CircPOSTN/miR-361-5p/TPX2 axis regulates cell growth, apoptosis and aerobic glycolysis in glioma cells

The landscape of circRNAs in gliomas temozolomide resistance: Insights into molecular pathways

As the deadliest type of primary brain tumor, gliomas represent a significant worldwide health concern. Circular RNA (circRNA), a unique non-coding RNA molecule, seems to be one of the most alluring target molecules involved in the pathophysiology of many kinds of cancers. CircRNAs have been identified as prospective targets and biomarkers for the diagnosis and treatment of numerous disorders, particularly malignancies. Recent research has established a clinical link between temozolomide (TMZ) resistance and certain circRNA dysregulations in glioma tumors. CircRNAs may play a therapeutic role in controlling or overcoming TMZ resistance in gliomas and may provide guidance for a novel kind of individualized glioma therapy. To address the biological characteristics of circRNAs and their potential to induce resistance to TMZ, this review has highlighted and summarized the possible roles that circRNAs may play in molecular pathways of drug resistance, including the Ras/Raf/ERK PI3K/Akt signaling pathway and metabolic processes in gliomas.

Prognostic model for hepatocellular carcinoma based on necroptosis-related genes and analysis of drug treatment responses

Objective

Recent studies reveal that necroptosis is pivotal in tumorigenesis, cancer metastasis, cancer immunity, and cancer subtypes. Apoptosis or necroptosis of hepatocytes in the liver microenvironment can determine the subtype of liver cancer. However, necroptosis-related genomes have rarely been analyzed in hepatocellular carcinoma (HCC). Therefore, this study aims to construct an HCC risk scoring model based on necroptosis-related genes and to validate its predictive performance in overall survival prediction and immunotherapy efficacy evaluation in HCC, as well as to analyze drug treatment responses.

Methods

This study analyzed clinical information and RNA-seq expression data of liver cancer patients from TCGA public data, identified necroptosis-related genes, and conducted GO and KEGG enrichment analyses. Using Cox regression analysis and LASSO analysis to identify independent prognostic factors, a predictive model was established and validated in clinical subgroups, and correlation analysis with immune cells and ssGSEA differential analysis were conducted. Finally, potential drugs for HCC were screened to explore the drug sensitivity of different subtypes.

Results

We identified 19 differentially expressed necroptosis-related genes and constructed a predictive model with 3 independent prognostic factors through stepwise Cox regression. Validation results from clinical subgroups showed that the constructed model performed well in risk prediction, and ssGSEA differential analysis results were significant. We analyzed 55 immunotherapy drugs, and clustered them by distinct IC50 values to guide drug selection for HCC patients. Notable, Bleomycin, Obatoclax. Mesylate, PF.562271, PF.02341066, QS11, X17. AAG, and Bl. D1870 exhibited significantly different sensitivities in different subtypes, providing references for clinical practice in HCC patients.

Synthesis and Antitumour Evaluation of Tricyclic Indole-2-Carboxamides against Paediatric Brain Cancer Cells

Antitumour properties of some cannabinoids (CB) have been reported in the literature as early as 1970s, however there is no clear consensus to date on the exact mechanisms leading to cancer cell death. The indole-based WIN 55,212-2 and SDB-001 are both known as potent agonists at both CB1 and CB2 receptors, yet we demonstrate herein that only the former can exert in vitro antitumour effects when tested against a paediatric brain cancer cell line KNS42. In this report, we describe the synthesis of novel 3,4-fused tricyclic indoles and evaluate their functional potencies at both cannabinoid receptors, as well as their abilities to inhibit the growth or proliferation of KNS42 cells. Compared to our previously reported indole-2-carboxamides, these 3,4-fused tricyclic indoles had either completely lost activities, or, showed moderate-to-weak antagonism at both CB1 and CB2 receptors. Compound 23 displayed the most potent antitumour properties among the series. Our results further support the involvement of non-CB pathways for the observed antitumour activities of amidoalkylindole-based cannabinoids, in line with our previous findings. Transcriptomic analysis comparing cells treated or non-treated with compound 23 suggested the observed antitumour effects of 23 are likely to result mainly from disruption of the FOXM1-regulated cell cycle pathways.

Scutellarin Protects against Myocardial Ischemia-reperfusion Injury by Enhancing Aerobic Glycolysis through miR-34c-5p/ALDOA Axis

Background

Aerobic glycolysis has recently demonstrated promising potential in mitigating the effects of ischemia-reperfusion (IR) injury. Scutellarin (Scu) possesses various cardioprotective properties that warrant investigation. To mimic IR injury in vitro, this study employed hypoxia/reoxygenation (H/R) injury.

