title: Targeted induction of endogenous NKX3-1 by small activating RNA inhibits prostate tumor growth.
abstract: BACKGROUND
  RNA activation (RNAa) is a small RNA-mediated gene regulation mechanism by which expression of a particular gene can be induced by targeting its promoter using small double-stranded RNA also known as small activating RNA (saRNA). We used saRNA as a molecular tool to examine NKX3-1's role as a tumor suppressor and tested in vitro and in vivo antitumor effects of NKX3-1 induction by saRNA.
  
  
  METHODS
  NKX3-1 saRNA was transfected into human prostate cancer cells including LNCaP, CWR22R, PC-3, CWR22RV1, DuPro, LAPC4, and DU145. The transfected cells were used for analysis of gene expression by RT-PCR and immunoblotting, proliferation, apoptosis and cell cycle distribution. PC-3 xenograft models were established in immunocompromised mice and treated with NKX3-1 saRNA.
  
  
  RESULTS
  NKX3-1 saRNA induced NKX3-1 expression in different prostate cancer cell lines, resulting in inhibited cell proliferation and survival, cell cycle arrest and apoptotic cell death. These effects were partly mediated by NKX3-1's regulation of several downstream genes including the upregulation of p21 and p27, and the inhibition of VEGFC expression. Treatment of mouse xenograft prostate tumors with intratumoral delivery of NKX3-1 saRNA formulated in lipid nanoparticles significantly inhibited tumor growth and prolonged animal survival.
  
  
  CONCLUSIONS
  By revealing several important target genes of NKX3-1, our findings corroborated NKX3-1's role as a tumor suppressor gene through direct regulation of the cell cycle and growth/survival pathways. This study also validated the therapeutic potential of saRNA for the treatment of prostate cancer via targeted activation of tumor suppressor genes.
authors.affiliation: Department of Urology and Helen-Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California, USA.
authors.forename: Shancheng
authors.initials: S
authors.lastname: Ren
authors.forename: Moo Rim
authors.initials: MR
authors.lastname: Kang
authors.forename: Ji
authors.initials: J
authors.lastname: Wang
authors.forename: Vera
authors.initials: V
authors.lastname: Huang
authors.forename: Robert F
authors.initials: RF
authors.lastname: Place
authors.forename: Yinhao
authors.initials: Y
authors.lastname: Sun
authors.forename: Long-Cheng
authors.initials: LC
authors.lastname: Li
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002468:Cell Physiological Phenomena / Q000187:drug effects* / Q000235:genetics; D016147:Genes, Tumor Suppressor; D018398:Homeodomain Proteins / Q000235:genetics / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D023421:Models, Animal; D010957:Plasmids; D011467:Prostate / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012330:RNA, Double-Stranded / Q000235:genetics / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects; D014162:Transfection; D014183:Transplantation, Heterologous; D016896:Treatment Outcome
chemical_list: D018398:Homeodomain Proteins; C491178:NKX3-1 protein, human; D012330:RNA, Double-Stranded; D014157:Transcription Factors
keywords: NKX3-1; RNAa; prostate cancer; saRNA; xenograft