Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultraviolet (UV) light has been associated with the development of human non-melanoma skin cancers (NMSC). Such cancers often exhibit mutations in the p53 tumour suppressor gene. In order to determine the UV-induced p53 mutation spectrum, a yeast expression vector that harbours a human wild-type p53 cDNA was UV-irradiated in vitro and transfected into a yeast strain that contained the ADE2 gene regulated by a p53-responsive promoter. Forty-five mutant clones contained 51 mutations. Seven mutations were tandem base pair substitutions, four of which being CC-->TT, hallmark mutations of UV mutagenesis. Eighty percent (41/51) of the mutations were single or non-tandem base pair substitutions, the majority of which (27/41) were C-->T transitions. Ninety-five percent of such mutations occurred at dipyrimidine sites. Through a rigorous statistical test, the UV-induced p53 mutation spectrum appears to differ significantly (P < 0.008) from the one induced by the antineoplastic drug chloroethyl-cyclohexyl-nitrosourea, and to be indistinguishable from the one observed in NMSC (P = 0.4). These results demonstrate that the assay allows the determination of carcinogen-specific p53 mutation fingerprints and represents a new tool for molecular epidemiology.
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PMID:Ultraviolet-light induced p53 mutational spectrum in yeast is indistinguishable from p53 mutations in human skin cancer. 963 58

Mutations at the tumour suppressor gene TP53 are associated with nearly half of human cancers, but they appear to be rare ( approximately 10%) in feline neoplasms. The reasons for this difference are presently unclear but might be related to evolutionary divergence of p53 functions. To begin exploring this issue, we developed a yeast-based functional assay to measure the transcriptional ability of wild-type (wt) or mutant feline p53 (fe_p53) in comparison with human or murine p53 (hu_p53, mo_p53). fe_p53 cDNA was cloned and expressed in a panel of yeast reporter strains engineered to contain the ADE2 or the luciferase gene under p53 control via different p53 response elements. We established that wt fe_, hu_ and mo_p53 can act as transcription factors in yeast with overlapping DNA sequence specificities. Random mutagenesis and phenotypic evaluation of fe_ and hu_p53 cDNAs was also performed, revealing equal susceptibility to deleterious mutations. Five tumour-associated fe_p53 mutants exhibited a similar impact on the transactivation capacity (partial or complete loss) compared to the corresponding hu_p53 mutants. Given the high conservation of the intrinsic functional properties of fe_p53, further studies will be needed to clarify the role of p53 in feline carcinogenetic pathways.
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PMID:Transcriptional properties of feline p53 and its tumour-associated mutants: a yeast-based approach. 1794 39

A genetically engineered diploid yeast strain named yJC2, was specifically developed for environmental mutagen detection and characterization of induced mutations. This strain contains one copy of the human TP53 tumour suppressor gene coding sequence which is used as a molecular target for mutagens and two copies of the ADE2 reporter gene allowing accurate measurement of the TP53 transcriptional activity. The strain sensitivity to mutagens was evaluated by exposing cells to UVC, 4-nitroquinoline (NQO) or to an organic extract of sediment from the Seine estuary. For all studied mutagens, a significant and dose-dependent increase of mutant frequency was observed. The present assay named FACIM II (Functional Analysis of Chemical-Induced TP53 Mutations) is more convenient than the FACIM I and more inducible than the SOS Chromotest to detect direct-acting mutagens in the environment.
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PMID:Detection of environmental mutagens using the FACIM assay. 1842 Feb 66