The Emerging Role of Non-Coding RNAs in Pituitary Gland Tumors and Meningioma

Expression analysis of necroptosis related genes and lncRNAs in patients with pituitary neuroendocrine tumors

Necroptosis can either be the cause of tumorigenesis or it can impede its process. Recently, it has been proved that long non-coding RNAs (lncRNAs) have different crucial roles at cellular level, especially on cell death. Regarding the important role of necroptosis and lncRNAs in the pathogenesis of different cancers, especially pituitary adenomas (PAs), we assessed expression levels of two necroptosis related genes, namely TRADD and BIRC2, in addition to three related lncRNAs, namely FLVCR1-DT, MAGI2-AS3, and NEAT1 in PAs compared with adjacent normal tissues (ANTs). TRADD had no significant difference between two groups; however, BIRC2, FLVCR1-DT, MAGI2-AS3, and NEAT1 were upregulated in PAs compared to ANTs (Expression ratios [95% CI] = 2.3 [1.47-3.6], 2.13 [1.02-4.44], 3.01 [1.76-5.16] and 2.47 [1.37-4.45], respectively). When taking into account different types of PAs, significant upregulation of BIRC2, MAGI2-AS3 and NEAT1 was recorded in non-functioning PAs compared with corresponding ANTs (Expression ratios [95% CI] =1.9 [1.04-3.43], 2.69 [1.26-5.72] and 2.22 [0.98-5.01], respectively). Additionally, higher levels of BIRC2 were associated with higher flow of CSF (P value=0.048). Moreover, higher Knosp classified tumors had lower levels of BIRC2 (P value=0.001). Finally, lower levels of MAGI2-AS3 were associated with larger tumor size (P value=0.006). NEAT1 expression was correlated with FLVCR1-DT and TRADD. TRADD expression was correlated with FLVCR1-DT. Additional correlation was observed between expression of BIRC2 and MAGI2-AS3. In sum, this study provides evidence that dysregulated levels of studied genes could contribute to the pathogenesis of pituitary tumors.

LncRNA taurine upregulated gene 1 in liver disease

Long non-coding RNAs (lncRNAs) are RNA sequences exceeding 200 nucleotides in length that lack protein-coding capacity and participate in diverse biological processes in the human body, particularly exerting a pivotal role in disease surveillance, diagnosis, and progression. Taurine upregulated gene 1 (TUG1) is a versatile lncRNA, and recent studies have revealed that the aberrant expression or function of TUG1 is intricately linked to the pathogenesis of liver diseases. Consequently, we have summarized the current understanding of the mechanism of TUG1 in liver diseases such as liver fibrosis, fatty liver, cirrhosis, liver injury, hepatitis, and liver cancer. Moreover, mounting evidence suggests that interventions targeting TUG1 or its downstream pathways may hold therapeutic promise for liver diseases. This review elucidates the characteristics, mechanisms, and targets of TUG1 in liver diseases, offering a theoretical basis for the prevention, diagnosis, treatment, and prognostic biomarkers of liver diseases.

Hsa_circ_0004872 mitigates proliferation, metastasis and immune escape of meningioma cells by suppressing PD-L1

Meningioma is a prevalent intracranial malignancy known for its aggressive growth. Circular RNAs (circRNAs) play a crucial role in the development of various cancers. However, their involvement in meningioma remains understudied. This study aimed to investigate the function and underlying mechanism of hsa_circ_0004872 in meningioma. The molecular expression of hsa_circ_0004872, PD-L1 and EIF4A3 was identified by RT-qPCR and/or western blot assays. Cell viability, migration, and invasion were assessed through CCK-8 and Transwell assays, respectively. Cytotoxicity was determined using an LDH assay, and cell apoptosis was monitored by flow cytometry. The RNA and protein interactions were assessed through RNA-protein immunoprecipitation (RIP) and RNA pull down analyses. Our findings revealed that hsa_circ_0004872 expression was significantly downregulated in both meningioma tissue samples and cells. Overexpression of hsa_circ_0004872 inhibited the proliferation, metastasis, and immune escape of meningioma cells, as well as enhanced the cytotoxicity of CD8+ T cells by suppressing PD-L1. Furthermore, hsa_circ_0004872 directly interacted with EIF4A3, leading to the degradation of PD-L1 mRNA. Finally, inhibiting EIF4A3 improved the proliferation, metastasis, and immune escape of meningioma cells, as well as the cytotoxicity of CD8+ T cells. Our study demonstrated that hsa_circ_0004872 mitigated the proliferation, metastasis,and immune escape of meningioma cells by targeting the EIF4A3/PD-L1 axis. These findings suggested that hsa_circ_0004872 and EIF4A3 might serve as promising biological markers and therapeutic targets for meningioma treatment.

