title: Negative regulation of signal transducer and activator of transcription-3 signalling cascade by lupeol inhibits growth and induces apoptosis in hepatocellular carcinoma cells.
abstract: BACKGROUND
  Constitutive activation of signal transducer and activator of transcription signalling 3 (STAT3) has been linked with survival, proliferation and angiogenesis in a wide variety of malignancies including hepatocellular carcinoma (HCC).
  
  
  METHODS
  We evaluated the effect of lupeol on STAT3 signalling cascade and its regulated functional responses in HCC cells.
  
  
  RESULTS
  Lupeol suppressed constitutive activation of STAT3 phosphorylation at tyrosine 705 residue effectively in a dose- and time-dependent manner. The phosphorylation of Janus-activated kinases (JAKs) 1 and 2 and Src was also suppressed by lupeol. Pervanadate treatment reversed the downregulation of phospho-STAT3 induced by lupeol, thereby indicating the involvement of a phosphatase. Indeed, we observed that treatment with lupeol increased the protein and mRNA levels of SHP-2, and silencing of SHP-2 abolished the inhibitory effects of lupeol on STAT3 activation. Treatment with lupeol also downregulated the expression of diverse STAT3-regulated genes and decreased the binding of STAT3 to VEGF promoter. Moreover, the proliferation of various HCC cells was significantly suppressed by lupeol, being associated with substantial induction of apoptosis. Depletion of SHP-2 reversed the observed antiproliferative and pro-apoptotic effects of lupeol.
  