Methods and Results

First, we conducted an assessment of the protective properties of Scu against HR in H9c2 cells, encompassing inflammation damage, apoptosis injury, and oxidative stress. Then, we verified the effects of Scu on the Warburg effect in H9c2 cells during HR injury. The findings indicated that Scu augmented aerobic glycolysis by upregulating p-PKM2/PKM2 levels. Following, we built a panel of six long noncoding RNAs and seventeen microRNAs that were reported to mediate the Warburg effect. Based on the results, miR-34c-5p was selected for further experiments. Then, we observed Scu could mitigate the HR-induced elevation of miR-34c-5p. Upregulation of miR-34c-5p could weaken the beneficial impacts of Scu in cellular viability, inflammatory damage, oxidative stress, and the facilitation of the Warburg effect. Subsequently, our investigation revealed a decrease in both ALDOA mRNA and protein levels following HR injury, which could be restored by Scu administration. Downregulation of ALDOA or Mimic of miR-34c-5p could reduce these effects induced by Scu.

Conclusions

Scu provides cardioprotective effects against IR injury by upregulating the Warburg effect via miR-34c-5p/ALDOA.

Induction of perineural invasion in salivary adenoid cystic carcinoma by circular RNA RNF111

OBJECTIVE

Local recurrence, distant metastasis, and perineural invasion (PNI) viciously occur in salivary adenoid cystic carcinoma (SACC), resulting in a poor prognosis. This study aimed to explore the mechanism by which circular RNA RNF111 (circ-RNF111) regulates PNI in SACC by targeting the miR-361-5p/high mobility group box 2 (HMGB2) axis.

METHOD

Circ-RNF111 and HMGB2 were highly expressed in SACC specimens, while miR-361-5p was underexpressed. Functional experiments showed that ablating circ-RNF111 or promoting miR-361-5p hindered the biological functions and PNI of SACC-LM cells.

RESULTS

HMGB2 overexpression induced the reversal of SACC-LM cell biological functions and PNI caused by circ-RNF111 knockout. Furthermore, reduction of circ-RNF111 suppressed PNI in a SACC xenograft model. Circ-RNF111 regulated HMGB2 expression through targeted modulation of miR-361-5p.

CONCLUSION

Taken together, circ-RNF111 stimulates PNI in SACC by miR-361-5p/HMGB2 axis and may serve as a potential therapeutic target for SACC.

Circ_0021350 plays an oncogene role by regulating miR-1207-3p/PIK3R3 in glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most malignant glioma, with poor survival rates and prognosis. Several studies have reported the abnormal expression of circular RNAs (circRNAs) and their functions in the malignant biological behavior of GBM. However, such research is still in the preliminary stages, and further study is needed to confirm the therapeutic potential of circRNAs in GBM.

METHODS

RNA-seq was performed using four tumor tissues from patients with GBM and their adjacent non-tumor brain tissues to screen differentially expressed circRNAs. Fluorescence in situ hybridization assay was used to examine the location of circ_0021350 in glioma cells. In addition, a series of biological function assays were employed to verify the oncogenic role of circ_0021350 in GBM. Quantitative reverse transcription PCR was used to examine circular, micro- (miRNA), and messenger RNA (mRNA) levels. Furthermore, dual-luciferase reporter, RNA pull-down, and RNA binding protein immunoprecipitation assays were applied to verify the interaction between circ_0021350 and its downstream effectors.

RESULTS

Circ_0021350 was significantly elevated in GBM tissues and glioma cells. Overexpression of circ_0021350 promoted glioma cell proliferation and metastatic ability; silencing of circ_0021350 had the opposite effect. Mechanistic analysis revealed that circ_0021350 sponged miR-1207-3p to regulate PIK3R3, whose overexpression reversed the reduction in the malignant biological behavior of glioma cells caused by silencing circ_0021350.

CONCLUSION

Our findings suggest that circ_0021350 is an oncogenic circRNA in GBM, and the circ_0021350/miR-1207-3p/PIK3R3 axis may serve as a potential therapeutic target in GBM treatment.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Roles of circular RNAs in regulating the development of glioma

BACKGROUND

Glioma is the most common malignant tumor in the central nervous system. In patients with glioma, the prognosis is poor and median survival is only 12-15 months. With the recent development of sequencing technology, important roles of noncoding RNAs are being discovered in cells, especially those of circular RNAs (circRNAs). Because circRNAs are stable, abundant, and highly conserved, they are regarded as novel biomarkers in the early diagnosis and prognosis of diseases.

