Histochemical detection of intranuclear DNA fragmentation and its relation to the expression of bcl-2 oncoprotein in human prostatic cancer.
OBJECTIVE
To assess the incidence of intranuclear DNA fragmentation and the expression of the bcl-2 oncoprotein in prostatic carcinoma, both of which are related to programmed cell death.


METHODS
Specimens of tumour obtained from 17 patients with newly diagnosed prostatic carcinoma and 16 with hormone-treated prostatic carcinoma undergoing total prostatectomy were evaluated. DNA fragmentation was detected using the terminal-labelling method (d-uridine triphosphate conjugated with digoxigenin) and the expression of bcl-2 was detected immunohistochemically.


RESULTS
There was a high incidence of intranuclear DNA fragmentation in 14 of 17 untreated tumours and 15 of 16 hormone-treated tumours. There were no differences between the positive cases in hormone-treated tumours and untreated tumours. There was significantly greater expression of bcl-2 in tumours treated with non-steroidal anti-androgen drugs (eight of nine were positive) than in those untreated (seven of 17) or treated with other drugs (one of seven) (P < 0.05). There was a consistent and marked dissociation between DNA fragmentation and bcl-2 positivity; most of the cells positive for bcl-2 showed no DNA fragmentation.


CONCLUSIONS
The results indicated that cells positive for bcl-2 might potentially be hormone resistant and that the administration of non-steroidal anti-androgen drugs might have a role in the induction of hormone-resistant cells.
Taniguchi
J
J
Department of Urology, University of Tokyo, Japan.
Moriyama
N
N
Kurimoto
S
S
Kameyama
S
S
Kawabe
K
K
D000368:Aged; D017209:Apoptosis / Q000235:genetics*; D004273:DNA, Neoplasm; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2
D004273:DNA, Neoplasm; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2