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
2171 - CCND1 Amplification Contributes to Immunosuppression in Head and Neck Squamous Cell Carcinoma and the Association with a Poor Response to Immune Checkpoint Inhibitors
Presenter: Chloe Huang
Session: Poster Display session 3
Resources:
Abstract
2624 - Efficacy of PD-1/PD-L1 inhibitors in the treatment of non-small cell lung cancer patients with sensitive genes mutation
Presenter: Hui-Juan Cui
Session: Poster Display session 3
Resources:
Abstract
3494 - Neutrophil to Lymphocyte Ratio (NLR) kinetics as predictors of outcomes in metastatic renal cell carcinoma (mRCC) and non-small cell lung cancer (NSCLC) patients treated with nivolumab (N).
Presenter: Audrey Simonaggio
Session: Poster Display session 3
Resources:
Abstract
3964 - Predictive markers of checkpoint inhibitor activity in adult metastatic solid tumours
Presenter: Alexandra Pender
Session: Poster Display session 3
Resources:
Abstract
3041 - Blood-based TMB (bTMB) correlates with tissue-based TMB (tTMB) in a multi-cancer Phase I IO Cohort
Presenter: Daniel Araujo
Session: Poster Display session 3
Resources:
Abstract
3910 - Analysis of Molecular Profile Complexities for Immunotherapy Decision Support
Presenter: Robert Dóczi
Session: Poster Display session 3
Resources:
Abstract
4836 - The Role of Tumor Neoantigens in the Differential Response to Immunotherapy (IO) in EGFR and BRAF Mutated Lung Cancers - Quantity or Quality?
Presenter: Katrina Case
Session: Poster Display session 3
Resources:
Abstract
1929 - Impact of previous corticosteroid (CS) exposure on efficacy of Programmed Cell Death-(Ligand) 1 blockade in patients with advanced Non-Small-Cell Lung Cancer (NSCLC): a single Center retrospective analysis
Presenter: Fabrizio Nelli
Session: Poster Display session 3
Resources:
Abstract
2601 - Comparison 18F-FDG-PET/CT criteria for prediction of therapy response and clinical outcome in patients with metastatic melanoma treated with Ipilimumab and PD-1 inhibitors
Presenter: Sabrina Vari
Session: Poster Display session 3
Resources:
Abstract
3628 - Predictive model for survival in advanced non-small-cell lung cancer (NSCLC) treated with frontline pembrolizumab
Presenter: Xabier Mielgo Rubio
Session: Poster Display session 3
Resources:
Abstract