Effect of Carvacrol on Ca²âº Movement and Viability in PC3 Human Prostate Cancer Cells.

Carvacrol, a monoterpenic phenol compound, has been shown to possess various biological effects in different models. However, the effect of carvacrol on intracellular Ca²âº and its related physiology in human prostate cancer is unknown. This study explored the effect of carvacrol on cytosolic free Ca²âº levels ([Ca²âº]i) and viability in PC3 human prostate cancer cells. Fura-2, a Ca²âº- sensitive fluorescent dye, was used to assess [Ca²âº]i. Cell viability was measured by the detecting reagent WST-1. Carvacrol at concentrations of 200-800 µM caused [Ca²âº]i rises in a concentration-dependent manner. Removal of extracellular Ca²âº reduced carvacrol's effect by approximately 60%. Carvacrol-induced Ca²âº entry was confirmed by Mn²âº entry-induced quench of fura-2 fluorescence, and was inhibited by approximately 30% by nifedipine, econazole, SKF96365, and the protein kinase C (PKC) inhibitor GF109203X. In Ca²âº-free medium, treatment with the endoplasmic reticulum Ca²âº pump inhibitor thapsigargin (TG) abolished carvacrol-induced [Ca²âº]i rises. Treatment with carvacrol also abolished TG-induced [Ca²âº]i rises. Carvacrol-induced Ca²âº release from the endoplasmic reticulum was abolished by inhibition of phospholipase C (PLC). Carvacrol killed cells at concentrations of 200-600 µM in a concentration-dependent fashion. Chelating cytosolic Ca²âº with BAPTA/AM did not prevent carvacrol's cytotoxicity. Together, in PC3 cells, carvacrol induced [Ca²âº]i rises by inducing PLC-dependent Ca²âº release from the endoplasmic reticulum and Ca²âº entry via PKC-sensitive store-operated Ca²âº channels and other unknown channels. Carvacrol also induced Ca²âº-dissociated cell death.

The Mechanism of Safrole-Induced [Ca²âº]i Rises and Non-Ca²âº-Triggered Cell Death in SCM1 Human Gastric Cancer Cells.

Safrole is a carcinogen found in plants. The effect of safrole on cytosolic free Ca²âº concentrations ([Ca²âº](i)) and viability in SCM1 human gastric cancer cells was explored. The Ca²âº-sensitive fluorescent dye fura-2 was applied to measure [Ca²âº](i). Safrole at concentrations of 150-450 µM induced a [Ca²âº](i) rise in a concentration-dependent manner. The response was reduced by 60% by removing extracellular Ca²âº. Safrole-evoked Ca²âº entry was not altered by nifedipine, econazole, SKF96365, and protein kinase C activator or inhibitor. In Ca²âº-free medium, treatment with the endoplasmic reticulum Ca²âº pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) abolished safrole-evoked [Ca²âº](i) rises. Conversely, treatment with safrole abolished thapsigargin or BHQ-evoked [Ca²âº](i) rises. Inhibition of phospholipase C (PLC) with U73122 abolished safrole-induced [Ca²âº](i) rises. At 250-550 µM, safrole decreased cell viability concentration-dependently, which was not reversed by chelating cytosolic Ca²âº with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/propidium iodide staining data suggest that safrole (350-550 µM) induced apoptosis concentration-dependently. These studies suggest that in SCM1 human gastric cancer cells, safrole induced [Ca²âº](i) rises by inducing PLC-dependent Ca²âº release from the endoplasmic reticulum and Ca²âº influx via non-store-operated Ca²âº entry pathways. Safrole-induced cell death may involve apoptosis.

The mechanism of protriptyline-induced Ca2+ movement and non-Ca2+-triggered cell death in PC3 human prostate cancer cells.

