Variations in activin receptor, inhibin/activin subunit and follistatin mRNAs in human prostate tumour tissues.

The possible role of activin in the regulation of malignant prostatic growth was studied using RNAase protection assays of activin receptors, inhibin/activin subunits and follistatin mRNAs in the human prostatic carcinoma cell lines LNCaP-FGC, -R and -LNO, in human prostatic carcinoma xenografts and in human prostatic tissue. Activin receptor types IA (ActRIA), IB (ActRIB), IIA (ActRIIA) and IIB (ActRIIB) mRNAs were generally expressed in prostate epithelial cells, with significantly lower levels of ActRIB mRNA in prostate tumour material when compared to non-malignant tissue (P < 0.05; Mann-Whitney U-test).

Temporal changes in inhibin subunit mRNAs during atresia of preovulatory follicles in the rat.

This study aimed to investigate the time course of disappearance of the mRNAs of the various subunits of inhibin in follicles which become atretic. An animal model was used in which atresia of preovulatory follicles could be studied in a chronological order. Injection of gonadotrophin-releasing hormone (GnRH) antagonist (20 microg) at the morning of pro-oestrus (P) blocked ovulation and the 10-12 preovulatory follicles became gradually atretic.

Human growth-differentiation factor 3 (hGDF3): developmental regulation in human teratocarcinoma cell lines and expression in primary testicular germ cell tumours.

We describe the cloning and initial characterization of a novel cDNA from human embryonal carcinoma (EC) cells. This cDNA, which we named human growth differentiation factor 3 (hGDF3), encodes the homologue of mouse GDF3, a TGFbeta superfamily member belonging to the Growth/Differentiation Factors. We have analysed the expression of hGDF3 in human embryonal carcinoma cell lines and in primary testicular germ cell tumours of adolescents and adults (TGCTs).

Effects of progesterone on the secondary surge of follicle-stimulating hormone in the rat.

In the cyclic rat, the secondary surge of FSH on estrus appears to depend on the LH surge-induced fall in serum concentrations of inhibin. To investigate the involvement of progesterone in the regulation of the secondary surge of FSH, 4-day cyclic rats were treated on proestrus with an antagonist of LHRH (LHRHant) and with an ovulatory dose of ovine (o) LH, progesterone, the antiprogestin RU486, or the combination of RU486 and oLH. Serum concentrations of gonadotropins and inhibin at 1830 h on proestrus and at 0030 h on estrus were determined, and the expression of inhibin/activin subunit mRNAs in the ovary at 0030 h on estrus was analyzed by in situ hybridization.

Human testicular germ cell tumours express inhibin subunits, activin receptors and follistatin mRNAs.

Germ cell development is influenced by activin and inhibin, which are produced by Sertoli cells. Activin also affects differentiation of mouse embryonal carcinoma cells, which, to a certain extent, resemble the embryonal carcinoma component of germ cell tumours. Therefore, the expression of inhibin/activin subunits, of activin receptors and of the activin-binding protein follistatin was studied in testicular germ cell tumours, using RNAase protection assays.