Isolation of Transcription Factor Involved in Expression of Tgfb II Receptor

Kim, S J.

Abstract

Aberrant TGF-beta function has been implicated in the pathogenesis of many diseases and it has also suggested that diminished responsiveness to TGF- beta may contribute to the process of malignant transformation. This decreased responsaiveness to TGF-beta could be caused by defects not only in TGF-beta expression of activation but also by defects in the regulation of TGF-beta receptors. We have studied several TGF-beta resistant cell lines in which Southern analysis failed to show gross deletions or rearrangements, yet in which no TGF-beta RII protein or mRNA was produced. This suggested that abnormalities in transcriptional regulation of the RII might also be found to underlie certain instances of escape from TGF-beta mediated growth inhibition. In order to identify potential transcriptional activators of the TGF- beta RII gene, we adapted the yeast one-hybrid system to find proteins that recognize the second positive regulatory element of the TGF-beta RII gene. We isolated a 2.5-kb cDNA clone that encodes a 371 amino acid novel transcription factor from a human placenta cDNA library which belongs to a novel member of the ets transcription factor family. Using constructs of the TGF-beta RII promoter linked to the luciferase gene, we have demonstrated that this transcription factor, ERT, activates transcription of the TGF-beta RII gene. A specific interaction between ERT and the TGF-beta promoter element was also demonstrated using an electrophoretic mobility shift assay. We also demonstrated that there is a good correlation between expression patterns of TGF-beta RII mRNA and ERT mRNA in human gastric cancer cell lines. Our results suggest that ERT might be a major transcription factor involved in the transcriptional regulation of the TGF-beta RII gene.

Funding Agency

• Agency: National Institute of Health (NIH)
• Institute: National Cancer Institute (NCI)
• Type: Intramural Research (Z01)
• Project #: 1Z01BC005617-10
• Application #: 6100833
• Study Section: Special Emphasis Panel (LC)
• Support Year: 10
• Fiscal Year: 1998

Institution

• Name: National Cancer Institute Division of Basic Sciences
• Country: United States

Publications

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Lucas, Philip J; Kim, Seong-Jin; Mackall, Crystal L et al. (2006) Dysregulation of IL-15-mediated T-cell homeostasis in TGF-beta dominant-negative receptor transgenic mice. Blood 108:2789-95

Kim, Byung-Gyu; Li, Cuiling; Qiao, Wenhui et al. (2006) Smad4 signalling in T cells is required for suppression of gastrointestinal cancer. Nature 441:1015-9

Choi, Kyung-Chul; Lee, Youn Sook; Lim, Seunghwan et al. (2006) Smad6 negatively regulates interleukin 1-receptor-Toll-like receptor signaling through direct interaction with the adaptor Pellino-1. Nat Immunol 7:1057-65

Zhang, Qiang; Yang, Ximing J; Kundu, Shilajit D et al. (2006) Blockade of transforming growth factor-{beta} signaling in tumor-reactive CD8(+) T cells activates the antitumor immune response cycle. Mol Cancer Ther 5:1733-43

Yoo, Byung Moo; Yeo, Marie; Oh, Tae Young et al. (2005) Amelioration of pancreatic fibrosis in mice with defective TGF-beta signaling. Pancreas 30:e71-9

Zhang, Qiang; Rubenstein, Jonathan N; Jang, Thomas L et al. (2005) Insensitivity to transforming growth factor-beta results from promoter methylation of cognate receptors in human prostate cancer cells (LNCaP). Mol Endocrinol 19:2390-9

Zhang, Qiang; Yang, Ximing; Pins, Michael et al. (2005) Adoptive transfer of tumor-reactive transforming growth factor-beta-insensitive CD8+ T cells: eradication of autologous mouse prostate cancer. Cancer Res 65:1761-9

Ju, Eun Mi; Choi, Kyung-Chul; Hong, Seung-Hee et al. (2005) Apoptosis of mink lung epithelial cells by co-treatment of low-dose staurosporine and transforming growth factor-beta1 depends on the enhanced TGF-beta signaling and requires the decreased phosphorylation of PKB/Akt. Biochem Biophys Res Commun 328:1170-81