The NADPH oxidases NOX4 and DUOX2 regulate cell cycle entry via a p53-dependent pathway

• Published in: Oncogene Vol. 29; no. 31; pp. 4473 - 4484
• Main Authors: Salmeen, A, Park, B O, Meyer, T
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.08.2010; Nature Publishing Group
• Subjects: 631/136/2091; 631/45/607/1168; 631/45/612/1244; 631/80/86; Apoptosis; Biological and medical sciences; Cancer; Cell Biology; Cell cycle; Cell Cycle - drug effects; Cell Cycle - genetics; Cell cycle, cell proliferation; Cell growth; Cell physiology; Cell proliferation; Cell Proliferation - drug effects; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cells, Cultured; Cip protein; Cyclin D1; Cyclin-dependent kinase inhibitor p21; Dual Oxidases; Enzymes; Fibroblasts; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Knockdown Techniques; Genetic aspects; Genetic screening; Growth factors; GTP-binding protein; Human Genetics; Humans; Internal Medicine; Medicine; Medicine & Public Health; Mitogen-Activated Protein Kinase 3 - metabolism; Models, Biological; Molecular and cellular biology; NAD(P)H oxidase; NADPH Oxidase 4; NADPH Oxidases - antagonists & inhibitors; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; NADPH Oxidases - physiology; NOX4 protein; Oncology; original-article; Oxidases; p53 Protein; Phosphorylation; Phosphorylation - drug effects; Physiological aspects; Platelet-derived growth factor; Platelet-Derived Growth Factor - pharmacology; Proteins; Reactive oxygen species; Retina; Retinoblastoma; Retinoblastoma protein; Retinoblastoma Protein - metabolism; RNA, Small Interfering - pharmacology; Signal transduction; Signal Transduction - drug effects; Signal Transduction - genetics; Signal Transduction - physiology; siRNA; Transcription; Tumor suppressor genes; Tumor Suppressor Protein p53 - physiology; Tumors; Validation Studies as Topic; United States; NOX4; redox signaling; NADPH oxidases; DUOX2; p53; NADPH; Enzyme; Oxidase; Carcinogenesis; Regulation(control); TP53 Gene; Cell cycle; Oxidoreductases; Tumor suppressor gene
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/onc.2010.200

Reactive oxygen species (ROS) are produced in growth factor-signaling pathways leading to cell proliferation, but the mechanisms leading to ROS generation and the targets of ROS signals are not well understood. Using a focused siRNA screen to identify redox-related proteins required for growth factor-induced cell cycle entry, we show that two ROS-generating proteins, the NADPH oxidases NOX4 and DUOX2, are required for platelet-derived growth factor (PDGF) induced retinoblastoma protein (Rb) phosphorylation in normal human fibroblasts. Unexpectedly, NOX4 and DUOX2 knockdown did not inhibit the early signaling pathways leading to cyclin D1 upregulation. However, hours after growth factor stimulation, NOX4 and DUOX2 knockdown reduced ERK1 phosphorylation and increased levels of the tumor suppressor protein p53 and a cell cycle inhibitor protein p21 (Waf1/Cip1) that is transcriptionally regulated by p53. Co-knockdown of NOX4 or DUOX2 with either p53 or with p21 overcame the inhibition of Rb phosphorylation that occurred with NOX4 or DUOX2 knockdown alone. Our results argue that rather than primarily affecting growth factor receptor signaling, NOX4 and DUOX2 regulate cell cycle entry as part of a p53-dependent checkpoint for proliferation.