Protriptyline, a tricyclic anti-depressant, is used primarily to treat the combination of symptoms of anxiety and depression. However, the effect of protriptyline on prostate caner is unknown. This study examined whether the anti-depressant protriptyline altered Ca(2+) movement and cell viability in PC3 human prostate cancer cells. The Ca(2+)-sensitive fluorescent dye fura-2 was used to measure [Ca(2+)](i). Protriptyline evoked [Ca(2+)](i) rises concentration-dependently. The response was reduced by removing extracellular Ca(2+). Protriptyline-evoked Ca(2+) entry was inhibited by store-operated channel inhibitors (nifedipine, econazole and SKF96365), protein kinase C activator (phorbol 12-myristate 13 acetate, PMA) and protein kinase C inhibitor (GF109203X). Treatment with the endoplasmic reticulum Ca(2+) pump inhibitor 2,5-di-tert-butylhydr-oquinone (BHQ) in Ca(2+)-free medium inhibited 60% of protriptyline-evoked [Ca(2+)](i) rises. Conversely, treatment with protriptyline abolished BHQ-evoked [Ca(2+)](i) rises. Inhibition of phospholipase C with U73122 suppressed 50% of protriptyline-evoked [Ca(2+)](i) rises. At concentrations of 50-70 µM, protriptyline decreased cell viability in a concentration-dependent manner; which were not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Collectively, in PC3 cells, protriptyline evoked [Ca(2+)](i) rises by inducing phospholipase C-associated Ca(2+) release from the endoplasmic reticulum and other stores, and Ca(2+) influx via protein kinase C-sensitive store-operated Ca(2+) channels. Protriptyline caused cell death that was independent of [Ca(2+)](i) rises.

Effect of sertraline on Ca²âº fluxes in rabbit corneal epithelial cells.

The effect of sertraline, a selective serotonin reuptake inhibitor (SSRI), on cytosolic free Ca²âº concentrations ([Ca²âº](i)) in a rabbit corneal epithelial cell line (SIRC) is unclear. This study explored whether sertraline changed basal [Ca²âº](i) levels in suspended SIRC cells by using fura-2 as a Ca²âº-sensitive fluorescent dye. Sertraline at concentrations between 10-100 µM increased [Ca²âº](i) in a concentration-dependent manner. The Ca²âº signal was reduced by 23% by removing extracellular Ca²âº. Sertraline induced Mn²âº influx, leading to quench of fura-2 fluorescence, suggesting Ca²âº influx. This Ca²âº influx was inhibited by phospholipase A2 inhibitor aristolochic acid, but not by store-operated Ca²âº channel blockers and protein kinase C/A modulators. In Ca²âº-free medium, pretreatment with the endoplasmic reticulum Ca²âº pump inhibitor thapsigargin, cyclopiazonic acid or 2,5-di-tert-butylhydroquinone greatly inhibited sertraline-induced Ca²âº release. Inhibition of phospholipase C with U73122 abolished sertraline-induced [Ca²âº](i) rise. At concentrations of 5-50 µM, sertraline killed cells in a concentration-dependent manner. The cytotoxic effect of 25 µM sertraline was not reversed by prechelating cytosolic Ca²âº with BAPTA/AM. Collectively, in SIRC cells, sertraline induced [Ca²âº](i) rises by causing phospholipase C-dependent Ca²âº release from the endoplasmic reticulum and Ca²âº influx via phospholipase A2-sensitive Ca²âº channels. Sertraline-caused cytotoxicity was mediated by Ca²âº-independent pathways.

Effect of melamine on [Ca(2+)]i and viability in PC3 human prostate cancer cells.

Melamine is thought to be an endocrine disrupter that affects physiology in cells. This study examined the effect of melamine on cytosolic free Ca(2+) concentrations ([Ca(2+)]i) and viability in PC3 human prostate cancer cells. Melamine evoked [Ca(2+)]i rises concentration-dependently. Melamine-evoked Ca(2+) entry was inhibited by nifedipine, econazole, SKF96365, GF109203X and phorbol 12-myristate 13 acetate. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin inhibited melamine-evoked [Ca(2+)]i rise. Conversely, treatment with melamine abolished thapsigargin-evoked [Ca(2+)]i rise. Inhibition of phospholipase C with U73122 did not alter melamine-evoked [Ca(2+)]i rise. Melamine at 500-800µM decreased cell viability, which was not reversed by pretreatment with the Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Collectively, our data suggest that in PC3 cells, melamine induced [Ca(2+)]i rises by evoking phospholipase C-independent Ca(2+) release from the endoplasmic reticulum, and Ca(2+) entry via protein kinase C-regulated store-operated Ca(2+) entry. Melamine also caused Ca(2+)-independent cell death.