Integrated bioinformatics approaches and expression assays identified new markers in pituitary adenomas

Pituitary adenomas (PA) include about one third of primary central nervous tumors in adolescent and young adult. Despite extensive research, the underlying mechanism of PA tumorigenesis is still unknown. In the present study, through bioinformatics analysis of a PA-related dataset downloaded from GEO database, we attempted to identify pair(s) of lncRNA/target mRNA whose expression changes may be involved in the tumorigenesis of PAs. For this end, we evaluated expression of a set of bioinformatically obtained genes in 46 PA tissues against adjacent non-tumor pituitary tissues. The bioinformatics step led to selection of four genes for validation through expression assays. Expression levels of HIF1A and MAPK1 were increased in NFPA tissues (P < 0.0001 and =0.0042, respectively). Expression level of BANCR was significantly decreased in tumor tissues (P < 0.0001). However, expression of STAT3 was not meaningfully different between the two tissue types (P = 0.56). Since there was no significant correlation between MAPK1 and BANCR expressions in either tumor or adjacent normal tissues, the regulatory effect of BANCR on MAPK1 was not confirmed. In conclusion, this study offers information about deregulation of bioinformatically identified genes in PA tumors and indicates that further studies in this field is needed to understand the involved molecular mechanisms.

Expression of cAMP and oxidative phosphorylation-related lncRNAs in non-functioning pituitary adenomas

Non-functioning pituitary adenomas (NFPAs) are benign lesions in the pituitary gland with important morbidities. In this study, based on a bioinformatics analysis to identify the genes and pathways that display significant differences between tumour tissues of NFPA patients and normal pituitary tissues, we selected lncRNAs related to cAMP and oxidative phosphorylation pathways, namely DNAH17-AS1, LINC00706 and SLC25A5-AS1. Then, we aimed to investigate by means of RT-qPCR, the expression of these lncRNAs along with two other lncRNAs, namely CADM3-AS1 and MIR7-3HG in NFPA samples compared to that in healthy tissues adjacent to the tumours. Transcripts of DNAH17-AS1, LINC00706 and MIR7-3HG were lower in NFPA samples compared with controls (Expression ratios (95% CI) = 0.43 (0.23-0.78), 0.58 (0.35-0.96) and 0.58 (0.35-0.96); p-values = 0.009, 0.025 and 0.036, respectively). AUC values of ROC curves of DNAH17-AS1, LINC00706 and MIR7-3HG were 0.62, 0.61 and 0.62, respectively. Expression of CADM3-AS1 was associated with the gender of patients in a way that it was lower in female patients (p-value = 0.04). The level of SLC25A5-AS1 was lower in subjects with disease duration lower than 1 year (p-value = 0.048). We showed dysregulation of three lncRNAs in NFPA tissues and potentiates these lncRNAs as important regulators of pathogenic events in these tumours.

Interplay between lncRNA/miRNA and Wnt/ß-catenin signaling in brain cancer tumorigenesis

Brain cancers are among the most aggressive malignancies with high mortality and morbidity worldwide. The pathogenesis of brain cancers is a very complicated process involving various genetic mutations affecting several oncogenic signaling pathways like Wnt/β-catenin axis. Uncontrolled activation of this oncogenic signaling is associated with decreased survival rate and poor prognosis in cancer patients. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) were shown to play important roles in regulating cell proliferation, differentiation, and apoptosis by regulating the expression of their target genes. Aberrant expression of these non-coding RNAs (ncRNAs) was reported in many human cancers, including glioblastoma, medulloblastoma, meningioma, and pituitary adenoma. Multiple lncRNAs were shown to participate in brain tumor pathogenesis by targeting Wnt signaling regulatory miRNAs. SNHG7/miR-5095, PCAT6/miR-139-3p, SNHG6/miR-944, SNHG1/ miR-556-5p, SNHG17/ miR-506-3p, LINC00702/miR-4652-3p, DLGAP1-AS1/miR-515-5p, HOTAIR/miR-1, HOTAIR/miR-206, CRNDE/miR-29c-3p, AGAP2-AS1/ miR-15a/b-5p, CLRN1-AS1/miR-217, MEG3/miR-23b-3p, and GAS5/miR-27a-5p are identified lncRNA/miRNA pairs that are involved in this process. Therefore, recognition of the expression profile and regulatory role of ncRNAs on the Wnt signaling may offer a novel approach to the diagnosis, prognosis, and treatment of human cancers. This review summarizes previous data on the modulatory role of lncRNAs/miRNAs on the Wnt/β-catenin pathway implicated in tumor growth, EMT, metastasis, and chemoresistance in brain cancers.

