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)

The genetic mechanisms of carcinomas of the small intestine are not well understood. We report the results of analysis of genetic alterations in a case of small intestinal carcinoma. A tumor in the terminal ileum was resected in a 59-yr-old woman. Histologically, the tumor was classified as well-differentiated adenocarcinoma. We screened for genetic alterations in adenomatous polyposis coli (APC), beta-catenin, K-ras, and p53 genes, as well as microsatellite instability, which are known to be involved in colorectal tumorigenesis. The tumor exhibited somatic interstitial deletion of 425-bp, which included the entire exon 3 in beta-catenin gene. Immunohistochemical staining confirmed accumulation of aberrant beta-catenin protein in the cytoplasm and nuclei of the malignant tissue. Furthermore, a frameshift mutation in the transforming growth factor beta receptor type II gene with replication error phenotype was detected in the tumor DNA. In contrast, no genetic alterations were found in the APC, K-ras, and p53 genes. Our results suggested that both beta-catenin gene mutation and replication error phenotype might contribute to carcinogenesis of the small intestinal tumor in our case. This is the first report that activation of beta-catenin gene by somatic gene mutation is involved in the development of carcinoma of the small intestine.
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PMID:Molecular and biological analysis of carcinoma of the small intestine: beta-catenin gene mutation by interstitial deletion involving exon 3 and replication error phenotype. 1089

Primary carcinoma of the small intestine is rare and represent about 0.5% of all gastrointestinal malignancies. The aim of this study was to examine the biological characteristics of primary carcinoma of the small intestine by immunohistochemical and nested polymerase chain reaction methods. Thirty-five primary carcinomas (12 in the duodenum and 23 in the jejunum or ileum) from 35 patients were studied clinicopathologically and examined for overexpression of p53 protein. In 22 of these 35 cases, point mutation at codon 12 of the K-ras gene was detected by the nested polymerase chain reaction and restriction fragment length polymorphism method. All the duodenal carcinomas were well-differentiated type and the rate of these carcinomas was significantly higher than that of jejunal or ileal carcinomas (100% vs. 65%). Fourteen cases showed overexpression of p53 (40%), and p53 tended to be expressed more frequently in poorly-differentiated type (71%) compared to well-differentiated type (30%). Only 2 out of 22 carcinoma cases showed K-ras gene mutation, and both were duodenal carcinomas. These findings suggest that p53 plays a major role in the progression of carcinoma of the small intestine, whereas the role of K-ras mutation is much less significant.
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PMID:Overexpression of p53 protein and point mutation of K-ras genes in primary carcinoma of the small intestine. 1183 95