PURPOSE

In this review, roles and mechanisms of circRNAs in the development of glioma are summarized.

METHODS

This paper collects and reviews relevant PubMed literature.

CONCLUSION

Several classes of circRNAs are highly expressed in glioma and are associated with malignant biological behaviors of gliomas, including proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. Further studies are needed to clarify the roles of circRNAs in glioma and to determine whether it is possible to increase therapeutic effects on tumors through circRNA intervention.

Circular RNAs: Biogenesis, Biological Functions, and Roles in Myocardial Infarction

Non-coding RNAs have been excavated as important cardiac function modulators and linked to heart diseases. Significant advances have been obtained in illuminating the effects of microRNAs and long non-coding RNAs. Nevertheless, the characteristics of circular RNAs are rarely mined. Circular RNAs (circRNAs) are widely believed to participate in cardiac pathologic processes, especially in myocardial infarction. In this review, we round up the biogenesis of circRNAs, briefly describe their biological functions, and summarize the latest literature on multifarious circRNAs related to new therapies and biomarkers for myocardial infarction.

CircRNA circ_POSTN promotes the malignancy of glioma by regulating the miR-433-3p/SPARC axis

Glioma is a common tumor in the brain. CircRNA hsa_circ_0030018, also termed as hsa_circPOSTN_001 (circ_POSTN), is reported to exert a promoting influence on the development of glioma. Our study intends to deeply explore its regulation mechanism of circ_POSTN. Expression of circ_POSTN, microRNA-433-3p (miR-433-3p) and Secreted protein acidic and rich in cysteine (SPARC) was detected by qRT-PCR or western blot assay. The function of circ_POSTN was analyzed by loss-of-function experiments. The targeting relationship between miR-433-3p and circ_POSTN or SPARC was predicted by bioinformatics analysis and validated by dual-luciferase reporter assay. Xenograft modeling was employed to validate the function of circ_POSTN in glioma in vivo. circ_POSTN and SPARC were upregulated while miR-433-3p was downregulated in glioma tissues and cells. Both circ_POSTN and SPARC knockdown inhibited clonogenicity, migration, and promoted apoptosis of glioma cells. Circ_POSTN sponged miR-433-3p to regulate SPARC expression. Gain of SPARC largely attenuated circ_POSTN knockdown or miR-433-3p overexpression-mediated effects on glioma cell clonogenicity, migration, and apoptosis. Furthermore, silencing of circ_POSTN decreased xenograft tumor growth in vivo. Inhibition of circ_POSTN repressed glioma development, at least in part, via regulating the miR-433-3p/SPARC axis, providing evidence for circ_POSTN as a potential therapeutic target for glioma.

Diagnostic and therapeutic potential of circular RNA in brain tumors

Circular RNAs (circRNAs) are a class of RNA with a stable cyclic structure. They are expressed in various tissues and cells with conserved, specific characteristics. CircRNAs have been found to play critical roles in a wide range of cellular processes by regulating gene expression at the epigenetic, transcriptional, and posttranscriptional levels. There is an accumulation of evidence on newly discovered circRNAs, their molecular interactions, and their roles in the development and progression of human brain tumors, including cell proliferation, cell apoptosis, invasion, and chemoresistance. Here we summarize the current state of knowledge of the circRNAs that have been implicated in brain tumor pathogenesis, particularly in gliomas and medulloblastomas. In providing a comprehensive overview of circRNA studies, we highlight how different circRNAs have oncogenic or tumor-suppressive roles in brain tumors, making them attractive therapeutic targets and biomarkers for personalized therapy and precision diagnostics. This review article discusses circRNAs' functional roles and the prospect of using them as diagnostic biomarkers and therapeutic targets in patients with brain tumors.

Epigenetic regulation in myocardial infarction: Non-coding RNAs and exosomal non-coding RNAs

Myocardial infarction (MI) is one of the leading causes of deaths globally. The early diagnosis of MI lowers the rate of subsequent complications and maximizes the benefits of cardiovascular interventions. Many efforts have been made to explore new therapeutic targets for MI, and the therapeutic potential of non-coding RNAs (ncRNAs) is one good example. NcRNAs are a group of RNAs with many different subgroups, but they are not translated into proteins. MicroRNAs (miRNAs) are the most studied type of ncRNAs, and have been found to regulate several pathological processes in MI, including cardiomyocyte inflammation, apoptosis, angiogenesis, and fibrosis. These processes can also be modulated by circular RNAs and long ncRNAs via different mechanisms. However, the regulatory role of ncRNAs and their underlying mechanisms in MI are underexplored. Exosomes play a crucial role in communication between cells, and can affect both homeostasis and disease conditions. Exosomal ncRNAs have been shown to affect many biological functions. Tissue-specific changes in exosomal ncRNAs contribute to aging, tissue dysfunction, and human diseases. Here we provide a comprehensive review of recent findings on epigenetic changes in cardiovascular diseases as well as the role of ncRNAs and exosomal ncRNAs in MI, focusing on their function, diagnostic and prognostic significance.

