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.
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ABSTRACT: Abstract Clotrimazole is an antimycotic imidazole derivative that interferes with cellular Ca(2+) homeostasis. This study examined the effect of clotrimazole on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in HA59T human hepatoma cells. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). Clotrimazole induced [Ca(2+)](i) rises in a concentration-dependent manner. The response was reduced by removing extracellular Ca(2+). Clotrimazole-evoked Ca(2+) entry was suppressed by store-operated channel inhibitors (nifedipine, econazole and SK&F96365) and protein kinase C modulators (GF109203X and phorbol, 12-myristate, 13-acetate). In Ca(2+)-free medium, incubation with the endoplasmic reticulum Ca(2+) pump inhibitor 2,5-di-tert-butylhydroquinone abolished clotrimazole-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 abolished clotrimazole-induced [Ca(2+)](i) rise. At 10-40 µM, clotrimazole inhibited cell viability, which was not reversed by chelating cytosolic Ca(2+). Clotrimazole at 10 and 30 µM also induced apoptosis. Collectively, in HA59T cells, clotrimazole-induced [Ca(2+)](i) rises by evoking phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via store-operated Ca(2+) channels. Clotrimazole also caused apoptosis.Journal of Receptor and Signal Transduction Research 02/2013; · 1.63 Impact Factor
- Archives of Toxicology 03/2012; 86(4):519-20. · 5.22 Impact Factor
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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.Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 06/2011; 728(1-2):47-66. · 3.90 Impact Factor