Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.44 (AGT)
 770 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using three antibodies (JG8, CM-1 and 1081) directed to the p53 protein, strong positivity was found in 16/47 (34.0%) of mucosal squamous cell carcinomas of the head and neck and in two squamous carcinoma cell lines (LICR-LON- HN5 and HN6Rr). The presence of the mutant p53 was confirmed in the cell lines as substitutions in exon 7 (codon 238, TGT greater than AGT) and exon 5 (codon 152, CCG greater than CTG) respectively. Positive staining was seen only in the undifferentiated cells and progressively lost as the cells keratinized, both in the tumour specimens and in the cell lines. Similar results were seen in areas of dysplasia, well removed from the site of the primary tumour. Staining of epidermal lesions showed positivity in 2/12 (16.6%) cases of Bowen's disease, 0/12 (0.0%) cases of solar keratosis, 0/10 (0.0%) basal cell carcinomas and in 3/20 (15.0%) squamous cell carcinomas. These results are discussed in relation to the multifocal origin of squamous cell carcinomas, the role of p53 mutations in squamous cell carcinomas from different sites and the significance of the 'basal' distribution of p53 as a normal growth regulator. The possible significance of the distribution of p53 in squamous epithelium as it relates to papilloma virus infection is also considered.
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PMID:Expression of p53 in premalignant and malignant squamous epithelium. 171 23

The incidence of point mutations of H-, K- and N-ras and p53 oncogenes in male BALB/c mouse stomach tumors induced with N-methyl-N-nitrosourea (MNU) was examined by direct sequencing and PCR single-strand conformation polymorphism (PCR-SSCP). A mutation of GGT to AGT at K-ras codon 12 was found by SSCP in one adenocarcinoma from a total of 19 specimens including 5 adenocarcinomas, 9 adenomatous hyperplastic regions, 1 squamous cell carcinoma and 4 normal-like stomach regions from 4 mice. No mutations were detected by direct sequencing of H-, K- and N-ras oncogenes at exons 1 (codons 12 and 13) and 2 (codon 61) in a total of 26 specimens comprising 10 adenocarcinomas, 10 adenomatous hyperplastic regions, 2 squamous cell carcinomas and 4 normal-like stomach regions from 6 mice. No mutations were detected by direct sequencing of p53 oncogene at exons 5, 6, 7 and 8 in a total of 30 specimens including 13 adenocarcinomas, 8 adenomatous hyperplastic regions, 2 squamous cell carcinomas, 1 papilloma and 6 normal-like stomach regions from 7 mice. These results suggest that ras and p53 oncogenes do not play a role in mouse stomach carcinogenesis induced by MNU.
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PMID:Rare occurrence of ras and p53 gene mutations in mouse stomach tumors induced by N-methyl-N-nitrosourea. 919 27