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.

Expression pattern of lncRNAs in pituitary adenomas

Non-functioning pituitary adenomas (NFPAs) are a group of pituitary tumors lacking manifestations linked to high hormone production, such as acromegaly and Cushing's syndrome. NFPA carcinogenesis depends on several molecular players. Long non-coding RNAs (lncRNAs) are a class of molecular players whose role in tumorigenesis has just recently been recognized. In the current study, we appraised expressions of 5 lncRNAs, namely FGD5-AS1, ATP6V0E2-AS1, ARHGAP5-AS1, WWC2-AS2 and EPB41L4A-AS1 in NFPAs versus their corresponding non-tumoral samples. Expressions of ATP6V0E2-AS1, EPB41L4A-AS1, FGD5-AS1 and WWC2-AS2 were significantly increased in NFPA samples compared with adjacent non-tumoral samples (P values = 0.037, 0.007, 0.008 and 0.03, respectively). However, expression of ARHGAP5-AS1 was not different between NFPA samples and controls (P value = 0.62). EPB41L4A-AS1 and FGD5-AS1 could discriminate between NFPA samples and adjacent non-tumoral samples (P values = 0.03 and 0.04, respectively). However, the AUC values were not appropriate. There was a significant positive association between age of NFPA patients and invasiveness of NFPA (χ2 = 4.24, P value = 0.039). Moreover, there was a significant positive association between diseases duration and CSF leak (χ2 = 11.4, p value = 0.023). Finally, there was a significant positive association between tumor size and Knosp classification (χ2 = 11.5, p value = 0.02) and invasiveness of NFPA (χ2 = 6.12, p value = 0.04). The current study provides information about dysregulation of lncRNAs in NFPAs and warrants additional studies in this field.

Upregulation of MAPKAPK5-AS1, PXN-AS1 and URB1-AS1 lncRNAs in non-functioning pituitary adenoma

Long non-coding RNAs (lncRNAs) have been shown to be dysregulated in a variety of malignant and non-malignant lesions including non-functioning pituitary adenomas (NFPAs). In the current experimental study, we have selected six lncRNAs, namely MAPKAPK5-AS1, NUTM2B-AS1, ST7-AS1, LIFR-AS1, PXN-AS1 and URB1-AS1 to assess their expression in a cohort of Iranian patients with NFPA. MAPKAPK5-AS1, PXN-AS1 and URB1-AS1 were shown to be over-expressed in NFPA tissues compared with control samples (Expression ratios (95% CI) = 10 (3.94-25.36), 11.22 (4.3-28.8) and 9.33 (4.12-21.12); p values < 0.0001, respectively). The depicted ROC curves showed the AUC values of 0.73, 0.80 and 0.73 for MAPKAPK5-AS1, PXN-AS1 and URB1-AS1, respectively. Relative expression level of PXN-AS1 was associated with tumour subtype (p value = 0.49). Besides, relative expression levels of MAPKAPK5-AS1 and LIFR-AS1 were associated with gender of patients (p values = 0.043 and 0.01, respectively). Cumulatively, the current study indicates the possible role of MAPKAPK5-AS1, PXN-AS1 and URB1-AS1 lncRNAs in the pathogenesis of NFPAs.

The hallmarks of cancer… in pituitary tumors?

