HIPK3 silencing promotes M2 macrophage polarization through NF-κB signaling pathway to enhance oral cancer progression.

The tumor microenvironment (TME) is crucial for the progression of oral cancer. A key feature of the TME is the dynamic plasticity of tumor-associated macrophages (TAMs), which can polarize into either pro-inflammatory M1 or anti-inflammatory M2 phenotypes. This study aimed to investigate the role of homeodomain-interacting protein kinase 3 (HIPK3) in regulating macrophage polarization and its consequent impact on the behavior of oral squamous cell carcinoma (OSCC) cell line CAL-27. Following transfection of M0 with si-HIPK3 to downregulate HIPK3 expression, we assessed macrophage polarization markers via ELISA. Protein levels of iNOS and Arg1 were further evaluated by Western blot. We subsequently examined the effect of HIPK3-silenced macrophage polarization on the behavior of OSCC cells using functional assays. Finally, the molecular mechanism through which HIPK3 silencing regulates macrophage polarization was investigated. HIPK3 knockdown induced a significant shift from anti-tumor M1 polarization, characterized by decreased iNOS and TNF-α expression, to a tumor-promoting M2 phenotype, as evidenced by elevated levels of Arg1 and CD163. Functional assays further demonstrated that HIPK3 silencing markedly enhanced the proliferation, migration, and invasion capabilities of CAL-27 cells. Mechanistically, HIPK3 likely facilitates macrophage M2 polarization by inhibiting the NF-κB signaling pathway. In conclusion, inhibition of HIPK3 promotes M2 macrophage polarization, which in turn enhances the proliferation and migration of OSCC cells, ultimately contributing to pro-tumorigenic effects.