Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epithelial dysplasia is usually used to establish the prognosis of oral premalignant lesions. Its assessment, however, is subjective and does not always correctly predict the outcome of the lesions in terms of malignant transformation. Early molecular alteration(s) that dictate the development of cancer should be identified and used to evaluate oral premalignant lesions. In this context, alterations in the expression of p53 were investigated. Thirty-five oral premalignant lesions and 11 carcinomas that developed from them in a period of 16 years were investigated for p53 expression by immunohistochemistry. Normal oral mucosa from healthy individuals and oral benign lesions were used as controls. In benign lesions and normal mucosa, p53 staining, when present, was confined to the basal cell layer. Seven out of 35 (20 per cent) premalignant lesions showed p53 expression clearly above the basal cell layer and six of these (86 per cent) developed carcinomas. Suprabasal p53 expression was found in three lesions with no or mild dysplasia that developed carcinomas. All carcinomas derived from premalignant lesions with p53 suprabasal expression showed p53 expression in neoplastic cells. The combined use of histological parameters (presence of moderate or severe dysplasia) with p53 expression patterns (p53 staining above the basal cell layer) showed the highest sensitivity for the detection of lesions that progressed to carcinoma (91 per cent). When used individually, the p53 expression pattern showed higher specificity than assessment of dysplasia (96 per cent vs. 54 per cent) and higher positive predictive value (86 per cent vs. 44 per cent) for correct prediction of the malignant transformation of the lesions. The results suggest that clear expression of p53 above the basal cell layer is an early event in oral carcinogenesis and an indicator of a developing carcinoma, even preceding morphological tissue alterations. However, since immunohistochemistry cannot always detect changes in p53 expression in lesions preceding carcinoma, p53 immunohistochemical analysis is strongly recommended in conjunction with histological parameters, to increase the sensitivity of detection of cases that will progress to carcinoma.
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PMID:p53 expression above the basal cell layer in oral mucosa is an early event of malignant transformation and has predictive value for developing oral squamous cell carcinoma. 966 1

Alterations of the p53 gene are the most frequently documented genetic abnormalities in human cancer. The aim of the present study was to analyse if this alteration is an early event in oral tumorigenesis and if the suprabasal expression of p53 is a marker of the presence and severity of epithelial dysplasia. Immunohistochemical p53 expression in 78 specimens of oral squamous cell carcinoma and non-tumoral adjacent epithelium was analysed. Non-tumoral epithelium was observed in 53 cases (67.9 per cent), being normal in six cases (7.6 per cent), hyperplastic in 24 cases (30.7 per cent) and dysplastic in 48 cases (61.5 per cent). Epithelial dysplasia was mild (23 cases, 47.9 per cent); moderate (23 cases, 47.9 per cent) and severe (two cases, 4.1 per cent). Twenty-one cases of the dysplasias (43.8 per cent) expressed p53. No p53 expression appeared in any normal epithelium. Basal p53 expression always appeared in mild dysplasias (two cases). Suprabasal p53 expression appeared in mild and moderate dysplasias in nine cases and in one severe dysplasia. No statistical correlation was observed between suprabasal expression of p53 and the presence or severity of the dysplasia. The expression of p53 is an early event in oral tumorigenesis but it does not behave as an objective marker of the presence or severity of epithelial dysplasia.
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PMID:Significance of p53 expression in non-tumoral epithelium adjacent to oral squamous cell carcinomas. 1208 Sep 92

A study was conducted in rats with early tongue carcinoma induced by 4-nitroquinoline 1-oxide (4NQO), in order to investigate the early diagnosis of malignant potential of epithelial dysplasia. The rat tongue lesions were classified by their severity into three groups corresponding to early cancer, dysplasia and no change. The grade of epithelial changes was determined according to 13 items of WHO Epithelial Dysplasia Criteria. The expression levels of p53 and Bcl-2 proteins were detected immunohistochemically, and apoptotic cells were detected using the TUNEL method. In addition, a p53 mutation by lesions was detected. The expression ratio of p53 protein was high in dysplasia, and the ratio of Bcl-2 protein was high in early cancer and dysplasia. The TUNEL-positive cells were observed primarily in the granular layers of the no change cells, and their numbers decreased as the cells shifted to the early cancer stage. The p53 mutation was detected using a microdissection method in dysplasia, where it was found in three out of nine lesions. All the mutations in dysplasia detected were on the same codon that was found to be mutated in the early cancer. These results indicate that the association between the p53 mutation and histological changes in carcinogenesis epithelial dysplasia is strong, and that both the identification of p53- and Bcl-2-positive epithelium, and decrease in the TUNEL positive ratio, were useful for the diagnosis of the malignant potential of precancerous lesions.
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PMID:Investigation of environmental factors for diagnosing malignant potential in oral epithelial dysplasia. 1216 34

Epithelial dysplasia is considered the only one true histological marker of gastric cancer. In the present study we have evaluated the real clinical importance of epithelial dysplasia divided into low-grade (70 patients, mean age 59.2 years) and high-grade (50 patients, mean age 58 years) dysplasia. Furthermore, it has been made a comparison with the corresponding endoscopic picture and an evaluation of the real meaning of p53 positivity. The clinical outcome subdivision of epithelial dysplasia was effected according to the criteria of Rugge: association with or progression to gastric cancer, persistence or regression. The endoscopic patterns have been divided into ulcerous lesions and non-ulcerous lesions. The immunohistochemical study has been carried out with the utilization of a p53 antibody (Dako, Glostrup, Denmark). From the analysis of the data it comes out that low-grade dysplasia is associated with or progressed to gastric cancer in a low percentage of cases (about 8.5%), while high-grade dysplasia is associated with or progressed to gastric cancer in a high percentage of cases (about 74%), by this proving itself to be a real histological marker of gastric cancer. The cases of epithelial dysplasia associated with or progressed to gastric cancer are significantly associated with an endoscopic picture of gastric ulcer (ulcer-cancer). Nonetheless, the cases of epithelial dysplasia in correspondence of non-ulcerous lesions have been noticed to be associated with or progressed to advanced gastric cancer. The evaluation of p53 did not positively correlate with the clinical progression of the epithelial dysplasia and with TNM classification in case of gastric cancer. Therefore, the evaluation of p53 does not represent a useful marker in the clinical practice.
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PMID:[High and low grade gastric epithelial dysplasia: clinical management, endoscopic assessment of p53]. 1497 11

Differentiated-type Intraepithelial Neoplasia (DIN) is defined as HPV-negative squamous intraepithelial proliferation with abnormal keratinocyte differentiation and basal cell atypia, originally described in the vulva, with following descriptions in the oral cavity. DIN occurring in the anus is quite rare, and to the best of our knowledge, only one publication reported it. In this report, we describe the clinicopathological features of this entity on anal margin, associated with invasive squamous cell carcinoma. In addition, using the next generation sequencing (NGS) technique, we have demonstrated TP53 mutation in the invasive component but not in the associated DIN-like lesion, where p53 immunohistochemical expression was restricted to basal layers.
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PMID:Differentiated-Type Intraepithelial Neoplasia-Like Lesion Associated with Squamous Cell Carcinoma of the Anus: A Case Report with Molecular Profile. 3080 8