Comprehensive Analysis of the Oncogenic Role of Targeting Protein for Xklp2 (TPX2) in Human Malignancies

Mitosis and spindle assembly require the microtubule-associated protein Xenopus kinesin-like protein 2 (TPX2). Although TPX2 is highly expressed in several malignant tumor forms, little is known about its role in cancer. In this study, we performed the gene set enrichment analysis of TPX2 in 33 types of cancers and an extensive pan-cancer bioinformatic analysis using prognosis, tumor mutational burdens, microsatellite instability, tumor microenvironment, and immune cell infiltration data. According to the differential expression study, TPX2 was found to be overexpressed across all studied cancer types. Based on the survival analysis, increased TPX2 expression was associated with a poor prognosis for most cancers. The TPX2 expression level was confirmed to correlate with the clinical stage, microsatellite instability, and tumor mutational burden across all cancer types. Furthermore, TPX2 expression has been linked to tumor microenvironments and immune cell infiltration, particularly in bladder urothelial carcinoma, liver hepatocellular carcinoma, lung adenocarcinoma, stomach adenocarcinoma, and uterine corpus endometrial carcinoma. Finally, the gene set enrichment analysis implicated TPX2 in the regulation of aminoacyl tRNA biosynthesis, which is the most important tumor cell cycle signaling pathway. This comprehensive pan-cancer analysis shows that TPX2 is a prognostic molecular biomarker for most cancers and suggests its potential as an effective therapeutic target for the treatment of these diseases.

LncRNA MDRL Mitigates Atherosclerosis through miR-361/SQSTM1/NLRP3 Signaling

Objective

Long non-coding RNAs (lncRNAs) play many important roles in gene regulation and disease pathogenesis. Here, we sought to determine that mitochondrial dynamic related lncRNA (MDRL) modulates NLRP3 inflammasome activation and apoptosis of vascular smooth muscle cells (VSMCs) and protects arteries against atherosclerosis.

Methods

In vivo experiments, we applied LDLR knockout (LDLR^−/−) mice fed the high-fat diet to investigate the effects of MDRL on atherosclerosis. In vitro experiments, we applied mouse aortic smooth muscle cells to determine the mechanism of MDRL in abrogating NLRP3 inflammasome and inhibiting cell apoptosis through miR-361/sequentosome 1 (SQSTM1) by TUNEL staining, quantitative RT-PCR, western blot, microribonucleoprotein immunoprecipitation, and luciferase reporter assay.

Results

Downregulated MDRL and increased NLRP3 were observed in mouse atherosclerotic plaques, accompanied with the increase of miR-361. The results showed that MDRL overexpression significantly attenuated the burden of atherosclerotic plaque and facilitated plaque stability through inhibiting NLRP3 inflammasome activation and cell apoptosis, and vice versa. Mechanically, MDRL suppressed NLRP3 inflammasome activation and VSMC apoptosis via suppressing miR-361. Furthermore, miR-361 directly bound to the 3'UTR of SQSTM1 and inhibited its translation, subsequently activating NLRP3 inflammasome. Systematic delivery of miR-361 partly counteracted the beneficial effects of MDRL overexpression on atherosclerotic development in LDLR^−/− mice.

Conclusions

In summary, MDRL alleviates NLRP3 inflammasome activation and apoptosis in VSMCs through miR-361/SQSTM1/NLRP3 pathway during atherogenesis. These data indicate that MDRL and inhibition of miR-361 represent potential therapeutic targets in atherosclerosis-related diseases.

Circular RNAs in Alzheimer's Disease: A New Perspective of Diagnostic and Therapeutic Targets

BACKGROUND

Circular RNAs (circRNAs), as covalently closed single-stranded noncoding RNA molecules, have been recently identified to involve in several biological processes, principally through targeting microRNAs. Among various neurodegenerative diseases (NDs), accumulating evidence has proposed key roles for circRNAs in the pathogenesis of Alzheimer's disease (AD); although the exact relationship between these RNA molecules and AD progression is not clear, they have been believed to mostly act as miRNA sponges or gene transcription modulators through correlating with multiple proteins, involved in the accumulation of Amyloid β (Aβ) peptides, as well as tau protein, as AD's pathological hallmark. More interestingly, circRNAs have also been reported to play diagnostic and therapeutic roles during AD progression.

