Abstract 5163
Background
Insulin Receptor (INSR) signalling may play a role in resistance to insulin-like growth factor receptor (IGF1R) therapy. Although IGF1R is frequently expressed in triple negative breast cancer (TNBC), we found that an IGF1R monoclonal antibody did not inhibit the growth of TNBC cells. Thus, we hypothesised that dual targeting of IGF1R and INSR may be more effective in TNBC.
Methods
Relative mRNA expression of INSR and IGFIR were analysed across different subtypes of breast cancer using the BreastMark database. INSR-A, INSR-B, IGF1R and insulin like growth factor 2 (IGFII) was quantified by qRT-PCR in a panel of 11 TNBC cell lines. Proliferation assays were performed on TNBC cell lines treated with the dual IR/INSR inhibitor Linsitinib (OSI-906). Combinations were performed by testing Linsitinib with Xentuzumab (BI-836845), cisplatin, docetaxel, or the PI3K inhibitor Dactolisib (NVP-BEZ235). We also tested the anti-proliferative effect of Linsitinib in combination with Xentuzumab when stimulated with IGF-I and IGF-II following serum-starvation for 24 hours. Finally, Linsitinib was tested in HCC-1143 xenografts to assess the effect of low-dose treatment on tumour formation.
Results
No significant differences were observed between the basal-like and non-basal-like cell lines for IR or IGF1R mRNA expression. However, IGF-II mRNA was more frequently detected in non-basal-like (80%, 4/5) compared to basal-like cell lines (20%, 1/5). Only three of the 12 cell lines tested showed sensitivity to Linsitinib with IC50 values less than 10 µM. The two most sensitive cell lines, HDQ-P1 and HCC1143, expressed detectable levels of IGF1R, INSR-A and INSR-B mRNAs. Although Linsitinib blocked IGF-I and IGF-II stimulated proliferation in both HCC1143 and HDQ-P1 cells, addition of Linsitinib to either chemotherapy or Dactolisib did not enhance therapeutic response. Linisitinib did not reduce tumour formation or tumour growth in an in vivo TNBC cell-line xenograft model.
Conclusions
Although IGF1R has been shown to be frequently expressed in TNBC, our in vitro and in vivo data suggest that it may not be a good therapeutic target in the TNBC subtype.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Boehringer Ingleheim.
Disclosure
N. O’Donovan: Research grant / Funding (institution): Boehringer Ingleheim. J. Crown: Honoraria (self), Speaker Bureau / Expert testimony, Research grant / Funding (institution): Boehringer Ingleheim; Shareholder / Stockholder / Stock options, Full / Part-time employment: OncoMark Limited; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Eisai; Honoraria (self): Amgen; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Puma Biotechnology; Honoraria (self), Advisory / Consultancy: Seattle Genetics; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Advisory / Consultancy: Vertex; Honoraria (self), Speaker Bureau / Expert testimony: Genomic Health; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Honoraria (self), Travel / Accommodation / Expenses: MSD Oncology; Travel / Accommodation / Expenses: AstraZeneca; Travel / Accommodation / Expenses: Abbvie. All other authors have declared no conflicts of interest.
Resources from the same session
5822 - Greek nursing students experience facing death in clinical practice
Presenter: Maria Dimoula
Session: Poster Display session 3
Resources:
Abstract
2866 - HOPEVOL: Hospice care appropriate to the wishes and needs of patients in the palliative terminal phase.
Presenter: Merel van Klinken
Session: Poster Display session 3
Resources:
Abstract
829 - Mindfulness-based stress reduction in early palliative care for advanced cancer patients : an italian single-centre study. MINDEEP
Presenter: Emilia Gianotti
Session: Poster Display session 3
Resources:
Abstract
2702 - Optimising Inpatient Oncology Care
Presenter: Lisa Judge
Session: Poster Display session 3
Resources:
Abstract
1527 - Analysis on the Implementation Results of Family Sickbed for Oncology Patients in Dongshi Township Health Centers from 2015 to 2017
Presenter: Yayu Huang
Session: Poster Display session 3
Resources:
Abstract
2054 - Exploring needs for palliative care and quality of life for oncology patients with advanced disease who undergo radiotherapy
Presenter: Foteini Antonopoulou
Session: Poster Display session 3
Resources:
Abstract
5605 - Cytotoxic contamination in cancer care settings – Risks and safety awareness among cancer nurses
Presenter: Sandra Lundman Vikberg
Session: Poster Display session 3
Resources:
Abstract
5769 - Understanding Chemotherapy - group education sessions prior to commencing chemotherapy
Presenter: Aileen McHale
Session: Poster Display session 3
Resources:
Abstract
2620 - Estimation of HPQ-based absenteeism and presenteeism in cancer patients via ResearchKit
Presenter: Shunsuke Kondo
Session: Poster Display session 3
Resources:
Abstract
4705 - Identifying falls-related variables and risk factors in hospitalised cancer patients
Presenter: Maria Montserrat Martí Dillet
Session: Poster Display session 3
Resources:
Abstract