MiR-320 inhibits the growth of glioma cells through downregulating PBX3

LncRNA NEAT1 Inhibits Neuronal Apoptosis and Induces Neuronal Viability of Depressed Rats Via microRNA-320-3p/CRHR1 Axis

Long noncoding RNA nuclear enriched abundant transcript 1 (NEAT1) has been reported to be involved in depression. This study aims to investigate the mechanism of NEAT1/microRNA (miR)-320-3p/Corticotropin-releasing hormone receptor 1 (CRHR1) axis in depressed rats. Rats with depression-like behaviors were prepared by exposing the rats to chronic unpredictable mild stress. Behavioral functions, pathological damage, neuronal apoptosis and monoamine neurotransmitter were examined in depressed rats . Primary hippocampal neurons were injured through simulation with corticosterone(CORT). Cell viability and apoptosis were measured in CORT-Induced hippocampal neurons. The binding relationship between NEAT1 and miR-320-3p and the targeting relationship between miR-320-3p and CRHR1 were detected. Elevated NEAT1, CRHR1 and reduced miR-320-3p exhibited in depressed rats and CORT-treated hippocampal neurons, NEAT1 bound to miR-320-3p to target CRHR1. Silencing NEAT1 or elevating miR-320-3p improved behavioral functions, attenuated pathological damage and apoptosis in the hippocampus, and increased monoamine neurotransmitter in depressed rats. Repression of NEAT1 or promotion of miR-320-3p enhanced viability and suppressed apoptosis of CORT-treated hippocampal neurons. The study highlights that NEAT1 competitively binds to miR-320-3p to up-regulate CRHR1 expression, thereby promoting hippocampal damage of depressed rats.

Plasma microRNA-320c as a Potential Biomarker for the Severity of Knee Osteoarthritis and Regulates cAMP Responsive Element Binding Protein 5 (CREB5) in Chondrocytes

Objective

Osteoarthritis (OA) is a commonly known prevalent joint disease, with limited therapeutic methods. This study aimed to investigate the expression of plasma microRNA-320c (miR-320c) in patients with knee OA and to explore the clinical value and potential mechanism of miR-320c in knee OA.

Methods

Forty knee OA patients and 20 healthy controls were enrolled. The levels of plasma miR-320c and plasma inflammatory cytokines were measured by real-time PCR or ELISA. Correlations of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and cytokine levels with the miR-320c expression level were evaluated by Pearson correlation analysis. Then, a receiver operating characteristic (ROC) curve was drawn to analyse the diagnostic value of miR-320c in OA. Finally, the interaction of miR-320c and cAMP responsive element binding protein 5 (CREB5) was determined using a luciferase reporter assay, and the effect of CREB5 on the cAMP pathway was assessed.

Results

The expression level of plasma miR-320c was significantly higher in OA patients than in healthy controls (p  < 0.05). The increased plasma miR-320c level was positively correlated with the WOMAC score (r = 0.796, p  < 0.001) and the plasma interleukin (IL)-1β (r = 0.814, p  < 0.001) and IL-6 (r = 0.695, p  < 0.001) levels in patients with OA. ROC curve analysis demonstrated the relatively high diagnostic accuracy of plasma miR-320c for OA. Furthermore, the luciferase reporter assay results showed that miR-320c regulates CREB5 expression by binding to the CREB5 3'-untranslated region. Moreover, suppression of CREB5 significantly reduced the expression levels of c-fos and c-jun.

Conclusion

Our results indicate that plasma miR-320c may serve as a potential novel predictor of the severity of knee OA and that miR-320c may play an important role in the pathogenesis of OA through inhibiting the cAMP pathway by targeting CREB5.

Circulating serum miR-362-3p and miR-6721-5p as potential biomarkers for classification patients with adult-type diffuse glioma

According to the fifth edition of the WHO Classification of Tumours of the Central Nervous System (CNS) published in 2021, grade 4 gliomas classification includes IDH-mutant astrocytomas and wild-type IDH glioblastomas. Unfortunately, despite precision oncology development, the prognosis for patients with grade 4 glioma remains poor, indicating an urgent need for better diagnostic and therapeutic strategies. Circulating miRNAs besides being important regulators of cancer development could serve as promising diagnostic biomarkers for patients with grade 4 glioma. Here, we propose a two-miRNA miR-362-3p and miR-6721-5p screening signature for serum for non-invasive classification of identified glioma cases into the highest-grade 4 and lower-grade gliomas. A total of 102 samples were included in this study, comprising 78 grade 4 glioma cases and 24 grade 2-3 glioma subjects. Using the NanoString platform, seven miRNAs were identified as differentially expressed (DE), which was subsequently confirmed via RT-qPCR analysis. Next, numerous combinations of DE miRNAs were employed to develop classification models. The dual panel of miR-362-3p and miR-6721-5p displayed the highest diagnostic value to differentiate grade 4 patients and lower grade cases with an AUC of 0.867. Additionally, this signature also had a high AUC = 0.854 in the verification cohorts by RT-qPCR and an AUC = 0.842 using external data from the GEO public database. The functional annotation analyses of predicted DE miRNA target genes showed their primary involvement in the STAT3 and HIF-1 signalling pathways and the signalling pathway of pluripotency of stem cells and glioblastoma-related pathways. For additional exploration of miRNA expression patterns correlated with glioma, we performed the Weighted Gene-Co Expression Network Analysis (WGCNA). We showed that the modules most associated with glioma grade contained as many as six DE miRNAs. In conclusion, this study presents the first evidence of serum miRNA expression profiling in adult-type diffuse glioma using a classification based on the WHO 2021 guidelines. We expect that the discovered dual miR-362-3p and miR-6721-5p signatures have the potential to be utilised for grading gliomas in clinical applications.

