as a Liver-Specific Biomarker for Hepatocellular Carcinoma: Diagnostic and Prognostic Implications.

Hepatocellular carcinoma (HCC) critically lacks reliable biomarkers for early detection. By mining the TCGA_LIHC and two GEO cohorts, we identified the liver-specific long non-coding RNA as the most consistently down-regulated transcript in tumors. This finding was validated in 97 paired tissues, with expression lost in 95% of cases (*** < 0.0001). It demonstrated excellent diagnostic performance in discriminating tumor from non-tumor tissue (AUC = 0.95), which was maintained in early-stage (I/II) disease. Low expression correlated with shorter overall and disease-free survival and was inversely associated with serum α-fetoprotein (AFP) levels, highlighting its complementary clinical value. Mechanistic investigation revealed a potential competing endogenous RNA (ceRNA) axis. The microRNA miR-190b-5p was highly expressed in tumors and predicted to bind , while its target, , was significantly suppressed. Survival analysis confirmed that concurrent high expression of and conferred superior outcomes. These findings establish as a liver-specific, ceRNA-mediated tumor suppressor with robust diagnostic and prognostic potential. It represents a promising adjunct to existing HCC surveillance strategies, such as ultrasound and AFP measurement, for high-risk populations.