Regulatory Mechanisms of Somatostatin Expression

Somatostatin is a peptide hormone, which most commonly is produced by endocrine cells and the central nervous system. In mammals, somatostatin originates from pre-prosomatostatin and is processed to a shorter form, i.e., somatostatin-14, and a longer form, i.e., somatostatin-28. The two peptides repress growth hormone secretion and are involved in the regulation of glucagon and insulin synthesis in the pancreas. In recent years, the processing and secretion of somatostatin have been studied intensively. However, little attention has been paid to the regulatory mechanisms that control its expression. This review provides an up-to-date overview of these mechanisms. In particular, it focuses on the role of enhancers and silencers within the promoter region as well as on the binding of modulatory transcription factors to these elements. Moreover, it addresses extracellular factors, which trigger key signaling pathways, leading to an enhanced somatostatin expression in health and disease.

Benigne prostate hyperplasya and adenocarcinoma: the role of signal molecules for diagnostics and therapy in patients of various age

In the last years, new data on the role of microenvironment in involution of prostate cells (fibroblasts) and age-associated prostate oncogenesis have been obtained. The goal of this work is the investigation of expression of prostate fibroblasts, CXCL12, SDC1 proteins and hormones in normal and pathological prostate in subjects o different age. Materials were obtained from 78 patients with benignant prostate hyperplasia (BPH), 96 patients with prostate adenocarcinoma and 52 dead men without prostate pathology. All subjects were divided in 3 age groups (middle aged, elderly, and old) and investigated by electron, confocal and light microscopy and immunohistochemical methods. It was shown, that CXCL12 hyperexpression was characteristic of BPH and adenocarcinoma; this correlation became more pronounced with age. SDC1 expression in normal prostate decreased with age which may suggest age-related prostate involution. SDC1 expression in adenocarcinoma increased with. A slight decrease of chromogranin A and somatostatin expression was associated with normal prostate ageing. This process increased in BPH and prostate carcinoma. Chromogranin A and somatostatin decrease correlated with prostate ageing and oncopathology.