3,3′-Diindolylmethane Alters Ca2+ Homeostasis and Viability in MG63 Human Osteosarcoma Cells

• Published in: Basic & clinical pharmacology & toxicology Vol. 110; no. 4; pp. 314 - 321
• Main Authors: Lu, Yi-Chau, Chen, I-Shu, Chou, Chiang-Ting, Huang, Jong-Khing, Chang, Hong-Tai, Tsai, Jeng-Yu, Hsu, Shu-Shong, Liao, Wei-Chuan, Wang, Jue-Long, Lin, Ko-Long, Liu, Shuih-Inn, Kuo, Chun-Chi, Ho, Chin-Man, Jan, Chung-Ren
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2012; Blackwell
• Subjects: Annexin V; Anticarcinogenic Agents - administration & dosage; Anticarcinogenic Agents - pharmacology; Apoptosis; Apoptosis - drug effects; Biological and medical sciences; Ca super(2+)-transporting ATPase; Calcium; Calcium (extracellular); Calcium - metabolism; Calcium channels; Calcium Channels - metabolism; Calcium homeostasis; Calcium influx; Cell Line, Tumor; Cell Survival; Cytotoxicity; Data processing; Diseases of the osteoarticular system; Dose-Response Relationship, Drug; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Fluorescent Dyes - metabolism; Fluorescent indicators; Fura-2; Fura-2 - metabolism; Homeostasis; Humans; Indoles - administration & dosage; Indoles - pharmacology; Medical sciences; natural products; Osteosarcoma - drug therapy; Osteosarcoma - pathology; Osteosarcoma cells; Pharmacology. Drug treatments; Phospholipase C; propidium iodide; Protein kinase C; thapsigargin; Tumors of striated muscle and skeleton; Type C Phospholipases - metabolism; Human; Calcium; Sarcoma; Diseases of the osteoarticular system; Homeostasis; Malignant tumor; Inorganic element; In vitro; Osteoarticular system; Osteosarcoma; Bone; Viability; Cancer
• ISSN: 1742-7835; 1742-7843
• DOI: 10.1111/j.1742-7843.2011.00816.x

:  The effect of the natural product 3,3′‐diindolylmethane (DIM) on cytosolic Ca2+ concentrations ([Ca2+]i) and viability in MG63 human osteosarcoma cells was explored. The Ca2+‐sensitive fluorescent dye fura‐2 was applied to measure [Ca2+]i. DIM at concentrations of 40–80 μM induced a [Ca2+]i rise in a concentration‐dependent manner. The response was reduced partly by removing Ca2+. DIM‐evoked Ca2+ entry was suppressed by nifedipine, econazole, SK&F96365 and protein kinase C modulators. In the absence of extracellular Ca2+, incubation with the endoplasmic reticulum Ca2+ pump inhibitors thapsigargin or 2,5‐di‐tert‐butylhydroquinone (BHQ) inhibited or abolished DIM‐induced [Ca2+]i rise. Incubation with DIM also inhibited thapsigargin or BHQ‐induced [Ca2+]i rise. Inhibition of phospholipase C with U73122 abolished DIM‐induced [Ca2+]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 Ca2+ 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 [Ca2+]i rise by evoking phospholipase C‐dependent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via protein kinase C‐sensitive store‐operated Ca2+ channels. DIM caused cell death that may involve apoptosis.