Identifying critical protein-coding genes and long non-coding RNAs in non-functioning pituitary adenoma recurrence

Differential expression of cancer-related lncRNAs in different subtypes of pituitary adenomas

Recent investigations have demonstrated abnormal expression of non-coding RNAs in pituitary adenomas. Cntribution of many lncRNAs to the pathogenesis of these tumors has not been evaluated yet. HOTTIP, ANRIL, PANDAR, PCGEM1 and HOTAIR are among lncRNAs with established roles in the pathogenesis of human cancers, particularly those originated from endocrine organs. The current study aims at assessment of expression of these lncRNAs in pituitary adenomas in comparison with the adjacent non-cancerous pituitary tissues. HOTAIR expression was absent from the majority of adenoma and non-tumoral samples. Expression of HOTTIP was significantly higher in non-functioning pituitary adenoma (NFPA) samples compared with paired normal samples (expression ratio (95 % CI)= 2.1 (1.13-2.1), P value=0.03). Expression of PANDAR was higher in total adenoma samples compared with paired normal samples (expression ratio (95 % CI)= 1.91 (1.16-3.13), P value=0.02). Expression of ANRIL was higher in NFPA samples compared with paired normal samples (expression ratio (95 % CI)= 1.94 (1.05-3.6), P value=0.048) and in total adenoma samples compared with paired normal samples (expression ratio (95 % CI)= 1.82 (1.11-2.98), P value=0.025). The current study raises the possibility of contribution of lncRNAs in the pathogenesis of at least some subtypes of pituitary adenomas and warrant further functional studies in this field.

Regulation of long noncoding RNAs in the pathogenesis and clinical implications of pituitary adenomas

BACKGROUND

Pituitary adenoma (PA) is a type of tumor that develops in the sella turcica and is one of the most frequent intracranial tumors. It belongs to a type of adenoma derived from a single clone of cells in the pituitary gland. PA ranks third among all intracranial tumors, following only gliomas and meningioma. The average prevalence rate is approximately 15% at autopsy and 22.5% at radiological examinations.

OBJECTIVE AND SIGNIFICANCE

Most PAs are benign and non-invasive adenomas that can be removed surgically or controlled with medication. However, approximately 35% of them show invasion into nearby anatomical structures and cannot be completely resected. 0.1%~0.2% of PA cases eventually develop into pituitary carcinomas. Additionally, PA may cause severe morbidity due to mass effects and the disorder of pituitary hormone secretion. Therefore, there is an urgent need to clarify the pathological mechanism of PA, improve the accuracy of diagnosis, and develop targeted therapies.

RESEARCH STATUS

Although current knowledge about the pathogenesis of PA remains limited, epigenetic modulation of PA has been increasingly implicated. Long non-coding RNAs (lncRNAs) are known to regulate gene expression post-transcriptionally and exert substantial roles in the initiation, progression, or suppression of various tumors. Accumulating evidence has shown close relationships between lncRNA dysregulation and PA development.

CONCLUSIONS

This review highlights recent progress in the study of lncRNAs in PA pathogenesis and their potential as diagnostic/prognostic biomarkers or therapeutic targets for PA patients.

Dysregulation of PVT1 and NEAT1 lncRNAs in pituitary adenomas

Pituitary adenomas are slow-growing tumors originated from the anterior part of pituitary gland. These tumors are associated with dysregulation of a number of long non-coding RNAs (lncRNAs). PVT1, TUG1, MALAT1, NEAT1 and GAS5 are among lncRNAs with important roles in the regulation of cell proliferation, cell apoptosis, cell differentiation and cell cycle transition. In the current study, we assessed expression levels of PVT1, TUG1, MALAT1, NEAT1 and GAS5 in the pituitary adenoma samples compared with adjacent non-cancerous samples to find their relevance with this type of tumors and their potential as diagnostic markers in these tumors. Expression of NEAT1 was significantly higher in total adenoma tissues (Expression ratio (95% CI)= 7.06 (2.31-21.4), P value= 0.02) and in non-functioning pituitary adenoma (NFPA) samples (Expression ratio (95% CI)= 8.5 (2.17-33.12), P value= 0.04) compared with corresponding controls. Although both lncRNAs had appropriate sensitivity values for discrimination of NFPAs from adjacent non-cancerous tissues (0.84 and 0.90 for PVT1 and NEAT1, respectively), the calculated AUC values were not adequate for either lncRNAs (0.63 ± 0.04 and 0.58 ± 0.04 for PVT1 and NEAT1, respectively). Therefore, NEAT1 and PVT1 lncRNAs are dysregulated in NFPA. The current study suggests the role of NEAT1 and PVT1 in the pathogenesis of NFPA.

