title: Overexpression and gene amplification of EGFR, HER2, and HER3 in biliary tract carcinomas, and the possibility for therapy with the HER2-targeting antibody pertuzumab.
abstract: BACKGROUND
  Pertuzumab is a humanized monoclonal antibody that binds to HER2 at an epitope that prevents HER2 from dimerizing with ligand-activated HER-family receptors. To assess the potential of pertuzumab as a new therapy, the expression status of HER family members was determined in biliary tract carcinoma (BTC), and the antitumor activity of pertuzumab was investigated by assessing the inhibition of BTC cell growth.
  
  
  METHODS
  The expression status of HER family members in 113 archival specimens of BTC was analyzed by using immunohistochemistry and fluorescence in situ hybridization. Using ten BTC cell lines, heregulin-alpha (HRG-α) stimulated cell proliferation and its inhibition by pertuzumab was tested in vitro. The phosphorylated HER family proteins and their respective downstream molecules were analyzed. In vivo antitumor activity of pertuzumab was evaluated in a xenograft model.
  
  
  RESULTS
  Protein overexpression of HER2 and/or HER3 was observed in 23-34 % of the specimens and gene amplification in 17-27 %. Seven of the ten cell lines showed HER2 and/or HER3 protein overexpression and gene amplification, and HRG-α stimulated cell proliferation was observed in four of the ten cell lines. In a BTC cell line co-overexpressing HER2 and HER3, pertuzumab potently inhibited the HRG-α stimulated cell proliferation in a dose-dependent manner, and completely blocked the phosphorylation of HER3. Suppression of downstream pathway molecules including p-AKT was also observed. Pertuzumab inhibited the in vivo growth of subcutaneous tumors, and increased the number of apoptotic cancer cells.
  