OBJECTIVE

Literature review indicated that circRNAs could essentially contribute to the onset and development of AD. Thus, in the current review, the circRNAs' biogenesis and functions are addressed at first, and then the interplay between particular circRNAs and AD is comprehensively discussed. Eventually, the diagnostic and therapeutic significance of these noncoding RNAs is highlighted in brief.

RESULTS

A large number of circRNAs are expressed in the brain. Thereby, these RNA molecules are noticed as potential regulators of neural functions in healthy circumstances, as well as neurological disorders. Moreover, circRNAs have also been reported to have potential diagnostic and therapeutic capacities in relation to AD, the most prevalent ND.

CONCLUSION

CircRNAs have been shown to act as sponges for miRNAs, thereby regulating the function of related miRNAs, including oxidative stress, reduction of neuroinflammation, and the formation and metabolism of Aβ, all of which developed in AD. CircRNAs have also been proposed as biomarkers that have potential diagnostic capacities in AD. Despite these characteristics, the use of circRNAs as therapeutic targets and promising diagnostic biomarkers will require further investigation and characterization of the function of these RNA molecules in AD.

CircRNA: An emerging star in the progression of glioma

Circular RNAs (circRNAs), a class of single-stranded noncoding RNAs with a covalently closed loop structure, are recognized as promising biomarkers and targets for diagnosing and treating dozens of diseases, especially cancers. CircRNAs are extremely stable, abundant and conserved and have tissue- or developmental stage-specific expression. Currently, the biogenesis and biological functions of circRNAs have been increasingly revealed with deep sequencing and bioinformatics. Studies have indicated that circRNAs are frequently expressed in brain tissues and that their expression levels change in different stages of neural development, suggesting that circRNAs may play an important role in diseases of the nervous system, such as glioma. However, because the biogenesis and functions of circRNAs do not depend on a single mechanism but are coregulated by multiple factors, it is necessary to further explore the underlying mechanisms. In this review, we summarized the classification, mechanisms of biogenesis and biological functions of circRNAs. Meanwhile, we emphatically expounded on the process of abnormal expression of circRNAs, methods used in circRNA research, and their effects on the malignant biological capabilities of glioma.

Downregulation of TPX2 impairs the antitumor activity of CD8+ T cells in hepatocellular carcinoma

Targeting key genes that play dominant roles in T cell dysfunction is an efficient strategy for cancer immunotherapy. Here, we aimed to investigate the role of TPX2 in the antitumor effect of CD8 + T cells in hepatocellular carcinoma (HCC). Flow cytometry was used to assay the level of cell surface markers and cytokines in T cells, through which we found that TPX2 was downregulated in HCC-infiltrating CD8 + T cells. TPX2 depletion restricted the antitumor activity of CD8 + T cells, and TPX2 overexpression increased the antitumor effect of CD8 + T cells in tumor-bearing Cd8^−/− mice. TPX2 overexpression improved the antitumor function of human CD8 + T cells and response to anti-PD-1 therapy in an HCC patient-derived xenograft (PDX) mouse model with or without anti-PD-1 therapy. In mechanism, TPX2 promotes the phosphorylation of P65, thus increases the level of p-P65 in nuclear, and p-P65 binds to the promoter of CXCR5, activates its transcription, and increases the level of CXCR5 on CD8 + T cells in a TPX2-dependent way. In conclusion, TPX2 maintains the antitumor effect of CD8 + T cells in HCC by regulating CXCR5 via the NF-κB signaling pathway. Increased TPX2 expression in CD8 + T cells exerts synergistic effects with anti-PD-1 therapy, suggesting a promising immunotherapeutic method in HCC.

Non-Coding RNAs and Brain Tumors: Insights Into Their Roles in Apoptosis

A major terrifying ailment afflicting the humans throughout the world is brain tumor, which causes a lot of mortality among pediatric and adult solid tumors. Several major barriers to the treatment and diagnosis of the brain tumors are the specific micro-environmental and cell-intrinsic features of neural tissues. Absence of the nutrients and hypoxia trigger the cells' mortality in the core of the tumors of humans' brains: however, type of the cells' mortality, including apoptosis or necrosis, has been not found obviously. Current studies have emphasized the non-coding RNAs (ncRNAs) since their crucial impacts on carcinogenesis have been discovered. Several investigations suggest the essential contribution of such molecules in the development of brain tumors and the respective roles in apoptosis. Herein, we summarize the apoptosis-related non-coding RNAs in brain tumors.

