Apoptosis levels increase after castration in the CWR22 human prostate cancer xenograft

Prostate. 2003 Sep 15;57(1):24-31. doi: 10.1002/pros.10271.


Background: The role of apoptosis in the regression of human prostate cancer after androgen deprivation therapy remains controversial. Detection of caspase-3, an ubiquitous effector of apoptosis, is a highly specific technique for in vivo evaluation of apoptosis.

Methods: Apoptotic rates were evaluated in the androgen-dependent CWR22 human prostate cancer xenograft in tumors that represented time points throughout the progression from androgen-stimulated to recurrent prostate cancer. Caspase-3 levels in formalin-fixed, paraffin-embedded specimens were quantified using immunohistochemical detection and video image analysis. Western blot analysis was used to confirm the results of immunodetection.

Results: Expression of caspase-3 reached a maximum on day 2 after castration, decreased on day 6, and remained low until tumor recurrence. The percentage of tumor area expressing caspase-3 increased from 2.51 +/- 0.44% in tumors from intact mice to 20.84 +/- 1.75% on day 2 after castration. Among immunopositive cells, the intensity of caspase-3 expression measured using the mean optical density (MOD) increased 45% (0.3762 +/- 0.003 to 0.5461 +/- 0.001) on day 2 after castration compared to levels detected in tumors from intact mice.

Conclusions: Apoptosis contributes to tumor regression after castration in the CWR22 human prostate cancer xenograft model.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis*
  • Caspase 3
  • Caspases / analysis
  • Humans
  • Immunohistochemistry
  • Male
  • Mice
  • Mice, Nude
  • Microscopy, Video
  • Neoplasm Transplantation
  • Orchiectomy*
  • Paraffin Embedding
  • Prostatic Neoplasms / enzymology
  • Prostatic Neoplasms / pathology*
  • Transplantation, Heterologous


  • CASP3 protein, human
  • Casp3 protein, mouse
  • Caspase 3
  • Caspases