title: Endoplasmic reticulum calcium pumps and cancer cell differentiation.
abstract: The endoplasmic reticulum (ER) is a major intracellular calcium storage pool and a multifunctional organelle that accomplishes several calcium-dependent functions involved in many homeostatic and signaling mechanisms. Calcium is accumulated in the ER by Sarco/Endoplasmic Reticulum Calcium ATPase (SERCA)-type calcium pumps. SERCA activity can determine ER calcium content available for intra-ER functions and for calcium release into the cytosol, and can shape the spatiotemporal characteristics of calcium signals. SERCA function therefore constitutes an important nodal point in the regulation of cellular calcium homeostasis and signaling, and can exert important effects on cell growth, differentiation and survival. In several cell types such as cells of hematopoietic origin, mammary, gastric and colonic epithelium, SERCA2 and SERCA3-type calcium pumps are simultaneously expressed, and SERCA3 expression levels undergo significant changes during cell differentiation, activation or immortalization. In addition, SERCA3 expression is decreased or lost in several tumor types when compared to the corresponding normal tissue. These observations indicate that ER calcium homeostasis is remodeled during cell differentiation, and may present defects due to decreased SERCA3 expression in tumors. Modulation of the state of differentiation of the ER reflected by SERCA3 expression constitutes an interesting new aspect of cell differentiation and tumor biology.
authors: Institut National de la Santé et de la Recherche Médicale, Inserm UMR U978, UFR SMBH Université Paris 13-Paris Nord, 74, rue Marcel Cachin 93000 Bobigny, France. belapapp2@yahoo.fr.
authors: Béla
authors: B
authors: Papp
authors: Service d'Anatomie et Cytologie Pathologique, Hôpital Lariboisière, 1, rue Ambroise Paré, 75010 Paris, France. jean-philippe.brouland@lrb.aphp.fr.
authors: Jean-Philippe
authors: JP
authors: Brouland
authors: Inserm UMR U 940, IUH Université Paris 7-Paris Diderot, 16, rue de la Grange aux Belles, 75010 Paris, France. atoussa-arbabian@hotmail.fr.
authors: Atousa
authors: A
authors: Arbabian
authors: Department of Laboratory Medicine and Pathology, Cross Cancer Institute and University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada. pascalgelebart@hotmail.com.
authors: Pascal
authors: P
authors: Gélébart
authors: Semmelweis University, Department of Medical Biochemistry, Tűzoltó u. 37-47, H-1094-Budapest, Hungary. kovax@kkk.org.hu.
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authors: Kovács
authors: Inserm UMR U770, Université Paris-Sud 11. 80, rue du Général Leclerc, 94276 Le Kremlin-Bicêtre, France. regis.bobe@inserm.fr.
authors: Régis
authors: R
authors: Bobe
authors: Inserm UMR U689, Université Paris 7-Paris Diderot, Hôpital Lariboisière, 1, rue Ambroise Paré, 75010 Paris, France. jocelyne.enouf@inserm.fr.
authors: Jocelyne
authors: J
authors: Enouf
authors: Institut National de la Santé et de la Recherche Médicale, Inserm UMR U978, UFR SMBH Université Paris 13-Paris Nord, 74, rue Marcel Cachin 93000 Bobigny, France. nadine.varin@inserm.fr.
authors: Nadine
authors: N
authors: Varin-Blank
authors: Membrane Research Group of the Hungarian Academy of Sciences, Diószegi út 64, H-1113-Budapest, Hungary. apati@biomembrane.hu.
authors: Agota
authors: A
authors: Apáti