title: Array-based genome-wide RNAi screening to identify shRNAs that enhance p53-related apoptosis in human cancer cells.
abstract: p53 transduction is a potentially effective cancer therapy but does not result in a good therapeutic response in all human cancers due to resistance to apoptosis. To discover factors that overcome resistance to p53-induced apoptosis, we attempted to identify RNAi sequences that enhance p53-induced apoptosis. We screened a genome-wide lentiviral shRNA library in liver cancer Huh-7 and pancreatic cancer Panc-1 cells, both of which resist p53-induced apoptosis. After the infection of adenovirus expressing p53 or LacZ as a control, shRNA-treated populations were analyzed by microarray. We identified shRNAs that were significantly decreased in p53-infected cells compared with control cells. Among these shRNAs, shRNA-58335 was markedly decreased in both cancer cell lines tested. shRNA-58335 enhanced p53-related apoptosis in vitro and augmented the inhibitory effect of adenoviral p53 transduction on tumor growth in vivo. Furthermore, the enhanced apoptotic response by shRNA-58335 was also confirmed by treatment with PRIMA-1, which reactivates mutant p53, instead of adenoviral p53 transduction. We found that shRNA-58335 evokes the apoptotic response following p53 transduction or functional restoration of p53 with a small molecule drug in cancer cells resistant to p53-induced apoptosis. The combination of p53 restoration and RNAi-based drugs is expected to be a promising novel cancer therapy.
authors.affiliation: Department of Medical Genome Sciences, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan. Contributed equally to this work.
authors.forename: Masashi
authors.initials: M
authors.lastname: Idogawa
authors.affiliation: Department of Medical Genome Sciences, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan. Contributed equally to this work.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ohashi
authors.affiliation: Department of Medical Genome Sciences, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Sugisaka
authors.affiliation: Department of Medical Genome Sciences, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sasaki
authors.affiliation: Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Hiromu
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Medical Genome Sciences, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tokino
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D055028:Comparative Genomic Hybridization; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D064593:Heterografts; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D014161:Transduction, Genetic; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D034741:RNA, Small Interfering; D016159:Tumor Suppressor Protein p53