Exosomes from hepatitis B virus-infected hepatocytes activate hepatic stellate cells and aggravate liver fibrosis through the miR-506-3p/Nur77 pathway

Cumulative evidence indicates the important role of Nur77 in organ fibrogenesis. However, the role of Nur77 in hepatitis B virus (HBV)-related liver fibrosis (LF) remains unclear. Cells were transfected with the microRNA mimic miRNA-506-3p or inhibitor, and pcDNA3.1-Nur77 or Nur77 guide RNA. Exosomes were isolated from HBV-infected HepG2-sodium taurocholate cotransporting polypeptide cells. The levels of miR-506-3p, Nur77, and LF-related genes and proteins were detected by quantitative polymerase chain reaction (qPCR) and western blot analysis, respectively. The pathology of the liver from HBV-infected patients was examined using hematoxylin-eosin and Masson's staining. The expression of Nur77 in liver tissue was determined by immunohistochemistry, and the LF score was assessed using the METAVIR system. The relationship between miR-506-3p/Nur77 and LF score was analyzed by correlation analysis. HBV infection downregulated miR-506-3p expression and upregulated Nur77 levels in hepatocytes. Exosomes from HBV-infected hepatocytes also displayed decreased gene expression of miR-506-3p and increased expressions of Nur77- and LF-related genes in stellate cells compared with exosomes from hepatocytes with mock infection. These changes were reversed by Nur77 guide RNA. Nur77 expression in liver tissue was strongly correlated with LF, whereas serum miR-506-3p was strongly negatively correlated with LF. Exosomes from HBV-infected hepatocytes activate stellate cells and aggravate LF through the miR-506-3p/Nur77 pathway. These exosomes may be the basis of a promising therapeutic strategy.

PBX3 promotes pentose phosphate pathway and colorectal cancer progression by enhancing G6PD expression

Metabolic reprogramming is a hallmark of cancers crucial for fulfilling the needs of energy, building blocks, and antioxidants to support tumor cells' rapid proliferation and to cope with the harsh microenvironment. Pre-B-cell leukemia transcription factor 3 (PBX3) is a member of the PBX family whose expression is up-regulated in various tumors, however, whether it is involved in tumor cell metabolic reprogramming remains unclear. Herein, we report that PBX3 is a positive regulator of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the pentose phosphate pathway (PPP). PBX3 promoted G6PD transcriptional activity in tumor cells by binding directly to its promoter, leading to PPP stimulation and enhancing the production of nucleotides and NADPH, a crucial reductant, thereby promoting nucleic acid and lipid biosynthesis while decreasing intracellular reactive oxygen species levels. The PBX3/G6PD axis also promoted tumorigenic potential in vitro and in vivo. Collectively, these findings reveal a novel function of PBX3 as a regulator of G6PD, linking its oncogenic activity with tumor cell metabolic reprogramming, especially PPP. Furthermore, our results suggested that PBX3 is a potential target for metabolic-based anti-tumor therapeutic strategies.

Comparison of Selected Non-Coding RNAs and Gene Expression Profiles between Common Osteosarcoma Cell Lines

Simple Summary

Osteosarcoma (OS) is a malignant tumour affecting mainly children and elderly people. Despite significant advances in cancer medicine, osteosarcoma patients’ survival is not improving. The primary treatment methods are established using in vitro models that rely upon the application of well-established cell lines, including U-2 OS, Saos-2 and MG-63. The molecular phenotype of these cell lines is still not fully outlined. Therefore, our study aimed to establish the expression profile of molecular markers related to osteosarcoma survival, progression and metastasis. Non-bone-related cells were used as a reference, i.e. HeLa cell line and human adipose-derived stromal cells (hASCs). Evaluated osteosarcoma cell lines showed characteristic phenotypes with unique patterns related to upregulation of MMP-7, MMP-14, BMP-7, miR-21-5p, miR-124-3p and downregulation of lncRNA MEG3. Our findings may facilitate the selection of the most reliable cellular model for pre-clinical investigations focused on developing new and satisfying methods of osteosarcoma therapy.

