Immunohistochemical detection of p53 protein in basal cell skin cancer after microwave-assisted antigen retrieval

Abstract

p53 is the most frequently altered tumor-suppressor gene in skin cancer. In normal tissues the p53 protein (wild type) has a very short half-life and it is not detectable immunohistochemically. In contrast, the mutant p53 protein has an extended half-life in tumor cells and can be detected by immunohistochemical methods. p53 is widely used as an indicator of tumor aggression and progression. Fixation methods especially formaldehyde based fixation may mask the immunohistochemical detection of p53 protein but antigen retrieval methods enhance the inmmunohistochemical detection of p53 protein by remodification of protein structure. This study was designed to evaluate the efficacy of different fixatives, of microwaving and microwave pretreatment method to retrieve p53 immunoreactivity in paraffin-embedded non-lesioned (adjacent normal tissue) human skin samples or pathological human skin samples diagnosed as basal cell carcinoma. The samples were fixed at RT and/or in microwave oven either in neutral buffered formalin or alcohol for different time periods. For antigen retrieval, the sections were irradiated in a microwave oven for 5 cycles in 10 mM citrate buffer (pH 6.00). In this study the effects of six different fixation methods on the immunohistochemical staining have been investigated in basal cell tumor specimens. The application of antigen retrieval method was also examined and compared. Optimal results were obtained using samples fixed in alcohol either at room temperature (24 h) or in microwave oven.

4-Methylthio-3-butenyl isothiocyanate (raphasatin) exerts chemopreventive effects against esophageal carcinogenesis in rats

“…p53 is a short-lived protein in normal tissues; however, mutant p53 protein has an extended half-life and is often highly expressed in tumor cells 35 . Mutations in the p53 gene have been observed in NMBA-induced esophageal tumors in rats 36 and in esophageal tumors in humans 37 .…”

Mutant p53 (p53-R248Q) functions as an oncogene in promoting endometrial cancer by up-regulating REGγ

“…However, mutant p53 is reported to own a much longer half-life and to be more stable compared with wild-type one, the wild-type p53 is vulnerable to degradation which makes it usually undetectable by antibodies [52][53][54][55], thus making it feasible to probe mutant p53 using the p53 antibody with only slight or even no influence of wild-type one. We detected positive p53 staining in 35% of our endometrioid adenocarcinoma specimens, primarily in highergrade (G2-G3) tumors and those associated with lymph node metastasis (Supplementary Table S4), which agrees with previous reports [8][9][10].…”