A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Androgen-dependent expression of prolactin in rat prostate epithelium in vivo and in organ culture
Tekijät: Nevalainen MT, Valve EM, Ahonen T, Yagi A, Paranko J, Härkönen PL
Julkaisuvuosi: 1997
Journal: FASEB Journal
Tietokannassa oleva lehden nimi: FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Lehden akronyymi: FASEB J
Vuosikerta: 11
Numero: 14
Aloitussivu: 1297
Lopetussivu: 307
Sivujen määrä: 11
ISSN: 0892-6638
Tiivistelmä
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.
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.
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