Architectural assessment of p53 immunoexpression in oral potentially malignant disorders and oral and lower lip squamous cell carcinoma

• Grant number: 23/16206-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2024
• End date: March 31, 2025
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Jorge Esquiche León
• Grantee: Larissa Witzel Silva dos Santos
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Initial studies, evaluating oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs), indicated that the detection of p53 protein accumulation in the nuclei of tumor/dysplastic cells occurs secondary to genetic mutations. More recently, several studies show a better understanding of the relationship between p53 protein expression and TP53 gene mutation in carcinomas and OPMDs. In fact, in carcinomas, the immunohistochemistry (IHC) patterns of "overexpression", "null" and "cytoplasmic" are recognized as being indicative of TP53 gene mutation, rather than just the evaluation of the p53 protein as a "percentage of immunostaining". Similarly, in OPMDs, the architectural assessment of the p53 protein, rather than the "percentage of immunostaining" seem relevant in correlating with TP53 gene mutation. Thus, IHC, considering the previously mentioned patterns, becomes reliable for evaluating TP53 gene mutation status in various types of lesions. However, it is still little explored in OPMDs (especially in proliferative verrucous leukoplakia [PVL] and actinic cheilitis [AC]) and SCC of the lower lip (SCC-LI). Thus, the objective of this study is to evaluate the architectural pattern of p53 in cases of normal oral mucosa (n=30), leukoplakia (n=30), PVL (n=30), AC (n=30), OSCC (n=30) and CEC-LI (n=30), through IHC. Therefore, determining the architectural pattern of p53 in each type of lesion can help to better understand the mutation status of the TP53 gene, provide prognostic data, characterize lesions with a high risk of malignant transformation and therapeutic planning, contributing to survival and quality of life of patients.