SOAT1 Activates NLRP3 Inflammasome to Promote Cancer‐Related Lymphangiogenesis and Metastasis via IL‐1β/IL‐1R‐1 Axis in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer in the head and neck region, significantly impacting patient survival rates and quality of life. Lymph node (LN) metastasis is a lead contributor to the poor prognosis associated with OSCC. SOAT1 plays a critical role in cholesterol metabolism and has been implicated in various cancers, although its specific mechanisms in OSCC are poorly understood. Additionally, NLRP3 inflammasome has been identified as a factor that promotes cancer progression by influencing various processes involved in tumor development, with its activation linked to cancer metastasis. Lymphangiogenesis enhancing cancer metastasis has been identified in OSCC, while the molecule networks of regulating it remains unclear. In our study, we found that SOAT1 is overexpressed in OSCC and promotes proliferation, migration, and invasion of OSCC cells. Knockdown SOAT1 expression impaired OSCC progression both in vitro and in vivo, and reduced the rate of LN metastasis. RNA sequencing analysis revealed that NLRP3 is a downstream regulated by SOAT1, with NLRP3 inflammasome reactivation having recovered cancer malignancy inhibited by SOAT1 knockdown. Furthermore, we revealed that IL-1β, released by NLRP3 inflammasome activation, could directly bind to IL-1R-1 in lymphatic endothelial cells (LECs), and enhance tube formation capacity of LECs, indicating the potential role of NLRP3 inflammasome in promoting lymphangiogenesis and metastasis in OSCC. In conclusion, SOAT1 could promote OSCC malignancy and regulate the activation of NLRP3 inflammasome to increase the rate of lymphangiogenesis and cancer metastasis via IL-1β/IL-1R-1 axis in OSCC.