title: Effect of NPC-14686 (Fmoc-L-homophenylalanine) on intracellular Ca2+ levels in human hepatoma cells.
abstract: The effect of NPC-14686, a potential anti-inflammatory drug, on cytosolic free Ca(2+) levels ([Ca(2+)](i)) in HA22/VGH human hepatoma cells was explored by using fura-2 as a fluorescent Ca(2+) indicator. NPC-14686 at concentrations above 10 microM increased [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 100 microM. The Ca(2+) signal was reduced by removing extracellular Ca(2+) or by 10 microM nifedipine and was not changed by verapamil or diltiazem. Pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) to deplete the endoplasmic reticulum Ca(2+) abolished 200 microM NPC-14686-induced Ca(2+) release; and conversely pretreatment with NPC-14686 abolished thapsigargin-induced Ca(2+) release. The Ca(2+) release induced by 200 microM NPC-14686 was not changed by inhibiting phospholipase C with 2 microM U73122. Together, the results suggest that in human hepatoma cells, NPC-14686 induced a [Ca(2+)](i) increase by causing store Ca(2+) release from the endoplasmic reticulum in an phospholipase C-independent manner, and by inducing nifedipine-sensitive Ca(2+) influx.
authors.affiliation: Department of Medical Education and Research, Kaohsiung Veterans General Hospital, 386 Ta Chung 1st Road, Kaohsiung 813, Taiwan. crjan@isca.vghks.gov.tw
authors.forename: Chung-Ren
authors.initials: CR
authors.lastname: Jan
authors.forename: Soong-Yu
authors.initials: SY
authors.lastname: Kuo
authors.forename: Jin-Shiung
authors.initials: JS
authors.lastname: Cheng
authors.forename: Yuk-Keung
authors.initials: YK
authors.lastname: Lo
authors.forename: Chun-Peng
authors.initials: CP
authors.lastname: Liu
authors.forename: Wei-Chung
authors.initials: WC
authors.lastname: Chen
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004963:Estrenes / Q000494:pharmacology; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D011760:Pyrrolidinones / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
chemical_list: D000613:Aminobutyrates; D002121:Calcium Channel Blockers; D004338:Drug Combinations; D004963:Estrenes; D005456:Fluorescent Dyes; C417979:NPC 14686; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D019284:Thapsigargin; D010738:Type C Phospholipases; D002118:Calcium; D016257:Fura-2