Send to

Choose Destination
Lung Cancer. 2008 May;60(2):277-84. Epub 2007 Dec 3.

Alteration of APE1/ref-1 expression in non-small cell lung cancer: the implications of impaired extracellular superoxide dismutase and catalase antioxidant systems.

Author information

Department of Physiology, College of Medicine, Chungnum National University, Jung-gu, Daejeon 301-131, Republic of Korea.



Apurinic/apyrimidinic endonuclease1/ref-1(APE1/ref-1) is a key enzyme in the base excision repair and in transcriptional modulation against oxidative stress. We investigated the altered expression of APE1/ref-1 and antioxidant systems in lung cancer.


Tumor specimens from 48 patients with operable non-small cell lung cancer were obtained from 2004 to 2006. Immunohistochemistry, Western blot, lipid peroxidation and superoxide production were performed on the tumor samples and a cultured H460 cell line.


APE1/ref-1 was mainly localized to the nucleus in the non-tumor regions of the lung cancer tissue specimens. However, nuclear and cytoplasmic expressions of APE1/ref-1 in the lung cancers were markedly up-regulated in the non-small cell lung cancer (NSCLC) specimens including squamous cell and adenocarcinoma specimens. Extracellular superoxide dismutase (ECSOD) and catalase were down-regulated and manganese superoxide dismutase (MnSOD) was up-regulated in the tumor regions of the NSCLC. Tumor regions of the NSCLC showed higher superoxide production and lipid peroxidation levels than non-tumor regions. In the lung adenocarcinoma cell line, H460, treatment with hydrogen peroxide in the presence of a catalase inhibitor, aminotriazole, increased APE1/ref-1 expression, suggesting oxidative stress might have contributed to the induction of APE1/ref-1.


The results of this study suggest that APE1/ref-1 is up-regulated in the tumor regions of NSCLC. Altered expression of antioxidant systems lead to enhanced production of superoxide production and lipid peroxidation, which can induce APE1/ref-1 in the tumor regions of NSCLS.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center