Long non-coding RNA EPIC1 inhibits viability and invasion of osteosarcoma cells by promoting MEF2D ubiquitylation

The role of lncRNA and miRNA on the effects of occurrence and development of osteosarcoma

Osteosarcoma is a common primary malignant bone tumor with a high incidence in children and adolescents, with high invasiveness and lung metastases. Even after traditional surgical excision, chemoradiotherapy, and comprehensive treatment, the survival rate of patients is still low, and the prognosis is not ideal. As an important part of non-coding RNA family, lncRNA and miRNA have significant regulatory effects on the growth, proliferation, metastasis and apoptosis of osteosarcoma cells. Therefore, exploring the roles of lncRNAs and miRNAs in the occurrence and development of osteosarcoma is of great help for the subsequent diagnosis, treatment, and prognosis of osteosarcoma. This paper mainly reviews the current research progress on the effects and mechanisms of lncRNAs and miRNAs on osteosarcoma cells, in order to provide new ideas for future research on the development process, treatment methods, and prognosis of osteosarcoma.

The Role of Ubiquitination in Osteosarcoma Development and Therapies

The ubiquitin-proteasome system (UPS) maintains intracellular protein homeostasis and cellular function by regulating various biological processes. Ubiquitination, a common post-translational modification, plays a crucial role in the regulation of protein degradation, signal transduction, and other physiological and pathological processes, and is involved in the pathogenesis of various cancers, including osteosarcoma. Osteosarcoma, the most common primary malignant bone tumor, is characterized by high metastatic potential and poor prognosis. It is a refractory bone disease, and the main treatment modalities are surgery combined with chemotherapy. Increasing evidence suggests a close association between UPS abnormalities and the progression of osteosarcoma. Due to the complexity and pleiotropy of the ubiquitination system, each step in the ubiquitination process can be targeted by drugs. In recent years, research and development of inhibitors targeting the ubiquitin system have increased gradually, showing great potential for clinical application. This article reviews the role of the ubiquitination system in the development and treatment of osteosarcoma, as well as research progress, with the hope of improving the therapeutic effects and prognosis of osteosarcoma patients by targeting effective molecules in the ubiquitination system.

Identification of two MEF2s and their role in inhibiting the transcription of the mstn2a gene in the yellowfin seabream, Acanthopagrus latus (Hottuyn, 1782)

Myocyte-specific enhancer binding factor 2 (MEF2), which belongs to the MADS superfamily, is a pivotal and conserved transcription factor that combines with the E-box motif to control the expression of muscle genes. Myostatin (mstn), a muscle growth inhibitor, is a vital member of the TGF-β superfamily. Currently, an understanding of the mechanisms of A. latus mstn (Almstn) transcriptional regulation mediated by MEF2 in fish muscle development is lacking. In the present study, two AlMEF2s (AlMEF2A and AlMEF2B) and Almstn2a were characterized from Acanthopagrus latus. AlMEF2A and AlMEF2B had 456 and 315 amino acid (aa) residues, respectively. Two typical regions, a MADS-box, MEF2, and transcriptionally activated (TAD) domains, are present in both AlMEF2s. The expression profiles of the two AlMEF2 genes were similar. The AlMEF2 genes were mainly expressed in the brain, white muscle, and liver, while Almstn2a expression was higher in the brain than in other tissues. Moreover, the expression trends of AlMEF2s and Almstn2a were significantly changed after starvation and refeeding in the five groups. Additionally, truncation experiments showed that -987 to +168 and -105 to +168 were core promoters of Almstn2a that responded to AlMEF2A and AlMEF2B, respectively. The point mutation experiment confirmed that Almstn2a transcription relies on the mutation binding sites 1 or 5 (M1/5) and mutation binding sites 4 or 5 (M4/5) for AlMEF2A and AlMEF2B regulation, respectively. The electrophoretic mobile shift assay (EMSA) further verified that M1 (-527 to -512) was a pivotal site where AlMEF2A acted on the Almstn2a gene. Furthermore, a siRNA interference gene expression experiment showed that reduced levels of AlMEF2A or AlMEF2B could prominently increase Almstn2a transcription. These results provide new information about the regulation of Almstn2a transcriptional activity by AlMEF2s and a theoretical basis for the regulatory mechanisms involved in muscle development in fish.

