Endocrine Abstracts

Blood-borne bacteria, fungi and viral agents can activate cells of the innate immune system by interacting with pattern-recognition or Toll receptors on the surface of immune cells. We demonstrate here that mRNA for Toll receptors is ubiquitously expressed in a range of transformed and normal cell types. These findings raise the possibility that infection could induce an inflammatory response in somatic tissues and this might i), provide a milieu for changes in normal cells th...

Acromegaly is caused by excessive growth hormone (GH) secretion frequently due to GH-secreting pituitary tumors. Acromegalic tumors (ACRO) display reduced microvascular density versus normal pituitaries, suggesting they are under hypoxic conditions. Under hypoxia, tumors gain a survival advantage by stabilizing the transcription factor known as hypoxia-inducible factor 1 alpha (HIF1a). Western blot screening of ACRO (n=40) revealed significantly higher HIF1a protein l...

Hypoxia inducible factor-1alpha (HIF-1α) is a transcription factor regulating expression of many genes related to oxygen homeostasis in response to hypoxic stress. RSUME is a sumoylation enhancer, which was recently cloned from a pituitary cell line with an increased tumorigenic and angiogenic potential. It has been shown that RSMUE is induced by hypoxia and enhances the sumoylation of HIF-1α. Although many studies demonstrated that the level of HIF-1α is remark...

The chemotherapeutic agent temozolomide (TMZ) has been applied for the treatment of pituitary carcinomas, atypical pituitary adenomas and prolactinomas resistant to dopamine agonist treatment with considerable success. Both shrinkage of the tumors and a drop of excessive hormone production were observed in TMZ-responsive patients. In order to clarify whether the TMZ-induced suppression of hormone secretion was a consequence of tumor shrinkage or caused by direct effects on hor...

Folliculostellate (FS) cells were found to regulate hormonal secretion in pituitary endocrine cells. This cell type share properties with components of the innate immune response such as dendritic cells and macrophages, and it is suggested that they are able to initiate immune responses and act as part of an immunoendocrine regulation system. Members of toll-like receptor (TLR) family recognize bacterial cell wall components and initiate an immune response. Recently, we detect...

The factors triggering pancreatic neuroendocrine tumor (PanNET) progression are largely unknown. Here we investigated the role and mechanisms of the sumoylation enhancing protein RSUME in PanNET tumorigenesis. Immunohistochemical studies showed that RSUME is strongly expressed in normal human pancreas, in particular in β-cells. RSUME expression is reduced in insulinomas and is nearly absent in other types of PanNETs suggesting a role in PanNET tumorigenesis. In human panc...