title: Identification of Ras-related nuclear protein, targeting protein for xenopus kinesin-like protein 2, and stearoyl-CoA desaturase 1 as promising cancer targets from an RNAi-based screen.
abstract: To identify new candidate cancer drug targets, we used RNAi as a tool to functionally evaluate genes that play a role in maintaining human tumor cell survival. We screened a small interfering RNA (siRNA) library directed against approximately 3,700 individual genes to assess the ability of siRNAs to induce cell death in an in vitro cell cytotoxicity assay. We found that siRNAs specifically targeting ras-related nuclear protein (Ran), targeting protein for Xenopus kinesin-like protein 2 (TPX2), and stearoyl-CoA desaturase 1 (SCD1), significantly reduced the survival of multiple human tumor cell lines. Further target validation studies revealed that treatment with Ran and TPX2 siRNAs differentially reduced the survival of activated K-Ras-transformed cells compared with their normal isogenic counterparts in which the mutant K-Ras gene had been disrupted (DKS-8). Knockdown of Ran and TPX2 in activated mutant K-Ras cells selectively induced S-phase arrest or transient G(2)-M arrest phenotypes, respectively, that preceded apoptotic cell death. Given our observations that Ran and TPX2 depletion preferentially reduces the survival of activated K-Ras-transformed cells, these two proteins may serve as useful anticancer targets in tumors expressing the activated K-Ras oncogene.
authors.affiliation: Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064, USA. susan.morgan-lappe@abbott.com
authors.forename: Susan E
authors.initials: SE
authors.lastname: Morgan-Lappe
authors.forename: Lora A
authors.initials: LA
authors.lastname: Tucker
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Huang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Aparna V
authors.initials: AV
authors.lastname: Sarthy
authors.forename: Dorothy
authors.initials: D
authors.lastname: Zakula
authors.forename: Lawrence
authors.initials: L
authors.lastname: Vernetti
authors.forename: Mark
authors.initials: M
authors.lastname: Schurdak
authors.forename: Jieyi
authors.initials: J
authors.lastname: Wang
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Fesik
mesh_terms: D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics*; D016923:Cell Death / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics; D015723:Gene Library; D011905:Genes, ras; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics*; D010750:Phosphoproteins / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D013230:Stearoyl-CoA Desaturase / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics*; D020931:ran GTP-Binding Protein / Q000235:genetics*
chemical_list: D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D034741:RNA, Small Interfering; C486551:TPX2 protein, Xenopus; D029867:Xenopus Proteins; D013230:Stearoyl-CoA Desaturase; D020931:ran GTP-Binding Protein