title: Regulation of p53 expression in HeLa cells.
abstract: Incubation of Hela cells in the presence of insulin results in suppression of p53 expression. Treatment of cells with vanadate, an inhibitor of protein tyrosine phosphatase, likewise led to a dramatic reduction in the level of p53 transcript. On the other hand, significant induction of p53 message was demonstrated when Hela cells were exposed to genistein, a protein tyrosine kinase inhibitor. When cells were cultured in the presence of phosphotyrosine, there was a marked decrease in p53 expression. Neither phosphoserine nor phosphothreonine had an effect on p53 expression. Furthermore, simultaneous presence of both insulin and phosphotyrosine did not result in a greater suppression of the p53 message than when either of the agents was acting singly.
authors.affiliation: Department of Biochemistry, University of Hong Kong, Hong Kong.
authors.forename: Z P
authors.initials: ZP
authors.lastname: Chen
authors.forename: D C
authors.initials: DC
authors.lastname: Yeung
mesh_terms: D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein; D006367:HeLa Cells; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D007529:Isoflavones / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*; D014638:Vanadates / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D007328:Insulin; D007529:Isoflavones; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53; D014638:Vanadates; D019833:Genistein; D011505:Protein-Tyrosine Kinases