title: RNA-sequencing analysis of HepG2 cells treated with atorvastatin.
abstract: The cholesterol-lowering drug atorvastatin is among the most prescribed drug in the world. Alternative splicing in a number of genes has been reported to be associated with variable statin response. RNA-seq has proven to be a powerful technique for genome-wide splice variant analysis. In the present study, we sought to investigate atorvastatin responsive splice variants in HepG2 cells using RNA-seq analysis to identify novel candidate genes implicated in cholesterol homeostasis and in the statin response. HepG2 cells were treated with 10 µM atorvastatin for 24 hours. RNA-seq and exon array analyses were performed. The validation of selected genes was performed using Taqman gene expression assays. RNA-seq analysis identified 121 genes and 98 specific splice variants, of which four were minor splice variants to be differentially expressed, 11 were genes with potential changes in their splicing patterns (SYCP3, ZNF195, ZNF674, MYD88, WHSC1, KIF16B, ZNF92, AGER, FCHO1, SLC6A12 and AKAP9), and one was a gene (RAP1GAP) with differential promoter usage. The IL21R transcript was detected to be differentially expressed via RNA-seq and RT-qPCR, but not in the exon array. In conclusion, several novel candidate genes that are affected by atorvastatin treatment were identified in this study. Further studies are needed to determine the biological significance of the atorvastatin responsive splice variants that have been uniquely identified using RNA-seq.
authors.affiliation: Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Stormo
authors.affiliation: Department of Pharmacology, Oslo University Hospital, Ullevål, Oslo, Norway.
authors.forename: Marianne K
authors.initials: MK
authors.lastname: Kringen
authors.affiliation: Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway.
authors.forename: Robert
authors.initials: R
authors.lastname: Lyle
authors.affiliation: Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway.
authors.forename: Ole Kristoffer
authors.initials: OK
authors.lastname: Olstad
authors.affiliation: Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sachse
authors.affiliation: Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Jens P
authors.initials: JP
authors.lastname: Berg
authors.affiliation: Fürst Medical Laboratory, Oslo, Norway.
authors.forename: Armin P
authors.initials: AP
authors.lastname: Piehler
mesh_terms: D000924:Anticholesteremic Agents / Q000494:pharmacology*; D000069059:Atorvastatin; D005091:Exons; D015870:Gene Expression / Q000187:drug effects*; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006538:Heptanoic Acids / Q000494:pharmacology*; D006801:Humans; D011758:Pyrroles / Q000494:pharmacology*; D012326:RNA Splicing; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D000924:Anticholesteremic Agents; D006538:Heptanoic Acids; D011758:Pyrroles; D000069059:Atorvastatin