Endocrine Abstracts

The growth hormone (GH) receptor is a key regulator of cellular metabolism. Using model cell systems we have investigated how GH-induced signaling is regulated, both in paracrine and autocrine conditions.Three features render GHR unique: (a) an active ubiquitination system is required for both endocytosis and degradation in lysosomes; (b) uptake of receptor is a continuous process, independent of GH binding and Jak2 signal transduction; (c) only cell sur...

GH receptor stimulation changes intracellular protein phosphorylation and activates the JAK-STAT signalling pathway. The JAK2 - STAT5 components of this pathway seem critical for growth. Factors of essence for cellular effects of GH include the duration of GH receptor stimulation and in different species there are sex differences in GH secretion where males have an episodic and females have a more continuous mode of GH secretion. At the cellular level, these two types of GH se...

The 16-kDa N-terminal fragment of human prolactin (16K hPRL) is a potent angiostatic factor described to prevent tumor growth in mouse models. Using microarray experiments, we have dissected how the endothelial-cell genome responds to 16K hPRL treatment. Of the 23.000 transcripts present on the chips, 210 are regulated by 16K hPRL. Bio-informatic analysis and experiments performed on endothelial cells with various chemical inhibitors clearly suggest that NF-κB is crucial ...

Experimental, clinical and/or epidemiological evidence points to a role for prolactin (PRL) in the promotion of benign and malignant tumors of the breast and the prostate. However, therapies reducing PRL levels (dopamine agonists) are currently not considered for the treatment of these pathologies. Dopamine agonists only target PRL secretion from the pituitary, while recent observations suggest that the involvement of autocrine PRL is perhaps even more relevant than circulatin...