title: ΔNp63α enhances the oncogenic phenotype of osteosarcoma cells by inducing the expression of GLI2.
abstract: BACKGROUND
  ΔNp63, a splice variant of p63, is overexpressed and exhibits oncogenic activity in many cancers including pancreatic and breast cancer and promotes cell survival by inhibiting apoptosis. Despite its role in tumorigenesis, mechanistic activity of ΔNp63 mediated oncogenic function in osteosarcoma is poorly understood.
  
  
  METHODS
  The expression levels of p63 isoforms in osteosarcoma cell lines were identified using quantitative techniques. Expression profiling using microarray, siRNA mediated loss-of-function, and chromatin immunoprecipitation assays were employed to identify novel ΔNp63α targets in p63-null osteosarcoma SaOS-2 cells that were engineered to express ΔNp63α. The phenotype of SaOS-2-ΔNp63α cells was assessed using wound-healing, colony formation, and proliferation assays.
  
  
  RESULTS
  The comparative expression analyses identified ΔNp63α as the predominant p63 isoform expressed by invasive OS cell lines. Phenotypic analyses of SaOS-2-ΔNp63α cells in vitro indicate that ΔNp63α imparted tumorigenic attributes upon tumor cells. Further, we show that in osteosarcoma cells ΔNp63α directly regulated the transcription factor GLI2, which is a component of the hedgehog signaling pathway, and that functional interactions between ΔNp63α and GLI2 confer oncogenic properties upon OS cells.
  
  
  CONCLUSIONS
  Here, we report that GLI2 is the novel target gene of ΔNp63α and that ΔNp63α-GLI2 crosstalk in osteosarcoma cells is a necessary event in osteosarcoma progression. Defining the exact mechanisms involved in this interaction that mediate the pathogenesis of osteosarcoma promises to identify targets for drug therapy.
authors.affiliation: Laboratory for Orthopaedic Research, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland. rkumar@research.balgrist.ch.
authors.forename: Ram Mohan
authors.initials: RM
authors.lastname: Ram Kumar
authors.forename: Michael M
authors.initials: MM
authors.lastname: Betz
authors.forename: Bernhard
authors.initials: B
authors.lastname: Robl
authors.forename: Walter
authors.initials: W
authors.lastname: Born
authors.forename: Bruno
authors.initials: B
authors.lastname: Fuchs
mesh_terms: D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D046888:Tissue Array Analysis; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism*; D000075746:Zinc Finger Protein Gli2
chemical_list: C082593:GLI2 protein, human; D051741:Kruppel-Like Transcription Factors; D009687:Nuclear Proteins; D020033:Protein Isoforms; C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D000075746:Zinc Finger Protein Gli2
references.citation: Cell Stem Cell. 2011 Feb 4;8(2):164-76
references.pmid: 21295273
references.citation: J Orthop Sci. 2009 Jul;14(4):397-404
references.pmid: 19662473
references.citation: Cancer Cell. 2006 Jan;9(1):45-56
references.pmid: 16413471
references.citation: Mol Cell. 2006 Nov 17;24(4):593-602
references.pmid: 17188034
references.citation: Nature. 2010 Oct 21;467(7318):986-90
references.pmid: 20962848
references.citation: Oncogene. 2003 Jun 5;22(23):3635-44
references.pmid: 12789272
references.citation: Biochem Biophys Res Commun. 2013 Feb 8;431(2):274-9
references.pmid: 23291185
references.citation: Clin Exp Metastasis. 2000;18(3):261-71
references.pmid: 11315100
references.citation: Mol Cell Biol. 2002 Dec;22(24):8601-11
references.pmid: 12446779
references.citation: Nucleic Acids Res. 2009 Oct;37(18):6092-104
references.pmid: 19700772
references.citation: PLoS One. 2011;6(10):e26815
references.pmid: 22053213
references.citation: Am J Clin Pathol. 2006 Apr;125(4):555-81
references.pmid: 16627266
references.citation: J Pathol. 2011 Jun;224(2):169-79
references.pmid: 21506130
references.citation: Oncotarget. 2013 Sep;4(9):1416-26
references.pmid: 23965832
references.citation: Proc Natl Acad Sci U S A. 2007 May 15;104(20):8455-60
references.pmid: 17494766
references.citation: Cancer Lett. 2008 May 8;263(1):26-34
references.pmid: 18194839
references.citation: Cancer. 2014 Feb 15;120(4):537-47
references.pmid: 24151134
references.citation: Cancer Res. 2014 Jan 1;74(1):320-9
references.pmid: 24154873
references.citation: Nature. 1999 Apr 22;398(6729):708-13
references.pmid: 10227293
references.citation: J Clin Oncol. 2002 Feb 1;20(3):776-90
references.pmid: 11821461
references.citation: Oncogene. 2001 May 31;20(25):3193-205
references.pmid: 11423969
references.citation: J Cancer Res Clin Oncol. 1996;122(9):559-65
references.pmid: 8781571
references.citation: Cancer Res. 2005 Feb 1;65(3):758-66
references.pmid: 15705872
references.citation: Mol Cancer. 2010 Jan 12;9:5
references.pmid: 20067614
references.citation: Sarcoma. 2014;2014:261804
references.pmid: 24799831
references.citation: Cancer Res. 2003 May 15;63(10):2351-7
references.pmid: 12750249
references.citation: Int J Cancer. 1998 May 4;76(3):418-22
references.pmid: 9579581
references.citation: Nat Protoc. 2007;2(2):329-33
references.pmid: 17406593
references.citation: J Pathol. 2002 Dec;198(4):417-27
references.pmid: 12434410
references.citation: EMBO J. 2006 Nov 1;25(21):5105-16
references.pmid: 17036050
references.citation: Cancer Res. 2011 May 15;71(10):3688-700
references.pmid: 21576089
references.citation: Chin Med J (Engl). 2005 Apr 20;118(8):687-90
references.pmid: 15899125
references.citation: Clin Exp Metastasis. 2002;19(6):477-85
references.pmid: 12405284
references.citation: Cancer Sci. 2010 Nov;101(11):2417-24
references.pmid: 20950370
references.citation: J Orthop Res. 2013 Mar;31(3):502-9
references.pmid: 22968906
references.citation: Eur J Cancer. 2012 Dec;48(18):3429-38
references.pmid: 22868198
references.citation: J Orthop Res. 2011 Jun;29(6):938-46
references.pmid: 21284029
references.citation: Mol Cell. 1998 Sep;2(3):305-16
references.pmid: 9774969
references.citation: Clin Cancer Res. 2002 Feb;8(2):494-501
references.pmid: 11839669
references.citation: Cancer. 2012 Apr 15;118(8):2117-27
references.pmid: 21935912