  
  CONCLUSIONS
  Lupeol exhibited its potential anticancer effects in HCC through the downregulation of STAT3-induced pro-survival signalling cascade.
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
authors.forename: K S
authors.initials: KS
authors.lastname: Siveen
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
authors.forename: A H
authors.initials: AH
authors.lastname: Nguyen
authors.affiliation: Department of Pathology, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
authors.forename: F
authors.initials: F
authors.lastname: Li
authors.affiliation: 1] Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore [2] Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, Singapore 117599, Singapore.
authors.forename: S S
authors.initials: SS
authors.lastname: Singh
authors.affiliation: 1] Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore [2] Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, Singapore 117599, Singapore [3] Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, Western Australia 6009, Australia [4] Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Kumar
authors.affiliation: 1] Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, Singapore 117599, Singapore [2] Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
authors.forename: G
authors.initials: G
authors.lastname: Low
authors.affiliation: 1] Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, Singapore 117599, Singapore [2] Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
authors.forename: S
authors.initials: S
authors.lastname: Jha
authors.affiliation: Institute of Molecular and Cell Biology, A*STAR, Biopolis Drive Proteos, Singapore, Singapore.
authors.forename: V
authors.initials: V
authors.lastname: Tergaonkar
authors.affiliation: Department of Pathology, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors.forename: K S
authors.initials: KS
authors.lastname: Ahn
authors.affiliation: 1] Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore [2] Cancer Science Institute of Singapore, Centre for Translational Medicine, 14 Medical Drive, Singapore 117599, Singapore.
authors.forename: G
authors.initials: G
authors.lastname: Sethi
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D006528:Carcinoma, Hepatocellular; D002465:Cell Movement; D049109:Cell Proliferation / Q000187:drug effects; D054377:Chemokine CXCL12 / Q000502:physiology; D004815:Epidermal Growth Factor / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006801:Humans; D053613:Janus Kinase 1 / Q000235:genetics / Q000378:metabolism; D053614:Janus Kinase 2 / Q000235:genetics / Q000378:metabolism; D008113:Liver Neoplasms; D053978:Pentacyclic Triterpenes / Q000494:pharmacology*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D015533:Transcriptional Activation; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D000094042:Lupanes
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D054377:Chemokine CXCL12; D004815:Epidermal Growth Factor; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053978:Pentacyclic Triterpenes; D050796:STAT3 Transcription Factor; D042461:Vascular Endothelial Growth Factor A; C515255:CXCL12 protein, human; C494086:STAT3 protein, human; C467484:VEGFA protein, human; C507904:JAK1 protein, human; C507924:JAK2 protein, human; C010480:lupeol; D000094042:Lupanes
references.citation: Cell Cycle. 2008 Dec;7(23):3759-67
references.pmid: 19029824
references.citation: Cancer Biol Ther. 2009 Sep;8(17):1632-9
references.pmid: 19625778
references.citation: J Hepatol. 2008 Dec;49(6):977-84
references.pmid: 18845354
references.citation: Mol Interv. 2011 Feb;11(1):18-26
references.pmid: 21441118
references.citation: Science. 1995 Jul 7;269(5220):81-3
references.pmid: 7541555
references.citation: Cancer Cell. 2009 Feb 3;15(2):79-80
references.pmid: 19185839
references.citation: Front Biosci. 2008 May 01;13:4925-32
references.pmid: 18508557
references.citation: Oncotarget. 2012 Mar;3(3):236-60
references.pmid: 22470194
references.citation: Expert Opin Investig Drugs. 2009 Jan;18(1):45-56
references.pmid: 19053881
references.citation: Mol Carcinog. 2014 Oct;53(10):793-806
references.pmid: 23765383
references.citation: Clin Cancer Res. 2006 Jan 1;12(1):11-9
references.pmid: 16397018
references.citation: Br J Pharmacol. 2011 May;163(2):283-98
references.pmid: 21198544
references.citation: Expert Opin Ther Pat. 2011 Jan;21(1):65-83
references.pmid: 21114420
references.citation: PLoS One. 2013;8(3):e59591
references.pmid: 23555719
references.citation: J Gastrointest Surg. 2006 May;10(5):761-80
references.pmid: 16713550
references.citation: J Biol Chem. 2004 Jan 9;279(2):821-4
references.pmid: 14607831
references.citation: CA Cancer J Clin. 2011 Mar-Apr;61(2):69-90
references.pmid: 21296855
references.citation: Clin Cancer Res. 2007 May 15;13(10):3024-32
references.pmid: 17505005
references.citation: J Med Chem. 2008 May 8;51(9):2589-99
references.pmid: 18393402
references.citation: Biochem Biophys Res Commun. 2007 Nov 23;363(3):738-44
references.pmid: 17904524
references.citation: J Immunol. 2002 Jan 1;168(1):466-74
references.pmid: 11751994
references.citation: J Biol Chem. 1999 Aug 13;274(33):23013-9
references.pmid: 10438468
references.citation: Biochim Biophys Acta. 2013 Jan;1835(1):46-60
references.pmid: 23103770
references.citation: Mol Cancer Ther. 2010 Apr;9(4):953-62
references.pmid: 20371721
references.citation: Proc Natl Acad Sci U S A. 2004 Jul 20;101(29):10602-7
references.pmid: 15249664
references.citation: Cell Stem Cell. 2011 Jul 8;9(1):50-63
references.pmid: 21726833
references.citation: Nat Cell Biol. 2012 Dec;14(12):1270-81
references.pmid: 23159929
references.citation: J Mol Med (Berl). 2011 Jul;89(7):713-27
references.pmid: 21465181
references.citation: Cancer Prev Res (Phila). 2012 Apr;5(4):631-43
references.pmid: 22369852
references.citation: Cell. 1996 Feb 9;84(3):331-4
references.pmid: 8608586
references.citation: Life Sci. 2011 Feb 14;88(7-8):285-93
references.pmid: 21118697
references.citation: Br J Pharmacol. 2011 Nov;164(5):1506-21
references.pmid: 21506956
references.citation: Clin Cancer Res. 2011 Aug 15;17(16):5379-91
references.pmid: 21712449
references.citation: Nat Rev Immunol. 2003 Nov;3(11):900-11
references.pmid: 14668806
references.citation: Cancer Res. 2007 Sep 15;67(18):8800-9
references.pmid: 17875721
references.citation: Int J Biol Sci. 2011 Apr 27;7(5):536-50
references.pmid: 21552420
references.citation: Cancer Cell. 2009 Apr 7;15(4):283-93
references.pmid: 19345327
references.citation: J Hepatol. 2012 Jun;56(6):1384-91
references.pmid: 22326465
references.citation: Cytokine Growth Factor Rev. 2010 Feb;21(1):11-9
references.pmid: 20018552
references.citation: Cancer Prev Res (Phila). 2013 Aug;6(8):843-54
references.pmid: 23803415
references.citation: Carcinogenesis. 2010 Oct;31(10):1844-53
references.pmid: 20732907
references.citation: Hepatology. 2011 Jan;53(1):160-70
references.pmid: 20979057
references.citation: Oncogene. 2001 Nov 29;20(55):7925-34
references.pmid: 11753675
references.citation: Oncogene. 2001 May 3;20(20):2499-513
references.pmid: 11420660
references.citation: Clin Cancer Res. 2006 Dec 1;12(23):7140-8
references.pmid: 17145839