Expression of p53 protein in oral squamous cell carcinomas and adjacent non‐tumorous mucosa of the floor of the mouth: an archival immunohistochemical study using wet autoclave pretreatment for antigen retrieval

Abstract

Routinely formalin-fixed and paraffin-embedded material of 22 squamous cell carcinomas of the floor of the mouth (T2NoMo, Ro), together with adjacent dysplastic or normal mucosa, were immunohistochemically investigated using a panel of four anti-p53 antibodies (CM1, PAb1801, DO7, PAb240) subsequent to wet autoclave pretreatment for antigen retrieval. p53 immunoreactivity was detected in 9/22 (40%) carcinomas with PAb1801 and DO7 antibodies, and in 8/22 cases using CM1 and PAb 240. p53-positive tumour cells accumulated predominantly at the invasive front of the carcinomas. A focal or scattered p53 immunoreactivity was observed in the adjacent normal and/or dysplastic mucosa in 17/22 (77%) cases using both CM1 and PAb1801 antibodies, in 10/22 with DO7, and in 8/22 with PAb240. This study has demonstrated examples of different p53 immunophenotypes in the non-tumorous and neoplastic oral mucosa of the same patient without significant correlation to the clinicopathological parameters studied.

Oral squamous cell carcinomas in age distinct population: A comparison of p53 immunoexpression

“…This might also indicate a normally working p53 system activated in genetically stressed cells that could either be restored or pushed towards apoptosis or enter the vicious circle of malignant transformation. [16] In OSCC cases, including both the study groups, we found that 31 out of total 60 cases (51.67%) showed positive expression for p53 protein by IHC analysis. Our findings were in agreement with Kurokawa, who performed a study to evaluate a potential association between the histological grade of malignancy at the deep invasive front and the expression of Ki-67 antigen and p53 protein in OSCC patients and found p53 immunoexpression in 54% of tumours.…”

“…It was consistent with the studies of Langdon, Partridge (1992), Rich et al (1999), Nylander et al (2000), and with most other reports in the literature, regardless of differences in antibodies, IHC procedures, and types of specimens (frozen or paraffin-embedded sections) used. [20][21][22][23][24][25] On the contrary, the normal oral mucosa was found to be p53 positive by Piffko et al (1995), but this was tissue adjacent to malignant epithelium that might represent an early event in oral carcinogenesis. This might also indicate a normally working p53 system activated in genetically stressed cells that could either be restored or pushed towards apoptosis or enter the vicious circle of malignant transformation.…”

“…Similarly, p53 stabilization and accumulation could be the result of p53 binding to cellular or viral proteins. Type and dilution of primary antibody [16] as well as pretreatment used [18] are also the factors of influence in IHC results. On the other hand, our p53-negative cases, apart from technique failures, could result from biallelic deletion of TP53 gene, very low levels of mutant or wild-type p53, a nonsense mutation or a truncated p53 protein in its N-terminal portion, which would not be recognized by the antibody.…”

“…[10,15] For secondary antibody application, the slides were incubated with polymer-HRP reagent (anti-mouse and anti-rabbit IgG labelled with enzyme polymer in PBS) for 30 min. [16] Slides were then incubated in freshly prepared 3,3-Diaminobenzidene Tetrahydrochloride (DAB) solution, and, for counter staining, the slides were dipped once in Mayer's Haematoxylin. [17,18] When a distinct brown staining was confined to the nuclei, p53 expression was considered positive.…”

p53 Immunoexpression in Oral Squamous Cell Carcinomas from Different Anatomical Sites: A Comparative Study

“…Moreover, some studies (Kropveld et al, 1999 andBalz et al, 2003) have shown that the analysis of the entire coding region of TP53 (exons 2-11) in head and neck SCC increases the frequency of mutations and yields a greater concordance level with immunohistochemistry results, although many caveats may lead to false-positive or false-negative results (Piffkó et al, 1995;Dowell & Ogden, 1996;McNicol & Richmond, 1998;Stoll et al, 1998;Saunders et al, 1999;Nylander et al and Gonzalez-Moles et al).…”