Faculty Collaboration Database

Androgen-dependent expression of prolactin in rat prostate epithelium in vivo and in organ culture. FASEB J 1997 Dec;11(14):1297-307

Date

12/31/1997

Pubmed ID

9409549

DOI

10.1096/fasebj.11.14.9409549

Scopus ID

2-s2.0-0030713289 (requires institutional sign-in at Scopus site)   73 Citations

Abstract

Peptide hormones and growth factors are involved in the regulation of prostatic cell proliferation, differentiation, and programmed cell death, which functions are primarily controlled by androgen. In carcinogenesis, prostatic cancer cells often lose androgen dependence and become largely dependent on local growth factors. The prostatic cancer cells able to respond to factors other than androgen by proliferation and inhibition of apoptosis are possibly able to survive. We demonstrate that prostatic epithelium expresses prolactin mRNA and protein in a characteristic manner. By using in situ hybridization, an overall distribution of prolactin mRNA was demonstrated in the epithelium of rat dorsal and lateral prostate, whereas a very specific localization of prolactin protein to single cells was observed by immunohistochemistry in the same tissues. In these cells, immunoelectron microscopy showed that prolactin was primarily localized to the secretory granules. These data demonstrate a selective regulation of prostatic prolactin at least at the level of transcript processing/translation and/or protein accumulation and secretion. In addition, the expression of prolactin protein in rat dorsal and lateral prostate was found to be androgen dependent in vivo in castrated and in castrated, testosterone-treated rats, as well as in vitro in organ cultures. Our results support the concept of an autocrine/paracrine loop of prolactin action in prostate where it could mediate some of androgen actions. Also, locally synthesized prolactin might belong to the factors that take over androgen regulation of prostatic cancer cells during the development of androgen-independent growth.

Author List

Nevalainen MT, Valve EM, Ahonen T, Yagi A, Paranko J, Härkönen PL

MESH terms used to index this publication - Major topics in bold

Androgens
Animals
Cytoplasmic Granules
Epithelium
Gene Expression Regulation
In Situ Hybridization
Male
Microscopy, Immunoelectron
Orchiectomy
Organ Culture Techniques
Prolactin
Prostate
RNA, Messenger
Rats
Rats, Sprague-Dawley
Testis
Testosterone