A Murine Floor-of-Mouth Model for Investigation of Fusobacterium nucleatum-Associated Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy of the oral cavity and a major subtype of head and neck squamous cell carcinoma (HNSCC). While established risk factors such as tobacco use, alcohol consumption, and human papillomavirus (HPV) infection contribute to OSCC, they do not fully account for its incidence or biological behavior. Emerging evidence suggests that oral pathogens, particularly those associated with periodontal disease, may contribute to carcinogenesis. Among these, Fusobacterium nucleatum has garnered attention for its pro-inflammatory and immunomodulatory properties. Here, we present a step-by-step protocol to evaluate the contribution of F. nucleatum to OSCC development using a murine floor-of-mouth tumor model. This protocol enables the assessment of microbial influences on oral tumor initiation and progression in vivo.