cells Review Mitochondrial Calcium Regulation of Redox Signaling in Cancer 1, 2, 3 2 Céline Delierneux y , Sana Kouba y, Santhanam Shanmughapriya , Marie Potier-Cartereau , Mohamed Trebak 1 and Nadine Hempel 1,4,* 1 Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA;
[email protected] (C.D.);
[email protected] (M.T.) 2 Inserm U1069 Nutrition, Croissance et Cancer, Université de Tours, 10 Boulevard Tonnellé, 37032 Tours, France;
[email protected] (S.K.);
[email protected] (M.P.-C.) 3 Department of Medicine, The Pennsylvania State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA;
[email protected] 4 Department of Pharmacology, and Obstetrics and Gynecology, The Pennsylvania State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA * Correspondence:
[email protected]; Tel.: +717-531-4037 These authors contributed equally to this work. y Received: 8 January 2020; Accepted: 10 February 2020; Published: 12 February 2020 Abstract: Calcium (Ca2+) uptake into the mitochondria shapes cellular Ca2+ signals and acts as a key effector for ATP generation. In addition, mitochondria-derived reactive oxygen species (mROS), produced as a consequence of ATP synthesis at the electron transport chain (ETC), modulate cellular signaling pathways that contribute to many cellular processes. Cancer cells modulate mitochondrial Ca2+ ([Ca2+]m) homeostasis by altering the expression and function of mitochondrial Ca2+ channels and transporters required for the uptake and extrusion of mitochondrial Ca2+. Regulated elevations in [Ca2+]m are required for the activity of several mitochondrial enzymes, and this in turn regulates metabolic flux, mitochondrial ETC function and mROS generation.