Promising immunohistochemical and circulating markers of insulinoma

Abstract

Insulinoma is the most common functioning pancreatic neuroendocrine tumor. The review examines the currently used immunohistochemical and circulating markers for its diagnosis, and discusses the sensitivity and specificity of these parameters. At the same time, the relevance of searching for new biochemical indicators of the presence of insulinoma and its characteristics, as well as studying the mechanisms of tumor growth and hormonal hypersecretion is emphasized. One of the primary methods for solving these problems is immunohistochemical testing with the determination of circulating markers. The results of recent studies of alternative secretory products, in particular, cocaine - and amphetamine - regulated transcript (CART), chromogranin B, and neuroendocrine secretory protein 55 (NESP55) are presented. In addition, the question of expression of various receptors in the insulinoma tissue is considered, including in the context of determining molecular targets for its visualization or radiotherapy. In particular, the expression of receptors for glucagon-like peptide 1 in the tumor tissue is characterized. The possible role of melatonin receptors MT1 (MTNR1a) and MT2 (MTNR1b) in the pathogenesis of insulinoma is clarified. The article also discusses the possible use of tumor protein D52 (TPD52) as a new predictive biomarker for the differential diagnosis of benign and malignant insulinoma.