Abstract

Osteosarcoma (OS) is a bone tumour affecting adolescents and elderly people. Unfortunately, basic treatment methods are still underdeveloped, which has a high impact on the poor survivability of the patients. Studies designed to understand the underlying mechanisms of osteosarcoma development, as well as preclinical investigations aimed at establishing novel therapeutic strategies, rely significantly upon in vitro models, which apply well-established cell lines such as U-2 OS, Saos-2 and MG-63. In this study, the expression of chosen markers associated with tumour progression, metastasis and survival were identified using RT-qPCR. Levels of several onco-miRs (miR-21-5p, miR-124-3p, miR-223-3p and miR-320a-3p) and long non-coding RNA MEG3 were established. The mRNA expression of bone morphogenetic proteins (BMPs), including BMP-2, BMP-3, BMP-4, BMP-6, BMP-7, as well as their receptors: BMPR-IA, BMPR-IB and BMPR-II was also determined. Other tested markers included metalloproteinases, i.e., MMP-7 and MMP-14 and survivin (BIRC5), C-MYC, as well as CYCLIN D (CCND1). The analysis included comparing obtained profiles with transcript levels established for the osteogenic HeLa cell line and human adipose-derived stromal cells (hASCs). The tested OS cell lines were characterised by a cancer-related phenotype, such as increased expression of mRNA for BMP-7, as well as MMP-7 and MMP-14. Osteosarcoma cells differ considerably in miR-21-5p and miR-124-3p levels, which can be related to uncontrolled tumour growth. The comprehensive examination of osteosarcoma transcriptome profiles may facilitate the selection of appropriate cell models for preclinical investigations aimed at the development of new strategies for OS treatment.

miR-320 regulates myogenesis by targeting growth factor receptor-bound protein-2 and ameliorates myotubes atrophy

Loss of muscle mass can lead to diseases such as sarcopenia, diabetes, and obesity, which can worsen the quality of life and increase the incidence of disease. Therefore, understanding the mechanism underlying skeletal muscle differentiation is vital to prevent muscle diseases. We previously found that microRNA-320 (miR-320) is highly expressed in the lean muscle-type pigs, but its regulatory role in myogenesis remains unclear. The bioinformatics prediction indicated that miR-320 could bind to the 3 'untranslated region of growth factor receptor-bound protein-2 (Grb2). We hypothesized that miR-320 targets Grb2 to regulate myoblasts differentiation. To verify this, we transfected miR-320 mimic and inhibitor into C2C12 myoblasts to assess the role of miR-320 during myoblasts differentiation. We used real-time qPCR, luciferase reporter assays, and western blotting to confirm that miR-320 directly targets Grb2 to promote myoblasts differentiation. Moreover, by using a dexamethasone-induced atrophic model of myotubes, we discovered that miR-320 promotes the repair of damaged myotubes. Our findings expand understanding of miRNAs and genes related to regulating skeletal muscle differentiation, and provide insight into underlying therapeutic strategies for muscle diseases.

MiR-372-3p Functions as a Tumor Suppressor in Colon Cancer by Targeting MAP3K2

MicroRNAs (miRNAs) as small non-coding RNA transcripts bind their complementary sequences in the 3′-untranslated region (3′-UTR) of target messenger RNAs (mRNAs) to regulate their expression. It is known that miR-372 belongs to the miR-371–373 gene cluster and has been found to be abnormally expressed in a variety of cancers, but its precise mechanism in cancer remains to be discovered. In this study, miR-372-3p expression was assessed in 153 frozen tissue samples, including primary diagnosed colon cancer and matched normal and adjacent tissues, using real time quantitative polymerase chain reaction (qPCR). An analysis of qPCR data revealed a significant reduction in miR-372-3p expression (by >2-fold) in colon cancer tissues in 51.5% (34/66) of patients. Consistent with this, mimicking the increased miR-372-3p levels in SW480 colon cancer cells significantly suppressed cell growth and proliferation. Although no direct correlation was found between the low level of miR-372-3p and certain tumor-related factors, such as p53, HRE-2, PMS2, MLH1, MSH2, MSH6, HDAC4, p21, and Wee1, in colon cancer tissues, an inverse relationship between miR-372-3p and Ki67 (a marker of proliferation) or miR-372-3p and MAP3K2(MEKK2), which plays a critical role in the MAPK signaling pathways, was confirmed using tissue samples. The target relationship between miR-372-3p and MAP3K2 was verified using luciferase assays in SW480 colon cancer cells. As expected, miR-372-3p mimics significantly suppressed the luciferase activity of pMIR-luc/MAP3K2 3′-UTR in cells, suggesting that miR-372-3p modulates the expression of MAP3K2 by directly targeting its 3′-UTR. Overall, the results obtained herein suggest that miR-372-3p may function as a tumor-suppressor miRNA in colon cancer by targeting MAP3K2.

The regulation of PBXs and their emerging role in cancer

Pre‐B‐cell leukaemia transcription factor (PBX) proteins are a subfamily of evolutionarily conserved, atypical homeodomain transcription factors that belong to the superfamily of three amino acid loop extension (TALE) homeodomain proteins. Members of the PBX family play crucial roles in regulating multiple pathophysiological processes, such as the development of organs, congenital cardiac defects and carcinogenesis. The dysregulation of PBXs has been shown to be closely associated with many diseases, particularly cancer. However, the detailed mechanisms of PBX dysregulation in cancer progression are still inconclusive. In this review, we summarize the recent advances in the structures, functions and regulatory mechanisms of PBXs, and discuss their underlying mechanisms in cancer progression. We also highlight the great potential of PBXs as biomarkers for the early diagnosis and prognostic evaluation of cancer as well as their therapeutic applications. The information reviewed here may expand researchers’ understanding of PBXs and could strengthen the clinical implication of PBXs in cancer treatment.

