ETS1-mediated Regulation of SOAT1 Enhances the Malignant Phenotype of Oral Squamous Cell Carcinoma and Induces Tumor-associated Macrophages M2-like Polarization.

Oral squamous cell carcinoma (OSCC) is an aggressive cancer that poses a substantial threat to human life and quality of life globally. Lipid metabolism reprogramming significantly influences tumor development, affecting not only tumor cells but also tumor-associated macrophages (TAMs) infiltration. SOAT1, a critical enzyme in lipid metabolism, holds high prognostic value in various cancers. This study revealed that SOAT1 is highly expressed in OSCC tissues and positively correlated with M2 TAMs infiltration. Increased SOAT1 expression enhanced the capabilities of cell proliferation, tumor sphere formation, migration, and invasion in OSCC cells, upregulated the SREBP1-regulated adipogenic pathway, activated the PI3K/AKT/mTOR pathway and promoted M2-like polarization of TAMs, thereby contributing to OSCC growth both in vitro and in vivo. Additionally, we explored the upstream transcription factors that regulate SOAT1 and discovered that ETS1 positively regulates SOAT1 expression levels. Knockdown of ETS1 effectively inhibited the malignant phenotype of OSCC cells, whereas restoring SOAT1 expression significantly mitigated this suppression. Based on these findings, we suggest that SOAT1 is regulated by ETS1 and plays a pivotal role in the development of OSCC by facilitating lipid metabolism and M2-like polarization of TAMs. We propose that SOAT1 is a promising target for OSCC therapy with tremendous potential.