title: Phenethyl isothiocyanate suppresses inhibitor of apoptosis family protein expression in prostate cancer cells in culture and in vivo.
abstract: BACKGROUND
  Cruciferous vegetable constituent phenethyl isothiocyanate (PEITC) causes apoptosis in prostate cancer cells through mechanisms not fully understood. The present study was designed to determine the role of inhibitor of apoptosis (IAP) family proteins in PEITC-induced apoptosis induction.
  
  
  METHODS
  Effect of PEITC treatment on protein and mRNA expression of IAP in cells was determined by Western blotting and reverse transcription PCR, respectively. Immunohistochemistry was performed to determine the in vivo effect of PEITC administration on X-linked IAP (XIAP) and Survivin protein expression. Overexpression of desired protein was achieved by transient transfection. Cell viability was determined by trypan blue dye exclusion assay, whereas apoptosis was quantified by measurement of histone-associated DNA fragment release into the cytosol. Transwell chamber assay was used to determine cell migration.
  
  
  RESULTS
  Exposure of PC-3 and LNCaP human prostate cancer cells to PEITC resulted in downregulation of XIAP and Survivin proteins and Survivin mRNA. PEITC administration to transgenic adenocarcinoma of mouse prostate mice caused modest but significant downregulation of XIAP and Survivin proteins in the dorsolateral prostate. Proapoptotic response to PEITC was significantly attenuated by ectopic expression of XIAP and Survivin proteins. Survivin overexpression also conferred modest but significant protection against PEITC-mediated inhibition of PC-3 cell migration.
  
  
  CONCLUSIONS
  The present study demonstrates that cellular responses to PEITC, including apoptosis induction and inhibition of cell migration, in prostate cancer cells are mediated by downregulation of XIAP and/or Survivin, which may serve as valid biomarkers of PEITC response in future clinical investigations.
authors.affiliation: Department of Pharmacology & Chemical Biology, and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
authors.forename: Kozue
authors.initials: K
authors.lastname: Sakao
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Desineni
authors.forename: Eun-Ryeong
authors.initials: ER
authors.lastname: Hahm
authors.forename: Shivendra V
authors.initials: SV
authors.lastname: Singh
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D017879:Isothiocyanates / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D051034:Inhibitor of Apoptosis Proteins; D017879:Isothiocyanates; C058305:phenethyl isothiocyanate