LncRNA NONHSAT114552 Sponges miR-320d to Promote Proliferation and Invasion of Chordoma Through Upregulating NRP1

Chordoma is a relatively rare malignant bone tumor with high local recurrence. To date, the mechanism remains unclear. lncRNAs play a pivotal role in tumorigenesis by acting as competitive endogenous RNAs of microRNAs. However, the biological role of lncRNA is still unclear in chordoma. In this research, our aim is to investigate the roles and regulation mechanisms of lncRNA NONHSAT114552 in chordoma development. The expression level of NONHSAT114552 and miR-320d in chordoma tissues was determined by qRT-PCR. Meantime, the correlation between NONHSAT114552 and clinical prognosis was also studied. Bioinformatics analysis and luciferase reporter assays were used to verify the relationship between NONHSAT114552 and miR-320d, and between miR-320d and Neuropilin 1 (NRP1). In addition, effects of NONHSAT114552 on chordoma cells (U-CH1 and U-CH2) proliferation and invasion and its regulation on miR-320d were also evaluated. Furthermore, the influences of NONHSAT114552/miR-320d/NRP1 axis on chordoma tumorigenesis were investigated in vivo. NONHSAT114552 was overexpressed while miR-320d was down-regulated in chordoma tissue compared to fetal nucleus pulposus. Kaplan-Meier survival analysis showed that NONHSAT114552 overexpression was associated with patients’ poor prognosis. Knockdown of NONHSAT114552 significantly suppressed chordoma cell proliferation and invasion. In vitro studies confirmed that NONHSAT114552 acted as ceRNA to regulate NRP1 by directly sponging miR-320d, thus facilitating chordoma cell proliferation and invasion. In vivo study demonstrated that NONHSAT114552 moderated chordoma growth by sponging miR-320d to regulating NRP1. Our findings indicate that lncRNA NONHSAT114552 exhibits a critical role in the tumorigenesis and development of chordoma and it may become one potential prognostic marker and therapeutic target for this disease. .

MicroRNAs and Stem-like Properties: The Complex Regulation Underlying Stemness Maintenance and Cancer Development

Embryonic stem cells (ESCs) have the extraordinary properties to indefinitely proliferate and self-renew in culture to produce different cell progeny through differentiation. This latter process recapitulates embryonic development and requires rounds of the epithelial-mesenchymal transition (EMT). EMT is characterized by the loss of the epithelial features and the acquisition of the typical phenotype of the mesenchymal cells. In pathological conditions, EMT can confer stemness or stem-like phenotypes, playing a role in the tumorigenic process. Cancer stem cells (CSCs) represent a subpopulation, found in the tumor tissues, with stem-like properties such as uncontrolled proliferation, self-renewal, and ability to differentiate into different cell types. ESCs and CSCs share numerous features (pluripotency, self-renewal, expression of stemness genes, and acquisition of epithelial-mesenchymal features), and most of them are under the control of microRNAs (miRNAs). These small molecules have relevant roles during both embryogenesis and cancer development. The aim of this review was to recapitulate molecular mechanisms shared by ESCs and CSCs, with a special focus on the recently identified classes of microRNAs (noncanonical miRNAs, mirtrons, isomiRs, and competitive endogenous miRNAs) and their complex functions during embryogenesis and cancer development.

LncRNA CD27-AS1 promotes acute myeloid leukemia progression through the miR-224-5p/PBX3 signaling circuit

Acute myeloid leukemia (AML) is a hematological malignancy with a low cure rate, especially in the elderly. Previous studies have shown that long non-coding RNA (lncRNA) may be an important factor in the pathogenesis of hematological malignancies, including acute myeloid leukemia (AML). However, the biological roles and clinical significances of most lncRNAs in AML are not fully understood. LncRNA CD27 Antisense RNA 1 (CD27-AS1), as a member of lncRNA family, has rare reports on its function. In present study, we found that the expression of CD27-AS1 examined by quantitative real-time PCR was markedly increased in the AML patients (N = 40) compared with healthy volunteers (N = 40). The overall survival time was significantly shorter in patients with higher CD27-AS1 expression than that in patients with lower CD27-AS1 (P < 0.01). Furthermore, downregulation of CD27-AS1 in AML cells suppressed proliferative ability, arrested cell cycle in G0/G1 phase, and induced apoptosis. However, CD27-AS1 overexpression further enhanced the malignant phenotype of AML cells. Additionally, CD27-AS1 was proved to increase PBX3 expression through sponging miR-224-5p. CD27-AS1 knockdown blocked the MAPK signaling through PBX3 silencing and further inhibited the cell growth of AML cells. Taken together, we demonstrate that CD27-AS1 may be a potential prognostic biomarker of AML, and our finding also provides a new insight for non-coding RNA-based therapeutic intervention of AML.

CircHECTD1 Regulates Cell Proliferation and Migration by the miR-320-5p/SLC2A1 Axis in Glioblastoma Multiform

