Retinoblastoma (RB) is an ocular malignancy of early childhood. Although mutations in the Rb1 gene and expression of stem cell markers have been identified in RB, additional information on RB-specific alterations in signaling pathways and protein expression would be useful for the design of targeted RB therapies. Here we have evaluated the expression of HER2 (ERBB2) in RB. HER2 is a member of the epidermal growth factor family, which is overexpressed in breast, ovarian, gastric, colorectal, pancreatic, and endometrial cancers in a stratified manner. Overexpression and gene amplification of HER2 is associated with aggressive malignancies, accompanied by chemoresistance and poor outcomes. In this study, we present the first evidence of HER2 immunoreactivity in retinoblastoma, as shown by immunocytochemistry, flow cytometry, and western immunoblot, with validation by reverse transcription PCR (RT-PCR) in both RB cell lines and clinical RB tumors. Our results suggest that the HER2 protein expressed in RB is a truncated version that spares the trastuzumab binding site, while HER2 is not detected in normal ocular tissues. Our discovery of HER2 expression in RB may lead to innovative and targeted drug treatment options designed to spare the eye and preserve vision in RB patients.
Retinoblastoma HER2 ERBB2 Target discovery Drug target Targeted therapy
This is a preview of subscription content, log in to check access
The authors thank Dr. Bruce Ksander for providing the RB116 and RB143 cells. We also thank Dr. John Ludlow for providing the WERI-RB27 cells. GMS is supported by the Cornell Center on the Microenvironment and Metastasis through Award Number U54CA143876 from the National Cancer Institute, as well as a grant from the SUNY Brain Network of Excellence. ASH is supported by the Karl Kirchgessner Foundation. Institutional support to Bascom Palmer Eye Institute was provided by a Research to Prevent Blindness Unrestricted Grant and an NEI Center Core Grant P30 EY014801. SS is supported by a Postdoctoral Fellowship grant from Roche Inc. to DKS. This work was in part supported by NIH grant GM114179 to DKS, and funding from the Center for Protein Therapeutics at the State University of New York at Buffalo.
All authors (GMS, SS, ASH, and DKS) participated in experimental design, analysis, and manuscript preparation. GMS carried out immunohistochemical and immunocytochemical experiments and analysis. SS performed western blot and flow cytometry with analysis. ASH provided RT-PCR results and analysis. All authors have read and approved of the final manuscript.
Compliance with ethical standards
Conflicts of interest
Hynes NE, Stern DF. The biology of erB-2/neu/HER-2 and its role in cancer. Biochim Biophys Acta. 1994;1198:165–84.PubMedGoogle Scholar
Slamon DJ, Clark GM, Wong SG, Levin WJ, Ullrich A, McGuire WL. Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene. Science. 1987;235:177–82.CrossRefPubMedGoogle Scholar
Balselga J, Norton L, Albanell J, et al. Recombinant humanized anti-HER2 antibody enhances the antitumor activity of paclitaxel and doxorubicin against HER2/neu overexpression human breast cancer xenografts. Cancer Res. 1998;58:2825–31.Google Scholar
Kulhari H, Pooja D, Rompicharla SV, Sistla R, Adams DJ. Biomedical applications of trastuzumab: as a therapeutic agent and a targeting ligand. Med Res Rev. 2015;35(4):849–76. doi:10.1002/med.21345.CrossRefPubMedGoogle Scholar
Färkkilä A, Andersson N, Bützow R, Leminen A, Heikinheimo M, Anttonen M, et al. HER2 and GATA4 are new prognostic factors for early-stage ovarian granulosa cell tumor—a long-term follow-up study. Cancer Med. 2014;3(3):526–36.CrossRefPubMedPubMedCentralGoogle Scholar
Gravalos C, Jimeno A. HER2 in gastric cancer: a new prognostic factor and a novel therapeutic target. Ann Oncol. 2008;19(9):1523–9.CrossRefPubMedGoogle Scholar
Arnaout AH, Dawson PM, Soomro S, Taylor P, Theodorou NA, Feldmann M, et al. HER2 (c-erbB-2) oncoprotein expression in colorectal adenocarcinoma: an immunohistological study using three different antibodies. J Clin Pathol. 1992;45(8):726–7.CrossRefPubMedPubMedCentralGoogle Scholar
Hansel DE, Ashfaq R, Rahman A, Wanzer D, Yeo CJ, Wilentz RE, et al. A subset of pancreatic adenocarcinomas demonstrates coamplification of topoisomerase II alpha and HER2/neu: use of immunolabeling and multicolor FISH for potential patient screening and treatment. Am J Clin Pathol. 2005;123(1):28–35.CrossRefPubMedGoogle Scholar
Seigel GM, Campbell LM, Narayan M, Gonzalez-Fernandez F. Cancer stem cell characteristics in retinoblastoma. Mol Vis. 2005;11:729–37.PubMedGoogle Scholar
Seigel GM, Hackam AS, Ganguly A, Mandell LM, Gonzalez-Fernandez F. Human embryonic and neuronal stem cell markers in retinoblastoma. Mol Vis. 2007;13:823–32.PubMedPubMedCentralGoogle Scholar
Sharom FJ. ABC multidrug transporters: structure, function and role in chemoresistance. Pharmacogenomics. 2008;9(1):105–27.CrossRefPubMedGoogle Scholar
Bösch D, Pache M, Simon R, Schraml P, Glatz K, Mirlacher M, et al. Expression and amplification of therapeutic genes in retinoblastoma. Graefes Arch Clin Exp Ophthalmol. 2005;243(2):156–62.CrossRefPubMedGoogle Scholar
Koletsa T, Kostopoulos I, Charalambous E, Christoforidou B, Nenopoulou E, Kotoula V. A splice variant of HER2 corresponding to Herstatin is expressed in the noncancerous breast and in breast carcinomas. Neoplasia. 2008;10(7):687–96.CrossRefPubMedPubMedCentralGoogle Scholar
Hoff ER, Tubbs RR, Myles JL, Procop GW. HER2/neu amplification in breast cancer: stratification by tumor type and grade. Am J Clin Pathol. 2002;117(6):916–21.CrossRefPubMedGoogle Scholar
Omenn GS, Guan Y, Menon R. A new class of protein cancer biomarker candidates: differentially expressed splice variants of ERBB2 (HER2/neu) and ERBB1 (EGFR) in breast cancer cell lines. J Proteomics. 2014;107:103–12.CrossRefPubMedGoogle Scholar
Jackson C, Browell D, Gautrey H, Tyson-Capper A. Clinical significance of HER-2 splice variants in breast cancer progression and drug resistance. Int J Cell Biol. 2013;2013:97358.CrossRefGoogle Scholar
Hillig T, Thode J, Breinholt MF, Franzmann MB, Pedersen C, Lund F, et al. Assessing HER2 amplification by IHC, FISH, and real-time polymerase chain reaction analysis (real-time PCR) following LCM in formalin-fixed paraffin embedded tissue from 40 women with ovarian cancer. APMIS. 2012;120(12):1000–7.CrossRefPubMedPubMedCentralGoogle Scholar