Identification of AKT-regulated genes in inducible MERAkt cells

• Published in: Physiological genomics Vol. 7; no. 2; pp. 105 - 114
• Main Authors: KUHN, IRENE, BARTHOLDI, MARTY F, SALAMON, HUGH, FELDMAN, RICHARD I, ROTH, RICHARD A, JOHNSON, PAUL H
• Format: Journal Article
• Language: English
• Published: United States Am Physiological Soc 21.12.2001
• Subjects: 3T3 Cells; Animals; Cell Transformation, Neoplastic; DNA-Binding Proteins - antagonists & inhibitors; DNA-Binding Proteins - metabolism; Early Growth Response Protein 1; Enzyme Activation - drug effects; Estrogen Antagonists - pharmacology; Fibroblasts - cytology; Fibroblasts - metabolism; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Immediate-Early Proteins; Mice; Oligonucleotide Array Sequence Analysis; Phosphorylation - drug effects; Protein Structure, Tertiary - physiology; Protein-Serine-Threonine Kinases; Proteoglycans - antagonists & inhibitors; Proteoglycans - metabolism; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc - antagonists & inhibitors; Proto-Oncogene Proteins c-myc - metabolism; Proto-Oncogene Proteins c-sis - pharmacology; Receptors, Estrogen - genetics; Receptors, Transforming Growth Factor beta - antagonists & inhibitors; Receptors, Transforming Growth Factor beta - metabolism; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Selective Estrogen Receptor Modulators - pharmacology; Signal Transduction - drug effects; Thrombospondin 1 - antagonists & inhibitors; Thrombospondin 1 - metabolism; Transcription Factors - antagonists & inhibitors; Transcription Factors - metabolism
• ISSN: 1094-8341; 1531-2267
• DOI: 10.1152/physiolgenomics.00052.2001

1 Departments of Cancer Research 2 Genomics and Gene Therapy 3 Immunology, Berlex Biosciences, Richmond 94804-0099 4 Department of Molecular Pharmacology, Stanford University Medical School, Stanford, California 94305-5174 AKT/protein kinase B plays a critical role in the phosphoinositide 3-kinase (PI3-kinase) pathway regulating cell growth, differentiation, and oncogenic transformation. Akt1-regulated genes were identified by cDNA array hybridization analysis using an inducible AKT1 protein, MERAKT. Treatment of MERAkt cells with estrogen receptor ligands resulted in phosphorylative activation of MERAKT. Genes differentially expressed in MERAkt/NIH3T3 cells treated with tamoxifen, raloxifene, ICI-182780, and ZK955, were identified at 3 and 20 h. AKT activation resulted in the repression of c-myc, early growth response 1 (EGR1), transforming growth factor ß receptor III (TGF-ßr III), and thrombospondin-1 (THBS1). Although c-myc induction is often associated with oncogenic transformation, the c-myc repression observed here is consistent with the anti-apoptotic function of AKT. Repression of THBS1 and EGR1 is consistent with the known pro-angiogenic functions of AKT. AKT-regulated genes were found to be largely distinct from platelet-derived growth factor-ß (PDGFß)-regulated genes; only T-cell death-associated gene 51 (TDAG51) was induced in both cases. In contrast to their repression by AKT, c-myc, THBS1, and EGR1 were induced by PDGFß, indicating negative interference between elements upstream and downstream of AKT1 in the PDGFß signal transduction pathway. protein kinase B; cDNA array hybridization; estrogen inducible expression; oncogenesis; gene regulation; signal transduction networks