Glioblastoma multiform (GBM) is the most common and malignant primary brain cancer in adults, and thus, novel potential therapeutic targets for diagnosis and treatment are urgently needed. Circular RNAs (circRNAs) are a class of widespread and diverse endogenous RNAs that have been suggested as potential critical mediators during progression of various tumors. In this study, we investigated the involvement of circHECTD1 in GBM progression. CircHECTD1 Lentivirus, miR-320-5p mimic, and SLC2A1 Lentivirus were transduced into cancer cells independently or together. circHECTD1, miR-320-5p, and SLC2A1 level were detected by qRT-PCR. Western blot and qRT-PCR were applied to measure the expression of SLC2A1, CyclinD1, CDK2, and PCNA. Flow cytometry, EdU, colony formation, Transwell and wound-healing assays were conducted to assess cell proliferation and migration. Luciferase reporter assays were performed to determine the effect of miR-320-5p on circHECTD1 or SLC2A1. Xenograft experiments were implemented to evaluate tumor growth in vivo. CircHECTD1 expression led to the promotion of proliferation and migration of GBM cells. In addition, circHECTD1 acted as a ceRNA to interact with miR-320-5p, which targeted the solute carrier family 2 member 1 (SLC2A1). In vivo experiments also revealed that circHECTD1 promoted tumor growth. Collectively, our findings showed that the circHECTD1-miR-320-5p-SLC2A1 regulatory pathway promoted the progression of GBM, suggesting that circHECTD1 may be a therapeutic target for GBM.

MicroRNA-320c inhibits articular chondrocytes proliferation and induces apoptosis by targeting mitogen-activated protein kinase 1 (MAPK1)

AIM

To clarify the interaction of microRNA-320c (miR-320c) and mitogen-activated protein kinase 1 (MAPK1), and to investigate the effects of miR-320c on articular chondroctye proliferation and apoptosis.

METHODS

Lentiviral expression vectors were constructed and dual luciferase assays containing MAPK1 3'-untranslated regions (3'-UTRs) were performed. Small hairpin RNA (shRNA) was utilized to modulate MAPK1 expression. The messenger RNA and protein expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting respectively. Cell Counting Kit-8 and flow cytometry were conducted to detect the proliferation and apoptosis of Human Chondrocyte-articular (HC-a) cells. Besides that, the influences of miR-320c and MAPK1 on MAPK pathway activation were also evaluated.

RESULTS

Our data identified MAPK1 as a direct target gene of miR-320c, and miR-320c can negatively regulate MAPK1 expression by directly binding to MAPK1 3'-UTR in HC-a cells. Further functional study displayed that miR-320c overexpression and MAPK1 shRNA significantly suppressed the proliferation of HC-a cells and promoted cell apoptosis. Meanwhile, MAPK1 shRNA could attenuate miR-320c inhibitor promotive effects on HC-a cell proliferation and reverse its inhibitory effect on cell apoptosis. MAPK1 overexpression could rescue the inhibitory effect of miR-320c on HC-a cell proliferation, and weaken the accelerating effect of miR-320c on cell apoptosis. However, neither miR-320c or MAPK1 shRNA regulate the expression of c-JUN, JNK and c-Fos.

CONCLUSION

miR-320c inhibits articular chondrocyte proliferation and induces apoptosis by targeting MAPK1, suggesting that miR-320c perhaps participates in the pathogenesis of osteoarthritis and acts as a potential target for the therapeutic treatment of osteoarthritis.

The role of miR-320 in glucose and lipid metabolism disorder-associated diseases

Glucose and lipids are important nutrients that provide the majority of energy for each organ to maintain homeostasis of the body. With the continuous improvement in living standards, the incidence of metabolic disorder-associated diseases, such as diabetes, hyperlipidemia, and atherosclerosis, is increasing worldwide. Among them, diabetes, which could be induced by both glucose and lipid metabolic disorders, is one of the five diseases with the highest incidence and mortality worldwide. However, the detailed molecular mechanisms underlying glucose and lipid metabolism disorders and target-organ damage are still not fully defined. MicroRNAs (miRNAs) are small, non-coding, single-stranded RNAs, which usually affect their target mRNAs in the cytoplasm by post-transcriptional regulation. Previously, we have found that miR-320 contributed to glucose and lipid metabolism via different signaling pathways. Most importantly, we identified that nuclear miR-320 mediated diabetes-induced cardiac dysfunction by activating the transcription of fatty acid metabolic genes to cause lipotoxicity in the heart. Here, we reviewed the roles of miR-320 in glucose and lipid metabolism and target-organ damage.

The miRNA Content of Exosomes Released from the Glioma Microenvironment Can Affect Malignant Progression

Low-grade gliomas (LGG) are infiltrative primary brain tumors that in 70% of the cases undergo anaplastic transformation, deeply affecting prognosis. However, the timing of progression is heterogeneous. Recently, the tumor microenvironment (TME) has gained much attention either as prognostic factor or therapeutic target. Through the release of extracellular vesicles, the TME contributes to tumor progression by transferring bioactive molecules such as microRNA. The aim of the study was to take advantage of glioma-associated stem cells (GASC), an in vitro model of the glioma microenvironment endowed with a prognostic significance, and their released exosomes, to investigate the possible role of exosome miRNAs in favoring the anaplastic transformation of LGG. Therefore, by deep sequencing, we analyzed and compared the miRNA profile of GASC and exosomes obtained from LGG patients characterized by different prognosis. Results showed that exosomes presented a different signature, when compared to their cellular counterpart and that, although sharing several miRNAs, exosomes of patients with a bad prognosis, selectively expressed some miRNAs possibly responsible for the more aggressive phenotype. These findings get insights into the value of TME and exosomes as potential biomarkers for precision medicine approaches aimed at improving LGG prognostic stratification and therapeutic strategies.

