STAT3-mediated upregulation of TRIM6 promotes hepatocellular carcinoma invasion through the DDX58-Snail1 axis.

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy with poor prognosis, driven by complex molecular mechanisms that remain inadequately understood. Among these, the ubiquitin-proteasome system plays a crucial role in regulating protein stability and function, with E3 ubiquitin ligases emerging as key players in cancer progression. Here, we identify Tripartite Motif-containing 6 (TRIM6), an E3 ubiquitin ligase, as a critical regulator of HCC metastasis. We demonstrate that TRIM6 is significantly upregulated in HCC tissues and correlates with poor overall survival. Mechanistically, we uncover that STAT3 directly regulates TRIM6 by binding to its promoter and enhancing its transcription. Functionally, TRIM6 promotes epithelial-mesenchymal transition (EMT) and cell invasion by upregulating the key EMT transcription factor Snail1. Importantly, we reveal that TRIM6 interacts with and ubiquitinates DDX58 (RIG-I), leading to its proteasomal degradation. The degradation of DDX58 by TRIM6 alleviates its inhibitory effects on Snail1, thereby facilitating EMT and enhancing the invasive potential of HCC cells. These findings establish the STAT3-TRIM6-DDX58-Snail1 axis as a pivotal pathway in HCC progression, offering novel insights into the molecular underpinnings of HCC metastasis and highlighting TRIM6 as a potential therapeutic target and prognostic biomarker in HCC.