Abstract
BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality due to delayed diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are key cancer regulators, yet the role of C1orf21-DT (PIG13-DT) in HCC remains unclear. METHODS: We evaluated PIG13-DT expression in HCC and paired adjacent non-tumorous tissues. Functional studies were conducted using cell culture, cell-derived xenotransplantation (CDX) models, and molecular techniques including RNA pull-down, mass spectrometry, RIP-qPCR, and RNA sequencing. We explored the interplay between PIG13-DT, RNA-binding protein YBX3, and USP15 mRNA. RESULTS: PIG13-DT was highly expressed in HCC tissues compared with normal tissues and associated with poor prognosis. Functionally, PIG13-DT enhanced cancer stem cell (CSC) function, reduced reactive oxygen species (ROS) levels, and promoted HCC cell proliferation and migration. Mechanistically, PIG13-DT interacted with YBX3, stabilizing YBX3 and promoting USP15 mRNA translation and stability, thus driving HCC progression. Clinical data from lenvatinib-treated HCC patients showed that PIG13-DT expression was correlated with poor treatment response. CONCLUSION: Our study identifies a novel PIG13-DT/YBX3/USP15 axis driving HCC progression, suggesting PIG13-DT as a potential biomarker and therapeutic target. This work provides new insights into HCC molecular mechanisms and offers potential diagnostic and therapeutic implications.