Comparative immunohistochemical analysis of Regulatory T lymphocyte infiltration in actinic cheilitis and squamous cell carcinoma of the lower lip

• Grant number: 18/04043-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2018
• Effective date (End): August 31, 2019
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Jorge Esquiche León
• Grantee: Bárbara Francé Vanzolin
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Oral squamous cell carcinoma (OSCC) is one of the most common types of cancer of the head and neck region. Unlike OSCC, which is associated with risk factors such as tobacco and alcohol, SCC of the lower lip (SCC-LL), often associated with sun exposure, follows a less aggressive clinical course and with low rates of metastasis. Actinic cheilitis (AC), a potentially malignant disorder commonly located in the lower lip, is also associated with chronic exposure to solar radiation, may give rise to SCC-LI. Studies have shown that interactions between neoplastic cells and immune system cells may modulate tumor progression and development. In this process, neoplastic cells appear to have abilities in recruiting different types of immune cells inducing a suppression of the immune response in the tumor microenvironment. In particular, regulatory T lymphocytes (Tregs), which constitutively express CD4, CD25 and the nuclear transcription factor FOXP3, are cells that regulate immunotolerance and mediate immunosuppressive responses. Previous studies in OSCC have shown a significant presence of Tregs in the stromal compartment of the tumor microenvironment, probably favoring tumorigenesis. However, the establishment of these populations of Tregs in lower lip carcinogenesis is still not well understood. Studies of this nature may help to understand the interaction of Tregs with the pathogenesis of AC (n=30) and SCC-LL (n=30), with immunotherapeutic implications.