Abstract 4357
Background
Triple negative breast cancers (TNBC) are enriched with cells bearing stem-like features (CSC), which underlie cancer progression, thus targeting stemness could be an interesting treatment approach. In turn, the epigenetic machinery is crucial for the maintenance of the stemness phenotype. The BET family of epigenetic readers are emerging as novel targets for cancer therapy and have shown preclinical effect in breast cancer. In this work we evaluate the effect of the BET inhibitor (BETi) JQ1 on stemness in TNBC.
Methods
Transcriptomic, functional annotation and qPCR studies were performed on JQ1-exposed TNBC cells. Results were confirmed on spheroids and spheroid-derived tumours. Limiting dilution assays, matrigel invasion experiments, immunofluorescence staining, and flow cytometry studies were also performed to evaluate the effect of JQ1 on CSC features. For the outcome analysis, the online tool Kaplan-Meier Plotter and an integrated response database were used.
Results
JQ1 can modify the expression of stemness-related genes incultured TNBC cells. Among these changes, the CD44/CD24 and ALDH1A1 expression, both classical stemness markers, were diminished by JQ1. Using a validated spheroid model, to mimic the intrinsic characteristics of CSCs, we show that JQ1 decreased surface expression of CD44, inhibited self-renewal and invasion, and induced cells arrest in G0/G1, therefore altering the stemness phenotype in TNBC. Four of the identified stemness genes, GJA1, CD24, EPCAM, and SOX9, were found to be associated with worse patient outcome in TNBC. Furthermore, ABCG2 and RUNX2 predicted low response to chemotherapy in TNBC patients.
Conclusions
In this work we show how BETi modify the stemness landscape in TNBC. Thus, we propose a novel role for JQ1 as a stemness-targeting drug. Loss of the stem cell phenotype via JQ1 treatment could lead to less aggressive and more chemo-sensitive tumours, which would reflect in better patient prognosis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5760 - Landscape of PD-L1 expression status in Chinese solid tumor patients.
Presenter: Yi Zhong
Session: Poster Display session 3
Resources:
Abstract
3733 - Anti-cancer and immunomodulatory effects of cobimetinib in triple negative breast cancer
Presenter: Chun-Yu Liu
Session: Poster Display session 3
Resources:
Abstract
4426 - Differential expression of immunoregulatory molecules and highly-associated cancer genes may provide novel insights into strategic trial design for therapeutics
Presenter: Jacob Adashek
Session: Poster Display session 3
Resources:
Abstract
2752 - Insights into the Tumor Immune Microenvironment using Tissue Phenomics to Drive Cancer Immunotherapy
Presenter: Martin Groher
Session: Poster Display session 3
Resources:
Abstract
5713 - Immune competent somatic mosaic model of colorectal cancer
Presenter: Stefania Napolitano
Session: Poster Display session 3
Resources:
Abstract
1898 - Genomic correlates of response to anti-PDL1 Atezolizumab in non-small-cell lung cancer OAK and POPLAR trials
Presenter: Hari Singhal
Session: Poster Display session 3
Resources:
Abstract
3246 - Erdafitinib (erda) versus available therapies in advanced urothelial cancer: A matching adjusted indirect comparison
Presenter: Yohann Loriot
Session: Poster Display session 3
Resources:
Abstract
3311 - High level of activity of Nivolumab anti-PD-1 immunotherapy and favorable outcome in metastatic/refractory MSI-H non-colorectal cancer: Results of the MSI cohort from the French AcSé program
Presenter: Christophe Tournigand
Session: Poster Display session 3
Resources:
Abstract
2314 - TP53 and ATM Co-mutation Predicts Response to Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer
Presenter: Yu Chen
Session: Poster Display session 3
Resources:
Abstract
4692 - Immune cell biomarkers on neo-adjuvant chemo-immunotherapy treatment for resectable stage IIIA NSCLC patients
Presenter: Raquel Laza-Briviesca
Session: Poster Display session 3
Resources:
Abstract