  
  CONCLUSIONS
  Pertuzumab exerts potent antitumor activity in BTC cells co-overexpressing HER2 and HER3. Pertuzumab provides a new therapeutic option against BTC.
authors.affiliation: Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kawamoto
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ishige
authors.forename: Melanie
authors.initials: M
authors.lastname: Thomas
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Yamashita-Kashima
authors.forename: Sei
authors.initials: S
authors.lastname: Shu
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ishikura
authors.forename: Shunichi
authors.initials: S
authors.lastname: Ariizumi
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kurosaki
authors.forename: Junichi
authors.initials: J
authors.lastname: Shoda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001661:Biliary Tract Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008297:Male; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D058990:Molecular Targeted Therapy / Q000379:methods; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D020893:Receptor, ErbB-3 / Q000096:biosynthesis / Q000235:genetics; D000068878:Trastuzumab / Q000627:therapeutic use; D023041:Xenograft Model Antitumor Assays
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D066246:ErbB Receptors; D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D000068878:Trastuzumab; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C581292:ERBB3 protein, human; C485206:pertuzumab
references.citation: J Clin Oncol. 2010 Mar 1;28(7):1138-44
references.pmid: 20124182
references.citation: World J Surg. 2003 Mar;27(3):289-93
references.pmid: 12607053
references.citation: Cancer Res. 2001 Oct 1;61(19):6971-6
references.pmid: 11585718
references.citation: J Clin Oncol. 2001 Jan 15;19(2):354-63
references.pmid: 11208826
references.citation: Stem Cells. 1998;16(6):413-28
references.pmid: 9831867
references.citation: N Engl J Med. 2012 Jan 12;366(2):109-19
references.pmid: 22149875
references.citation: World J Gastroenterol. 2005 Jun 14;11(22):3392-7
references.pmid: 15948244
references.citation: Proc Natl Acad Sci U S A. 1996 Nov 26;93(24):13704-8
references.pmid: 8942998
references.citation: N Engl J Med. 2010 Apr 8;362(14):1273-81
references.pmid: 20375404
references.citation: J Hepatol. 1985;1(6):579-96
references.pmid: 4056357
references.citation: Lancet. 2010 Aug 28;376(9742):687-97
references.pmid: 20728210
references.citation: Histopathology. 2008 Jun;52(7):797-805
references.pmid: 18422971
references.citation: Toxicol Pathol. 1996 Jan-Feb;24(1):90-9
references.pmid: 8839286
references.citation: J Clin Pathol. 2005 Jul;58(7):710-4
references.pmid: 15976337
references.citation: Ann Surg. 2005 Mar;241(3):385-94
references.pmid: 15729060
references.citation: Science. 1987 Jan 9;235(4785):177-82
references.pmid: 3798106
references.citation: Int J Oncol. 1998 Dec;13(6):1269-74
references.pmid: 9824643
references.citation: Nat Rev Cancer. 2005 May;5(5):341-54
references.pmid: 15864276
references.citation: J Hepatol. 1992 Jul;15(3):288-98
references.pmid: 1332997
references.citation: Cancer Sci. 2013 Sep;104(9):1211-6
references.pmid: 23763511
references.citation: J Pathol. 2005 Jul;206(3):356-65
references.pmid: 15892172
references.citation: J Clin Oncol. 1993 Oct;11(10):1936-42
references.pmid: 8105035
references.citation: J Clin Oncol. 2013 Mar 20;31(9):1157-63
references.pmid: 23382472
references.citation: Nat Rev Mol Cell Biol. 2001 Feb;2(2):127-37
references.pmid: 11252954
references.citation: Am J Pathol. 1997 Dec;151(6):1685-94
references.pmid: 9403719
references.citation: Cancer Res. 2005 Mar 1;65(5):1778-82
references.pmid: 15753374
references.citation: Am J Surg. 2004 May;187(5):612-7
references.pmid: 15135676
references.citation: World J Gastroenterol. 2008 Dec 14;14(46):7033-58
references.pmid: 19084911
references.citation: Science. 1989 May 12;244(4905):707-12
references.pmid: 2470152
references.citation: J Clin Oncol. 2005 Apr 10;23(11):2534-43
references.pmid: 15699478
references.citation: Cancer Cell. 2004 Apr;5(4):317-28
references.pmid: 15093539
references.citation: Hum Pathol. 1993 Jan;24(1):37-40
references.pmid: 8093356
references.citation: Cancer Cell. 2002 Aug;2(2):127-37
references.pmid: 12204533
references.citation: Cancer Sci. 2007 Sep;98(9):1498-503
references.pmid: 17627612
references.citation: Dig Liver Dis. 2003 May;35(5):332-8
references.pmid: 12846405
references.citation: J Biol Chem. 1994 May 20;269(20):14661-5
references.pmid: 7514177
references.citation: Hepatology. 1987 May-Jun;7(3):551-6
references.pmid: 3032760
references.citation: Cancer Res. 2004 Apr 1;64(7):2601-9
references.pmid: 15059917
references.citation: Nature. 2001 Mar 1;410(6824):37-40
references.pmid: 11242034
references.citation: Clin Cancer Res. 2011 Aug 1;17(15):5060-70
references.pmid: 21700765
references.citation: EMBO J. 1997 Apr 1;16(7):1647-55
references.pmid: 9130710
references.citation: Br J Cancer. 1998 Nov;78(10):1385-90
references.pmid: 9823984
references.citation: Cancer Res. 2009 Dec 15;69(24):9330-6
references.pmid: 19934333
references.citation: J Gastroenterol Hepatol. 2004 Jul;19(7):812-8
references.pmid: 15209630
references.citation: J Gastroenterol Hepatol. 2014 Aug;29(8):1582-94
references.pmid: 24787096
references.citation: Cancer Res. 2004 Apr 1;64(7):2343-6
references.pmid: 15059883
references.citation: Gastrointest Cancer Res. 2007 Nov;1(6):221-7
references.pmid: 19262900
references.citation: Br J Cancer. 2007 Aug 20;97(4):453-7
references.pmid: 17667926
references.citation: J Biol Chem. 2001 Nov 9;276(45):42153-61
references.pmid: 11546794
references.citation: J Gastroenterol Hepatol. 2001 Apr;16(4):363-72
references.pmid: 11357901
references.citation: Cancer. 1992 Sep 15;70(6):1493-7
references.pmid: 1516000
references.citation: J Biol Chem. 1999 Dec 10;274(50):35985-90
references.pmid: 10585488
references.citation: Hepatology. 2005 Jan;41(1):5-15
references.pmid: 15690474
references.citation: Ann Surg. 2001 Oct;234(4):507-17; discussion 517-9
references.pmid: 11573044
references.citation: Semin Liver Dis. 2002 Aug;22(3):303-13
references.pmid: 12360423