Apurinic/apyrimidinic endonuclease-1 (APE-1) is overexpressed via the activation of NF-κB-p65 in MCP-1-positive esophageal squamous cell carcinoma tissue
Apurinic/apyrimidinic endonuclease-1 (APE-1), a key enzyme responsible for DNA base excision repair (BER), has been linked to cancer chemoradiosensitivity. The phosphorylation of p65 plays a role in the activation of this pathway. In this study, we investigated APE-1 expression and its interaction w...
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Published in | Journal of Clinical Biochemistry and Nutrition Vol. 52; no. 2; pp. 112 - 119 |
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Main Authors | , , , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Japan
SOCIETY FOR FREE RADICAL RESEARCH JAPAN
01.03.2013
the Society for Free Radical Research Japan |
Subjects | |
Online Access | Get full text |
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Summary: | Apurinic/apyrimidinic endonuclease-1 (APE-1), a key enzyme responsible for DNA base excision repair (BER), has been linked to cancer chemoradiosensitivity. The phosphorylation of p65 plays a role in the activation of this pathway. In this study, we investigated APE-1 expression and its interaction with p65 in esophageal squamous cell carcinoma (ESCC) tissue. The expression of APE-1, p65, p65 nuclear localization sequence (p65-NLS), and monocyte chemoattractant protein-1 (MCP-1) was assessed by immunohistochemical analysis in 67 human ESCC tissue samples. Real-time PCR and western blotting were also performed. p65 siRNA was evaluated to determine the role of p65 in the regulation of APE-1 expression. We found nuclear localization of APE-1 in 89.6% (60/67) of ESCC tissue samples. We also observed the colocalization of p65-NLS and APE-1 in esophageal cancer tissue. In KYSE220 cells, pretreatment of MG-132 significantly abrogated upregulation of p65 and APE-1 levels induced by MCP-1, and treatment with 10 and 20 nM p65 siRNA significantly inhibited APE-1 mRNA expression. siRNA for p65 treatment significantly increased the apoptotic index in 5-FU-treated KYSE220 cells. We conclude that APE-1 is overexpressed and mainly localized in the nuclear compartment of cancer cells, and partly regulated by p65 in the NF-κB pathway in ESCC tissue. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 |
ISSN: | 0912-0009 1880-5086 |
DOI: | 10.3164/jcbn.12-95 |