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)

p53 protein expression in 34 thymic epithelial tumors was examined immunohistochemically, and p53 gene mutation was detected in selected cases by DNA sequencing, using formalin-fixed and paraffin-embedded tissues. The tumors comprised 12 noninvasive thymomas, 9 invasive/metastatic thymomas, and 13 thymic carcinomas. All the tumors were immunoreactive for p53 protein. The p53-positive tumor cells in noninvasive thymoma were less than 10% (low expressor) in 7 cases and 10% to 50% (moderate expressor) in 5 cases. In invasive/metastatic thymoma, two were low expressors and seven were moderate expressors. In thymic carcinomas, there were nine moderate expressors and four high expressors (with > 50% positive cells). There was significant difference in p53 protein immunopositivity between thymic carcinoma and each of the noninvasive or invasive/metastatic thymomas. The DNA sequencing study confirmed the presence of p53 gene point mutation in all 10 cases examined, including three low expressors. These results suggest that p53 gene mutation is an early event in thymic tumorigenesis, and the p53 protein-positive cells increase with the progression of the tumor. Immunostaining reactivity of p53 may be a useful adjunct to differentiate thymic carcinoma from thymoma.
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PMID:p53 protein expression and p53 gene mutation in thymic epithelial tumors. An immunohistochemical and DNA sequencing study. 757 85

As clinicopathological features may not be sufficient to predict the progression of thymoma, we have carried out what we believe to be the first immunohistochemical study describing the relationship between the different types of thymoma and the tumour stage, on the one hand, and the expression of epidermal growth factor (EGF), EGF-receptor (EGFR), p53, v-erb B and ras p21, on the other. The positive rates versus histological types and Masaoka's clinical stages in the 47 cases were as follows: p53 (non-invasive thymoma: 41.7%; malignant thymoma category I: 82.4%; malignant thymoma category II: 83.3%), EGF (non-invasive thymoma: 4.2%; malignant thymoma category I: 11.8%; malignant thymoma category II: 33.3%) and EGFR (non-invasive thymoma: 8.3%; malignant thymoma category I: 35.3%; malignant thymoma category II: 66.7%); p53 (stages I and II: 51.7%; stages III and IV: 77.8%), EGF (stages I and II: 3.4%; stages III and IV: 22.2%) and EGFR (stages I and II: 13.8%; stages III and IV: 44.4%). These data suggest that p53 may be implicated in the initial stages of tumorigenesis and that increased expression of EGF and EGFR may play a role in thymoma progression.
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PMID:Thymoma: tumour type related to expression of epidermal growth factor (EGF), EGF-receptor, p53, v-erb B and ras p21. 770 23

We examined p53 protein expression, p53 gene mutation, proliferating cell nuclear antigen (PCNA), and argyrophilic nuclear organizer regions (AgNOR), in 30 patients with surgically-treated thymic tumors (26 thymoma and 4 thymic carcinoma cases). p53 expression ratio with DO-1 was divided as p53 negative (0% positivity), low expressor (<10% positivity), high expressor (>10% positivity). The incidence of p53 low and high expressor in thymoma were 19% (5/26) and 8% (2/26), respectively. p53 immunopositivity in thymoma was significantly correlated with PCNA labeling index (LI). p53 expression ratio in invasive thymoma (33%) tended to be higher than that in non-invasive thymoma (18%). p53 expression was detected in one of the thymic carcinoma. There were no p53 gene mutations in 15 invasive thymoma, although one of four (25%) thymic carcinomas showed two point mutations. p53 gene alterations seem to be associated with malignant activity of tumor cells, and therefore detection of p53 gene mutations is useful as a diagnostic factor.
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PMID:p53 alteration, proliferating cell nuclear antigen, and nucleolar organizer regions in thymic epithelial tumors. 985 2