Over 20 years ago, Hanahan and Weinberg published a seminal review that addressed the biological processes that underly malignant transformation. This classical review, along with two revisions published in 2011 and 2022, has remain a classic of the oncology literature. Since many of the addressed biological processes may apply to non-malignant tumorigenesis, we evaluated to what extent these hallmarks pertain to the development of pituitary adenomas.Some of the biological processes analyzed in this review include genome instability generated by somatic USP8 and GNAS mutations in Cushing's diseases and acromegaly respectively; non-mutational epigenetic reprograming through changes in methylation; induction of angiogenesis through alterations of VEGF gene expression; promotion of proliferative signals mediated by EGFR; evasion of growth suppression by disrupting cyclin dependent kinase inhibitors; avoidance of immune destruction; and the promotion of inflammation mediated by alteration of gene expression of immune check points. We also elaborate further on the existence of oncogene induced senescence in pituitary tumors. We conclude that a better understanding of these processes can help us dilucidated why pituitary tumors are so resistant to malignant transformation and can potentially contribute to the development of novel anticancer treatments.

Expression pattern of non-coding RNAs in non-functioning pituitary adenoma

Non-functioning pituitary adenoma (NFPA) is a benign tumor arising from the adenohypophyseal cells. They can be associated with symptoms arising from mass effect. Although these tumors are regarded to be benign tumors, they are associated with increased comorbidity and mortality. Several studies have indicated abnormal expression of genes in these tumors. In the current study, we have used existing methods to identify differentially expressed genes (DEGs) including DE long non-coding RNAs (DElncRNAs) and DE microRNAs (DEmiRNAs) in NFPAs compared with normal samples. Then, we have assessed the relation between these genes and important signaling pathways. Our analyses led to identification of 3131 DEGs, including 189 downregulated DEGs (such as RPS4Y1 and DDX3Y) and 2898 upregulated DEGs (such as ASB3 and DRD4), and 44 DElncRNAs, including 8 downregulated DElncRNAs (such as NUTM2B-AS1 and MALAT1) and 36 upregulated DElncRNAs (such as BCAR4 and SRD5A3-AS1). GnRH signaling pathway, Tight junction, Gap junction, Melanogenesis, DNA replication, Nucleotide excision repair, Mismatch repair and N-Glycan biosynthesis have been among dysregulated pathways in NFPAs. Taken together, our study has revealed differential expression of several genes and signaling pathways in this type of tumors.

DSCAM-AS1 Long Non-Coding RNA Exerts Oncogenic Functions in Endometrial Adenocarcinoma via Activation of a Tumor-Promoting Transcriptome Profile

Accumulating evidence suggests that lncRNA DSCAM-AS1 acts tumor-promoting in various cancer entities. In breast cancer, DSCAM-AS1 was shown to be the lncRNA being most responsive to induction by estrogen receptor α (ERα). In this study, we examined the function of DSCAM-AS1 in endometrial adenocarcinoma using in silico and different in vitro approaches. Initial analysis of open-source data revealed DSCAM-AS1 overexpression in endometrial cancer (EC) (p < 0.01) and a significant association with shorter overall survival of EC patients (HR = 1.78, p < 0.01). In EC, DSCAM-AS1 was associated with endometrial tumor promotor gene PRL and with expression of ERα and its target genes TFF1 and PGR. Silencing of this lncRNA by RNAi in two EC cell lines was more efficient in ERα-negative HEC-1B cells and reduced their growth and the expression of proliferation activators like NOTCH1, PTK2 and EGR1. DSCAM-AS1 knockdown triggered an anti-tumoral transcriptome response as revealed by Affymetrix microarray analysis, emerging from down-regulation of tumor-promoting genes and induction of tumor-suppressive networks. Finally, several genes regulated upon DSCAM-AS1 silencing in vitro were found to be inversely correlated with this lncRNA in EC tissues. This study clearly suggests an oncogenic function of DSCAM-AS1 in endometrial adenocarcinoma via activation of a tumor-promoting transcriptome profile.

Upregulation of long noncoding RNA linc02544 and its association with overall survival rate and the influence on cell proliferation and migration in lung squamous cell carcinoma

BACKGROUND

Long noncoding RNAs (lncRNAs) exert crucial biological functions by regulating miRNAs, which are implicated in cancer progression and tumorigenesis. A previous study has indicated that lncRNA linc02544 expression is upregulated in lung adenocarcinoma, whereas, the role of linc02544 in LUSC is elusive.

METHODS

The differential linc02544 expression in LUSC tissues and adjacent non-tumor tissues were evaluated with RT-qPCR. Kaplan-Meier curve was conducted to evaluate the clinical prognostic significance of linc02544. Then cellular experiments were performed to assess the influence of linc02544 in LUSC proliferation, invasion, and migration, and a western blot assay was used to measure the metastasis-related protein levels. The downstream miRNAs were verified using the LncBase Experimental v.2 database and dual-luciferase reporter assay.