CircPOSTN competes with KIF1B for miR-185-5p binding sites to promote the tumorigenesis of glioma

BACKGROUND

The involvement of certain circular RNAs (circRNAs) in the development of glioma has been revealed. CircRNA periostin (circPOSTN) was validated to be positively associated with glioma cell growth and metastasis. However, the mechanism underlying circPOSTN in glioma tumorigenesis remain vague.

METHODS

The expression of circPOSTN, KIF1B (Kinesin Family Member 1B) and miR-185-5p was detected using quantitative real-time polymerase chain reaction and Western blot. In vitro assays were conducted using cell counting kit-8 assay, colony formation assay, EdU assay, flow cytometry, Western blot, and transwell assay, respectively. The direct interactions between miR-185-5p and circPOSTN or KIF1B was confirmed by using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

CircPOSTN was highly expressed in glioma tissues and cells. Knockdown of circPOSTN restrained glioma cell proliferation, migration and invasion in vitro, as well as hindered glioma xenograft growth in vivo. Mechanistically, circPOSTN acted as miR-185-5p sponge to up-regulate the expression of its target KIF1B. Moreover, miR-185-5p inhibition reversed the anticancer effects of circPOSTN knockdown on glioma tumorigenesis, and miR-185-5p re-expression suppressed the malignant phenotype of glioma cells via targeting KIF1B.

CONCLUSION

CircPOSTN acted as an oncogene to expedite glioma tumorigenesis via targeting miR-185-5p/KIF1B axis, indicating a potential therapeutic target for glioma.

Corosolic acid reduces A549 and PC9 cell proliferation, invasion, and chemoresistance in NSCLC via inducing mitochondrial and liposomal oxidative stress

Corosolic acid is a pentacyclic triterpenoid isolated from Lagerstroemia speciosa, which is known to inhibit cancer cell proliferations. Whereas, the role of this compound on non-small cell lung cancer (NSCLC) cells still largely unclear. So, the aim of this study was to reveal the regulatory mechanism of corosolic acid to NSCLC. Here, we cultured A549 and PC9 cells in increasing corosolic acid concentrations, as well as treated mice with a physiologically relevant concentration of the compound, and used metabolomics analysis and high-throughput sequencing to examine its influences on cell invasion and proliferation, chemoresistance, and metastasis. We found that corosolic acid inhibited cell invasion and proliferation in vivo and in vitro, as well as increase the chemosensitivity of both cell types to cisplatin. Furthermore, we found that corosolic acid destabilized the glutathione peroxidase 2-mediated redox system, which increased mitochondrial and liposomal oxidative stress. Corosolic acid also decreased the targeting protein for TPX2 level, which inhibited PI3K/AKT signaling and induced apoptosis. In addition, the accumulation of reactive oxygen species dissociated the CCNB1/CDK1 complex and induced G2/M cell cycle arrest. Taken collectively, the data indicate that corosolic acid reduces NSCLC cell invasion and proliferation, as well as chemoresistance, by inducing mitochondrial and liposomal oxidative stress.

MiR-361-5p promotes oxygen-glucose deprivation/re-oxygenation induced neuronal injury by negatively regulating SQSTM1 in vitro

It has been reported that microRNAs (miRNAs) play essential roles in cerebral ischemia and reperfusion (I/R) injury. This study aimed to explore the role of miR-361-5p in oxygen-glucose deprivation/re-oxygenation-induced neuronal injury in vitro. Cerebral I/R injury cell model was established by using PC12 cells exposed to oxygen-glucose deprivation/re-oxygenation (OGD/R). The expression of miR-361-5p and SQSTM1 was evaluated by qRT-PCR or western blot. Neuronal apoptosis was detected by flow cytometry, and cell viability was assessed by CCK-8 assay. The effects of miR-361-5p on the release of LDH and the levels of MDA, SOD, and GSH-Px were investigated by respective detection kits. Dual-luciferase reporter assay and RIP assay were performed to determine the interaction between miR-361-5p and SQSTM1. Rescue experiments were performed to evaluate the function of miR-361-5p and SQSTM1. MiR-361-5p was significantly upregulated, and SQSTM1 was significantly downregulated in OGD/R-stimulated PC12 cells. MiR-361-5p could directly interact with SQSTM1 and negatively regulated it. Inhibition of miR-361-5p efficiently inhibited OGD/R-induced apoptosis and attenuated OGD/R-induced growth defect in PC12 cells. In addition, SQSTM1 overexpression partially attenuates the apoptosis and promoted the viability of OGD/R-treated PC12 cells, which were aggravated by miR-361-5p mimics. Our study demonstrated that miR-361-5p promotes OGD/R-induced neuronal injury via regulating SQSTM1 in PC12 cells.

