Endocrine Abstracts

Osteosarcoma (OS) is an aggressive malignant tumour of osteoblasts occurring predominantly in children and young adults. Despite chemotherapy relapse is common and mortality remains ~50%. Non-transformed osteoblasts are highly sensitive to glucocorticoids which reduce proliferation and induce apoptosis. Previously, we observed that OS cells, but not normal osteoblasts, express 11beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2). This enzyme powerfully inactivates cortis...

GH/IGF1 stimulate muscle function whereas excess glucocorticoids induce myopathy. Myocytes express 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), an enzyme which converts inactive cortisone to active cortisol. GH/IGF-I inhibit 11β-HSD1 expression in some tissues and thus reduce cellular glucocorticoid exposure. This suggests that anabolic actions of GH/IGF1 could be mediated indirectly through effects on 11β-HSD1. The regulation of 11β-HSD1 has be...

We have previously proposed a central role for locally generated glucocorticoids in the periarticular and systemic osteoporosis seen in rheumatoid arthritis (RA). Synovial fibroblasts (SFs) express the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme and this expression increases dramatically with inflammation. Recently, production of DKK-1 (a Wnt signalling inhibitor known to inhibit bone formation) by SFs in response to inflammation has been proposed to ex...