HER2
HER2/neu (also known as ErbB-2, ERBB2) stands for "Human Epidermal growth factor Receptor 2" and is a protein giving higher aggressiveness in breast cancers. It is a member of the ErbB protein family, more commonly known as the epidermal growth factor receptor family. HER2/neu has also been designated as CD340 (cluster of differentiation 340) and p185.
Function
HER2 is a cell membrane surface-bound receptor tyrosine kinase and is normally involved in the signal transduction pathways leading to cell growth and differentiation. It is encoded within the genome by HER2/neu, a known proto-oncogene. HER2 is thought to be an orphan receptor, with none of the EGF family of ligands able to activate it. However, ErbB receptors dimerise on ligand binding, and HER2 is the preferential dimerisation partner of other members of the ErbB family.[1] The HER2 gene is a proto-oncogene located at the long arm of human chromosome 17(17q21-q22)[2].
HER2 and cancer
Approximately 15-20 percent of breast cancers have an amplification of the HER2/neu gene or overexpression of its protein product.[3] Overexpression of this receptor in breast cancer is associated with increased disease recurrence and worse prognosis. Because of its prognostic role as well as its ability to predict response to trastuzumab (Herceptin US brand name) (see below), breast tumors are routinely checked for overexpression of HER2/neu. Overexpression also occurs in other cancer such as ovarian cancer, stomach cancer, and biologically aggressive forms of uterine cancer, such as uterine serous endometrial carcinoma.[4]
The oncogene neu is so-named because it was derived from a rodent glioblastoma cell line, which is a type of neural tumor, hence 'neu.' HER2 is named because it has a similar structure to human epidermal growth factor receptor, or HER1. ErbB2 was named for its similarity to ErbB (avian erythroblastosis oncogene B), the oncogene later found to code for EGFR. Gene cloning showed that neu, HER2, and ErbB2 were the same.
HER2 is co-localized, and thus most of the time co-amplified with the gene GRB7, which is also a proto-oncogene (active in e.g. breast cancer, testicular germ cell tumor, gastric cancer, and esophageal cancer).
Drugs targeting HER2
Clinically, HER2/neu is important as the target of the monoclonal antibody trastuzumab (marketed as Herceptin). Trastuzumab is only effective in breast cancer where the HER2/neu receptor is overexpressed. One of the mechanisms of how traztuzumab works after it binds to HER2 is by increasing p27, a protein that halts cell proliferation.[5]
Overexpression of the HER2 gene can be suppressed by the amplification of other genes and the use of the drug Herceptin. Research is currently being conducted to discover which disregulated genes may have this desired effect. Another monoclonal antibody, Pertuzumab [1], which inhibits dimerization of HER2 and HER3 receptors, is in advanced clinical trials.
The expression of HER2/ERBB2 protein is regulated by estrogen receptors. Furthermore estradiol and tamoxifen acting through the estrogen receptor normally down regulates the expression of HER2/ERBB2. However when the ratio of the coactivator AIB-3 exceeds that of the corepressor PAX2, the expression of HER2/ERBB2 is upregulated in the presence of tamoxifen leading to tamoxifen resistant breast cancer.[6][7]
Interactions
HER2/neu has been shown to interact with Beta-catenin,[8][9][10] Glycoprotein 130,[11] PLCG1,[12][13] Erbin,[14][15][16] MUC1,[17][18] Grb2,[19][20][21] Heat shock protein 90kDa alpha (cytosolic), member A1,[22][23] DLG4,[24] PIK3R2,[25] PICK1[14] and SHC1.[19][26][21]
References
- ^ Olayioye MA (2001). "Update on HER-2 as a target for cancer therapy: intracellular signaling pathways of ErbB2/HER-2 and family members". Breast Cancer Res. 3 (6): 385–389. doi:10.1186/bcr327. PMID 11737890.
{{cite journal}}
: CS1 maint: unflagged free DOI (link) - ^ Coussens L (1985). "Tyrosine Kinase Receptor with Extensive Homology to EGF Receptor Shares Chromosomal Location with neu Oncogene". Science. 230: 1132–1139. doi:10.1126/science.2999974.