Research Progress on Circular RNA in Glioma

The discovery of circular RNA (circRNA) greatly complements the traditional gene expression theory. CircRNA is a class of non-coding RNA with a stable cyclic structure. They are highly expressed, spatiotemporal-specific and conservative across species. Importantly, circRNA participates in the occurrence of many kinds of tumors and regulates the tumor development. Glioma is featured by limited therapy and grim prognosis. Cancer-associated circRNA compromises original function or creates new effects in glioma, thus contributing to oncogenesis. Therefore, this article reviews the biogenesis, metabolism, functions and properties of circRNA as a novel potential biomarker for gliomas. We elaborate the expression characteristics, interaction between circRNA and other molecules, aiming to identify new targets for early diagnosis and treatment of gliomas.

Curcumin Antagonizes Glucose Fluctuation-Induced Renal Injury by Inhibiting Aerobic Glycolysis via the miR-489/LDHA Pathway

It has been considered that glucose fluctuation (GF) plays a role in renal injury and is related to diabetic nephropathy (DN) development. But the mechanism is still unclear. Aerobic glycolysis has become a topical issue in DN in recent years. There is an internal connection between GF, aerobic glycolysis, and DN. Curcumin (Cur) is a principal curcuminoid of turmeric and possesses specific protective properties in kidney functions. Cur also participates in the regulation of aerobic glycolysis switch. In this study, we first measured the levels of aerobic glycolysis and evaluated Cur's inhibitory ability in a cell model of HEK-293 under the condition of oscillating high glucose. The results indicated that GF exacerbated inflammation injury, oxidative stress, and apoptosis in HEK-293 cell, while Cur alleviated this cytotoxicity induced by GF. We found that GF increased aerobic glycolysis in HEK-293 cells and Cur presented a dose-dependent weakening effect to this exacerbation. Next, we built a panel of 17 miRNAs and 8 lncRNAs that were previously reported to mediate the Warburg effect. Our RT-qPCR results indicated that GF reduced the miR-489 content in the HEK-293 cell model and Cur could prevent this downregulation. Then, we planned to explore the character of miR-489 in Cur-triggered attenuation of the Warburg effect under GF condition. Our findings presented that Cur prevented GF-triggered aerobic glycolysis by upregulating miR-489 in HEK-293 cells. Next, we choose the miR-489/LDHA axis for further investigation. We confirmed that Cur prevented GF-triggered aerobic glycolysis via the miR-489/LDHA axis in HEK-293 cells. In conclusion, this study presented that Cur prevented GF-triggered renal injury by restraining aerobic glycolysis via the miR-489/LDHA axis in the HEK-293 cell model.

MicroRNA-361-5p slows down gliomas development through regulating UBR5 to elevate ATMIN protein expression

MicroRNA (miR)-361-5p has been studied to suppress gliomas development. Based on that, an insight into the regulatory mechanism of miR-361-5p in gliomas was supplemented from ubiquitin protein ligase E3 component N-recognin 5 (UBR5)-mediated ubiquitination of ataxia-telangiectasia mutated interactor (ATMIN). miR-361-5p, ATMIN, and UBR5 levels were clinically analyzed in gliomas tissues, which were further validated in gliomas cell lines. Loss/gain-of-function method was applied to determine the roles of miR-361-5p and UBR5 in gliomas, as to cell viability, migration, invasion, colony formation ability, and apoptosis in vitro and tumorigenesis in vivo. The relationship between miR-361-5p and UBR5 was verified and the interaction between UBR5 and ATMIN was explored. It was detected that reduced miR-361-5p and ATMIN and enhanced UBR5 levels showed in gliomas. Elevating miR-361-5p was repressive in gliomas progression. UBR5 was directly targeted by miR-361-5p. UBR5 can ubiquitinate ATMIN. miR-361-5p suppressed gliomas by regulating UBR5-mediated ubiquitination of ATMIN. Downregulating UBR5 impeded gliomas tumor growth in vivo. Upregulating miR-361-5p targets UBR5 to promote ATMIN protein expression, thus to recline the malignant phenotype of gliomas cells.

