Small interference RNA-mediated silencing of prostate stem cell antigen attenuates growth, reduces migration and invasion of human prostate cancer PC-3M cells

Urol Oncol. 2013 Apr;31(3):343-51. doi: 10.1016/j.urolonc.2011.02.004. Epub 2011 Mar 23.

Abstract

Objectives: Prostate stem cell antigen (PSCA), a glycosylphosphatidylinositol (GPI)-anchored cell surface glycoprotein, is highly expressed in both local and metastatic prostate cancer (CaP). Elevated PSCA expression has been shown to correlate with malignant phenotype and clinical progression. The purpose of the current study is to investigate the therapeutic potential of small interference RNA (siRNA) targeting PSCA on human CaP cells.

Materials and methods: A set of two siRNAs directed different regions of human PSCA (siRNA-PSCA) were designed and transfected into a human CaP PC-3M cell line. The silencing effect was screened by RT-PCR and Western blotting. The biological effects of siRNA-PSCA on PC-3M cells were investigated by examining the cell proliferation through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle distribution through flow cytometry, and migration and invasion potencies through transwell invasion assay upon the PSCA silencing.

Results: PC-3M cells had positive PSCA expression on immunocytochemical assay. PSCA expression was depleted at 48 hours after transfection with siRNA-PSCA. Silencing of PSCA significantly suppressed cell proliferation. Cell cycle assay showed that the anti-proliferation effect of siRNA-PSCA was mediated by arresting cells in the G0/G1 phase rather than apoptosis. Furthermore, PSCA knockdown resulted in a marked decrease of cell migration and invasion capabilities in PC-3M cells.

Conclusions: The present study provides the first evidence that silencing PSCA using siRNA can inhibit the proliferation and invasiveness properties of human CaP cells, which may provide a promising therapeutic strategy for CaP and open a novel avenue toward the investigation of the role of PSCA overexpression in cancers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / metabolism
  • Blotting, Western
  • Cell Cycle / genetics
  • Cell Line, Tumor
  • Cell Movement / genetics*
  • Cell Proliferation*
  • Cell Survival / genetics
  • Flow Cytometry
  • GPI-Linked Proteins / genetics
  • GPI-Linked Proteins / metabolism
  • Humans
  • Immunohistochemistry
  • Male
  • Neoplasm Invasiveness
  • Neoplasm Proteins / genetics*
  • Neoplasm Proteins / metabolism
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • RNA Interference*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors

Substances

  • Antigens, Neoplasm
  • GPI-Linked Proteins
  • Neoplasm Proteins
  • PSCA protein, human