title: Diallyl disulfide induces Ca2+ mobilization in human colon cancer cell line SW480.
abstract: Diallyl disulfide (DADS), one of the major organosulfur compounds of garlic, is recognized as a group of potential chemopreventive compounds. In this study, we examines the early signaling effects of DADS on human colorectal cancer cells SW480 loaded with Ca(2+)-sensitive dye fura-2. It was found that DADS caused an immediate and sustained rise of [Ca(2+)](i) in a concentration-dependent manner (EC(50) = 232 μM). DADS also induced a [Ca(2+)](i) elevation when extracellular Ca(2+) was removed, but the magnitude was reduced by 45%. Depletion of intracellular Ca(2+) stores with 2 μM carbonylcyanide m-chlorophenylhydrazone, a mitochondrial uncoupler, didn't affect DADS's effect. In Ca(2+)-free medium, the DADS-induced [Ca(2+)](i) rise was abolished by depleting stored Ca(2+) with 1 μM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor). DADS-caused [Ca(2+)](i) rise in Ca(2+)-containing medium was not affected by modulation of protein kinase C activity. The DADS-induced Ca(2+) influx was blocked by nicardipine (10 μM). U73122, an inhibitor of phospholipase C, abolished ATP (but not DADS)-induced [Ca(2+)](i) rise. These findings suggest that DADS induced a significant rise in [Ca(2+)](i) in SW480 colon cancer cells by stimulating both extracellular Ca(2+) influx and thapsigargin-sensitive intracellular Ca(2+) release via as yet unidentified mechanisms.
authors: Department of Medical Laboratory Science and Biotechnology, School of Medical and Health Sciences, Fooyin University, 151 Chinhsueh Rd, Ta-Liao District, Kaohsiung City, 83102, Taiwan.
authors: Chung-Yi
authors: CY
authors: Chen
authors: Chien-Fu
authors: CF
authors: Huang
authors: Ya-Ting
authors: YT
authors: Tseng
authors: Soong-Yu
authors: SY
authors: Kuo
mesh_terms: D000498:Allyl Compounds / Q000494:pharmacology*; D016588:Anticarcinogenic Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control; D004220:Disulfides / Q000494:pharmacology*; D005737:Garlic / Q000737:chemistry; D014644:Genetic Variation; D005838:Genotype; D006801:Humans
chemical_list: D000498:Allyl Compounds; D016588:Anticarcinogenic Agents; D000975:Antioxidants; D004220:Disulfides; C028009:diallyl disulfide; D002118:Calcium