector of Kindlin-2. MiR-1258 expression was increased following Kindlin-2 knockdown and decreased after Kindlin-2 overexpression. Next, we identified transcription factor 7 like 2 (TCF7L2 or TCF4) as a target of miR-1258 and found that Kindlin-2 upregulated TCF4 expression by epigenetically suppressing miR-1258 in HCC. Furthermore, our results suggest that TCF4 binds to the Kindlin-2 promotor to enhance its transcription. Therefore, Kindlin-2-miR-1258-TCF4 interaction creates a positive feedback loop. Functional assays and animal experiments demonstrated critical roles of miR-1258 and TCF4 in HCC cell migration in vitro and HCC metastasis in vivo. In HCC tissues, Kindlin-2 expression correlated negatively with miR-1258 expression and positively with TCF4 expression. Meanwhile, miR-1258 expression correlated negatively with TCF4 expression. Conclusions This study illustrates a novel integrin-independent signaling pathway, Kindlin-2-miR-1258-TCF4, that regulates HCC invasion and metastasis and identifies Kindlin-2 as a promising therapeutic target in HCC.

Automated summary

This study reveals that Kindlin-2 regulates HCC cell migration and metastasis through the suppression of miR-1258 and the upregulation of TCF4 expression. It also identifies a positive feedback loop between Kindlin-2, miR-1258, and TCF4. These findings provide important evidence for the potential therapeutic targeting of Kindlin-2 in HCC.