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Role of Rac1 in regulation of NOX5-S function in Barrett's esophageal adenocarcinoma cells

Role of Rac1 in regulation of NOX5-S function in Barrett's esophageal adenocarcinoma cells Abstract We have shown that a novel NADPH oxidase isoform, NOX5-S, is the major isoform of NADPH oxidases in an esophageal adenocarcinoma (EA) cell line, FLO, and is overexpressed in Barrett's mucosa with high-grade dysplasia. NOX5-S is responsible for acid-induced reactive oxygen species production. In this study, we found that mRNA levels of NOX5-S were significantly higher in FLO EA cells than in the normal human esophageal squamous cell line HET-1A or in a Barrett cell line, BAR-T. The mRNA levels of NOX5-S were also significantly increased in EA tissues. The data suggest that NOX5-S may be important in the development of EA. Mechanisms of functional regulation of NOX5-S are not fully understood. We show that small G protein Rac1 was present in HET-1A cells, BAR-T cells, and EA cell lines FLO and OE33. Rac1 protein levels were significantly higher in FLO and OE33 cells than in HET-1A or BAR-T cells. Knockdown of Rac1 with Rac1 small interfering RNA significantly decreased acid-induced increase in H 2 O 2 production in FLO EA cells. Overexpression of constitutively active Rac1 significantly increased H 2 O 2 production, an increase that was blocked by knockdown of NOX5-S. By immunofluorescence staining and immunoprecipitation, we found that NOX5-S was present in the cytosol of FLO EA cells and colocalized with Rac1 and SERCA1/2 Ca 2+ -ATPase which is located in the endoplasmic reticulum membrane. We conclude that Rac1 may be important in activation of NOX5-S in FLO EA cells. Barrett's esophagus SERCA1/2 Ca 2+ -ATPase Copyright © 2011 the American Physiological Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png AJP - Cell Physiology The American Physiological Society

Role of Rac1 in regulation of NOX5-S function in Barrett's esophageal adenocarcinoma cells

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References (49)

Publisher
The American Physiological Society
Copyright
Copyright © 2011 the American Physiological Society
ISSN
0363-6143
eISSN
1522-1563
DOI
10.1152/ajpcell.00027.2011
pmid
21525435
Publisher site
See Article on Publisher Site

Abstract

Abstract We have shown that a novel NADPH oxidase isoform, NOX5-S, is the major isoform of NADPH oxidases in an esophageal adenocarcinoma (EA) cell line, FLO, and is overexpressed in Barrett's mucosa with high-grade dysplasia. NOX5-S is responsible for acid-induced reactive oxygen species production. In this study, we found that mRNA levels of NOX5-S were significantly higher in FLO EA cells than in the normal human esophageal squamous cell line HET-1A or in a Barrett cell line, BAR-T. The mRNA levels of NOX5-S were also significantly increased in EA tissues. The data suggest that NOX5-S may be important in the development of EA. Mechanisms of functional regulation of NOX5-S are not fully understood. We show that small G protein Rac1 was present in HET-1A cells, BAR-T cells, and EA cell lines FLO and OE33. Rac1 protein levels were significantly higher in FLO and OE33 cells than in HET-1A or BAR-T cells. Knockdown of Rac1 with Rac1 small interfering RNA significantly decreased acid-induced increase in H 2 O 2 production in FLO EA cells. Overexpression of constitutively active Rac1 significantly increased H 2 O 2 production, an increase that was blocked by knockdown of NOX5-S. By immunofluorescence staining and immunoprecipitation, we found that NOX5-S was present in the cytosol of FLO EA cells and colocalized with Rac1 and SERCA1/2 Ca 2+ -ATPase which is located in the endoplasmic reticulum membrane. We conclude that Rac1 may be important in activation of NOX5-S in FLO EA cells. Barrett's esophagus SERCA1/2 Ca 2+ -ATPase Copyright © 2011 the American Physiological Society

Journal

AJP - Cell Physiology – The American Physiological Society

Published: Aug 1, 2011

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