- ^ "Entrez Gene: ERBB2 v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian)".
- ^ Santin AD, Bellone S, Roman JJ, McKenney JK, Pecorelli S. (2008). "Trastuzumab treatment in patients with advanced or recurrent endometrial carcinoma overexpressing HER2/neu". Int J Gynaecol Obstet. 102 (2): 128–31. doi:10.1016/j.ijgo.2008.04.008. PMID 18555254.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ XF Le, Franz Pruefer, Robert Bast. (2005). "HER2-targeting antibodies modulate the cyclin-dependent kinase inhibitor p27Kip1 via multiple signaling pathways". Cell Cycle. 4 (1): 87–95. PMID 15611642.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ "Study sheds new light on tamoxifen resistance". Cordis News. Cordis. 2008-11-13. Retrieved 2008-11-14.
{{cite web}}
: Cite has empty unknown parameter:|coauthors=
(help) - ^ Hurtado A, Holmes KA, Geistlinger TR, Hutcheson IR, Nicholson RI, Brown M, Jiang J, Howat WJ, Ali S, Carroll JS (2008). "Regulation of ERBB2 by oestrogen receptor-PAX2 determines response to tamoxifen". Nature. 456: 663. doi:10.1038/nature07483. PMID 19005469.
{{cite journal}}
: Unknown parameter|month=
ignored (help)CS1 maint: multiple names: authors list (link) - ^ Schroeder, Joyce A (2002). "ErbB-beta-catenin complexes are associated with human infiltrating ductal breast and murine mammary tumor virus (MMTV)-Wnt-1 and MMTV-c-Neu transgenic carcinomas". J. Biol. Chem. 277 (25). United States: 22692–8. doi:10.1074/jbc.M201975200. ISSN 0021-9258. PMID 11950845.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: unflagged free DOI (link) CS1 maint: year (link) - ^ Bonvini, P (2001). "Geldanamycin abrogates ErbB2 association with proteasome-resistant beta-catenin in melanoma cells, increases beta-catenin-E-cadherin association, and decreases beta-catenin-sensitive transcription". Cancer Res. 61 (4). United States: 1671–7. ISSN 0008-5472. PMID 11245482.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Kanai, Y (1995). "c-erbB-2 gene product directly associates with beta-catenin and plakoglobin". Biochem. Biophys. Res. Commun. 208 (3). UNITED STATES: 1067–72. doi:10.1006/bbrc.1995.1443. ISSN 0006-291X. PMID 7702605.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Grant, Susan L (2002). "An unexpected biochemical and functional interaction between gp130 and the EGF receptor family in breast cancer cells". Oncogene. 21 (3). England: 460–74. doi:10.1038/sj.onc.1205100. ISSN 0950-9232. PMID 11821958.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Peles, E (1991). "Oncogenic forms of the neu/HER2 tyrosine kinase are permanently coupled to phospholipase C gamma". EMBO J. 10 (8). ENGLAND: 2077–86. ISSN 0261-4189. PMID 1676673.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Arteaga, C L (1991). "Elevated content of the tyrosine kinase substrate phospholipase C-gamma 1 in primary human breast carcinomas". Proc. Natl. Acad. Sci. U.S.A. 88 (23). UNITED STATES: 10435–9. ISSN 0027-8424. PMID 1683701.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ a b Jaulin-Bastard, F (2001). "The ERBB2/HER2 receptor differentially interacts with ERBIN and PICK1 PSD-95/DLG/ZO-1 domain proteins". J. Biol. Chem. 276 (18). United States: 15256–63. doi:10.1074/jbc.M010032200. ISSN 0021-9258. PMID 11278603.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: unflagged free DOI (link) CS1 maint: year (link) - ^ Borg, J P (2000). "ERBIN: a basolateral PDZ protein that interacts with the mammalian ERBB2/HER2 receptor". Nat. Cell Biol. 2 (7). ENGLAND: 407–14. doi:10.1038/35017038. ISSN 1465-7392. PMID 10878817.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Huang, Yang Z (2003). "Erbin suppresses the MAP kinase pathway". J. Biol. Chem. 278 (2). United States: 1108–14. doi:10.1074/jbc.M205413200. ISSN 0021-9258. PMID 12379659.