Identification of Serum miRNA-423-5p Expression Signature in Somatotroph Adenomas

Abstract

Circulating miRNAs are novel disease biomarkers that are valuable for diagnosis and prognosis. But the circulating miRNAs profile in somatotroph adenomas is still unknown. Therefore, serum exosomal miRNAs expression profiling in somatotroph adenomas was performed on 6 somatotroph adenomas and 6 normal controls. From the exosomal miRNAs expression profiling, we found 169 miRNAs differently expressed between somatotroph adenomas and healthy pituitary samples (p< 0.05, FC > 2). Among the 169 miRNAs, miR-423-5p was expressed lower in somatotroph adenomas than in healthy pituitary samples, which was proved by miRSCan Panel Chip™ qPCR. PTTG1 and SYT1 were the target mRNAs of miR-423-5p, and transcriptomics and proteomics profile both indicated the high expression of PTTG1 and SYT1 in somatotroph adenomas. H-scores were 223.1 ± 34.7 for PTTG1 and 163.4 ± 42.3 for SYT1 in 62 somatotroph adenomas specimens and 84.2 ± 21.3 for PTTG1 and 47.4 ± 17.2 for SYT1 in 6 healthy pituitary specimens by IHC. miR-423-5p inhibited the expression of SYT1 and PTTG1 at the mRNA and protein levels. Dual luciferase reporter gene assay shown was significantly reduced in the presence of miR-423-5p in GH3 cells transfected with wild-type PTTG1 3'UTR luciferase reporter plasmid but not reduced when transfected with the mutation PTTG1 3'UTR luciferase reporter plasmid (p<0.01). In vitro experiments showed that miR-423-5p induced cell apoptosis, inhibited cell proliferation, and reduced growth hormone release and migration of GH3 cells. The activity of miR-423-5p in GH3 cell was nearly blocked by its inhibitor. These results verified the central role of low miR-423-5p in promoting tumorigenesis in somatotroph adenomas. PTTG1 may act as biomarkers for clinical treatment of somatotroph adenomas.

Genetic and Epigenetic Causes of Pituitary Adenomas

“…First, miR-338-3p is upregulated in invasive somatotroph adenomas, and probably mediates the increased expression of PTTG1 ( 89 ). Second, miR-423-5p, which targets PTTG1 , shows decreased expression in somatotroph adenomas, and inhibits the expression of PTTG1 at both the mRNA and protein levels ( 90 ). Third, overexpression of miR-524-5p downregulates the expression of PTTG1 -binding factor, which interacts with PTTG1 to mediate downstream effects, and significantly attenuates proliferation, migration, and invasion in vitro ( 91 ).…”

JAG1, Regulated by microRNA-424-3p, Involved in Tumorigenesis and Epithelial–Mesenchymal Transition of High Proliferative Potential-Pituitary Adenomas

“…In theory, miRNAs are ideal therapeutic choice for cancers because their small size enables them to penetrate the dense architecture of cancer ( 30 ). We reported the circulating miRNAs profile of 169 miRNAs differently expressed between somatotroph adenomas and healthy samples ( 31 ). In vitro experiments verified that miR-424-3p relieved the migration and invasion of GH3 cell line, mimics or inhibitor of miR-424-3p can regulate the level of JAG1 which, in turn, affects cell proliferation and the levels of MMP2 and VIM in GH3 cell line, respectively.…”

Biomarkers for Liquid Biopsies of Pituitary Neuroendocrine Tumors

“…This miRNA is called miR-423-5p and was found underexpressed in plasma samples of six somatotroph adenomas versus six healthy pituitary samples. In vitro experiments further showed that this miRNA is inhibiting cell proliferation and growth hormone release in GH3 pituitary cells, which makes it interesting for diagnostics and therapies [85].…”