title: Adipocyte differentiation induced using nonspecific siRNA controls in cultured human mesenchymal stem cells.
abstract: RNA interference (RNAi) is gene silencing induced by double-stranded RNA of 21-23 nucleotides in length, termed small interfering RNA, or siRNA. RNAi-based techniques have been widely applied to elucidate gene function, identify drug targets, and used in trials as a promising adjunct to silence disease-causing genes. However, emerging evidence suggests unexpected changes in expression of untargeted genes as a consequence of an off-target effect by RNAi in mammalian cells. To date, our understanding of such effects on stem cells is limited. We transfected human fetal femur-derived mesenchymal stem cells using commercially available nonspecific siRNA controls and examined adipocyte differentiation in the cells using morphology, histochemistry, and quantitative real-time PCR to examine the expression of key genes for adipogenic or osteogenic differentiation. We report here the induction of adipocyte differentiation in human mesenchymal stem cells using nonspecific siRNAs raising concerns as to the specificity of RNAi in stem cells and, critically, a need to understand and delineate the rules governing the specificity of RNAi.
authors.affiliation: Bone and Joint Research Group, Developmental Origins of Health and Disease, Institute of Developmental Sciences, University of Southampton, Southampton, UK.
authors.forename: Yunhe
authors.initials: Y
authors.lastname: Xu
authors.forename: Sayed-Hadi
authors.initials: SH
authors.lastname: Mirmalek-Sani
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.forename: Junlong
authors.initials: J
authors.lastname: Zhang
authors.forename: Richard O C
authors.initials: RO
authors.lastname: Oreffo
mesh_terms: D017667:Adipocytes / Q000166:cytology*; D050156:Adipogenesis / Q000235:genetics*; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D005269:Femur / Q000166:cytology; D053686:Fetal Stem Cells / Q000166:cytology*; D020869:Gene Expression Profiling; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D020411:Oligonucleotide Array Sequence Analysis; D047495:PPAR gamma / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering; D014162:Transfection
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D047495:PPAR gamma; D034741:RNA, Small Interfering; C493709:RUNX2 protein, human