Abstract 5488
Background
In the course of tumor growth, the cells that are far from the blood vessel are exposed to hypoxic conditions. As part of this process transcription factors (TFs) of the Snail family (Snail, Slug, Twist1, and Zeb1) are activated launching the epithelial-mesenchymal transition (EMT) program. Snail family factors are the most studied as stimulators of EMT, promoting tumor progression, migration and invasion of tumor cells. The aim of our research is to study adaptive mechanisms of human breast cancer (BC) cells to hypoxia and the analysis of the role of the TF Snail in this process.
Methods
We used human BC cells MCF-7, MDA-MB-231 and HBL-100 which were cultured in standard DMEM containing 10% fetal calf serum at 37oC and 5% СО2. For hypoxia modeling, the cells were cultured in a CO2-incubator maintaining O2 concentration at 1%.
Results
Knockdown of the Snail by small interfering RNA (siRNA) leads to increased sensitivity of breast cancer cells to hypoxia, due to increased blocking of cells in the S-phase of cell cycle. Cells were more resistant to hypoxia at a lower density, where Snail expression was increased, but further hyperexpression of Snail had not lead to increased resistance to hypoxia. Knockdown of Snail leads to an compensatory increase of Slug`s expression, while the knockdown of Twist1 and Zeb1 leads to decreased Slug expression. Knockdown of Twist1 decreases cell proliferation both in hypoxia and normoxia, through activation of cell cycle inhibitor p21WAF1, specifically in the G2/M phase, in p53-wild type HBL-100 cells. We used a chemical inhibitor of p53-Snail interaction GN25, to examine if blocking of this interaction could lead to increased sensitivity in hypoxia. We have shown that this compound has a greater cytotoxic effect in normoxia than hypoxia, due to increased Snail activity.
Conclusions
Modulation of Snail-associated signaling pathways is a perspective target for increase of cancer cell tolerance to chronic hypoxia, and inhibition of metastatic process in breast cancer cells.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Grant no. 14.W03.31.0020 between the Ministry of Science and Education of the Russian Federation and Institute of Gene Biology, Russian Academy of Sciences.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2066 - Second-line (2L) real-world treatment (tx) patterns and outcomes in patients (pts) with advanced/metastatic non-small cell lung cancer (NSCLC) treated with first line (1L) immuno-oncology (IO) monotherapy (mono tx)
Presenter: Denis Talbot
Session: Poster Display session 1
Resources:
Abstract
5919 - Real-world effectiveness of nivolumab monotherapy after prior systemic therapy in advanced non-small cell lung cancer (NSCLC) in the United States
Presenter: David Stenehjem
Session: Poster Display session 1
Resources:
Abstract
3368 - Pembrolizumab as first-line treatment in NSCLC with PD-L1 ≥50%: Real life results from an all-comer population
Presenter: Nikolaj Frost
Session: Poster Display session 1
Resources:
Abstract
3775 - Patients with metastatic non-small cell lung cancer without molecular alterations or PD-L1 expression in Germany. Treatment and first outcome from the prospective German Registry Platform CRISP (AIO-TRK-0315)
Presenter: Frank Griesinger
Session: Poster Display session 1
Resources:
Abstract
3926 - Impact of second-line (2L) immune checkpoint inhibitors (ICIs) on the treatment (Tx) of advanced non-small cell lung cancer (NSCLC) in a UK centre: a REAL-Oncology analysis from the I-O Optimise initiative
Presenter: Michael Snee
Session: Poster Display session 1
Resources:
Abstract
5068 - First line pembrolizumab for NSCLC with PD-L1 TPS > 50% in a first French real life cohort
Presenter: Karim Amrane
Session: Poster Display session 1
Resources:
Abstract
1182 - Interstitial lung disease induced by immune-checkpoint inhibitors correlates with prognosis of advanced non-small-cell lung cancer patients
Presenter: Teppei Sugano
Session: Poster Display session 1
Resources:
Abstract
2297 - Phase II study to evaluate the peripheral blood mononuclear cell biomarker for nivolumab efficacy on previously treated non-small cell lung cancer subjects (NEJ029B: IMMUNITY-ONE)
Presenter: Yosuke Kawashima
Session: Poster Display session 1
Resources:
Abstract
2739 - Efficacy and safety of nintedanib + docetaxel in lung adenocarcinoma patients (pts) following treatment with immune checkpoint inhibitors (ICIs): Updated results of the ongoing non-interventional study (NIS) VARGADO (NCT02392455)
Presenter: Christian Grohe
Session: Poster Display session 1
Resources:
Abstract
1357 - Upfront atezolizumab chemoimmunotherapy-associated Immune-related adverse events in patients with advanced non-small cell lung cancer
Presenter: Francis Mogollon-Duffo
Session: Poster Display session 1
Resources:
Abstract