Korean J Urol.  2003 Nov;44(11):1157-1166.

Mechanism of Azaline B-induced Apoptosis of Ventral Prostate in Rat

• Park C
• Nam SI
• Yun EJ
• Park JI
• Lee JH
• Park SK
• Hwang BD
• Lim K

Abstract

PURPOSE: Androgen deprivation triggers a sequence of events that activates apoptotic cell death of the androgen-dependent epithelial cells within the rat ventral prostate, ultimately resulting in the involution of the gland. To investigate the mechanism of azaline B-dependent apoptosis in the rat ventral prostate, the regulation of apoptosis-related genes were examined.
MATERIALS AND METHODS
Azaline B was subcutaneously injected in Sprague-Dawley rat. Fas receptor(Fas), Fas ligand(FasL), bcl-2 mRNA, and protein levels were detected by RT-PCR and Western blot. Azaline B-dependent apoptosis was determined by TUNEL and DNA fragmentation assay. Transacting factor of FasL promoter was identified by DNA footprinting and DNA mobility shift assay.
RESULTS
The prostate regressed after azaline B treatment in rat, and the involuted ventral prostate regenerated after testosterone pretreatment. Apoptosis of the ventral prostate was detected by TUNEL assay and apoptotic DNA fragmentation assay after azaline B treatment. The levels of Fas and FasL mRNA and protein increased after azaline B treatment. In DNase I footprinting assay with FasL promoter using nuclear extract prepared from control prostate, at least two sites were protected: SP-1 binding site at -283bp and prostate-unidentified factor(P-UF) binding site at -247bp. SP-1 binding activity vanished in the nuclear extract prepared from azaline B-treated rats. In the DNA mobility shift assay, SP-1 binding activity decreased after azaline B treatment. Bcl-2 mRNA and protein were downregulated after azaline B treatment.
CONCLUSIONS
These results suggest that Fas/FasL system and Bcl-2 are important to azaline B-dependent apoptosis in rat ventral prostate and that SP-1 is related to azaline B-dependent regulation of the FasL gene.

Keyword

Azaline; Fas receptor; FasL protein; Bcl-2 genes; Apoptosis

MeSH Terms

Animals
Antigens, CD95
Apoptosis*
Binding Sites
Blotting, Western
Cell Death
Deoxyribonuclease I
DNA
DNA Footprinting
DNA Fragmentation
Electrophoretic Mobility Shift Assay
Epithelial Cells
Fas Ligand Protein
Genes, bcl-2
In Situ Nick-End Labeling
Prostate*
Rats*
Rats, Sprague-Dawley
RNA, Messenger
Testosterone
Antigens, CD95
DNA
Deoxyribonuclease I
Fas Ligand Protein
RNA, Messenger
Testosterone