title: Wild-type p53 gene-induced morphological changes and growth suppression in hepatoma cells.
abstract: The human hepatocellular carcinoma (HCC) cell line, HLF, expresses only mutant-type p53 (mt-p53), which has an amino acid substitution at the 244th residue from glycine to alanine. HLF cells were transfected with wild-type p53 (wt-p53) cDNA construct pC53-SN3, mt-p53 cDNA construct pC53-SCX [which differs by a single nucleotide, resulting in alanine instead of valine at the 143rd residue in p53 (p53-143)], or pCMV-Neo-Bam, as a control, by a liposome method. After G418 selection, three wt-p53 stable transformants (WT), four mt-p53 transformants (MT), and three control vector transformants (VT) were obtained. We analyzed the cell growth and morphological changes of these transformants under different culture conditions [fetal calf serum (FCS), 10%, 1%, and 0%]. Whereas no difference from control in the growth rate and morphology was observed under the 10% FCS conditions, serum starvation induced remarkable phenotypical changes in all three WTs, but not in the other transformant. Corresponding to these phenotypical changes, the transcriptional activity of wt-p53 was increased more than nine fold. These results indicated that serum starvation would induce wt-p53 biological function, which is tightly linked to morphological changes and growth suppression. To induce these changes, the introduction of the wt-p53 gene itself was not sufficient, and additional triggering, i.e., serum starvation, was indispensable.
authors.affiliation: First Department of Internal Medicine, Yamaguchi University School of Medicine, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Terai
authors.forename: T
authors.initials: T
authors.lastname: Noma
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: A
authors.initials: A
authors.lastname: Nakazawa
authors.forename: F
authors.initials: F
authors.lastname: Kurokawa
authors.forename: K
authors.initials: K
authors.lastname: Okita
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology*; D016158:Genes, p53 / Q000502:physiology*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000473:pathology*; D010641:Phenotype; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53