Tubocapsanolide A Inhibits Transforming Growth Factor-β-activating Kinase 1 to Suppress NF-κB-induced CCR7*
- ‡Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, the §Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, the **Institute of Biomedical Sciences, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 804, the ¶National Sun Yat-Sen University-Kaohsiung Medical University Joint Research Center, Kaohsiung 804, the ∥Department of Pathology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung 833, and the ‡‡Center for Gene Regulation and Signal Transduction Research, National Cheng Kung University, Tainan 701, Taiwan
- 1 To whom correspondence should be addressed. Tel.: 886-7-525-2000; Fax: 886-7-525-0197; E-mail: hung1228{at}ms10.hinet.net.
Abstract
Withanolides are C28 steroidal lactones isolated from plants that exhibit potent anti-cancer activity. The chemokine receptor CCR7 is important for lymphatic invasion of cancer cells and is overexpressed in metastatic breast cancer cells. A bioactive withanolide tubocapsanolide A (Tubo A) suppressed NF-κB-mediated CCR7 expression in breast cancer cells and attenuated their migration toward lymphatic endothelial cells. Chromatin immunoprecipitation assay confirmed that binding of NF-κBto the consensus site localized at the –398/–389 of human CCR7 promoter was repressed by Tubo A. Tubo A inhibited IκB kinase (IKK) and p38 kinase and downstream mitogen and stress-activated protein kinase 1 (MSK1) activity to reduce IκB degradation and to suppress NF-κB activation. Co-expression of IKK and MSK1 fully rescued Tubo A-induced inhibition. In addition, ectopic expression of transforming growth factor-β-activating kinase (TAK1), the common upstream kinase of IKK and MSK1, also completely reversed the inhibition by Tubo A. Most importantly, Tubo A reduced NF-κB activation, CCR7 expression, and lymph node metastasis of breast cancer in vivo. We conclude that Tubo A inhibits TAK1 to repress NF-κB-induced CCR7 expression in breast cancer cells and suggest that Tubo A may be useful for the prevention of lymphatic invasion of breast cancer cells.
Footnotes
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↵2 The abbreviations used are: LEC, lymphatic endothelial cell; Tubo A, tubocapsanolide A; FCS, fetal calf serum; MSK1, mitogen and stress-activated protein kinase 1; TAK1, transforming growth factor-β-activating kinase; RT, reverse transcription; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; IKK, IκB kinase; ERK, extracellular signal-regulated kinase; JNK, c-Jun NH2-terminal kinase; MEKK1, mitogen-activated protein kinase kinase 1.
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↵* This study was supported by the National Sun Yat-Sen University-Kaohsiung Medical University Joint Research Center and Center for Gene Regulation and Signal Transduction Research, National Cheng Kung University (to W.-C. H.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1–S6.
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- Received August 12, 2008.
- Revision received December 1, 2008.
- The American Society for Biochemistry and Molecular Biology, Inc.
