title: Mitochondriome and cholangiocellular carcinoma.
abstract: Cholangiocellular carcinoma (CCA) of the liver was the target of more interest, recently, due mainly to its increased incidence and possible association to new environmental factors. Somatic mitochondrial DNA (mtDNA) mutations have been found in several cancers. Some of these malignancies contain changes of mtDNA, which are not or, very rarely, found in the mtDNA databases. In terms of evolutionary genetics and oncology, these data are extremely interesting and may be considered a sign of poor fitness, which may conduct in some way to different cellular processes, including carcinogenesis. MitoChip analysis is a strong tool for investigations in experimental oncology and was carried out on three CCA cell lines (HuCCT1, Huh-28 and OZ) with different outcome in human and a Papova-immortalized normal hepatocyte cell line (THLE-3). Real time quantitative PCR, western blot analysis, transmission electron microscopy, confocal laser microscopy, and metabolic assays including L-Lactate and NAD+/NADH assays were meticulously used to identify mtDNA copy number, oxidative phosphorylation (OXPHOS) content, ultrastructural morphology, mitochondrial membrane potential (ΔΨm), and differential composition of metabolites, respectively. Among 102 mtDNA changes observed in the CCA cell lines, 28 were non-synonymous coding region alterations resulting in an amino acid change. Thirty-eight were synonymous and 30 involved ribosomal RNA (rRNA) and transfer RNA (tRNA) regions. We found three new heteroplasmic mutations in two CCA cell lines (HuCCT1 and Huh-28). Interestingly, mtDNA copy number was decreased in all three CCA cell lines, while complexes I and III were decreased with depolarization of mitochondria. L-Lactate and NAD+/NADH assays were increased in all three CCA cell lines. MtDNA alterations seem to be a common event in CCA. This is the first study using MitoChip analysis with comprehensive metabolic studies in CCA cell lines potentially creating a platform for future studies on the interactions between normal and neoplastic cells.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Wesam
authors.initials: W
authors.lastname: Bahitham
authors.affiliation: Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Liao
authors.affiliation: Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Fred
authors.initials: F
authors.lastname: Peng
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Fiona
authors.initials: F
authors.lastname: Bamforth
authors.affiliation: Department of Genetics, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Alicia
authors.initials: A
authors.lastname: Chan
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mason
authors.affiliation: Benaroya Research Institute, Seattle, Washington, United States of America.
authors.forename: Bradley
authors.initials: B
authors.lastname: Stone
authors.affiliation: Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Stothard
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada; Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Consolato
authors.initials: C
authors.lastname: Sergi
mesh_terms: D019943:Amino Acid Substitution; D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D056915:DNA Copy Number Variations; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D058977:Molecular Sequence Annotation; D009154:Mutation; D009243:NAD / Q000378:metabolism; D010085:Oxidative Phosphorylation; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism
chemical_list: D024101:Mitochondrial Proteins; D012335:RNA, Ribosomal; D009243:NAD; D019344:Lactic Acid; D012343:RNA, Transfer