title: Establishment of conditional vectors for hairpin siRNA knockdowns.
abstract: Small interference RNA (siRNA) is an emerging methodology in reverse genetics. Here we report the development of a new tetracycline-inducible vector-based siRNA system, which uses a tetracycline-responsive derivative of the U6 promoter and the tetracycline repressor for conditional in vivo transcription of short hairpin RNA. This method prevents potential lethality immediately after transfection of a vector when the targeted gene is indispensable, or the phenotype of the knockdown is lethal or results in a growth abnormality. We show that the controlled knockdown of DNA methyltransferase 1 (DNMT1) in human cancer resulted in growth arrest. Removal of the inducer, doxycycline, from treated cells led to re-expression of the targeted gene. Thus the method allows for a highly controlled approach to gene knockdown.
authors.affiliation: Department of Biochemistry and Molecular Biology, USC/Norris Comprehensive Cancer Center, Keck School of Medicine of the University of Southern California, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA.
authors.forename: Shiro
authors.initials: S
authors.lastname: Matsukura
authors.forename: Peter A
authors.initials: PA
authors.lastname: Jones
authors.forename: Daiya
authors.initials: D
authors.lastname: Takai
mesh_terms: D001483:Base Sequence; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000096:biosynthesis / Q000235:genetics; D004318:Doxycycline / Q000494:pharmacology; D005822:Genetic Vectors; D006801:Humans; D009690:Nucleic Acid Conformation; D010957:Plasmids; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D012342:RNA, Small Nuclear / Q000235:genetics; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D034741:RNA, Small Interfering; D012342:RNA, Small Nuclear; C405486:U6 small nuclear RNA; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human; D004318:Doxycycline