title: Strong EGFR signaling in cell line models of ERBB2-amplified breast cancer attenuates response towards ERBB2-targeting drugs.
abstract: Increasing the efficacy of targeted cancer therapies requires the identification of robust biomarkers suitable for patient stratification. This study focused on the identification of molecular mechanisms causing resistance against the anti-ERBB2-directed therapeutic antibodies trastuzumab and pertuzumab presently used to treat patients with ERBB2-amplified breast cancer. Immunohistochemistry and clinical data were evaluated and yielded evidence for the existence of ERBB2-amplified breast cancer with high-level epidermal growth-factor receptor (EGFR) expression as a separate tumor entity. Because the proto-oncogene EGFR tightly interacts with ERBB2 on the protein level, the hypothesis that high-level EGFR expression might contribute to resistance against ERBB2-directed therapies was experimentally validated. SKBR3 and HCC1954 cells were chosen as model systems of EGFR-high/ERBB2-amplified breast cancer and exposed to trastuzumab, pertuzumab and erlotinib, respectively, and in combination. Drug impact was quantified in cell viability assays and on the proteomic level using reverse-phase protein arrays. Phosphoprotein dynamics revealed a significant downregulation of AKT signaling after exposure to trastuzumab, pertuzumab or a coapplication of both antibodies in SKBR3 cells but no concomitant impact on ERK1/2, RB or RPS6 phosphorylation. On the other hand, signaling was fully downregulated in SKBR3 cells after coinhibition of EGFR and ERBB2. Inhibitory effects in HCC1954 cells were driven by erlotinib alone, and a significant upregulation of RPS6 and RB phosphorylation was observed after coincubation with pertuzumab and trastuzumab. In summary, proteomic data suggest that high-level expression of EGFR in ERBB2-amplified breast cancer cells attenuates the effect of anti-ERBB2-directed antibodies. In conclusion, EGFR expression may serve as diagnostic and predictive biomarker to advance personalized treatment concepts of patients with ERBB2-amplified breast cancer.
authors.affiliation: Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Henjes
authors.forename: C
authors.initials: C
authors.lastname: Bender
authors.forename: S
authors.initials: S
authors.lastname: von der Heyde
authors.forename: L
authors.initials: L
authors.lastname: Braun
authors.forename: H A
authors.initials: HA
authors.lastname: Mannsperger
authors.forename: C
authors.initials: C
authors.lastname: Schmidt
authors.forename: S
authors.initials: S
authors.lastname: Wiemann
authors.forename: M
authors.initials: M
authors.lastname: Hasmann
authors.forename: S
authors.initials: S
authors.lastname: Aulmann
authors.forename: T
authors.initials: T
authors.lastname: Beissbarth
authors.forename: U
authors.initials: U
authors.lastname: Korf
references.citation: Nature. 2006 Jan 12;439(7073):168-74
references.pmid: 16273093
references.citation: Nat Rev Mol Cell Biol. 2006 Jul;7(7):505-16
references.pmid: 16829981
references.citation: Cancer Res. 2008 Mar 1;68(5):1471-7
references.pmid: 18316611
references.citation: Mol Cell Biol. 1996 Oct;16(10):5276-87
references.pmid: 8816440
references.citation: Nucleic Acids Res. 2011 Jan;39(Database issue):D1005-10
references.pmid: 21097893
references.citation: J Biol Chem. 1994 May 20;269(20):14661-5
references.pmid: 7514177
references.citation: Lancet Oncol. 2012 Jan;13(1):25-32
