CDCA3 Regulates Tumor-Associated Macrophages Polarize to Promote the Malignant Progression of Hepatocellular Carcinoma.

BACKGROUND: Tumor-associated macrophages (TAMs) are pivotal components of the immune cell infiltrate in tumors and cell division cycle-associated protein-3 (CDCA3) is associated with tumor progression. The role of CDCA3 in regulating TAM polarization remains uncharacterized in hepatocellular carcinoma (HCC). METHODS: CDCA3 expression, its correlation with immune cell infiltration, and prognostic significance in HCC were analyzed using the TCGA and TIMER databases. Functional enrichment analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA), were performed to predict CDCA3-related pathways. The knockdown efficiency of CDCA3 in HCC cell lines was confirmed by RT-qPCR and Western blotting. Functional assays, including CCK-8, wound healing, and flow cytometry, were used to assess the role of CDCA3 in cell proliferation, migration, and apoptosis. Immunohistochemistry (IHC) was applied to evaluate the correlation between CDCA3 expression and M2 macrophage markers in clinical tissue samples. RESULTS: Bioinformatic analysis revealed that CDCA3 was significantly upregulated in HCC tissues, and its high expression was associated with advanced clinical stage, higher tumor grade, and poor prognosis. CDCA3 expression also correlated strongly with the level of immune infiltration. Notably, CDCA3 showed high diagnostic potential for HCC, with an area under the curve (AUC) of 0.869, cut-off value of 189.03 pg/mL, sensitivity of 81.9%, and specificity of 77.8%. Experimentally, CDCA3 knockdown significantly suppressed malignant phenotypes of HCC cells and inhibited M2 macrophage polarization. CONCLUSION: Our findings suggest that CDCA3 promotes the malignant progression of HCC by driving M2-like TAM polarization, potentially through the upregulation of cytokines such as TGF-β1, VEGFA, CD40, CXCL1, and CXCL5. CDCA3 thus represents a promising diagnostic biomarker and therapeutic target for HCC.