ARE MicroRNAs INVOLVED IN THE ENDOCRINE-SPECIFIC PATTERN OF TUMORIGENESIS IN MULTIPLE ENDOCRINE NEOPLASIA TYPE 1?

Objective: To provide a general background regarding current knowledge about microRNA (miRNA) involvement in endocrine functions and in multiple endocrine neoplasia type 1 (MEN 1) endocrine tumorigenesis. Methods: A literature search was conducted in the miRNA database for articles on the role of miRNAs in the initiation and progression of human malignant conditions, inasmuch as miRNAs show different patterns of expression in normal and neoplastic tissues. We address the potential role of miRNAs in the endocrine pancreas, the pituitary gland, and the parathyroid glands-areas where MEN 1 shows high penetrance. Results: Experimental studies have shown the involvement of miRNAs in regulation of endocrine functions, such as insulin secretion. Moreover, studies have provided evidence that dysregulation of miRNAs was responsible for endocrine carcinogenesis, including pancreatic, pituitary, and parathyroid tumors. Conclusion: miRNA expression profiles may become useful biomarkers for endocrine tumor diagnostics as well as potential targets of therapeutic strategies applied to pathologic conditions such as type 2 diabetes and endocrine tumors. Future studies should investigate the molecular and cellular mechanisms of tissue selectivity in MEN 1-associated tumorigenesis, in an effort to develop an RNA-based treatment that could prevent or delay the onset of MEN 1-associated tumors.