references.pmid: 22153890
references.citation: N Engl J Med. 2012 Jan 12;366(2):109-19
references.pmid: 22149875
references.citation: Mol Cancer Ther. 2010 Jun;9(6):1489-502
references.pmid: 20501798
references.citation: BMC Syst Biol. 2009 Jan 01;3:1
references.pmid: 19118495
references.citation: Cancer Cell. 2006 Dec;10(6):515-27
references.pmid: 17157791
references.citation: Cancer Cell. 2004 Aug;6(2):117-27
references.pmid: 15324695
references.citation: Oncology (Williston Park). 2003 Nov;17(11 Suppl 12):11-6
references.pmid: 14682118
references.citation: J Clin Oncol. 2009 Dec 1;27(34):5838-47
references.pmid: 19884552
references.citation: EMBO J. 1996 Jan 15;15(2):254-64
references.pmid: 8617201
references.citation: Cancer Res. 2003 Mar 1;63(5):1130-7
references.pmid: 12615732
references.citation: Anticancer Drugs. 2004 Mar;15(3):235-8
references.pmid: 15014356
references.citation: Curr Opin Cell Biol. 2009 Apr;21(2):177-84
references.pmid: 19208461
references.citation: EMBO J. 2000 Jul 3;19(13):3159-67
references.pmid: 10880430
references.citation: J Clin Oncol. 2010 Mar 1;28(7):1138-44
references.pmid: 20124182
references.citation: Breast Cancer Res Treat. 2011 Jul;128(2):447-56
references.pmid: 21594665
references.citation: Cancer Res. 2005 Dec 1;65(23):11118-28
references.pmid: 16322262
references.citation: Nat Med. 2000 Apr;6(4):443-6
references.pmid: 10742152
references.citation: Mol Syst Biol. 2005;1:2005.0008
references.pmid: 16729043
references.citation: Science. 1987 Jan 9;235(4785):177-82
references.pmid: 3798106
references.citation: J Cell Biol. 2004 Nov 8;167(3):399-403
references.pmid: 15533996
references.citation: Ann Oncol. 2001;12 Suppl 1:S21-2
references.pmid: 11521716
references.citation: Oncogene. 2010 Sep 16;29(37):5193-203
references.pmid: 20581867
references.citation: Clin Proteomics. 2011 Jul 08;8(1):11
references.pmid: 21906370
references.citation: Nucleic Acids Res. 2002 Jan 1;30(1):207-10
references.pmid: 11752295
references.citation: Nat Rev Mol Cell Biol. 2001 Feb;2(2):127-37
references.pmid: 11252954
references.citation: Clin Cancer Res. 2010 Mar 1;16(5):1509-19
references.pmid: 20179222
references.citation: Oncogene. 2007 May 14;26(22):3291-310
references.pmid: 17496923
references.citation: Cancer Res. 2001 Jun 15;61(12):4744-9
references.pmid: 11406546
references.citation: Proteomics. 2007 Feb;7(4):558-564
references.pmid: 17309101
references.citation: Mol Biol Rep. 2009 Nov;36(8):2165-8
references.pmid: 19109763
references.citation: Cancer Cell. 2009 May 5;15(5):429-40
references.pmid: 19411071
references.citation: Nat Rev Cancer. 2009 Jul;9(7):463-75
references.pmid: 19536107
references.citation: BMC Cancer. 2007 Aug 08;7:153
references.pmid: 17686164
references.citation: Cancer Cell. 2004 Apr;5(4):317-28
references.pmid: 15093539
references.citation: Proc Natl Acad Sci U S A. 1992 May 15;89(10):4285-9
references.pmid: 1350088
references.citation: Cancer Res. 2009 Dec 15;69(24):9330-6
references.pmid: 19934333
references.citation: J Biol Chem. 2001 Nov 9;276(45):42153-61
references.pmid: 11546794
references.citation: Mol Cancer Ther. 2009 Jul;8(7):1885-92
references.pmid: 19584234
references.citation: Nature. 2002 Mar 21;416(6878):279-80
references.pmid: 11907566
references.citation: Cancer Res. 2007 Feb 15;67(4):1487-93
references.pmid: 17308086
references.citation: N Engl J Med. 2001 Mar 15;344(11):783-92
references.pmid: 11248153