Dual oxidase 2 and pancreatic adenocarcinoma: IFN-γ-mediated dual oxidase 2 overexpression results in H2O2-induced, ERK-associated up-regulation of HIF-1α and VEGF-A

Abstract

Several NADPH oxidase family members, including dual oxidase 2 [DUOX2], are expressed in human tumors, particularly gastrointestinal cancers associated with long-standing chronic inflammation. We found previously that exposure of pancreatic ductal adenocarcinoma cells to the pro-inflammatory cytokine IFN-γ increased DUOX2 expression (but not other NADPH oxidases) leading to long-lived H2O2 production. To elucidate the pathophysiology of DUOX2-mediated H2O2 formation in the pancreas further, we demonstrate here that IFN-γ-treated BxPC-3 and CFPAC-1 pancreatic cancer cells (known to increase DUOX2 expression) produce significant levels of intracellular oxidants and extracellular H2O2 which correlate with concomitant up-regulation of VEGF-A and HIF-1α transcription. These changes are not observed in the PANC-1 line that does not increase DUOX2 expression following IFN-γ treatment. DUOX2 knockdown with short interfering RNA significantly decreased IFN-γ-induced VEGF-A or HIF-1α up-regulation, as did treatment of pancreatic cancer cells with the NADPH oxidase inhibitor diphenylene iodonium, the multifunctional reduced thiol N-acetylcysteine, and the polyethylene glycol-modified form of the hydrogen peroxide detoxifying enzyme catalase. Increased DUOX2-related VEGF-A expression appears to result from reactive oxygen-mediated activation of ERK signaling that is responsible for AP-1-related transcriptional effects on the VEGF-A promoter. To clarify the relevance of these observations in vivo, we demonstrate that many human pre-malignant pancreatic intraepithelial neoplasms and frank pancreatic cancers express substantial levels of DUOX protein compared to histologically normal pancreatic tissues, and that expression of both DUOX2 and VEGF-A mRNAs is significantly increased in surgically-resected pancreatic cancers compared to the adjacent normal pancreas.

Manganese‐ and 1‐methyl‐4‐phenylpyridinium‐induced neurotoxicity display differences in morphological, electrophysiological and genome‐wide alterations: implications for idiopathic Parkinson's disease

“…; Wu et al . ), was elevated by 2‐ and 2.1‐fold in Mn and MPP + models respectively. Western blot indicated ~ 2‐ and ~ 5‐fold higher VEGF expression in the Mn and MPP + model respectively (data not shown).…”

Paradoxical roles of dual oxidases in cancer biology

“…These mucosal surface cell types typically express high levels of unique NOX isoforms, the dual oxidases DUOX1 and/or DUOX2. Analogous to other NOXes, several studies have highlighted that DUOX2 mRNA and protein is often overexpressed in colorectal cancers[105, 106], pancreatic adenocarcinoma [107, 108], Barrett esophagus [105], and gastric cancers[105]. Using a newly developed monoclonal antibody against DUOX2, increased immunohistochemical staining was observed in various tumor types, including prostate, lung, breast, and colon [109].…”

High Immunoreactivity of DUOX2 Is Associated With Poor Response to Preoperative Chemoradiation Therapy and Worse Prognosis in Rectal Cancers

“…Thus, the name of dual oxidase is due to containing both NADPH-oxidase (gp91 phox ) domain and peroxidase homology domain. The impact of dual oxidase 2 in carcinogenesis is recently investigated, including colon cancer 13 - 18 . Nevertheless, no relationship between DUOX2 expression and clinical outcome is reported in patients with rectal cancer.…”