MicroRNAs-based network: a novel therapeutic agent in pituitary adenoma.

Pituitary adenomas are common benign intracranial neoplasms representing about 10-25% of all intracranial neoplasm. Significant morbidity can occur along with pituitary adenomas due to hormonal dysfunction and mass effects. The pathogenesis of pituitary adenoma is unclear, however, etiologic factors include genetic events, hormonal stimulation, and growth factors [1], all of which promote cell proliferation and transformation in the tumor. However, genetic events play the most important role in tumorigenesis. MicroRNAs (miRNAs), a class of non-coding RNAs, not only have function in pituitary cell proliferation and apoptosis but also in neoplastic transformation. It has been shown that miRNAs are differentially expressed in pituitary adenoma when compared with the normal pituitary gland; moreover, miRNAs have been identified as a predictive signature of pituitary adenoma and can be used to predict the histotype. The expression of miRNAs can be used not only to differentiate microadenomas from macroadenomas, but to also distinguish samples of treated patients from samples of non-treated patients. Therefore, we hypothesized that a miRNA-based network may be involved in pituitary tumorigenesis and it can potentially serve as useful diagnostic markers to improve the classification of pituitary adenomas. Here, we reviewed the therapeutic potential that different types of miRNAs may play in tumorigenesis. Moreover, miRNAs may emerge as potential therapeutic targets. We speculated the mechanism of miR-21 is involved in tumorigenesis, leading to improvements in therapies and prevention of metastasis.