Abstract 5208
Background
Growth hormone (GH) signalling is initiated by binding of GH to the GH receptor (GHR) and activation of Janus kinase 2, which in turn, promotes phosphorylation of STAT5, PI3K/AKT and MAPK. High levels of GHR expression have been reported in melanoma. This project aims to characterise GH signalling in primary melanoma cell lines and identify cell lines which respond to GH and GHR inhibition, with a view to testing in preclinical xenograft studies.
Methods
Over 24 cell lines established at the Auckland Cancer Society Research Centre (ACSRC) in New Zealand were tested for response to GH, prolactin (PRL) and a GHR antagonist, by assessing STAT5 phosphorylation by western blot. mRNA expression was assessed by Nanostring PlexSet. Endogenous protein was assessed by ELISA.
Results
From the panel of melanoma cell lines, 62% responded to GH stimulation and GHR inhibition. mRNA expression analysis demonstrated that the IGF1 receptor and GHR were highly expressed across cell lines. Most of the cell lines expressing GHR mRNA responded to GH. GH1 mRNA was expressed at very low levels in a subset of cell lines, and ELISA analysis confirmed the presence of endogenous GH protein. siRNA-mediated knockdown of the GHR reduced GHR mRNA expression and STAT5 phosphorylation by GH. GH increased cell viability in a subset of melanoma cell lines. A vemurafenib-resistant melanoma cell line and B16/F10 mouse cell line were also sensitive to GH and GHR inhibition. Exon analysis will be performed for GH and related genes.
Conclusions
In this study, we have demonstrated GH stimulates signal transduction and promotes enhance of viability of primary melanoma cell lines, and that GHR blockade prevents this effect, indicating that blocking GHR signalling might be a useful strategy to treat melanoma. The next step is to understand whether GHR inhibition plays a role in regulating tumour growth in vivo.
Clinical trial identification
Editorial acknowledgement
Li Family PhD Scholarship.
Legal entity responsible for the study
Peter Shepherd.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2304 - Synthetic peptide of tumor–associated antigen L6 formulated with polymer-based adjuvant enhances anti-tumor effects in mice
Presenter: Shih-jen Liu
Session: Poster Display session 1
Resources:
Abstract
4419 - Improving detection level of somatic mosaicism in neurofibromatosis type 1
Presenter: Kristina Karandasheva
Session: Poster Display session 1
Resources:
Abstract
5283 - Preclinical pharmacokinetic/pharmacodynamic (PK/PD) relationship of ABN401, a highly selective Met inhibitor, in gastric and non-small-cell lung cancer models
Presenter: JooSeok Kim
Session: Poster Display session 1
Resources:
Abstract
5488 - Transcription factors of Snail family in the regulation of resistance of breast cancer cells to hypoxic conditions
Presenter: Alvina Khamidullina
Session: Poster Display session 1
Resources:
Abstract
5417 - Metastasis is impaired by endothelial-specific Dll4 loss-of-function through inhibition of epithelial-to-mesenchymal transition and reduction of cancer stem cells and circulating tumour cells
Presenter: Liliana Mendonça
Session: Poster Display session 1
Resources:
Abstract
5494 - Identification of novel and known FGFR gene fusions in Chinese non-small cell lung cancer
Presenter: Weixin Zhao
Session: Poster Display session 1
Resources:
Abstract
3412 - WNT pathway mutations (APC/CTNNB1) and immune checkpoint inhibitors (ICI) response in metastatic non-small cell lung cancer (NSCLC) patients.
Presenter: Francisco Javier Ros Montana
Session: Poster Display session 1
Resources:
Abstract
1815 - Leukocytosis as a negative prognostic factor in patients with lung cancer: Which subpopulation of leukocytes is responsible?
Presenter: Filip Kohutek
Session: Poster Display session 1
Resources:
Abstract
5022 - Identification of MET gene amplifications using next-generation sequencing in non-small cell lung cancer patients
Presenter: Sergi Clavé
Session: Poster Display session 1
Resources:
Abstract
4925 - Prognostic role of CD73 in metastatic Non Small Cell Lung Cancer according to the presence of driver alterations
Presenter: Giulia Galli
Session: Poster Display session 1
Resources:
Abstract