MicroRNA-145 inhibits the activation of the mTOR signaling pathway to suppress the proliferation and invasion of invasive pituitary adenoma cells by targeting AKT3 in vivo and in vitro

Abstract

PurposeThis study was designed to explore how miR-145 regulates the mTOR signaling pathway in invasive pituitary adenoma (IPA) by targeting AKT3.MethodsA total of 71 cases of IPA tissues and 66 cases of non-IPA tissues were obtained in this study. In vitro, the IPA cells were assigned into blank control, empty plasmid, miR-145 mimic, miR-145 inhibitor, miR-145 mimic + rapamycin, miR-145 inhibitor + rapamycin and rapamycin groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were performed to detect the protein expressions of PI3K, AKT3, mTOR mRNA and the mRNA expression of miR-145 both in vivo and in vitro. Additionally, the S6K and RPS6 mRNA and protein expressions as well as the relative phosphorylation levels were determined in vitro. MTT assay, flow cytometry and transwell assay were used to testify the cell proliferation, apoptosis and invasion ability, respectively.ResultsThe IPA tissues exhibited significantly lower expression of miR-145 but higher PI3K, AKT3 and mTOR mRNA and protein expressions when compared with the non-IPA tissues. Compared with the blank control and empty plasmid groups, the miR-145 mimic group showed significantly decreased PI3K, AKT3, mTOR, S6K and RPS6 mRNA and protein expressions as well as phosphorylation levels; besides, the IPA cell proliferation, migration and invasion ability were strongly inhibited, accompanied with the increased number of apoptotic cells. In the miR-145 inhibitor group, the PI3K, AKT3, mTOR, S6K and RPS6 mRNA and protein expressions as well as the phosphorylation levels were significantly increased; cell proliferation, migration and invasion ability were remarkably elevated, accompanied with reduced apoptotic cell number.ConclusionThe study demonstrates that miR-145 inhibits the mTOR signaling pathway to suppress the IPA cell proliferation and invasion and promotes its apoptosis by targeting AKT3.

Multiomics-Based Signaling Pathway Network Alterations in Human Non-functional Pituitary Adenomas

“…Many studies have shown that targeting some high-frequency hub-molecules in Table 1 has achieved good results in other types of pituitary adenomas. For example, TGFβ1 is used as a novel therapeutic target to treat resistant prolactinomas (66); the microRNA-145 inhibits the activation of the mTOR signaling by targeting AKT3 to suppress the proliferation and invasion of invasive pituitary adenoma cells (67); lncRNA H19 inhibits mTORC1 by disrupting 4E-BP1/Raptor interaction in pituitary tumors (68); and MAPK Pathways act as therapeutic targets in pituitary tumors (69). Because PI3K/Akt/mTOR and ERK/MAPK signaling pathways are significantly dysregulated in NFPA, and these two essential signaling pathways are not only related to rapid proliferation and apoptosis resistance of tumor cells, but also can regulate the activities of many other pathways and then regulate tumor growth in the multiple levels.…”

miR-499 Ameliorates Podocyte Injury by Targeting Calcineurin in Minimal Change Disease

“…Dual-luciferase reporter gene assays were then performed to confirm the correlation as previously described [17]. MiR-499 mimic was synthesized referring to the sequence of mature miR-499, and was cloned into the in-house pRNA-Lenti-EGFP lentivirus vector to construct miR-499 mimic plasmid.…”

MiRNAs as Noninvasive Biomarkers and Therapeutic Agents of Pituitary Adenomas

“…As a central regulator of cell growth, mTOR plays a key role in the development and aging of cells and is involved in the pathogenesis of cardiovascular diseases, endocrine diseases, metabolic disorders, and tumors [ 72 ]. Antiproliferative responses to mTOR inhibition have been reported in studies with aggressive PA in vitro and in vivo [ 73 , 74 ]. Zhou et al showed that the miR-145 expression strongly decreased while mTOR mRNA expressions significantly increased in invasive pituitary adenoma tissues compared with those in noninvasive pituitary adenoma tissues [ 74 ].…”

“…Antiproliferative responses to mTOR inhibition have been reported in studies with aggressive PA in vitro and in vivo [ 73 , 74 ]. Zhou et al showed that the miR-145 expression strongly decreased while mTOR mRNA expressions significantly increased in invasive pituitary adenoma tissues compared with those in noninvasive pituitary adenoma tissues [ 74 ]. In addition, miR-145 can not only suppress cell proliferation, migration, and invasion in invasive PA but also promote invasive PA cell apoptosis by the mTOR signaling pathway.…”