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.
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.
S
S
Akiyoshi
M
M
Ishii
N
N
Nemoto
M
M
Kawabata
H
H
Aburatani
K
K
Miyazono
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