title: S100A3 suppression inhibits in vitro and in vivo tumor growth and invasion of human castration-resistant prostate cancer cells.
abstract: OBJECTIVE
  To investigate the role of S100A3 and the effect of S100A3 inhibition on human castration-resistant prostate cancer (CRPC) cells by using in vitro and in vivo functional assays.
  
  
  METHODS
  Using human CRPC cells (PC3 and DU145), S100A3 expression levels were assessed by reverse transcription-polymerase chain reaction and Western blot analysis. After S100A3-specific small interfering ribonucleic acid (RNA) treatment, cell viability was determined by Cell Counting Kit-8 assay, and apoptotic cell fractions were evaluated by flow cytometry. The invasive properties of these cells and the expression pattern of matrix metalloproteinases (MMPs) were assessed using transwell migration assays, reverse transcription-polymerase chain reaction, and gelatin zymography. Finally, the in vivo efficacy of S100A3 inhibition on human CRPC cells was investigated using human tumor xenograft models in nude mice.
  
  
  RESULTS
  Human CRPC cells showed overexpression of S100A3, and its suppression reduced cell viability owing to apoptotic cell death. Additionally, S100A3 inhibition decreased the invasiveness of human CRPC cells. Moreover, MMP-2 and MMP-9 were downregulated in PC3, whereas only MMP-9 was downregulated in D145 after S100A3 inhibition. In human CRPC xenograft models, we noted a marked reduction in tumor growth in mice injected with S100A3 short hairpin RNA-transfected PC3 and DU145 cells.
  
  
  CONCLUSIONS
  Human CRPC cells showed upregulation of S100A3 expression, and S100A3 inhibition reduced tumor cell viability. S100A3 inhibition reduced invasion capability with downregulation of MMP expression. More importantly, S100A3 inhibition resulted in tumor growth suppression in human CRPC xenograft models, suggesting S100A3 could serve as a novel therapeutic target for the treatment of human CRPC.
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Minyong
authors.initials: M
authors.lastname: Kang
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hye Sun
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Urology, Konkuk University Hospital, Seoul, Korea.
authors.forename: Woo Suk
authors.initials: WS
authors.lastname: Choi
authors.affiliation: Department of Urology, Seoul St. Mary' Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Park
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Chang Wook
authors.initials: CW
authors.lastname: Jeong
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ja Hyeon
authors.initials: JH
authors.lastname: Ku
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyeon Hoe
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea. Electronic address: mdrafael@snu.ac.kr.
authors.forename: Cheol
authors.initials: C
authors.lastname: Kwak
mesh_terms: D000818:Animals; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D064129:Prostatic Neoplasms, Castration-Resistant / Q000188:drug therapy* / Q000473:pathology*; D009418:S100 Proteins / Q000037:antagonists & inhibitors*; D014407:Tumor Cells, Cultured
chemical_list: D009418:S100 Proteins; C082356:S100A3 protein, human