Tumor-derived p53 mutants induce oncogenesis by transactivating growth-promoting genes.
We have studied the mechanism of mutant p53-mediated oncogenesis using several tumor-derived mutants. Using a colony formation assay, we found that the majority of the mutants increased the number of colonies formed compared to the vector. Expression of tumor-derived p53 mutants increases the rate of cell growth, suggesting that the p53 mutants have 'gain of function' properties. We have studied the gene expression profile of cells expressing tumor-derived p53-D281G to identify genes transactivated by mutant p53. We report the transactivation of two genes, asparagine synthetase and human telomerase reverse transcriptase. Quantitative real-time PCR confirms this upregulation. Transient transfection promoter assays verify that tumor-derived p53 mutants transactivate these promoters significantly. An electrophoretic mobility shift assay shows that tumor-derived p53-mutants cannot bind to the wild-type p53 consensus sequence. The results presented here provide some evidence of a possible mechanism for mutant p53-mediated transactivation.
Scian
Mariano J
MJ
Department of Biochemistry and the Massey Cancer Center, Virginia Commonwealth University, PO Box 980614, Richmond, VA 23298, USA.
Stagliano
Katherine E R
KE
Deb
Debabrita
D
Ellis
Michelle A
MA
Carchman
Evie H
EH
Das
Anindita
A
Valerie
Kristopher
K
Deb
Swati Palit
SP
Deb
Sumitra
S
D019943:Amino Acid Substitution; D001217:Aspartate-Ammonia Ligase / Q000096:biosynthesis / Q000235:genetics; D002455:Cell Division; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D016158:Genes, p53; D006801:Humans; D020125:Mutation, Missense; D009369:Neoplasms / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013329:Structure-Activity Relationship; D019098:Telomerase / Q000096:biosynthesis / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics*; D000072160:Tumor Protein p73; D014410:Tumor Stem Cell Assay; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000502:physiology*; D025521:Tumor Suppressor Proteins
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D019098:Telomerase; D001217:Aspartate-Ammonia Ligase