Tumour Necrosis Factor Alpha (TNF-alpha) and Oral Squamous Cell Carcinoma

Simple Summary TNF-alpha is of interest in oral squamous cell carcinoma (OSCC), with its demonstrated presence affecting both tumour and stromal inflammatory cells to enhance proliferation and facilitate invasion. TNF-alpha gene polymorphisms have also been associated with an increased risk for both oral pre-cancer and cancer development. Here we present a review of the current knowledge of the role of TNF-alpha in the aetiology, pathogenesis, and potential therapy of OSCC. Uncovering the inflammatory mechanisms underpinning initiation, progression, and promotion of oral squamous cell carcinoma (OSCC) development is fundamental to the rational pursuit of targeted therapeutics. Here we present a review of the current knowledge of the role of TNF-alpha in the aetiology, pathogenesis, and potential therapies with regards to OSCC. TNF-alpha is worthy of particular attention in OSCC, with its presence demonstrated to enhance cell proliferation and its downregulation demonstrated to inhibit proliferation and migration in other carcinomas in both in vitro and in vivo models and oral cancer patients. Increased TNF-alpha in the OSCC tumour microenvironment has been demonstrated to favour invasion through promotion of firstly the pro-inflammatory, pro-invasive phenotypes of OSCC cells and secondly its paracrine mechanism mediating recruitment and activation of inflammatory cells. Polymorphisms affecting the gene expression of TNF-alpha have been strongly associated with an increased risk for oral squamous cell carcinoma. A number of studies have considered TNF-alpha within biofluids, including saliva and serum, as a potential biomarker for the early detection of OSCC, as well as its staging, differentiation, and prognosis. The broad and multifaceted role that TNF-alpha plays in many inflammatory states presents an obvious confounder, particularly with demonstrated increased TNF-alpha levels in common oral disease states. Lastly, biologic agents targeting TNF-alpha are currently in clinical use for immune-mediated inflammatory rheumatological and gastrointestinal diseases. There is the potential that these biological agents might have an adjunctive role in OSCC prevention and treatment.