Global microRNA profiling identified miR-10b-5p as a regulator of neurofibromatosis 1 (NF1)-glioma migration

AIMS

Neurofibromatosis 1 (NF1) is an autosomal-dominant cancer predisposition syndrome caused by loss of function alterations involving the NF1 locus on chromosome 17. The most common brain tumours encountered in affected patients are low-grade gliomas (pilocytic astrocytomas), although high-grade gliomas are also observed at increased frequency. While bi-allelic NF1 loss characterizes these tumours, previous studies have suggested noncoding RNA molecules (microRNA, miR) may have important roles in dictating glioma biology.

METHODS

To explore the contributions of miRs in NF1-associated gliomas, we analysed five high-grade gliomas (NF1-HGG) and five PAs (NF1-PA) using global microRNA profiling with NanoString-based microarrays followed by functional experiments with glioma cell lines.

RESULTS

miR-10b-5p, miR-135b-5p, miR-196a-5p, miR-196b-5p, miR-1247-5p and miR-320a (adjusted P < 0.05) were increased> 3-fold in NF1-HGG relative to NF1-PA tumours. In addition, miR-378b and miR-1305 were decreased 6.8- and 6-fold, respectively, whereas miR-451a was increased 2.7-fold (adjusted P < 0.05) in NF1-PAs compared to non-neoplastic NF1 patient brain specimens (n = 2). As miR-10b-5p was the microRNA overexpressed the most in NF1-high-grade glioma compared to NF1-low-grade glioma (5.76 fold), we examined its levels in glioma cell lines. miR-10b-5p levels were highest in adult glioma cell lines and lowest in paediatric low-grade glioma lines (P = 0.02). miR-10b-5p knockdown resulted in decreased invasion in NF1-deficient LN229 high-grade glioma line, whereas its overexpression in the NF1-PA derived line (JHH-NF1-PA1) led to increased invasion. There was no change in cell growth (viability and proliferation).

CONCLUSIONS

These proof-of-concept experiments support a role for microRNA regulation in NF1-glioma biology.

miR‑320‑3p is involved in morphine pre‑conditioning to protect rat cardiomyocytes from ischemia/reperfusion injury through targeting Akt3

Morphine pre-conditioning (MPC) can significantly reduce myocardial ischemic injury and inhibit cardiomyocyte apoptosis, but the underlying mechanism still remains unclear. The aim of the present study was to investigate the protective mechanism of MPC in myocardial hypoxia/reoxygenation (H/R) injury at the microRNA (miR) level. H9c2 cells were used as a model of H/R and subjected to morphine pre-treatment. The protective effects of MPC on H/R injury in cardiomyocytes were evaluated using MTT and colorimetric assay, as well as flow cytometry. In addition, reverse transcription-quantitative PCR, western blotting and dual-luciferase reporter assay experiments were performed to determine the relationship between MPC, miR-320-3p and Akt3, and their effects on H/R injury. The present study demonstrated that MPC enhanced cell activity, decreased LDH content, and reduced apoptosis in rat cardiomyocytes, suggesting that MPC could protect these cells from H/R injury. Moreover, MPC partially reversed the increase in miR-320-3p expression and the decrease in Akt3 levels caused by H/R injury. Inhibition of miR-320-3p expression also attenuated the effects of H/R on cardiomyocyte activity, LDH content and apoptosis. Furthermore, Akt3 was predicted to be a target gene of miR-320-3p, and overexpression of miR-320-3p inhibited the expression of Akt3, blocking the protective effects of MPC on the cells. The current findings revealed that MPC could protect cardiomyocytes from H/R damage through targeting miR-320-3p to regulate the PI3K/Akt3 signaling pathway.

MiR-4458/human antigen R (HuR) modulates PBX3 mRNA stability in melanoma tumorigenesis

Melanoma, a malignancy of the melanocyte, is characterized as the most fatal skin cancer with an increasing incidence. Of note, in spite of great attempts made for better treatment, the therapeutic outcome is barely satisfactory. Abnormal expression of microRNAs (miRNAs) acting as oncogenes or tumor suppressor genes, is frequently implicated in multiple human cancers, including melanoma. Here, we found that miRNA-4458, a reportedly tumor-suppressive miRNA in several cancers, was downregulated in melanoma cells. Besides, our findings indicated that microRNA-4458 (miR-4458) hindered cell proliferation and migration, yet induced apoptosis in melanoma. Mechanical interaction of miR-4458 and PBX3 mRNA, thereby inhibiting PBX3 expression in melanoma cells, was also presented in this work. Human antigen R (HuR) was reported to be greatly upregulated in diverse cancers and HuR-dependent stabilization of target gene contributed a lot to tumor progression. In this study, it revealed the stabilization of PBX3 mRNA by HuR, thereby boosting PBX3 expression. Lastly, we concluded that miR-4458 and HuR modulated the expression of PBX3 in a competitive manner in melanoma tumorigenesis, which might yield a novel insight into the molecular pathogenesis of melanoma.

