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
4526 - Long-term outcome of neoadjuvant tyrosine kinase inhibitors (TKI) in locally advanced dermatofibrosarcoma protuberans (DFSP)
Presenter: Jessica Beaziz
Session: Poster Display session 1
Resources:
Abstract
1214 - Neo-adjuvant (NA) Imatinib for gastrointestinal stromal tumours (GISTs): What is the optimal length of treatment?
Presenter: Tom Wilson
Session: Poster Display session 1
Resources:
Abstract
2690 - Gastrointestinal Stromal Tumours (GIST) in adolescents and young adults (AYA)
Presenter: Nikki Ijzerman
Session: Poster Display session 1
Resources:
Abstract
4558 - Radiomics improves response evaluation for desmoid tumors treated with chemotherapy
Presenter: Amandine Crombe
Session: Poster Display session 1
Resources:
Abstract
2751 - Radiomics of gastrointestinal stromal tumors; risk classification based on computed tomography images – a pilot study
Presenter: Milea Timbergen
Session: Poster Display session 1
Resources:
Abstract
2737 - Differentiating well-differentiated liposarcomas from lipomas using a radiomics approach
Presenter: Melissa Vos
Session: Poster Display session 1
Resources:
Abstract
1282 - The immune landscape of chondrosarcoma reveals an anti inflammatory environment
Presenter: Iseulys Richert
Session: Poster Display session 1
Resources:
Abstract
1572 - Impact of Immunotherapy and Targeted Therapy on Tumor Growth Rate in Sarcoma
Presenter: Esmail Al-ezzi
Session: Poster Display session 1
Resources:
Abstract
3414 - DNA methylation profiles of angiosarcoma subtypes.
Presenter: Marije Weidema
Session: Poster Display session 1
Resources:
Abstract
3411 - Prognostic significance of circulating PD-1, PD-L1, pan-BTN3As and BTN3A1 in patients with metastatic gastrointestinal stromal tumors (mGISTs)
Presenter: Daniele Fanale
Session: Poster Display session 1
Resources:
Abstract