title: 3,3'-Diindolylmethane alters Ca2+ homeostasis and viability in MG63 human osteosarcoma cells.
abstract: The effect of the natural product 3,3'-diindolylmethane (DIM) on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in MG63 human osteosarcoma cells was explored. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). DIM at concentrations of 40-80 μM induced a [Ca(2+)](i) rise in a concentration-dependent manner. The response was reduced partly by removing Ca(2+). DIM-evoked Ca(2+) entry was suppressed by nifedipine, econazole, SK&F96365 and protein kinase C modulators. In the absence of extracellular Ca(2+), incubation with the endoplasmic reticulum Ca(2+) pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished DIM-induced [Ca(2+)](i) rise. Incubation with DIM also inhibited thapsigargin or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 abolished DIM-induced [Ca(2+)](i) rise. At concentrations of 10-50 μM, DIM killed cells in a concentration-dependent manner. This cytotoxic effect was not altered by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Annexin V/propidium iodide staining data implicate that DIM (20 and 40 μM) induced apoptosis in a concentration-dependent manner. In sum, in MG63 cells, DIM induced a [Ca(2+)](i) rise by evoking phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via protein kinase C-sensitive store-operated Ca(2+) channels. DIM caused cell death that may involve apoptosis.
authors: Department of Orthopedics, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors: Yi-Chau
authors: YC
authors: Lu
authors: I-Shu
authors: IS
authors: Chen
authors: Chiang-Ting
authors: CT
authors: Chou
authors: Jong-Khing
authors: JK
authors: Huang
authors: Hong-Tai
authors: HT
authors: Chang
authors: Jeng-Yu
authors: JY
authors: Tsai
authors: Shu-Shong
authors: SS
authors: Hsu
authors: Wei-Chuan
authors: WC
authors: Liao
authors: Jue-Long
authors: JL
authors: Wang
authors: Ko-Long
authors: KL
authors: Lin
authors: Shuih-Inn
authors: SI
authors: Liu
authors: Chun-Chi
authors: CC
authors: Kuo
authors: Chin-Man
authors: CM
authors: Ho
authors: Chung-Ren
authors: CR
authors: Jan
mesh_terms: D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D016257:Fura-2 / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D007211:Indoles / Q000008:administration & dosage / Q000494:pharmacology*; D012516:Osteosarcoma / Q000188:drug therapy* / Q000473:pathology; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D016588:Anticarcinogenic Agents; D015220:Calcium Channels; D005456:Fluorescent Dyes; D007211:Indoles; D010738:Type C Phospholipases; C016392:3,3'-diindolylmethane; D002118:Calcium; D016257:Fura-2