1.The Mechanism of Safrole-Induced [Ca²⁺]i Rises and Non-Ca²⁺-Triggered Cell Death in SCM1 Human Gastric Cancer Cells.
Hung TY1, Chou CT2,3, Sun TK4, Liang WZ5, Cheng JS6, Fang YC1, Li YD1, Shieh P7, Ho CM5, Kuo CC8, Lin JR5, Kuo DH7, Jan CR5. Chin J Physiol. 2015 Oct 31;58(5):302-11. doi: 10.4077/CJP.2015.BAD315.
Safrole is a carcinogen found in plants. The effect of safrole on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) and viability in SCM1 human gastric cancer cells was explored. The Ca²⁺-sensitive fluorescent dye fura-2 was applied to measure [Ca²⁺](i). Safrole at concentrations of 150-450 μM induced a [Ca²⁺](i) rise in a concentration-dependent manner. The response was reduced by 60% by removing extracellular Ca²⁺. Safrole-evoked Ca²⁺ entry was not altered by nifedipine, econazole, SKF96365, and protein kinase C activator or inhibitor. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) abolished safrole-evoked [Ca²⁺](i) rises. Conversely, treatment with safrole abolished thapsigargin or BHQ-evoked [Ca²⁺](i) rises. Inhibition of phospholipase C (PLC) with U73122 abolished safrole-induced [Ca²⁺](i) rises. At 250-550 μM, safrole decreased cell viability concentration-dependently, which was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM).
2.Effect of sertraline on Ca²⁺ fluxes in rabbit corneal epithelial cells.
Yeh JH1,2, Sun TK3, Chou CT4,5, Chen WC6, Lee JK7, Yeh HC8, Liang WZ9, Kuo CC10, Shieh P11, Kuo DH11, Jan CR9. Chin J Physiol. 2015 Apr 30;58(2):85-94. doi: 10.4077/CJP.2015.BAC255.
The effect of sertraline, a selective serotonin reuptake inhibitor (SSRI), on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) in a rabbit corneal epithelial cell line (SIRC) is unclear. This study explored whether sertraline changed basal [Ca²⁺](i) levels in suspended SIRC cells by using fura-2 as a Ca²⁺-sensitive fluorescent dye. Sertraline at concentrations between 10-100 μM increased [Ca²⁺](i) in a concentration-dependent manner. The Ca²⁺ signal was reduced by 23% by removing extracellular Ca²⁺. Sertraline induced Mn²⁺ influx, leading to quench of fura-2 fluorescence, suggesting Ca²⁺ influx. This Ca²⁺ influx was inhibited by phospholipase A₂ inhibitor aristolochic acid, but not by store-operated Ca²⁺ channel blockers and protein kinase C/A modulators. In Ca²⁺-free medium, pretreatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin, cyclopiazonic acid or 2,5-di-tert-butylhydroquinone greatly inhibited sertraline-induced Ca²⁺ release.
3.The involvement of mitochondrial apoptotic pathway in eugenol-induced cell death in human glioblastoma cells.
Liang WZ1, Chou CT2, Hsu SS3, Liao WC4, Shieh P5, Kuo DH5, Tseng HW6, Kuo CC7, Jan CR8. Toxicol Lett. 2014 Oct 22;232(1):122-132. doi: 10.1016/j.toxlet.2014.10.023. [Epub ahead of print]
Eugenol, a natural phenolic constituent of clove oil, has a wide range of applications in medicine as a local antiseptic and anesthetic. However, the effect of eugenol on human glioblastoma is unclear. This study examined whether eugenol elevated intracellular free Ca2+ levels ([Ca2+]i) and induced apoptosis in DBTRG-05MG human glioblastoma cells. Eugenol evoked [Ca2+]i rises which were reduced by removing extracellular Ca2+. Eugenol-induced [Ca2+]i rises were not altered by store-operated Ca2+ channel blockers but were inhibited by the PKC inhibitor GF109203X and the transient receptor potential channel melastatin 8 (TRPM8) antagonist capsazepine. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) abolished eugenol-induced [Ca2+]i rises. The phospholipase C (PLC) inhibitor U73122 significantly inhibited eugenol-induced [Ca2+]i rises. Eugenol killed cells which were not reversed by prechelating cytosolic Ca2+ with 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA-AM).
4.Effect of Miconazole on [Ca²⁺]i and Cytotoxicity in ZR-75-1 Human Breast Cancer Cells.
Roan CJ1, Chou CT2,3, Liang WZ4, Chang HT5, Kuo DH6, Kuo CC7, Chen FA6, Shieh P6, Jan CR6. Chin J Physiol. 2015 Dec 31;58(6):377-84. doi: 10.4077/CJP.2015.BAD347.
The effect of the antifungal drug miconazole on Ca²⁺ signaling in human breast cancer cells is unknown. This study examined the effect of miconazole on cytosolic free Ca²⁺ concentrations ([Ca²⁺]i) in ZR-75-1 human breast cancer cells. The Ca²⁺-sensitive fluorescent dye fura-2 was used to measure [Ca²⁺]i. Miconazole induced [Ca²⁺]i rises concentration-dependently. The response was reduced by 60% by removing extracellular Ca²⁺. Miconazole-induced Ca²⁺ entry was abolished by the protein kinase C (PKC) inhibitor GF109203X, and nifedipine, but was insensitive to econazole, SKF96365 and the protein kinase C activator phorbol 12-myristate 13 acetate (PMA). In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) or thapsigargin (TG) greatly inhibited miconazole-evoked [Ca²⁺]i rises. Conversely, treatment with miconazole abolished TG and BHQ-evoked [Ca²⁺]i rises. Inhibition of phospholipase C (PLC) with U73122 abolished miconazole-induced [Ca²⁺]i rises.