Transcriptome of GH-producing pituitary neuroendocrine tumours and models are significantly affected by somatostatin analogues

Pituitary neuroendocrine tumours (PitNETs) are neoplasms of the pituitary that overproduce hormones or cause unspecific symptoms due to mass effect. Growth hormone overproducing GH-producing PitNETs cause acromegaly leading to connective tissue, metabolic or oncologic disorders. The medical treatment of acromegaly is somatostatin analogues (SSA) in specific cases combined with dopamine agonists (DA), but almost half of patients display partial or full SSA resistance and potential causes of this are unknown. In this study we investigated transcriptomic landscape of GH-producing PitNETs on several levels and functional models-tumour tissue of patients with and without SSA preoperative treatment, tumour derived pituispheres and GH3 cell line incubated with SSA to study effect of medication on gene expression. MGI sequencing platform was used to sequence total RNA from PitNET tissue, pituispheres, mesenchymal stromal stem-like cells (MSC), and GH3 cell cultures, and data were analysed with Salmon-DeSeq2 pipeline. We observed that the GH-producing PitNETs have distinct changes in growth hormone related pathways related to its functional status alongside inner cell signalling, ion transport, cell adhesion and extracellular matrix characteristic patterns. In pituispheres model, treatment regimens (octreotide and cabergoline) affect specific cell proliferation (MKI67) and core functionality pathways (RYR2, COL8A2, HLA-G, ARFGAP1, TGFBR2). In GH3 cells we observed that medication did not have transcriptomic effects similar to preoperative treatment in PitNET tissue or pituisphere model. This study highlights the importance of correct model system selection for cell transcriptomic profiling and data interpretation that could be achieved in future by incorporating NGS methods and detailed cell omics profiling in PitNET model research.

Evaluation of autoantibody signatures in pituitary adenoma patients using human proteome arrays

PURPOSE

To identify the specific diagnostic biomarkers related to pituitary adenomas (PAs), we performed serological antibody profiles for three types of PAs, namely Acromegaly, Cushing's and Nonfunctional Pituitary Adenomas (NFPAs), using the human proteome (HuProt) microarray. This is the first study describing the serum autoantibody profile of PAs.

EXPERIMENTAL DESIGN

We performed serological autoantibody profiling of four healthy controls, four Acromegaly, three Cushing's and three NFPAs patient samples to obtain their autoantibody profiles, which were used for studying expression, interaction and altered biological pathways. Further, significant autoantibodies of PAs were compared with data available for glioma, meningioma and AAgAtlas for their specificity.

RESULTS

Autoantibody profile of PAs led to the identification of differentially expressed significant proteins such as AKNAD1 (AT-Hook Transcription Factor [AKNA] Domain Containing 1), NINJ1 (Nerve injury-induced protein 1), L3HYPDH (Trans-3-hydroxy-L-proline dehydratase), RHOG (Rho-related GTP-binding protein) and PTP4A1 (Protein Tyrosine Phosphatase Type IVA 1) in Acromegaly. Protein ABR (Active breakpoint cluster region-related protein), ST6GALNAC6 (ST6 N-acetylgalactosaminide alpha-2, 6-sialyltransferase 6), NOL3 (Nucleolar protein 3), ANXA8 (Annexin A8) and POLR2H (RNA polymerase II, I and III subunit H) showed an antigenic response in Cushing's patient's serum samples. Protein dipeptidyl peptidase 3 (DPP3) and reticulon-4 (RTN4) exhibited a very high antigenic response in NFPA patients. These proteins hold promise as potential autoantibody biomarkers in PAs.

lncRNA–mRNA Expression Patterns in Invasive Pituitary Adenomas: A Microarray Analysis

