title: Stress response of mammalian cells incubated with landfill leachate.
abstract: Environmental contamination from landfill leachate has been linked to disturbances in human health. Often, however, only global parameters, such as dissolved organic content, chemical oxygen demand, and 5-d biological oxygen demand, are used to evaluate wastewater quality. In the present study, we determined leachate cytotoxicity and stress response of leachate-treated mammalian cells using in vitro bioassays and other molecular techniques. The modified E-screen assay using human breast cancer MCF-7 cells was used to determine the estrogenic potential and/or cytotoxicity of water samples from two solid-waste landfills in Tunisia. The cytotoxicity mechanism of the leachate was determined by DNA fragmentation and lactate dehydrogenase assays. The stress response of heat shock protein (HSP) 47-positive Chinese hamster ovary cells treated with leachate also was determined. Proteomics analyses and real-time reverse transcription-polymerase chain reaction were used to determine and confirm the enhanced expressions of certain stress-related proteins. Results showed that the leachate samples generally did not have estrogenic activity. Instead, they were cytotoxic toward MCF-7 cells, and the cytotoxicity was by necrosis during the early stages of incubation. Leachate also enhanced the expression of HSP and various stress-related proteins, such as heterogeneous nuclear ribonucleoprotein E1, phosphoglycerate mutase, and nuclear matrix protein 200, in MCF-7 cells. These can be considered as survival mechanisms against leachate-induced cytotoxicity.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba City, Ibaraki, Japan.
authors.forename: Terence
authors.initials: T
authors.lastname: Talorete
authors.forename: Atef
authors.initials: A
authors.lastname: Limam
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Kawano
authors.forename: Amel
authors.initials: A
authors.lastname: Ben Rejeb Jenhani
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ghrabi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Isoda
mesh_terms: D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D053938:DNA Fragmentation; D017931:DNA Primers; D050958:HSP47 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D040901:Proteomics; D012037:Refuse Disposal; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D017931:DNA Primers; D050958:HSP47 Heat-Shock Proteins; D014874:Water Pollutants, Chemical; D007770:L-Lactate Dehydrogenase