Circular RNAs Regulate Glucose Metabolism in Cancer Cells

Circular RNAs (circRNAs) were originally thought to result from RNA splicing errors. However, it has been shown that circRNAs can regulate cancer onset and progression in various ways. They can regulate cancer cell proliferation, differentiation, invasion, and metastasis. Moreover, they modulate glucose metabolism in cancer cells through different mechanisms such as directly regulating glycolytic enzymes and glucose transporter (GLUT) or indirectly regulating signal transduction pathways. In this review, we elucidate on the role of circRNAs in regulating glucose metabolism in cancer cells, which partly explains the pathogenesis of malignant tumors, and provides new therapeutic targets or new diagnostic and prognostic markers for human cancers.

Competing Endogenous RNA Networks in Glioma

Gliomas are the most common and malignant primary brain tumors. Various hallmarks of glioma, including sustained proliferation, migration, invasion, heterogeneity, radio- and chemo-resistance, contribute to the dismal prognosis of patients with high-grade glioma. Dysregulation of cancer driver genes is a leading cause for these glioma hallmarks. In recent years, a new mechanism of post-transcriptional gene regulation was proposed, i.e., "competing endogenous RNA (ceRNA)." Long non-coding RNAs, circular RNAs, and transcribed pseudogenes act as ceRNAs to regulate the expression of related genes by sponging the shared microRNAs. Moreover, coding RNA can also exert a regulatory role, independent of its protein coding function, through the ceRNA mechanism. In the latest glioma research, various studies have reported that dysregulation of certain ceRNA regulatory networks (ceRNETs) accounts for the abnormal expression of cancer driver genes and the establishment of glioma hallmarks. These achievements open up new avenues to better understand the hidden aspects of gliomas and provide new biomarkers and potential efficient targets for glioma treatment. In this review, we summarize the existing knowledge about the concept and logic of ceRNET and highlight the emerging roles of some recently found ceRNETs in glioma progression.

Circular RNAs in the Central Nervous System

Circular RNAs (circRNAs) are endogenous single-stranded RNAs characterized by covalently closed loop structures with neither 5′ to 3′ polarity nor poly(A) tails. They are generated most commonly from back-splicing of protein-coding exons. CircRNAs have a tissue-specific distribution and are evolutionarily conserved, and many circRNAs play important biological functions by combining with microRNAs and proteins to regulate protein functions and their own translation. Numerous studies have shown that circRNAs are enriched in the central nervous system (CNS) and play an important role in the development and maintenance of homeostasis. Correspondingly, they also play an important role in the occurrence and progression of CNS diseases. In this review, we highlight the current state of circRNA biogenesis, properties, function and the crucial roles they play in the CNS.

Circular RNA POSTN Promotes Myocardial Infarction-Induced Myocardial Injury and Cardiac Remodeling by Regulating miR-96-5p/BNIP3 Axis

Myocardial infarction (MI) is the most prevalent cardiac disease with high mortality, leading to severe heart injury. Circular RNAs (circRNAs) are a new type of regulatory RNAs and participate in multiple pathological cardiac progressions. However, the role of circRNAs Postn (circPostn) in MI modulation remains unclear. Here, we aimed to explore the effect of circPostn on MI-induced myocardial injury and cardiac remodeling. We identified that the expression of circPostn was elevated in the plasma of MI patients, MI mouse model, and hypoxia and reoxygenation (H/R)-treated human cardiomyocytes. The depletion of circPostn significantly attenuated MI-related myocardium injury and reduced the infarct size in MI mouse model. The circPostn knockdown obviously enhanced left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) and inhibited left ventricular anterior wall thickness at diastole (LVAWd) and left ventricular posterior wall thickness at diastole (LVPWd). The depletion of circPostn was able to decrease MI-induced expression of collagen 1α1 and collagen 3α1 in the ventricular tissues of mice. The protein expression of collagen and α-smooth muscle actin (SMA) was up-regulated in MI mice and was inhibited by circPostn knockdown. Meanwhile, the expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was repressed by circPostn depletion in the ventricular tissues of MI mice. Besides, the circPostn depletion attenuated cardiomyocyte apoptosis in mice. Mechanically, circPostn served as a miR-96-5p sponge and miR-96-5p-targeted BNIP3 in human cardiomyocytes, in which circPostn up-regulated BNIP3 expression by targeting miR-96-5p. circPostn promoted H/R-induced cardiomyocyte injury by modulating miR-96-5p/BNIP3 axis. Thus, we conclude that circPostn contributes to MI-induced myocardial injury and cardiac remodeling by regulating miR-96-5p/BNIP3 axis. Our finding provides new insight into the mechanism by which circPostn regulates MI-related cardiac dysfunction. circPostn, miR-96-5p, and BNIP3 are potential targets for the treatment of MI-caused heart injury.