Targets of transcriptional regulation by transforming growth factor-beta: expression profile analysis using oligonucleotide arrays.
Transforming growth factor-betas (TGF-betas) are potent inhibitors of cell proliferation, and disruption of components of the TGF-beta signaling pathway leads to tumorigenesis. Mutations of transmembrane receptors and Smads mediating intracellular signaling have been reported in various cancers. To identify transcriptional targets of TGF-beta, we conducted an expression profile analysis. HaCaT cells derived from human keratinocytes and highly sensitive to TGF-beta were treated with TGF-beta in the absence or presence of cycloheximide (CHX). mRNAs extracted from the HaCaT cells were used for hybridization of oligonucleotide arrays representing approximately 5600 human genes. TGF-beta increased the expression of PAI-1, junB, p21 cdk inhibitor, Smad7, betaIG-H3, and involucrin that have been reported to be up-regulated by TGF-beta, validating the usefulness of this approach. The induction of betaIG-H3 by TGF-beta was completely abolished by CHX, suggesting that the transcription of betaIG-H3 is not directly regulated by TGF-beta. Unexpectedly, we identified more genes down-regulated by TGF-beta than up-regulated ones. TGF-beta repressed the expression of epithelial specific Ets that may be involved in breast and lung tumorigenesis, which could contribute to tumor suppression by TGF-beta. Among a panel of cell cycle regulators, TGF-beta induced the expression of p21 cdk inhibitor; however, the induction of other cdk inhibitors was not significant in the present study. Taken together, the results suggest that TGF-beta may suppress tumorigenesis through positive and negative regulation of transcription.
Akiyoshi
S
S
Department of Biochemistry, The Cancer Institute of Japanese Foundation for Cancer Research (JFCR), and Research for the Future Program, the Japan Society for the Promotion of Science, Toshima-ku, Tokyo 170-8455, Japan.
Ishii
M
M
Nemoto
N
N
Kawabata
M
M
Aburatani
H
H
Miyazono
K
K
D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D016213:Cyclins / Q000235:genetics; D003513:Cycloheximide / Q000494:pharmacology; D004798:Enzymes / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D011506:Proteins / Q000235:genetics; D013936:Thymidine / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D016213:Cyclins; D004798:Enzymes; D011506:Proteins; D016212:Transforming Growth Factor beta; D003513:Cycloheximide; D013936:Thymidine