OLFML2B promotes hepatocellular carcinoma malignancy via the PI3K/AKT-EMT axis and correlates with an immunosuppressive tumor microenvironment.
INTRODUCTION: Hepatocellular carcinoma (HCC) is a leading cause of global cancer-related mortality, highlighting the need for novel biomarkers and therapeutic targets. METHODS: The role of Olfactomedin-like 2B (OLFML2B) in HCC was investigated through multi-database analyses (The Cancer Genome Atlas, International Cancer Genome Consortium, Gene Expression Omnibus) and experimental validation. RESULTS: OLFML2B was significantly upregulated in HCC tissues, correlated with poor overall and disease-specific survival, clinicopathological features (tumor grade, stage, age, gender), and robust diagnostic performance (AUC > 0.7 across 14/15 datasets). Transcriptomic and single-cell analyses further revealed that high OLFML2B expression was associated with an immunosuppressive tumor microenvironment, characterized by increased infiltration of M2 macrophages, cancer-associated fibroblasts (CAFs), and regulatory T cells (Tregs), as well as reduced abundance of cytotoxic T cells and NK cells. Knockdown of OLFML2B suppressed malignant phenotypes, including cell proliferation, migration, invasion, and angiogenesis, attenuated PI3K/AKT-EMT signaling, and enhanced sensitivity to sorafenib, cabozantinib, and regorafenib in Huh7 and HepG2 cells. Additionally, OLFML2B knockdown suppressed tumor growth and metastasis in zebrafish xenografts. DISCUSSION: Collectively, these findings indicate that OLFML2B is required for HCC progression and represents a prognostic biomarker and potential therapeutic target.