Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 28, 2016; 22(20): 4868-4880
Published online May 28, 2016. doi: 10.3748/wjg.v22.i20.4868
Wortmannin influences hypoxia-inducible factor-1 alpha expression and glycolysis in esophageal carcinoma cells
Ling Zeng, Hai-Yun Zhou, Na-Na Tang, Wei-Feng Zhang, Gui-Jun He, Bo Hao, Ya-Dong Feng, Hong Zhu
Ling Zeng, Hai-Yun Zhou, Na-Na Tang, Wei-Feng Zhang, Gui-Jun He, Bo Hao, Ya-Dong Feng, Hong Zhu, Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
Author contributions: Zhu H designed the research; Tang NN, Zhang WF and He GJ performed the research; Hao B, Feng YD and Zhu H analyzed the data; Zeng L and Zhou HY wrote the paper.
Supported by the National Natural Science Foundation of China, No. 30800511.
Institutional review board statement: The study was reviewed and approved by The First Affiliated Hospital of Nanjing Medical University Institutional Review Board.
Conflict-of-interest statement: To the best of our knowledge, no conflict of interest exists.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at zhuhong1059@126.com. Participants gave informed consent for data sharing. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hong Zhu, MD, PhD, Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guang Zhou Road, Gulou District, Nanjing 210029, Jiangsu Province, China. zhuhong1059@126.com
Telephone: +86-25-86862684 Fax: +86-25-86862684
Received: October 10, 2015
Peer-review started: October 12, 2015
First decision: March 7, 2016
Revised: March 20, 2016
Accepted: April 15, 2016
Article in press: April 15, 2016
Published online: May 28, 2016
Processing time: 221 Days and 22.8 Hours
Abstract

AIM: To investigate the influence of phosphatidylinositol-3-kinase protein kinase B (PI3K/AKT)-HIF-1α signaling pathway on glycolysis in esophageal carcinoma cells under hypoxia.

METHODS: Esophageal carcinoma cell lines Eca109 and TE13 were cultured under hypoxia environment, and the protein, mRNA and activity levels of hypoxia inducible factor-1 alpha (HIF-1α), glucose transporter 1, hexokinase-II, phosphofructokinase 2 and lactate dehydrogenase-A were determined. Supernatant lactic acid concentrations were also detected. The PI3K/AKT signaling pathway was then inhibited with wortmannin, and the effects of hypoxia on the expression or activities of HIF-1α, associated glycolytic enzymes and lactic acid concentrations were observed. Esophageal carcinoma cells were then transfected with interference plasmid with HIF-1α-targeting siRNA to assess impact of the high expression of HIF-1α on glycolysis.

RESULTS: HIF-1α is highly expressed in the esophageal carcinoma cell lines tested, and with decreasing levels of oxygen, the expression of HIF-1α and the associated glycolytic enzymes and the extracellular lactic acid concentration were enhanced in the esophageal carcinoma cell lines Eca109 and TE13. In both normoxia and hypoxic conditions, the level of glycolytic enzymes and the secretion of lactic acid were both reduced by wortmannin. The expression and activities of glycolytic enzymes and the lactic acid concentration in cells were reduced by inhibiting HIF-1α, especially the decreasing level of glycolysis was significant under hypoxic conditions.

CONCLUSION: The PI3K/AKT pathway and HIF-1α are both involved in the process of glycolysis in esophageal cancer cells.

Keywords: Hypoxia-inducible factor-1 alpha; Hypoxia; Glycolysis; Esophageal neoplasms; Cell metabolism

Core tip: Fluorescence analysis, spectrophotometry, real-time PCR, Western blot and siRNA interference technology were used to investigate the influence of phosphatidylinositol-3-kinase protein kinase B-HIF-1α signaling pathway on glycolysis under hypoxia in esophageal carcinoma cells. The results obtained provide experimental evidence for the mechanism of glycolysis enhanced by hypoxia.