Analysis of the Wnt/B-catenin/TCF4 pathway using SAGE, genome-wide microarray and promoter analysis: Identification of BRI3 and HSF2 as novel targets.
The Wnt signaling pathway is involved in many differentiation events during embryonic development and can lead to tumor formation after aberrant activation of its components. beta-catenin, a cytoplasmic component, plays a major role in the transduction of canonical Wnt signaling. The aim of this study was to identify novel genes that are regulated by active beta-catenin/TCF signaling in hepatocellular carcinoma-derived Huh7 cells with high (transfected) and low beta-catenin/TCF activities. High TCF activity Huh7 cells led to earlier and larger tumor formation when xenografted into nude mice. SAGE (Serial Analysis of Gene Expression), genome-wide microarray and in silico promoter analysis were performed in parallel, to compare gene expression between low and high beta-catenin/TCF activity clones, and also those that had been rescued from the xenograft tumors. SAGE and genome-wide microarray data were compared and contrasted. BRI3 and HSF2 were identified as novel targets of Wnt/beta-catenin signaling after combined analysis and confirming experiments including qRT-PCR, ChIP, luciferase assay and lithium treatment.
Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Turkey. ersen.kavak@ki.se
Ersen
E
Kavak
Ayaz
A
Najafov
Nuri
N
Ozturk
Tuncay
T
Seker
Kader
K
Cavusoglu
Tolga
T
Aslan
Adil Doganay
AD
Duru
Tahsin
T
Saygili
Gerta
G
Hoxhaj
Mahmut Can
MC
Hiz
Durisehvar Ozer
DO
Unal
Necla
N
Birgül-Iyison
Mehmet
M
Ozturk
Ahmet
A
Koman
D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D016678:Genome; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors; D000071679:Glycogen Synthase Kinase 3 beta; D006360:Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D018021:Lithium Chloride / Q000494:pharmacology; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008819:Mice, Nude; D009419:Nerve Tissue Proteins / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D015398:Signal Transduction; D000073940:Transcription Factor 4; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism*
C499959:BRI3 protein, human; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C532096:TCF4 protein, human; D000073940:Transcription Factor 4; D014157:Transcription Factors; D051153:Wnt Proteins; D051176:beta Catenin; C070389:HSF2 protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3; D018021:Lithium Chloride