Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A human colon carcinoma cell line designated OUMS-23 has been established from metastatic pericardial fluid of a male familial adenomatous polyposis patient with colon cancer. Since 1984, the epithelial cells have been maintained in culture. Ultrastructural studies revealed the presence of numerous microvilli on the cell surface and desmosomes between the adjacent cells. The cells secreted carcinoembryonic antigen into the culture medium (15 ng/10(6) cells-1 24 h-1). The cells expressed heat-stable placental-type-like alkaline phosphatase, whereas the normal counterparts expressed tissue-unspecific alkaline phosphatase. Karyotypic analysis showed that the cell line was of human origin and that the chromosome number was broadly distributed between 53 and 118. Southern blot analysis of the APC gene revealed no abnormalities in OUMS-24 cells, while Northern blot analysis demonstrated that the expression of the gene was about one-half that of the normal human fibroblasts. No mutations at the "hot spots" of codons 12 and 61 of H-, K- and N-ras proto-oncogenes were detected in the cells. The cells could grow in soft agar at a cloning efficiency of 6.5%, and upon transplantation into nude mice the cells formed tumors, which were diagnosed as differentiated adenocarcinoma.
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PMID:Establishment and characterization of a human colon cancer cell line, OUMS-23, from a patient with familial adenomatous polyposis. 857 85

We explored APC gene mutations and chromosome 5q21 allelic losses (5qLOH) in 18 neoplasms of the papilla of Vater, including 6 early-stage tumours (3 adenomas, 3 carcinomas) and 12 advanced-stage cancers. Eleven PCR-amplified polymorphic sequences were used to analyse 5qLOH. APC mutations were investigated both by an in vitro APC-protein truncation test and by single-strand conformation polymorphism analysis. Mutations in the Ki-ras, N-ras and p53 genes were also assessed. We found: 5qLOH in 8 of 16 cases (50%), including 1 adenoma, 3 early- and 4 advanced-stage cancers; APC mutations in 2 adenomas and 1 advanced-stage carcinoma; Ki- or N-ras mutations in 3 adenomas and 3 advanced-stage cancers; p53 mutations in 2 early-stage and 7 advanced-stage adenocarcinomas. Our results suggest that 5qLOH, APC mutations and ras mutations are present at early stages, whereas p53 inactivation is associated with progression of malignancy in a large proportion of cases. These data indicate that sporadic ampullary tumours differ from those occurring in familial adenomatous polyposis in the frequency (17% vs. 64%) as well as in the site of APC somatic mutations, suggesting a different molecular pathogenesis in the 2 conditions.
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PMID:APC gene mutations and allelic losses in sporadic ampullary tumours: evidence of genetic difference from tumours associated with familial adenomatous polyposis. 890 71

Although most gallbladder carcinomas evolve from dysplasia and carcinoma in situ, the role of gallbladder adenomas in the pathogenesis of gallbladder carcinoma is still controversial. A series of molecular changes including loss of heterozygosity (LOH) at 17p (TP53 gene), 13q (RB gene), 18q (DCC gene), and 9p21 (CDKN2a gene) chromosomal regions have been identified in dysplasias, carcinomas in situ, and invasive carcinomas of the gallbladder, whereas mutations in K- and N-ras genes are rare. To determine whether the molecular abnormalities of adenomas are similar to those found in carcinomas, we obtained extracted DNA from precisely microdissected tissue from 16 gallbladder adenomas (14 pyloric and 2 intestinal-type). We determined the presence of mutations in TP53, K- and N-ras genes, and LOH at five chromosomal regions (5q22 APC-MCC region, RB, TP53, DCC and 9p21-CDKN2a). For the TP53 mutation study, single strand conformational polymorphism (SSCP) analysis in exons 4 to 8 were performed. K- and N-ras mutations detection was performed by designed restriction fragment length polymorphism (RFLP) method and sequencing. Only a single LOH (at 5q22) was detected in a gallbladder adenoma of intestinal type. No mutations at the TP53 were detected. Four adenomas (25%) showed K-ras mutations (two in codon 12 and two in codon 61). We conclude that gallbladder adenoma lacks the molecular changes frequently detected in dysplasia, carcinoma in situ, and invasive carcinoma of the gallbladder. Likewise the occurrence of K-ras mutations at codon 12 and 61 in 25% of adenomas strongly suggests that these lesions are not precursors of invasive gallbladder carcinoma.
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PMID:Gallbladder adenomas have molecular abnormalities different from those present in gallbladder carcinomas. 992 22

A 42 year old man without familial adenomatous polyposis had recurrent desmoid tumours in the left subclavicular site. Histological examination showed a typical desmoid tumour. Molecular analysis was performed in genomic DNA from this tumour, using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequencing methods. No mutation could be detected in the entire coding sequence of the APC gene, nor in H-ras, K-ras, N-ras, or p53 genes. On seeking a mutation of the beta catenin gene (CTNNB1), an activating mutation from ACC (Thr) to GCC (Ala) at codon 41 was found. Immunohistochemical staining showed that accumulated beta catenin protein was predominantly localised in the nuclei of desmoid cells. This is the first example of a sporadic desmoid tumour in which a mutation of the beta catenin gene was revealed.
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PMID:A novel case of a sporadic desmoid tumour with mutation of the beta catenin gene. 1065 94

The molecular hallmarks of inflammation-mediated lung carcinogenesis have not been fully clarified, mainly due to the scarcity of appropriate animal models. We have used a silica-induced multistep lung carcinogenesis model driven by chronic inflammation to study the evolution of molecular markers and genetic alterations. We analyzed markers of DNA damage response (DDR), proliferative stress, and telomeric stress: gamma-H2AX, p16, p53, and TERT. Lung cancer-related epigenetic and genetic alterations, including promoter hypermethylation status of p16(CDKN2A), APC, CDH13, Rassf1, and Nore1A, as well as mutations of Tp53, epidermal growth factor receptor, K-ras, N-ras, and c-H-ras, have been also studied. Our results showed DDR pathway activation in preneoplastic lesions, in association with inducible nitric oxide synthase and p53 induction. p16 was also induced in early tumorigenic progression and was inactivated in bronchiolar dysplasias and tumors. Remarkably, lack of mutations of Ras and epidermal growth factor receptor, and a very low frequency of Tp53 mutations suggest that they are not required for tumorigenesis in this model. In contrast, epigenetic alterations in p16(CDKN2A), CDH13, and APC, but not in Rassf1 and Nore1A, were clearly observed. These data suggest the existence of a specific molecular signature of inflammation-driven lung carcinogenesis that shares some, but not all, of the molecular landmarks of chemically induced lung cancer.
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PMID:Molecular analysis of a multistep lung cancer model induced by chronic inflammation reveals epigenetic regulation of p16 and activation of the DNA damage response pathway. 1797 4