Role of STAT3 Phosphorylation in Ethanol-Mediated Proliferation of Breast Cancer Cells.
10.4048/jbc.2016.19.2.122
- Author:
Poornima Devi NARAYANAN
1
;
Sangeetha Kadapakkam NANDABALAN
;
Lakshmi Subhadra BADDIREDDI
Author Information
1. Department of Biotechnology, Anna University, Chennai, India. lakshmibs@annauniv.edu
- Publication Type:Original Article
- Keywords:
Breast neoplasms;
Cell proliferation;
Ethanol;
Inflammation
- MeSH:
Breast Neoplasms*;
Breast*;
Cell Proliferation;
Cyclins;
Cytokines;
Ethanol;
Flow Cytometry;
Gene Silencing;
Inflammation;
Interleukin-6;
Janus Kinase 2;
Matrix Metalloproteinases;
Phosphorylation*;
Polymerase Chain Reaction;
Reactive Oxygen Species;
Real-Time Polymerase Chain Reaction;
Reverse Transcription;
STAT3 Transcription Factor;
Tumor Necrosis Factor-alpha
- From:Journal of Breast Cancer
2016;19(2):122-132
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: In this study, we investigated the molecular mechanism involved in ethanol (EtOH)-mediated proliferation of breast cancer cells. METHODS: EtOH concentration was optimized by studying its effect on cell proliferation in MCF-7 and MDA MB-231 cells. We used flow cytometry and immunoblot analysis to evaluate the increased proliferation caused by the optimized concentrations of EtOH. The mechanism of EtOH-mediated proliferation was determined using reactive oxygen species (ROS) release assay, reverse transcription polymerase chain reaction, and immunoblot studies. Gene silencing followed by quantitative real-time polymerase chain reaction studies and inhibitor studies indicated the involvement of signal transducer and activator of transcription 3 (STAT3) in EtOH-mediated breast cancer proliferation. RESULTS: Exposure to EtOH caused an increase in cell proliferation and an accumulation of cells in S-phase in MCF-7 (347 µM EtOH) and MDA MB-231 (173 µM EtOH) cells. Additionally, increased release of ROS and the expression of pro-inflammatory cytokines, such as interleukin 6 and tumor necrosis factor α, confirmed that the proliferation was induced by the ROS-linked inflammatory response in breast cancer. The proinflammatory response was followed by phosphorylation of STAT3. The importance of STAT3 activation in EtOH-mediated proliferation was confirmed through the silencing of STAT3, followed by an investigation on the expression of cyclins and matrix metalloproteinases. Finally, studies using specific inhibitors indicated that the EtOH-mediated effect on STAT3 activation could be regulated by phosphoinositide-3-kinase and Janus kinase 2. CONCLUSION: The study demonstrates the involvement of STAT3 signaling in EtOH-mediated breast cancer proliferation.