LINC00174 is an oncogenic lncRNA of hepatocellular carcinoma and regulates miR-320/S100A10 axis

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. Multiple long non-coding RNAs (lncRNAs) are recently identified as crucial oncogenic factors or tumour suppressors. In this study, we explored the effects of LINC00174 on the progression of HCC. Expression levels of LINC00174 and microRNA-320 (miR-320) in HCC tissue samples were measured using quantitative real-time polymerase chain reaction (qRT-PCR). The association between pathological indices and LINC00174 was also analysed. Human HCC cell lines Hep3B and Huh7 were used as cell models. CCK-8 and bromodeoxyuridine (BrdU) assays were used to assess the effect of LINC00174 on HCC cell line proliferation. Flow cytometry was used to study the effect of LINC00174 on HCC apoptosis. Transwell assay was conducted to detect the effect of LINC00174 on migration and invasion. Furthermore, luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to confirm the binding relationship between miR-320 and LINC00174. Additionally, western blot was used to detect the regulatory function of LINC00174 on oncogene S100 calcium binding protein A10 (S100A10). We demonstrated that LINC00174 expression in HCC clinical samples was significantly increased and this was correlated with higher T stage. Its overexpression remarkably accelerated proliferation and metastasis of HCC cells while reduced apoptosis. Accordingly, knockdown of it suppressed the malignant phenotypes of HCC cells. Overexpression of LINC00174 significantly reduced the expression of miR-320 by sponging it, in turn enhanced the expression of S100A10. In conclusion, LINC00174 is a sponge of tumour suppressor miR-320, enhances the expression of S100A10 indirectly and functions as an oncogenic lncRNA in HCC. SIGNIFICANCE OF THE STUDY: LINC00174 is a novel lncRNA, whose function is rarely investigated. It is reported that it is oncogenic in colorectal cancer, while its role in HCC remains unclear. Herein, we report that LINC00174 is significantly up-regulated in HCC tissues and promotes the malignant phenotypes. We demonstrate that LINC00174 functions as a sponge for miR-320, increases the expression level of oncogene S100A10 in HCC. This study helps clarify the mechanism of HCC tumorigenesis and progression, and uncover the role of LINC00174 in human disease.

Dynamic Changes in miR-126 Expression in the Hippocampus and Penumbra Following Experimental Transient Global and Focal Cerebral Ischemia-Reperfusion

miR-126 which is considered one of the most important miRNAs for maintaining vascular integrity, plays an important role in neuroprotection after cerebral ischemia-reperfusion (I-R). Moreover, vascular endothelial growth factor A (VEGFA), sprouty-related EVH1 domain-containing protein 1 (SPRED1), and Raf-1 are also involved in physiological processes of vascular endothelial cells (ECs). This study investigated how miR-126 changes with reperfusion time in different brain tissues after global cerebral ischemia and focal cerebral ischemia and examined the underlying mechanism miR-126 involving VEGFA, SPRED1, and Raf-1 after I-R. The results indicated decreases in the levels of miR-126-3p and miR-126-5p expression in mice and gerbils after I-R, consistent with the results after oxygen and glucose deprivation and reperfusion (OGD/R) in PC12 cells. Glial cells were activated as neuronal damage gradually increased after I-R. Inhibition of miR-126-3p exacerbated the OGD/R-induced cell death and reduced cell viability. After miR-126-3p inhibition, the levels of SPRED1 and VEGFA expression were increased, and p-Raf-1 expression was decreased after OGD/R. Moreover, based on the intervention of miR-126-3p inhibition, we found that the expression of p-Raf-1 was significantly increased after the intervention of siSPRED1, while it was not statistically significant after intervention of siVEGFA. The reduction of miR-126 expression after global and focal cerebral ischemia exacerbated neuronal death, which was closely related to increasing the SPRED1 activation and inhibiting the Raf-1 expression.

PBX3 in Cancer

PBX3 is a homeodomain-containing transcription factor of the pre-B cell leukemia (PBX) family, members of which have extensive roles in early development and some adult processes. A number of features distinguish PBX3 from other PBX proteins, including the ability to form specific and stable interactions with DNA in the absence of cofactors. PBX3 has frequently been reported as having a role in the development and maintenance of a malignant phenotype, and high levels of PBX3 tumor expression have been linked to shorter overall survival in cancer. In this review we consider the similarities and differences in the function of PBX3 in different cancer types and draw together the core signaling pathways involved to help provide a better insight into its potential as a therapeutic target.

miR-129-5p suppresses proliferation, migration, and induces apoptosis in pancreatic cancer cells by targeting PBX3

Pancreatic cancer (PC) is the seventh most frequent cause of cancer-related deaths worldwide with a high mortality. MicroRNAs (miRNAs) act as important regulators for the development of PC and participate in the progression of PC. miR-129-5p was reported to regulate the progression of tumors, such as thyroid cancer and gastric cancer. However, the function of miR-129-5p in PC is still unclear. In this study, the down-regulation of miR-129-5p was detected in PC tissues and PC cells. miR-129-5p was overexpressed or knocked down in AsPC-1 and BxPC-3 cells. The results showed that miR-129-5p overexpression suppressed proliferation, migration and invasion, and induced apoptosis of PC cells, whereas miR-129-5p knockdown showed opposite effects. In addition, we found that pre-B-cell leukemia homeobox 3 (PBX3) overexpression promoted proliferation, migration and invasion, but reduced apoptosis of PC cells. PBX3 was identified as a target of miR-129-5p by informatics analysis and dual luciferase reporter assay. Finally, our results indicated that miR-129-5p suppressed cell proliferation and migration by targeting PBX3. This study demonstrated that miR-129-5p could function as a tumor suppressor in the progression and development of PC by targeting PBX3, providing a reliable prognostic factor and a new therapeutic strategy for PC.

