title: Decrease of Store-Operated Ca2+ Entry and Increase of Na+/Ca2+ Exchange by Pharmacological JAK2 Inhibition.
abstract: OBJECTIVE
  Cell proliferation and migration are regulated by cytosolic Ca2+ activity ([Ca2+]i). Mechanisms modifying [Ca2+]i include store-operated Ca(2+)-entry (SOCE) accomplished by the pore-forming ion channel unit Orai1 and its regulator STIM1, as well as Ca2+ extrusion by Na+/Ca2+ exchanger NCX1. Kinases participating in the orchestration of cell proliferation include the Janus activated kinase JAK2. The present study explored the impact of pharmacological JAK2 inhibition on SOCE and Na+/Ca2+ exchange.
  
  
  METHODS
  MCF-7 breast carcinoma cells were studied in the absence and presence of the JAK2 inhibitors TG101348 (250 nM - 1 µM) or of AG490 (20 - 40 µM). Transcript levels were quantified with RT-PCR, protein abundance with immunoblotting, [Ca2+]i with Fura-2-fluorescence, SOCE from increase of [Ca2+]i following Ca2+ re-addition after Ca(2+)-store depletion with sarcoendoplasmatic Ca(2+)-ATPase (SERCA) inhibitor thapsigargin (1 µM), and Na+/Ca2+ exchanger activity from increase of [Ca2+]i as well as Ca2+ current in whole cell patch clamp following extracellular Na+ removal. Migratory activity was determined by a wound healing assay.
  
  
  RESULTS
  JAK2 inhibitor TG101348 (1 µM) decreased Orai1 and STIM1 protein abundance, increased NCX1 transcript levels, decreased Ca2+ release from intracellular stores, decreased SOCE, increased Ca2+ entry as well as Ca(2+)-current following extracellular Na(+)-removal, and decreased migration. Similar effects on Ca2+ release, SOCE, and Ca(2+)-entry following extracellular Na(+)-removal were observed following treatment with AG490.
  
  
  CONCLUSIONS
  The present observations disclose a novel powerful mechanism regulating intracellular Ca2+ release, cellular Ca2+ entry, cellular Ca2+ extrusion and cell migration.
authors: Departments of Cardiology & Cardiovascular Medicine, University of Tx00FC;bingen, Tx00FC;bingen, Germany.
authors: Jing
authors: J
authors: Yan
authors: Zohreh
authors: Z
authors: Hosseinzadeh
authors: Bingbing
authors: B
authors: Zhang
authors: Mirjam
authors: M
authors: Froeschl
authors: Klaus
authors: K
authors: Schulze-Osthoff
authors: Christos
authors: C
authors: Stournaras
authors: Florian
authors: F
authors: Lang
mesh_terms: D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D006801:Humans; D053614:Janus Kinase 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D061986:MCF-7 Cells; D008565:Membrane Proteins / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D000071740:ORAI1 Protein; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000378:metabolism; D000071737:Stromal Interaction Molecule 1; D013449:Sulfonamides / Q000494:pharmacology*; D013843:Thiazines / Q000494:pharmacology; D020032:Tyrphostins / Q000494:pharmacology*; D000096926:Benzenesulfonamides
chemical_list: D002118:Calcium; D015220:Calcium Channels; D053614:Janus Kinase 2; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D011759:Pyrrolidines; D012964:Sodium; D019831:Sodium-Calcium Exchanger; D000071737:Stromal Interaction Molecule 1; D013449:Sulfonamides; D013843:Thiazines; D020032:Tyrphostins; C510746:ORAI1 protein, human; C103530:STIM1 protein, human; C517301:YM 58875; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; C110374:sodium-calcium exchanger 1; C528327:fedratinib; D000096926:Benzenesulfonamides; C507924:JAK2 protein, human