GRB7 is an oncogenic driver and potential therapeutic target in oesophageal adenocarcinoma
Open Access
- 1 August 2020
- journal article
- research article
- Published by Wiley in The Journal of Pathology
- Vol. 252 (3), 317-329
- https://doi.org/10.1002/path.5528
Abstract
Efficacious therapeutic approaches are urgently needed to improve outcomes in patients with oesophageal adenocarcinoma (OAC). However, oncogenic drivers amenable to targeted therapy are limited and their functional characterisation is essential. Among few targeted therapies available, anti‐human epidermal growth factor receptor 2 (HER2) therapy showed only modest benefit for patients with OAC. Herein, we investigated the potential oncogenic role of growth factor receptor bound protein 7 (GRB7), which is reported to be co‐amplified with HER2 (ERBB2) in OAC. GRB7 was highly expressed in 15% of OAC tumours, not all of which could be explained by co‐amplification with HER2, and was associated with a trend for poorer overall survival. Knockdown of GRB7 decreased proliferation and clonogenic survival, and induced apoptosis. Reverse phase protein array (RPPA) analyses revealed a role for PI3K, mammalian target of rapamycin ( mTOR), MAPK, and receptor tyrosine kinase signalling in the oncogenic action of GRB7. Furthermore, the GRB7 and HER2 high expressing OAC cell line Eso26 showed reduced cell proliferation upon GRB7 knockdown but was insensitive to HER2 inhibition by trastuzumab. Consistent with this, GRB7 knockdown in vivo with an inducible‐shRNA significantly inhibited tumour growth in cell line xenografts. HER2 expression did not predict sensitivity to trastuzumab, with Eso26 xenografts remaining refractory to trastuzumab treatment. Taken together, our study provides strong evidence for an oncogenic role for GRB7 in OAC and suggests that targeting GRB7 may be a potential therapeutic strategy for this cancer.Keywords
Funding Information
- Victorian Cancer Agency
- Department of Health and Human Services, State Government of Victoria
- Royal Australasian College of Surgeons
- University of Melbourne
- Australian Cancer Research Foundation
- National Health and Medical Research Council
- Peter MacCallum Cancer Centre
This publication has 43 references indexed in Scilit:
- Recurrence pattern in patients with a pathologically complete response after neoadjuvant chemoradiotherapy and surgery for oesophageal cancer17British Journal of Surgery, 2012
- Regulation of ERBB2 Receptor by t-DARPP Mediates Trastuzumab Resistance in Human Esophageal AdenocarcinomaCancer Research, 2012
- HER2 amplification, overexpression and score criteria in esophageal adenocarcinomaLaboratory Investigation, 2011
- Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trialThe Lancet, 2010
- Growth factor receptor-bound protein-7 (Grb7) as a prognostic marker and therapeutic target in breast cancerAnnals of Oncology, 2010
- Verification and Unmasking of Widely Used Human Esophageal Adenocarcinoma Cell LinesJNCI Journal of the National Cancer Institute, 2010
- Combination treatment with Grb7 peptide and Doxorubicin or Trastuzumab (Herceptin) results in cooperative cell growth inhibition in breast cancer cellsBritish Journal of Cancer, 2007
- Analysis of apoptosis by propidium iodide staining and flow cytometryNature Protocols, 2006
- Trastuzumab after Adjuvant Chemotherapy in HER2-Positive Breast CancerNew England Journal of Medicine, 2005
- A novel variant of human Grb7 is associated with invasive esophageal carcinoma.JCI Insight, 1998