miR-302a inhibits human HepG2 and SMMC-7721 cells proliferation and promotes apoptosis by targeting MAP3K2 and PBX3

Hepatocellular carcinoma (HCC) is the most common liver cancer and has a poor prognosis. miR-302a is an important regulator of tumor occurrence and deterioration, while MAP3K2 and PBX3 genes are involved in cancer cell proliferation and apoptosis. In this study, the expression of miR-302a and MAP3K2/PBX3 were evaluated by qPCR in liver cancer cell lines. Next, the target relationship between miR-302a and MAP3K2/PBX3 was verified using luciferase assays. Meanwhile, the expression correlation between miR-302a and target genes was analyzed in cancer tissue and para-cancerous tissue. In addition, an increased miR-302a level in HepG2 cells and SMMC-7721 cells were achieved through transfection with miR-302a mimics, and the effects on HepG2 cell and SMMC-7721 cell proliferation, apoptosis and MAPK pathways were determined using MTT, flow cytometry, qPCR and western blot assays. The results showed that liver cancer cell lines exhibited low miR-302a expression and MAP3K2 and PBX3 were confirmed to be the target genes of miR-302a. Meanwhile, the HE results showed that cells became enlarged with loose cytoplasm and formed balloon-like lesions in HCC specimens and we found a significant negative correlation between miR-302a and MAP3K2/PBX3 expression. In addition, treatment with miR-302a mimics inhibited HepG2 cells and SMMC-7721 cells proliferation and increased the apoptosis rate. Further research revealed that the MAPK key factors p-p38, p-ERK1/2 and p-JNK were significantly reduced in miR-302a transfected cells and MAP3K2/PBX3 silenced cells. Besides, MAP3K2 and PBX3 overexpression in miR-302a mimics-treated cells exerted the opposite effects. In conclusion, miR-302a inhibited proliferation and promoted apoptosis in human hepatoma cells by targeting MAP3K2 and PBX3.

An in vitro and in vivo study of the role of long non-coding RNA-HOST2 in the proliferation, migration, and invasion of human glioma cells

Gliomas are the most commonly occurring primary malignant brain tumors in the central nervous system of adults. They are rarely curable and the prognosis for high grade gliomas is generally poor. Recently, long non-coding RNA (lncRNA) human ovarian cancer-specific transcript 2 (HOST2) has been reported to be expressed at high levels in human ovarian cancer, involving tumorigenesis. However, little is still known about whether and how HOST2 regulates glioma development and progression. Therefore, this study aims to investigate the role of HOST2 in human glioma cells. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to determine the expression of lncRNA HOST2, let-7b, and PBX3 in human glioma cells. Cultured human glioma cells were treated with siRNA (si)-lncRNA HOST2, let-7b mimic, si-lncRNA HOST2 + let-7b inhibitor, and si-PBX3. Parameters including cell viability, colony formation, cell migration, and cell invasion were detected by cell counting kit-8 assay, colony formation assay, scratch test, and Transwell assay respectively to determine the effects of down-regulated HOST2 on glioma cells. Tumor formation in nude mice was evaluated by subcutaneous tumor formation experiment. Results showed that HOST2 and PBX3 were highly expressed in glioma tissue whereas let-7b was expressed at much lower levels. In response to treatment with si-lncRNA HOST2, si-PBX3, and let-7b mimic, glioma cell lines exhibited decreased cell viability, suppressed cell migration, invasion, and reduced colony formation of glioma cells. This was accompanied by an attenuated tumor formation with smaller volume and weight in nude mice, suggesting that down-regulated HOST2 could inhibit the tumorigenicity of glioma cells. Lastly, we found that lncRNA HOST2 was highly expressed in glioma tissues and its down-regulation could inhibit the growth and invasion of glioma cells. © 2018 IUBMB Life, 71(1):93-104, 2019.

Molecular pathogenesis of interstitial cystitis based on microRNA expression signature: miR-320 family-regulated molecular pathways and targets

Interstitial cystitis (IC), also known as bladder pain syndrome, is a chronic inflammatory disease that affects the bladder. The symptoms of IC vary, including feeling an urgent need for immediate urination and of needing to urinate often, as well as bladder or pelvic pain. Despite its high incidence, no molecular diagnostic methods are available for IC, and the molecular pathogenesis is unknown. microRNAs (miRNA) can regulate expression of RNA transcripts in cells and aberrant expression of miRNAs is associated with several human diseases. Here, we investigated the molecular pathogenesis of IC based on miRNA expression signatures. RNA sequencing of miRNA levels in IC tissues and comparison with levels in normal bladder tissue and bladder cancer revealed dysregulated expression of 366 miRNAs (203 and 163 down- and upregulated miRNAs, respectively). In particular, miR-320 family miRNAs(miR-320a, miR-320b, miR-320c, miR-320d and miR-320e) had downregulated expression in IC tissues. Genome-wide gene expression analyses and in silico database analyses showed that three transcription factors, E2F-1, E2F-2 and TUB, are regulated by miR-320 family miRNAs. Immunostaining of IC tissues confirmed that these transcription factors are overexpressed in IC tissues. Novel approaches that identify aberrantly expressed miRNA regulatory networks in IC could provide new prognostic markers and therapeutic targets for this disease.