Effect of Antidepressant Doxepin on Ca^(2+) Homeostasis and Viability in PC3 Human Prostate Cancer Cells

Ti Lu ； Chiang-Ting Chou ； Wei-Zhe Liang ； Chia-Cheng Yu ； Hong-Tai Chang ； Chun-Chi Kuo ； Wei-Chuan Chen ； Daih-Huang Kuo ； Chin-Man Ho ； Pochuen Shieh ； Chung-Ren Jan

《The Chinese Journal of Physiology》 預刊文章 Pp. d1-10

https://doi.org/10.4077/CJP.2015.BAD298

並列摘要

The effect of the antidepressant doxepin on cytosolic Ca^(2+) concentrations ([Ca^(2+)]i) and viability in PC3 human prostate cancer cells was explored. The Ca^(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca2+]i. Doxepin at concentrations of 500-1000 μM induced a [Ca^(2+)]i rise in a concentrationdependent manner. The response was reduced partly by removing Ca^(2+). Doxepin-evoked Ca2+ entry was suppressed by Ca^(2+) entry blockers (nifedipine, econazole, SK&F96365), and protein kinase C (PKC) modulators. In the absence of extracellular Ca^(2+), incubation with the endoplasmic reticulum Ca^(2+) pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) partly inhibit doxepin-induced [Ca2+]i rise. Incubation with doxepin nearly inhibited thapsigargin or BHQ-induced [Ca^(2+)]i rise. Inhibition of phospholipase C (PLC) with U73122 failed to alter doxepin-induced [Ca^(2+)]i rise. At concentrations of 200-250 μM, doxepin killed cells in a concentration-dependent manner. This cytotoxic effect was not reversed by chelating cytosolic Ca^(2+) with 1,2-bis (2-aminophenoxy)ethane-N,N,N',N'- tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/PI staining data implied that doxepin (200 and 250 μM) did not induce apoptosis. Collectively, in PC3 cells, doxepin induced a [Ca^(2+)]i rise by evoking PLC-independent Ca^(2+) release from stores including the endoplasmic reticulum and Ca^(2+) entry via PKC-sensitive store-operated Ca^(2+) channels. Doxepin caused cell death that was independent of [Ca^(2+)]i rises.

並列關鍵字

Ca^(2+) ； doxepin ； endoplasmic reticulum ； human prostate cancer cells ； phospholipase C ； protein kinase C