The Significance of p53 Immunoexpression with Different Clones (DO-7 and PAb-240) in Oral Squamous Cell Carcinoma

Abstract

Background/Aim: The TP53 gene is a tumor suppressor gene. Its product is a nuclear protein that regulates cell cycle arrest, apoptosis and DNA repair. Anti-p53 clones DO-7 and PAb-240 recognize the amino acid sequences 21-25 and 213-217, respectively. This study aimed to evaluate the expression of these clones and their relationship with clinicopathological features and survival analysis in oral squamous cell carcinomas (OSCC). Methods: Information on 53 primary OSCC was collected at the Brazilian National Cancer Institute. An immunohistochemical method was applied to evaluate p53 expression (DO-7 and PAb-240). Their expression was analyzed quantitatively and correlated with clinicopathological features. Kaplan-Meier survival curves and log rank test were used. Results: Immunopositivity for DO-7 was present in 64% of the cases, while 58% were positive for PAb-240. There was no correlation between immunoexpression of both antibodies and clinicopathological features or survival analysis. DO-7 expression was significantly higher (p = 0.001) than that of PAb-240. Conclusions: There were quantitative differences between the expression of the antibodies studied, which may reflect a different specificity of each one. To confirm immunohistochemical results and estimate the true prognostic role of TP53 in OSCC, it is important to perform mutation analysis.

p53, Cyclin D1, p21 (WAF1) and Ki-67 (MIB1) Expression at Invasive Tumour Fronts of Oral Squamous Cell Carcinomas and Development of Local Recurrence

“…We found no correlation between expression of p53 protein at the ITF and any of the clinicopathological parameters or LRFS. Previous reports on p53 expression at the ITF of OSCCs found no significant association with overall survival, although they did not examine the association with the development of local recurrence (Kato et al, 2011;Hassan et al, 2011;Heah et al, 2011;Silva Junior Jde et al, 2013;Verma et al, 2014). Why is it, if p21 is the main downstream effector of p53, that the expression of p21 was found to be important in prognosis but not p53?…”

“…To our knowledge, no published study on patients with OSCC assesses the association between p53, Cyclin D1, MIB1 and p21 protein expression at the ITF and the development of local recurrence. A few previous investigators evaluated the prognostic significance of p53 and MIB1 at the ITF of OSCC but they did not study local recurrence in particular or include measures of reliability in their methodology (Kato et al, 2011;Hassan et al, 2011;Heah et al, 2011;Silva et al, 2013;Verma et al, 2014).…”