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

ArticleinArchives of Toxicology 85(10):1257-66 · March 2011with11 Reads
Impact Factor: 5.98 · DOI: 10.1007/s00204-011-0670-9 · Source: PubMed

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.

  • [Show abstract] [Hide abstract] ABSTRACT: Emerging evidence provide credible support in favor of the potential role of bioactive products derived from ingesting cruciferous vegetables such as broccoli, brussel sprouts, cauliflower and cabbage. Among many compounds, 3,3'-diindolylmethane (DIM) is generated in the acidic environment of the stomach following dimerization of indole-3-carbinol (I3C) monomers present in these classes of vegetables. Both I3C and DIM have been investigated for their use in preventing, inhibiting, and reversing the progression of cancer - as a chemopreventive agent. In this review, we summarize an updated, wide-ranging pleiotropic anti-tumor and biological effects elicited by DIM against tumor cells. It is unfeasible to point one single target as basis of cellular target of action of DIM. We emphasize key cellular and molecular events that are effectively modulated in the direction of inducing apoptosis and suppressing cell proliferation. Collectively, DIM orchestrates signaling through Ah receptor, NF-κB/Wnt/Akt/mTOR pathways impinging on cell cycle arrest, modulation of key cytochrome P450 enzymes, altering angiogenesis, invasion, metastasis and epigenetic behavior of cancer cells. The ability of DIM to selectively induce tumor cells to undergo apoptosis has been observed in preclinical models, and thus it has been speculated in improving the therapeutic efficacy of other anticancer agents that have diverse molecular targets. Consequently, DIM has moved through preclinical development into Phase I clinical trials, thereby suggesting that DIM could be a promising and novel agent either alone or as an adjunct to conventional therapeutics such as chemo-radio and targeted therapies. An important development has been the availability of DIM formulation with superior bioavailability for humans. Therefore, DIM appears to be a promising chemopreventive agent or chemo-radio-sensitizer for the prevention of tumor recurrence and/or for the treatment of human malignancies.
    No preview · Article · Jun 2011 · Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
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  • [Show abstract] [Hide abstract] ABSTRACT: Emerging evidence suggest that bioactive phytochemical is achievable by consuming moderate amount of cruciferous vegetables, such as broccoli, brussel sprouts, cauliflower and cabbage. Evaluation for chemopreventive effectiveness of these vegetables led to the identification of 3,3’-Diindolylmethane (DIM) which is generated in the acidic environment of the stomach following dimerization of Indole-3-Carbinol (I3C) monomers originating from the aforementioned class of vegetables. This article evaluates the potential targets and biological effects elicited by DIM against tumor cells to ascertain chemopreventive and therapeutic efficacy. We provide mechanistic insight into their pleiotropic action resulting in the induction of cell cycle arrest and apoptosis, and the disruption of intracellular signaling network cascade that are known to regulate angiogenesis, metastasis and invasion. The beneficial effect of DIM has been observed by preclinical in vitro and in vivo studies, suggesting that DIM could be useful as a chemopreventive agent and an adjunct to conventional therapeutics. Moreover, DIM has moved through preclinical development into clinical trials and the outcome of such investigation would likely provide definitive role of DIM in human health and diseases.
    No preview · Chapter · Jan 2012
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  • Full-text · Article · Mar 2012 · Archives of Toxicology
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