title: Gadolinium chloride elicits apoptosis in human osteosarcoma U-2 OS cells through extrinsic signaling, intrinsic pathway and endoplasmic reticulum stress.
abstract: Gadolinium (Gd) compounds are important as magnetic resonance imaging (MRI) contrast agents, and are potential anticancer agents. However, no report has shown the effect of gadolinium chloride (GdCl3) on osteosarcoma in vitro. The present study investigated the apoptotic mechanism of GdCl3 on human osteosarcoma U-2 OS cells. Our results indicated that GdCl3 significantly reduced cell viability of U-2 OS cells in a concentration-dependent manner. GdCl3 led to apoptotic cell shrinkage and DNA fragmentation in U-2 OS cells as revealed by morphologic changes and TUNEL staining. Colorimetric assay analyses also showed that activities of caspase-3, caspase-8, caspase-9 and caspase-4 occurred in GdCl3-treated U-2 OS cells. Pretreatment of cells with pan-caspase inhibitor (Z-VAD-FMK) and specific inhibitors of caspase-3/-8/-9 significantly reduced cell death caused by GdCl3. The increase of cytoplasmic Ca2+ level, ROS production and the decrease of mitochondria membrane potential (ΔΨm) were observed by flow cytometric analysis in U-2 OS cells after GdCl3 exposure. Western blot analyses demonstrated that the levels of Fas, FasL, cytochrome c, Apaf-1, GADD153 and GRP78 were upregulated in GdCl3-treated U-2 OS cells. In conclusion, death receptor, mitochondria-dependent and endoplasmic reticulum (ER) stress pathways contribute to GdCl3-induced apoptosis in U-2 OS cells. GdCl3 might have potential to be used in treatment of osteosarcoma patients.
authors.affiliation: Department of Diagnostic Radiology, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Yuh-Feng
authors.initials: YF
authors.lastname: Tsai
authors.affiliation: Department of Diagnostic Radiology, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Huang
authors.affiliation: Department of Nursing, Chung-Jen Junior College of Nursing, Health Sciences and Management, Chiayi County, Taichung, Taiwan, R.O.C.
authors.forename: Jo-Hua
authors.initials: JH
authors.lastname: Chiang
authors.affiliation: Human Genetic Center, China Medical University Hospital, Taichung, Taiwan, R.O.C.
authors.forename: Fuu-Jen
authors.initials: FJ
authors.lastname: Tsai
authors.affiliation: Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, R.O.C.
authors.forename: Yuan-Man
authors.initials: YM
authors.lastname: Hsu
authors.affiliation: School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan, R.O.C.
authors.forename: Chi-Cheng
authors.initials: CC
authors.lastname: Lu
authors.affiliation: Department of Diagnostic Radiology, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Hsiao
authors.affiliation: Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan, R.O.C.
authors.forename: Jai-Sing
authors.initials: JS
authors.lastname: Yang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D005682:Gadolinium / Q000494:pharmacology*; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D012516:Osteosarcoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D017382:Reactive Oxygen Species; D005682:Gadolinium; D020169:Caspases; C038958:gadolinium chloride