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
1735 - mTOR inhibition in the treatment of resistant breast cancer
Presenter: María Rodriguez
Session: Poster Display session 1
Resources:
Abstract
6068 - Study of Photodynamic therapy in vitro
Presenter: Irene Jiménez Munguía
Session: Poster Display session 1
Resources:
Abstract
3011 - The potential of neratinib plus dasatinib in overcoming and preventing neratinib resistance in HER2-positive breast cancer models
Presenter: Neil Conlon
Session: Poster Display session 1
Resources:
Abstract
2644 - Novel HDACi, MHY446, induces apoptosis via regulation of mitochondria-endoplasmic reticulum interaction in HCT116 human colorectal cancer cells
Presenter: Nam Deuk Kim
Session: Poster Display session 1
Resources:
Abstract
3085 - Dual inhibition of TGF-β and AXL as a novel treatment for colorectal cancer
Presenter: Davide Ciardiello
Session: Poster Display session 1
Resources:
Abstract
1314 - PARP inhibition enhances cisplatin sensitivity in cervical cancer by modulating β-catenin signaling
Presenter: Minakshi Mann
Session: Poster Display session 1
Resources:
Abstract
2417 - Synergistic effect of DSF combined treatment with cisplatin in atypical teratoid/rhabdoid tumors (AT/RT)
Presenter: Seung Ah Choi
Session: Poster Display session 1
Resources:
Abstract
1149 - Reactive oxygen species induced by OSU-A9 inhibit the growth of duodenal cancer and gastric cancer cells through dephosphorylating intranuclear pyruvate kinase muscle isozyme M2
Presenter: Li-Yuan Bai
Session: Poster Display session 1
Resources:
Abstract
1862 - New therapy for intrahepatic cholangiocarcinoma targeted to cancer associated fibroblasts
Presenter: Takahiro Yamanaka
Session: Poster Display session 1
Resources:
Abstract
782 - Macrophage-cancer cell fusion is mediated by Phosphatidylserine-CD36 receptor interaction and induced by ionizing radiation
Presenter: Ivan Shabo
Session: Poster Display session 1
Resources:
Abstract