Effect of diindolylmethane on Ca(2+) movement and viability in HA59T human hepatoma cells.

Abstract

The effect of diindolylmethane, a natural compound derived from indole-3-carbinol in cruciferous vegetables, on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in HA59T human hepatoma cells is unclear. This study explored whether diindolylmethane changed [Ca(2+)](i) in HA59T cells. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). Diindolylmethane at concentrations of 1-50 μM evoked a [Ca(2+)](i) rise in a concentration-dependent manner. The signal was reduced by removing Ca(2+). Diindolylmethane-induced Ca(2+) influx was not inhibited by nifedipine, econazole, SK&F96365, and protein kinase C modulators but was inhibited by aristolochic acid. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished diindolylmethane-induced [Ca(2+)](i) rise. Incubation with diindolylmethane inhibited thapsigargin or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 reduced diindolylmethane-induced [Ca(2+)](i) rise. At concentrations of 10-75 μM, diindolylmethane killed cells in a concentration-dependent manner. The cytotoxic effect of diindolylmethane was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Propidium iodide staining data suggest that diindolylmethane (25-50 μM) induced apoptosis in a concentration-dependent manner. Collectively, in HA59T cells, diindolylmethane induced a [Ca(2+)](i) rise by causing phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx via phospholipase A(2)-sensitive channels. Diindolylmethane induced cell death that may involve apoptosis.

• Authors: Jin-Shiung Cheng, Su-Shung Shu, Chun-Chi Kuo, Chiang-Ting Chou, Wei-Lun Tsai, Yi-Chien Fang, Li-Ni Kuo, Jeng-Hsien Yeh, Wei-Chuan Chen, Jau-Min Chien, Ti Lu, Chih-Chuan Pan, He-Hsiung Cheng, Kuo-Liang Chai, Chung-Ren Jan
• Journal: Archives of toxicology (Arch Toxicol) Vol. 85 Issue 10 Pg. 1257-66 (Oct 2011) ISSN: 1432-0738 [Electronic] Germany
• PMID: 21409406 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium
• Calcium Channel Blockers
• Hydroquinones
• Imidazoles
• Indoles
• Tetrazolium Salts
• 2,5-di-tert-butylhydroquinone
• Thapsigargin
• Econazole
• Protein Kinase C
• Phospholipases A2
• 1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole
• Nifedipine
• 3,3'-diindolylmethane
• Calcium
• Fura-2

Topics

• Apoptosis (drug effects)
• Calcium (metabolism)
• Calcium Channel Blockers (pharmacology)
• Carcinoma, Hepatocellular (drug therapy, metabolism, pathology)
• Cell Line, Tumor
• Cell Survival
• Dose-Response Relationship, Drug
• Econazole (pharmacology)
• Endoplasmic Reticulum (drug effects, metabolism)
• Fura-2 (metabolism)
• Humans
• Hydroquinones (pharmacology)
• Imidazoles (pharmacology)
• Indoles (pharmacology)
• Liver Neoplasms (drug therapy, metabolism, pathology)
• Nifedipine (pharmacology)
• Phospholipases A2 (metabolism)
• Protein Kinase C (metabolism)
• Tetrazolium Salts (analysis, metabolism)
• Thapsigargin (pharmacology)