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: unflagged free DOI (link) CS1 maint: year (link) - ^ Li, Yongqing (2003). "Heregulin targets gamma-catenin to the nucleolus by a mechanism dependent on the DF3/MUC1 oncoprotein". Mol. Cancer Res. 1 (10). United States: 765–75. ISSN 1541-7786. PMID 12939402.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Schroeder, J A (2001). "Transgenic MUC1 interacts with epidermal growth factor receptor and correlates with mitogen-activated protein kinase activation in the mouse mammary gland". J. Biol. Chem. 276 (16). United States: 13057–64. doi:10.1074/jbc.M011248200. ISSN 0021-9258. PMID 11278868.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: unflagged free DOI (link) CS1 maint: year (link) - ^ a b Schulze, Waltraud X (2005). "Phosphotyrosine interactome of the ErbB-receptor kinase family". Mol. Syst. Biol. 1. England: 2005.0008. doi:10.1038/msb4100012. PMID 16729043.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
,|laysummary=
, and|month=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Bourguignon, L Y (2001). "Hyaluronan promotes CD44v3-Vav2 interaction with Grb2-p185(HER2) and induces Rac1 and Ras signaling during ovarian tumor cell migration and growth". J. Biol. Chem. 276 (52). United States: 48679–92. doi:10.1074/jbc.M106759200. ISSN 0021-9258. PMID 11606575.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: unflagged free DOI (link) CS1 maint: year (link) - ^ a b Olayioye, M A (1998). "ErbB-1 and ErbB-2 acquire distinct signaling properties dependent upon their dimerization partner". Mol. Cell. Biol. 18 (9). UNITED STATES: 5042–51. ISSN 0270-7306. PMID 9710588.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Xu, W (2001). "Sensitivity of mature Erbb2 to geldanamycin is conferred by its kinase domain and is mediated by the chaperone protein Hsp90". J. Biol. Chem. 276 (5). United States: 3702–8. doi:10.1074/jbc.M006864200. ISSN 0021-9258. PMID 11071886.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: unflagged free DOI (link) CS1 maint: year (link) - ^ Jeong, Jae-Hoon (2008). "Quercetin-induced ubiquitination and down-regulation of Her-2/neu". J. Cell. Biochem. 105 (2). United States: 585–95. doi:10.1002/jcb.21859. PMID 18655187.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Huang, Y Z (2000). "Regulation of neuregulin signaling by PSD-95 interacting with ErbB4 at CNS synapses". Neuron. 26 (2). UNITED STATES: 443–55. ISSN 0896-6273. PMID 10839362.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Gout, I (1992). "Expression and characterization of the p85 subunit of the phosphatidylinositol 3-kinase complex and a related p85 beta protein by using the baculovirus expression system". Biochem. J. 288 ( Pt 2). ENGLAND: 395–405. ISSN 0264-6021. PMID 1334406.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link) - ^ Wong, L (1999). "A differential requirement for the COOH-terminal region of the epidermal growth factor (EGF) receptor in amphiregulin and EGF mitogenic signaling". J. Biol. Chem. 274 (13). UNITED STATES: 8900–9. ISSN 0021-9258. PMID 10085134.
{{cite journal}}
: Check date values in:|year=
(help); Cite has empty unknown parameters:|laydate=
,|laysource=
, and|laysummary=
(help); Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help); Unknown parameter|quotes=
ignored (help)CS1 maint: year (link)
Further reading
External links
- AACR Cancer Concepts Factsheet on HER2
- Her2/neu Vaccine Protects Against Tumor Growth
- Chimeric molecules and Methods of Use
- Breast Friends for Life Network - A South African Breast Cancer Support Forum for HER2 Positive Women
- Receptor,+erbB-2 at the U.S. National Library of Medicine Medical Subject Headings (MeSH)