Stimulation of T-cell proliferation by pancreastatin and its C-terminal fragment (33-49)

The immunomodulatory functions of chromogranin A-derived peptide pancreastatin

Chromogranin A (CgA) is a 439 amino acid protein secreted by neuroendocrine cells. Proteolytic processing of CgA results in the production of different bioactive peptides. These peptides have been associated with inflammatory bowel disease, diabetes, and cancer. One of the chromogranin A-derived peptides is ∼52 amino acid long Pancreastatin (PST: human (h)CgA250-301, murine (m)CgA263-314). PST is a glycogenolytic peptide that inhibits glucose-induced insulin secretion from pancreatic islet β-cells. In addition to this metabolic role, evidence is emerging that PST also has inflammatory properties. This review will discuss the immunomodulatory properties of PST and its possible mechanisms of action and regulation. Moreover, this review will discuss the potential translation to humans and how PST may be an interesting therapeutic target for treating inflammatory diseases.

Effect of chromogranin A (pancreastatin) fragment on invasion of prostate cancer cells

We investigated the effect of chromogranin A (pancreastatin) fragment on the invasion of PC-3, DU-145 and LNCaP prostate cancer cells through a reconstituted basement membrane (Matrigel) using a Transwell cell culture chamber assay. Chromogranin A fragment increased the invasive capacity of both PC-3 and DU- 145 cells, whereas it had no significant effect of LNCaP cells. Chromogranin A fragment also increased the haptotactic migration of both PC-3 and DU-145 cells to fibronectin. Furthermore chromogranin A fragment increased the fibrinolytic activities of urokinase-type plasminogen activator (u-PA) in fibrin zymograms of both PC-3 and DU-145 cells and the expression of u-PA mRNA of PC-3 cells. However, the growth of these tumor cells was not affected by chromogranin A fragment at any concentrations used in this study. These results indicate that chromogranin A fragment increased the invasive potential of both PC-3 and DU-145 cells probably through enhancement of cell motility and the production of u-PA.