miR-23b and miR-130b expression is downregulated in pituitary adenomas

• Here we investigated the role of miR-23b and miR-130b in pituitary carcinogenesis.
• miR-23b and miR-130b are reduced in pituitary adenomas of different histotype.
• miR-23b and miR-130b target HMGA2 and cyclin A2 (CCNA2) genes, respectively.
• HMGA2 and cyclin A2 (CCNA2) play a critical role in pituitary tumorigenesis.

MicroRNA (miRNA) deregulation plays a critical role in tumorigenesis. miR-23b and miR-130b are induced by thyrotropin in thyroid cells in a cAMP-dependent manner.The aim of our work has been to investigate the possible role of miR-23b and miR-130b in pituitary tumorigenesis. We have analyzed their expression in a panel of pituitary adenomas (PAs) including GH and NFPA adenomas.We report that miR-23b and miR-130b are drastically reduced in GH, gonadotroph and NFPA adenomas in comparison with normal pituitary gland. Interestingly, the overexpression of miR-23b and miR-130b inhibits cell proliferation arresting the cells in the G1 and G2 phase of the cell cycle, respectively. Moreover, we demonstrate that miR-23b and miR-130b target HMGA2 and cyclin A2 (CCNA2) genes, respectively. Finally, downregulation of miR-23b and miR-130b expression is associated with increased levels of their respective targets in human PAs.These findings suggest that miR-23b and miR-130b downregulation may contribute to pituitary tumorigenesis.