Endocrine Abstracts

We have earlier shown that treatment with gonadotropin releasing hormone antagonist blocked adrenocortical tumour progression through gonadotropin suppression in inhibin α/SV40 T-antigen (inhα/Tag) transgenic (TG) mice. Hereby, we investigated the molecular mechanisms underlying the GnRH antagonist (Cetrorelix acetate; GnRH-a) treatment induced potential antitumor effects on gonadal somatic cell and adrenocortical tumors in vivo and in vitro. In...

Gonadotropin-releasing hormone (GnRH) analogues are now the standard hormonal treatment for prostate cancer. A fundamental difference between GnRH agonist and antagonist treatment is the permanent suppression of both gonadotropins (LH and FSH) by antagonist, while a rebound in FSH is associated with agonist treatment. The benefits of antagonist include the immediate onset of action and profound long-term suppression of FSH, suggested to be an independent growth factor in prost...

FSH receptor (FSHR) expression has been shown in gonadal tumours, as well as in endothelial tumour vessel cells of various cancers. FSHR, due to its transmembrane localization could be a good candidate for receptor-mediated targeted cancer therapy. In recent years, a number of membrane disrupting lytic peptides have been used for receptor-based cancer therapy. In the present study, we characterised the specificity and cytotoxicity of a lytic peptide Phor21 conjugated to three ...

Progesterone (P4) treatment has been shown to have a clear modulating effect on murine Leydig tumor cell (mLTC-1) function, including downregulation of luteinizing hormone receptor. We hypothesized that P4 would stimulate, whereas an antiprogestine mifepristone (MF) block tumor progression in vivo in a transgenic (TG) murine Leydig cell tumor model (inhibin-α promoter-driven SV40 T-antigen (inhα/Tag)) and act similarly on cell proliferation in vitro...

Antiprogestine mifepristone (MF) has been shown to inhibit ovarian epithelial cancer (OEC) cell growth in vitro and in vivo. Recent clinical trials with MF for human OEC were unsuccessful, for unknown reasons. Progesterone (P4) is believed to have preventive measures towards breast, endometrial or hOEC cancers. Hereby we analyzed the effects of P4 and MF on ovarian granulosa cell tumorigenesis (GCT) in vitro and in vivo...

The LH receptor (LHR) is a 7-transmembrane domain G-protein coupled receptor (GPCR) mainly expressed in the gonads with a major role in the development and maintenance of gonadal steroidogenesis and gametogenesis. Its ligand LH, secreted by the pituitary gland, binds to the extracellular domain of LHR triggering a conformational change in the transmembrane domain and leading to activation of intracellular signalling cascades.As a member of the GPCR famil...

Expression of the follicle-stimulating hormone receptor (FSHR) has been shown in gonads, gonadal tumors, and in endothelial tumor vessel cells of various cancers. We investigated the specificity and cytotoxicity of a fusion lytic peptide Phor21, conjugated to different FSHβ-chain fragments to ablate FSHR expressing cancer cells in vitro and in vivo. Cytotoxicity of 12 different Phor21-FSHβ conjugates was tested in HEK-293 cells, stably transfected w...

The adrenal cortex is a dynamic organ that undergoes self-renewal. In the mouse it is divided into two concentric layers, the outer zona glomerulosa (ZG) and the inner zona fasciculata (ZF), that secrete aldosterone and corticosterone, respectively. Capsular and subcapsular stem/progenitor cells differentiate and migrate in a centripetal fashion to repopulate the gland until they reach the juxtamedullary region where they undergo senescence and apoptosis. Our lab has previousl...

Prepubertally gonadectomized (GDX) wild-type DBA/2J mice develop adrenocortical neoplasms presenting with small spindle-shaped non steroidogenic A-cells and large lipid-laden, steroidogenic and mitotically active B-cells. Neoplastic B-cells overexpress estrogen receptor α (ERα, Ers1) and β (ERβ, Ers2), aromatase (CYP19a1) and produce sex-steroids, resembling gonadal rest tissue. To test the role of estrogen-ER system in adrenocortical tumor progression, GDX...

The role of luteinizing hormone (LH) and its receptor (LHCGR) signaling in the adrenal gland remains unknown. Gonadectomy-induced chronically elevated LH levels trigger neoplastic transformation in genetically susceptible mouse strains (DBA/2J) or transgenic mice expressing the Simian Virus 40 T antigen (SV40Tag) oncogene under inhibin-α promoter (inhα/Tag). In order to study the functional role of LHR and GATA4 in the onset and progression of adrenocortical tumors i...