title: Microcystin-LR-induced cytotoxicity and apoptosis in human embryonic kidney and human kidney adenocarcinoma cell lines.
abstract: Microcystin-LR (MC-LR) is a potent hepatotoxin, and increasing evidence suggests that it might also induce kidney injury. The aim of the present work was to evaluate the cytotoxicity and possible apoptotic effects of MC-LR on a human embryonic kidney cell line (HEK-293) and human kidney adenocarcinoma cell line (ACHN). Cells were exposed for 24 h to pure MC-LR (1.0-200 µM) and the cytotoxic effects were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and sulphorhodamine B (SRB) cell viability assays. Cell viability in both cell lines was significantly decreased after treatment with MC-LR at 50 µM for 24 h (P<0.001). Moreover, MC-LR-treated ACHN and HEK-293 cells exhibited a marked dose-dependent loss of confluence as judged by phase-contrast microscopy. Similarly, fluorescence microscopic observations following acridine orange-ethidium bromide (AO/EB) staining confirmed that both cell types were undergoing apoptosis after treatment with MC-LR for 24 h. Expression of three apoptosis-related genes, Bax, Survivin and p53, was analysed by quantitative reverse transcriptase PCR analysis. Both Bax and p53 functioned as promoters of MC-LR-mediated apoptosis in ACHN and HEK-293 cells. The Survivin gene acted as a suppressor of apoptosis at lower MC-LR concentration (1 µM) and the gene was upregulated at higher MC-LR concentration (10 µM) (P<0.001). Significant increases of caspase 3 (P<0.0001) and caspase 9 (P<0.0001) activity were detected in both cell lines after exposure to MC-LR for 24 h, indicating the MC-LR induces cytotoxicity and a marked apoptosis in both ACHN and HEK-293 kidney cell lines.
authors: Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda, Sri Lanka mapcpiyathilaka@gmail.com.
authors: M A P C
authors: MA
authors: Piyathilaka
authors: Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda, Sri Lanka.
authors: M M
authors: MM
authors: Pathmalal
authors: Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka.
authors: K H
authors: KH
authors: Tennekoon
authors: Department of Zoology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda, Sri Lanka.
authors: B G D N K
authors: BG
authors: De Silva
authors: Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka.
authors: S R
authors: SR
authors: Samarakoon
authors: Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka.
authors: S
authors: S
authors: Chanthirika
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism; D008387:Marine Toxins; D052998:Microcystins / Q000494:pharmacology*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D053148:Caspase 3; D053453:Caspase 9; C057862:cyanoginosin LR