Prostatic Ductal System in Rats: Regional Variation in Localization of an Androgen-Repressed Gene Product, Sulfated Glycoprotein-2*

Abstract

The rat prostate is a complex ductal system with branches and subbranches extending from one end to another. Owing to the relative distance of various regions from the urethra, the entire length of the ductal system can be divided into three segments, i.e. the proximal, intermediate, and distal segments. The present study was carried out to examine the pattern of localization of sulfated glycoprotein-2 (SGP-2), a marker protein associated with programmed cell death, in various regions of the prostatic ductal system under normal conditions and during castration-induced regression. SGP-2 has been considered an androgen-repressed gene product in the rat prostate and has previously been known as castration-induced protein or TRPM-2. In the normal rat prostate, immunoreactive SGP-2 was localized in epithelial cells lining the proximal segment in which signs of programmed cell death were apparent. Cells lining the distal and intermediate segments were, however, devoid of SGP-2. This observed regional variation in SGP-2 localization did not support an earlier hypothesis which stated that SGP-2 was constitutively expressed by all prostatic epithelial cells in the normal rat prostate. After castration in adult rats, there was a shift in the location of cells containing SGP-2 from the proximal segment toward the distal segment. Therefore, there is a regional variation in the distribution of SGP-2 in the rat prostate both before and after castration in the host. These findings are likely to be associated with a regional variation in cellular responsiveness to androgen stimulation and androgen depletion in the prostatic ductal system. Results also support the view that SGP-2 localization is associated with an early manifestation of programmed cell death in the rat prostate.

Studies of specific gene induction during apoptosis of cell lines conditionally immortalized by SV40

“…Rather, in agreement with other results [24,25], the high constitutive level of expression in REtsAF-Revl suggests a protective role for clusterin. Apoptosis of REtsAF cells in restrictive conditions appears to involve the release of p53 activity [5].…”

Clusterin as a possible predictor for biochemical recurrence of prostate cancer following radical prostatectomy with intermediate Gleason scores: a preliminary report

“…It is known that clusterin is expressed in both benign and malignant prostatic epithelial cells. 14,21 Clusterin can also be expressed in prostatic stromal cells. 22 Therefore, the staining intensity was evaluated separately in following four distinct types of cells: (a) benign epithelium, (b) cancerous epithelium, (c) stroma associated with benign epithelium, and (d) stroma associated with cancerous epithelium.…”

p53 is involved in tumor necrosis factor-α-induced apoptosis in the human prostatic carcinoma cell line LNCaP

“…It therefore could serve as a valuable model of human prostate cancer, allowing one to address the role of p53 in prostate cancer biology, including its sensitivity to anti-cancer therapy both by chemotherapeutic drugs and physiological regulators of cell proliferation and survival. It has been reported that LNCaP is highly sensitive to the cytotoxic eect of TNF-a (Nakajima et al, 1996;Sensibar et al, 1995;Zhao et al, 1992). TNF-a is a cytokine capable of initiating a broad range of biological eects including apoptosis of some tumor cells (reviewed in Wong et al, 1997).…”