International Journal of Molecular Sciences Review The Role of the BH4 Cofactor in Nitric Oxide Synthase Activity and Cancer Progression: Two Sides of the Same Coin Diego Assis Gonçalves 1,2 , Miriam Galvonas Jasiulionis 3 and Fabiana Henriques Machado de Melo 4,5,* 1 Micro-Imuno-Parasitology Department, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil;
[email protected] 2 Department of Parasitology, Microbiology and Immunology, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil 3 Pharmacology Department, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil;
[email protected] 4 Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil 5 Institute of Medical Assistance to Public Servants of the State (IAMSPE), São Paulo 04039-000, Brazil * Correspondence:
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[email protected] Abstract: Cancer development is associated with abnormal proliferation, genetic instability, cell death resistance, metabolic reprogramming, immunity evasion, and metastasis. These alterations are triggered by genetic and epigenetic alterations in genes that control cell homeostasis. Increased reactive oxygen and nitrogen species (ROS, RNS) induced by different enzymes and reactions with distinct molecules contribute to malignant transformation and tumor progression by modifying DNA, proteins, and lipids, altering their activities. Nitric oxide synthase plays a central role in oncogenic signaling modulation and redox landscape. Overexpression of the three NOS isoforms has been Citation: Gonçalves, D.A.; found in innumerous types of cancer contributing to tumor growth and development. Although Jasiulionis, M.G.; Melo, F.H.M.d. The the main function of NOS is the production of nitric oxide (NO), it can be a source of ROS in some Role of the BH4 Cofactor in Nitric pathological conditions.