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

Abstract

Non-functional pituitary adenoma (NFPA) seriously affects hypothanamus-pituitary-target organ axis system, with a series of molecule alterations in the multiple levels of genome, transcriptome, proteome, and post-translational modifications, and those molecules mutually interact in a molecular-network system. Meta analysis coupled with IPA pathway-network program was used to comprehensively analyze nine sets of documented NFPA omics data, including NFPA quantitative transcriptomics data [280 differentially expressed genes (DEGs)], NFPA quantitative proteomics data [50 differentially expressed proteins (DEPs)], NFPA mapping protein data (218 proteins), NFPA mapping protein nitration data (9 nitroproteins and 3 non-nitrated proteins), invasive NFPA quantitative transriptomics data (346 DEGs), invasive NFPA quantitative proteomics data (57 DEPs), control mapping protein data (1469 proteins), control mapping protein nitration data (8 nitroproteins), and control mapping phosphorylation data (28 phosphoproteins). A total of 62 molecular-networks with 861 hub-molecules and 519 canonical-pathways including 54 cancer-related canonical pathways were revealed. A total of 42 hub-molecule panels and 9 canonical-pathway panels were identified to significantly associate with tumorigenesis. Four important molecular-network systems, including PI3K/AKT, mTOR, Wnt, and ERK/MAPK pathway-systems, were confirmed in NFPAs by PTMScan experiments with altered expression-patterns and phosphorylations. Nineteen high-frequency hub-molecules were also validated in NFPAs with PTMScan experiment with at least 2.5-fold changes in expression or phosphorylation, including ERK, ERK1/2, Jnk, MAPK, Mek, p38 MAPK, AKT, PI3K complex, p85, PKC, FAK, Rac, Shc, HSP90, NFκB Complex, histone H3, AP1, calmodulin, and PLC. Furthermore, mTOR and Wnt pathway-systems were confirmed in NFPAs by immunoaffinity Western blot analysis, with significantly decreased expression of PRAS40 and increased phosphorylation levels of p-PRAS40 (Thr246) in mTOR pathway in NFPAs compared to controls, and with the decreased protein expressions of GSK-3β and GSK-3β, significantly increased phosphorylation levels of p-GSK3α (Ser21) and p-GSK3β (Ser9), and increased expression level of β-catenin in Wnt pathway in NFPAs compared to Long et al. Molecular Networks of Non-functional Pituitary Adenomas controls. Those findings provided a comphrensive and large-scale pathway network data for NFPAs, and offer the scientific evidence for insights into the accurate molecular mechanisms of NFPA and discovery of the effective biomarkers for diagnosis, prognosis, and determination of therapeutic targets.

Quantitative Analysis of Proteome in Non-functional Pituitary Adenomas: Clinical Relevance and Potential Benefits for the Patients

“…This result indicated that AKT1 was a DEG at the level of transcriptome, but it was not a DEP at the level of proteome, between NFPAs and controls. It might be derived from different protein PTMs to produce different AKT1 proteoforms (65)(66)(67)(68), which was confirmed by our another PTMScan experimental study that the phosphorylation levels at residues Ser473, Thr308, or Thr312 in AKT1 were significantly increased by at least 3 folds in NFPAs compared to controls (62). Therefore, the phosphorylated AKT1 (pAKT1) might contribute to NFPA pathogenesis.…”

“…Furthermore, this study used western blotting analysis to confirm that the expression of AKT1 protein in NFPA and control tissues although it was not changed significantly between NFPAs and controls. However, in our research group, another study found phosphorylated AKT1 in NFPA was significantly increased (62), which might lead to the activation of PI3K-AKT-mTOR pathway. In addition, studies also showed that low levels of APAF-1 were inversely related to invasiveness, and cathepsin B expression was positively related to invasiveness in pituitary adenomas (63).…”

Hormones Secretion and Rho GTPases in Neuroendocrine Tumors

“…Knock-down of FGD4 in PC-3 and LNCaP-104S prostate cell lines inhibited cell proliferation, cell cycle progression, and cell migration [60]. In pituitary adenoma, ARHGAP18 and ARHGEF17 are both upregulated, suggesting a modulation of the activity of the target Rho GTPases, most likely RhoA [44]. Variation in VAV isoforms (GEFs for Rho and Rac GTPases) expression levels was reported in small cell lung carcinoma [62,63].…”

“…However, only a few studies were performed in NETs, mainly in pituitary adenoma and neuroblastoma, as well as in tumors from the thyroid, parathyroid, and small cell lung. For instance, in pituitary adenoma, Rac1 overexpression and Cdc42 down-regulation may affect pathways controlling tumorigenesis such as mTOR-and Wnt-signalling pathways [44]. Arising from primitive cells of the sympathetic nervous systems, neuroblastoma is a common childhood extracranial solid tumor with neuroendocrine properties [45].…”

A Rare Case of Recurrent Pituitary Collision Tumors

“…Despite intensive molecular investigations, mechanisms of pathogenesis of NFPA are not completely understood [ 22 , 23 ]. However, evidence suggests that high levels of expression of β-CATENIN protein contribute to the development of NFPA [ 24 , 25 ].…”