Endocrine Abstracts

Cellular senescence is a state of permanent and stable proliferative arrest in G1 phase of the cell cycle through activation of the p53/p21 and pRb/p16 signalling pathways. Oncogene-induced senescence (OIS) is a highly proliferative state, which mimics transformation, but this mitotic burst is gradually replaced by senescence. Several lines of evidence have implicated OIS as a vital cause of arrest of benign neoplasms. Pituitary tumors are mostly benign, non-metasta...

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 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...