Background. Long noncoding RNAs (lncRNAs) play important roles in the tumorigenesis and progression of various cancer types; however, their roles in the development of invasive pituitary adenomas (PAs) remain to be investigated. Methods. lncRNA microarray analysis was performed for three invasive and three noninvasive PAs. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed, and coexpression networks between lncRNA and mRNA were constructed. Furthermore, three differentially expressed lncRNAs were selected for validation in PA samples by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The diagnostic values of these three lncRNAs were further evaluated by a receiver operating characteristic (ROC) curve analysis. Results. A total of 8872 lncRNAs were identified in invasive and paired noninvasive PAs via lncRNA microarray analysis. Among these, the differentially expressed lncRNAs included 81 that were upregulated and 165 that were downregulated. GO enrichment and KEGG pathway analysis showed that these differentially expressed lncRNAs were associated with the posttranslational modifications of proteins. Furthermore, we performed target gene prediction and coexpression analysis. The interrelationships between the significantly differentially expressed lncRNAs and mRNAs were identified. Additionally, three differentially expressed lncRNAs were selected for validation in 41 PA samples by qRT-PCR. The expression levels of FAM182B, LOC105371531, and LOC105375785 were significantly lower in the invasive PAs than in the noninvasive PAs ( $P<0.05$ ). These results were consistent with the microarray data. ROC curve analysis suggested that the expression levels of FAM182B and LOC105375785 could be used to distinguish invasive PAs from noninvasive PAs. Conclusion. Our findings demonstrated the expression patterns of lncRNAs in invasive PAs. FAM182B and LOC105375785 may be involved in the invasiveness of PAs and serve as new candidate biomarkers for the diagnosis of invasive PAs.

Long non-coding MELTF Antisense RNA 1 promotes and prognosis the progression of non-small cell lung cancer by targeting miR-1299

This paper explored the influence of long non-coding MELTF Antisense RNA 1 (lncRNA MELTF-AS1) on the prognosis of non-small cell lung cancer (NSCLC), and further deepened the understanding of NSCLC. A total of 130 patients with NSCLC participated in current study to detect and compare lncRNA MELTF-AS1 expression in cancer and normal tissues. Kaplan-Meier analysis and log-rank test were chosen to analyze the effect of MELTF-AS1 expression on the survival of patients within 5 years. The correlation between the expression of MELTF-AS1 and the clinical characteristics of NSCLC patients was analyzed, and the prognostic factors of NSCLC were analyzed by multivariate Cox regression. Subsequently, MELTF-AS1 expression in NSCLC cells were detected. The Cell Counting Kit-8 (CCK-8) and Transwell methods were selected to study the proliferation, migration capability and invasion level of NSCLC cells that silencing MELTF-AS1. Through the luciferase activity assay to explore the relationship between MELTF-AS1 and miR-1299, to further understand the effect of silencing MELTF-AS1 on NSCLC. MELTF-AS1 was increased in NSCLC tissues and cells. Silencing MELTF-AS1 suppressed the proliferation ability, migration capability and invasion level of NSCLC cells, which means that low expression of MELTF-AS1 may be more conducive to patient survival. In addition, through luciferase activity analysis and bioinformatics analysis, MELTF-AS1 has a negative effect on miR-1299, and silencing MELTF-AS1 enhanced miR-1299 expression in NSCLC cells. MELTF-AS1 is highly likely to be a promising prognostic biomarker, and associated with the progression of NSCLC.

Muti-omics integration analysis revealed molecular network alterations in human nonfunctional pituitary neuroendocrine tumors in the framework of 3P medicine

Nonfuctional pituitary neuroendocrine tumor (NF-PitNET) is highly heterogeneous and generally considered a common intracranial tumor. A series of molecules are involved in NF-PitNET pathogenesis that alter in multiple levels of genome, transcriptome, proteome, and metabolome, and those molecules mutually interact to form dynamically associated molecular-network systems. This article reviewed signaling pathway alterations in NF-PitNET based on the analyses of the genome, transcriptome, proteome, and metabolome, and emphasized signaling pathway network alterations based on the integrative omics, including calcium signaling pathway, cGMP-PKG signaling pathway, mTOR signaling pathway, PI3K/AKT signaling pathway, MAPK (mitogen-activated protein kinase) signaling pathway, oxidative stress response, mitochondrial dysfunction, and cell cycle dysregulation, and those signaling pathway networks are important for NF-PitNET formation and progression. Especially, this review article emphasized the altered signaling pathways and their key molecules related to NF-PitNET invasiveness and aggressiveness that are challenging clinical problems. Furthermore, the currently used medication and potential therapeutic agents that target these important signaling pathway networks are also summarized. These signaling pathway network changes offer important resources for insights into molecular mechanisms, discovery of effective biomarkers, and therapeutic targets for patient stratification, predictive diagnosis, prognostic assessment, and targeted therapy of NF-PitNET.