title: Cholest-4-en-3-one attenuates TGF-β responsiveness by inducing TGF-β receptors degradation in Mv1Lu cells and colorectal adenocarcinoma cells.
abstract: OBJECTIVE
  The transforming growth factor-beta (TGF-β) pathway is an important in the initiation and progression of cancer. Due to a strong association between an elevated colorectal cancer risk and increase fecal excretion of cholest-4-en-3-one, we aim to determine the effects of cholest-4-en-3-one on TGF-β signaling in the mink lung epithelial cells (Mv1Lu) and colorectal cancer cells (HT29) in vitro.
  
  
  METHODS
  The inhibitory effects of cholest-4-en-3-one on TGF-β-induced Smad signaling, cell growth inhibition, and the subcellular localization of TGF-β receptors were investigated in epithelial cells using a Western blot analysis, luciferase reporter assays, DNA synthesis assay, confocal microscopy, and subcellular fractionation.
  
  
  RESULTS
  Cholest-4-en-3-one attenuated TGF-β signaling in Mv1Lu cells and HT29 cells, as judged by a TGF-β-specific reporter gene assay of plasminogen activator inhibitor-1 (PAI-1), Smad2/3 phosphorylation and nuclear translocation. We also discovered that cholest-4-en-3-one suppresses TGF-β responsiveness by increasing lipid raft and/or caveolae accumulation of TGF-β receptors and facilitating rapid degradation of TGF-β and thus suppressing TGF-β-induced signaling.
  
  
  CONCLUSIONS
  Our results suggest that cholest-4-en-3-one inhibits TGF-β signaling may be due, in part to the translocation of TGF-β receptor from non-lipid raft to lipid raft microdomain in plasma membranes. Our findings also implicate that cholest-4-en-3-one may be further explored for its potential role in colorectal cancer correlate to TGF-β deficiency.
authors.affiliation: a Department of Biological Sciences , National Sun Yat-Sen University , Kaohsiung Taiwan , ROC.|b Doctoral Degree Program in Marine Biotechnology , National Sun Yat-Sen University and Academia Sinica , Kaohsiung , Taiwan , ROC.|c Center for Stem Cell Research, Kaohsiung Medical University , Kaohsiung , Taiwan , ROC.
authors.forename: Chun-Lin
authors.initials: CL
authors.lastname: Chen
authors.affiliation: c Center for Stem Cell Research, Kaohsiung Medical University , Kaohsiung , Taiwan , ROC.|d Division of Gastroenterology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan , ROC.
authors.forename: Deng-Chyang
authors.initials: DC
authors.lastname: Wu
authors.affiliation: e Taiwan Ocean Research Institute, National Applied Research Laboratories , Kaohsiung , Taiwan , ROC.
authors.forename: Min-Yun
authors.initials: MY
authors.lastname: Liu
authors.affiliation: c Center for Stem Cell Research, Kaohsiung Medical University , Kaohsiung , Taiwan , ROC.|f Department of Pharmacy , School of Pharmacy, Kaohsiung Medical University , Kaohsiung , Taiwan , ROC.
authors.forename: Ming-Wei
authors.initials: MW
authors.lastname: Lin
authors.affiliation: a Department of Biological Sciences , National Sun Yat-Sen University , Kaohsiung Taiwan , ROC.|g Division of Pathology, Department of Internal Medicine , Kaohsiung Medical University Hospital , Kaohsiung , Taiwan , ROC.
authors.forename: Hung-Tu
authors.initials: HT
authors.lastname: Huang
authors.affiliation: a Department of Biological Sciences , National Sun Yat-Sen University , Kaohsiung Taiwan , ROC.|c Center for Stem Cell Research, Kaohsiung Medical University , Kaohsiung , Taiwan , ROC.|e Taiwan Ocean Research Institute, National Applied Research Laboratories , Kaohsiung , Taiwan , ROC.|h Faculty of Pharmacy , Kaohsiung Medical University , Kaohsiung , Taiwan , ROC.
authors.forename: Yaw-Bin
authors.initials: YB
authors.lastname: Huang
authors.affiliation: i Department of Pharmacy , Zuoying Branch of Kaohsiung Armed Forces General Hospital , Kaohsiung , Taiwan , ROC.|j Department of Pharmacy and Graduate Institute of Pharmaceutical Technology , Tajen University , Taiwan , ROC.
authors.forename: Li-Chai
authors.initials: LC
authors.lastname: Chen
authors.affiliation: i Department of Pharmacy , Zuoying Branch of Kaohsiung Armed Forces General Hospital , Kaohsiung , Taiwan , ROC.
authors.forename: Yu-Yu
authors.initials: YY
authors.lastname: Chen
authors.affiliation: i Department of Pharmacy , Zuoying Branch of Kaohsiung Armed Forces General Hospital , Kaohsiung , Taiwan , ROC.|j Department of Pharmacy and Graduate Institute of Pharmaceutical Technology , Tajen University , Taiwan , ROC.|k Department of Medical Research , China Medical University Hospital, Taichung 404 , Taiwan.
authors.forename: Jih-Jung
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: a Department of Biological Sciences , National Sun Yat-Sen University , Kaohsiung Taiwan , ROC.
authors.forename: Pei-Hua
authors.initials: PH
authors.lastname: Yang
authors.affiliation: a Department of Biological Sciences , National Sun Yat-Sen University , Kaohsiung Taiwan , ROC.
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Kao
authors.affiliation: a Department of Biological Sciences , National Sun Yat-Sen University , Kaohsiung Taiwan , ROC.
authors.forename: Pei-Yu
authors.initials: PY
authors.lastname: Chen
mesh_terms: D000818:Animals; D002783:Cholestenones / Q000008:administration & dosage; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D019073:HT29 Cells; D006801:Humans; D008168:Lung / Q000473:pathology; D021962:Membrane Microdomains / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D008907:Mink / Q000235:genetics; D010766:Phosphorylation; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000235:genetics*; D059748:Proteolysis / Q000187:drug effects; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D002783:Cholestenones; D017395:Plasminogen Activator Inhibitor 1; D018125:Receptors, Transforming Growth Factor beta; C051321:SERPINE1 protein, human; D053773:Transforming Growth Factor beta1; C000475:cholest-4-en-3-one; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I
keywords: Cholest-4-en-3-one; TGF-beta; colorectal cancer; lipid raft