RESULTS

Linc02544 was overexpressed in LUSC tissues from positive lymph node metastasis-positive and TNM high-stage patients. Low linc02544 expression was associated with a longer survival rate. Downregulation of linc02544 by si-linc02544 restrained cell growth capacities, migration, and invasion abilities. Expression of MMP-2, MMP-9, and vimentin was decreased while E-cadherin was increased in si-linc02544 cells compared with that in untreated cells. Mechanistically, we identified that linc02544 acted as a sponge of miR-138-5p, which expression had a negative correlation. E2F3 was a potential target of miR-138-5p, CONCLUSIONS: Notably, high linc02544 expression was associated with severe clinical parameters and was a putative prognostic predictor for patients with LUSC. Downregulation of linc02544 may weaken the LUSC cell proliferation, migration, and invasion by regulating miR-138-5p/E2F3, which maybe serve as a biomarker for the prognosis and target treatment of LUSC.

Circulating Noncoding RNAs in Pituitary Neuroendocrine Tumors-Two Sides of the Same Coin

Pituitary neuroendocrine tumors (PitNET) are common intracranial neoplasms. While in case of hormone secreting tumors pituitary hormone measurements can be used for monitoring the disease, in non-functional tumors there is a need to discover non-invasive biomarkers. Non-coding RNAs (ncRNAs) are popular biomarker candidates due to their stability and tissue specificity. Among ncRNAs, miRNAs, lncRNAs and circRNAs have been investigated the most in pituitary tumor tissues and in circulation. However, it is still not known whether ncRNAs are originated from the pituitary, or whether they are casually involved in the pathophysiology. Additionally, there is strong diversity among different studies reporting ncRNAs in PitNET. Therefore, to provide an overview of the discrepancies between published studies and to uncover the reasons why despite encouraging experimental data application of ncRNAs in clinical routine has not yet taken hold, in this review available data are summarized on circulating ncRNAs in PitNET. The data on circulating miRNAs, lncRNAs and circRNAs are organized according to different PitNET subtypes. Biological (physiological and pathophysiological) factors behind intra- and interindividual variability and technical aspects of detecting these markers, including preanalytical and analytical parameters, sample acquisition (venipuncture) and type, storage, nucleic acid extraction, quantification and normalization, which reveal the two sides of the same coin are discussed.

miR‑217‑5p suppresses epithelial‑mesenchymal transition and the NF‑κB signaling pathway in breast cancer via targeting of metadherin

MicroRNAs (miRNAs) have been associated with a number of human malignancies, including breast cancer (BC). However, the expression, biological function and fundamental underlying mechanism of miR-217-5p in BC remain unclear. Therefore, in the present study, the expression levels of miR-217-5p and metadherin (MTDH) were examined in BC tissues and BC cell lines using reverse transcription-quantitative PCR. Cell Counting Kit-8 assays, cell proliferation, wound healing assays, Transwell assays and western blotting were used to examine the effects of miR-217-5p on cell proliferation, migration, the epithelial-mesenchymal transition (EMT) and NF-κB signaling pathway expression. The direct relationship between miR-217-5p and MTDH was assessed using a dual-luciferase reporter assay. The results demonstrated that significantly reduced expression levels of miR-217-5p but significantly increased mRNA expression levels of MTDH were observed in BC tissues from 35 patients with BC compared with non-tumor breast tissues. Furthermore, BC cell lines SK-BR3 and BT549 expressed miR-217-5p at markedly lower levels and MTDH at markedly higher levels compared with the breast epithelial MCF10A cell line. miR-217-5p overexpression significantly inhibited cell proliferation, invasion and migration and suppressed the EMT in BC cells. miR-217-5p overexpression also inhibited the NF-κB signaling pathway by markedly decreasing p65 mRNA and protein expression levels but significantly increasing IκBα expression levels. Furthermore, miR-217-5p knockdown markedly increased MTDH mRNA and protein expression levels. The expression levels of miR-217-5p were negatively correlated with those of MTDH in BC tissues. These results suggested that restoration of MTDH expression levels could potentially attenuate the inhibitory effects of miR-217-5p overexpression on BC cell proliferation. Therefore, in conclusion miR-217-5p overexpression may inhibit cell migration, invasion, the EMT and NF-κB signaling pathway in BC via targeting of MTDH. miR-217-5p may serve as an important potential target in BC therapy.