Combination of hsa_circ_0004674 and lncRNA OIP5‑AS1 as a novel clinical biomarker used to predict prognosis in patients with osteosarcoma

Osteosarcoma is a malignant tumor that predominantly occurs in children or adolescents under the age of 20 years old. Metastasis and chemotherapy resistance are two problems in the treatment of osteosarcoma, and the lack of definite biomarkers impairs the course of treatment. In recent years, non-coding RNA, as a biomarker of osteosarcoma, has become an area of research focus. The role of long non-coding RNAs (lncRNAs), such as lncRNA OIP5-AS1, and circular RNAs, such as hsa_circ_0004674, in osteosarcoma have previously been revealed, and the present study investigated their clinical significance. A total of 20 samples were collected from patients with osteosarcoma. The expression levels of lncRNA OIP5-AS1 and hsa_circ_0004674 were analyzed in tumor tissues and patient serum, and their associations with chemotherapy sensitivity, lung metastasis and prognosis were assessed. The results revealed that these two non-coding RNAs were significantly upregulated in the osteosarcoma tissues of patients compared with those in the adjacent tumor tissues. In addition, the expression levels of the two non-coding RNAs were increased in the serum of patients with osteosarcoma compared with those in patients with bone fractures (P<0.01). In patients with lung metastasis or chemotherapy resistance (tumor necrosis rate <90%), the expression levels of the two non-coding RNAs were similarly increased. By plotting the receiver operating characteristic curve, it was revealed that the combination of hsa_circ_0004674 and lncRNA OIP5-AS1 was better than ALP or either non-coding RNA alone in predicting chemotherapy sensitivity and metastasis. Kaplan-Meier survival analysis showed that, in patients with osteosarcoma, higher expression of both non-coding RNAs was associated with worse survival time (log-rank test P=0.006). In conclusion, the combination of hsa_circ_0004674 and lncRNA OIP5-AS1 may be used as a better biomarker than traditional biomarkers, such as ALP, in a clinical setting.

LncRNAs could play a vital role in osteosarcoma treatment: Inhibiting osteosarcoma progression and improving chemotherapy resistance

Osteosarcoma (OS) is one of the most common primary solid malignant tumors in orthopedics, and its main clinical treatments are surgery and chemotherapy. However, a wide surgical resection range, functional reconstruction of postoperative limbs, and chemotherapy resistance remain as challenges for patients and orthopedists. To address these problems, the discovery of new effective conservative treatments is important. Long non-coding RNAs (lncRNAs) are RNAs longer than 200 nucleotides in length that do not encode proteins. Researchers have recently found that long non-coding RNAs are closely associated with the development of OS, indicating their potentially vital role in new treatment methods for OS. This review presents new findings regarding the association of lncRNAs with OS and summarizes potential clinical applications of OS with lncRNAs, including the downregulation of oncogenic lncRNAs, upregulation of tumor suppressive lncRNAs, and lncRNAs-based treatment to improve chemotherapy resistance. We hope these potential methods will be translated into clinical applications and greatly reduce patient suffering.

Roles of lncRNAs in childhood cancer: Current landscape and future perspectives

According to World Health Organization (WHO), cancer is the leading cause of death for children and adolescents. Leukemias, brain cancers, lymphomas and solid tumors, such as neuroblastoma, ostesarcoma and Wilms tumors are the most common types of childhood cancers. Approximately 400,000 children and adolescents between the ages of 0 and 19 are diagnosed with cancer each year worldwide. The cancer incidence rates have been rising for the past few decades. Generally, the prognosis of childhood cancers is favorable, but the survival rate for many unresectable or recurring cancers is substantially worse. Although random genetic mutations, persistent infections, and environmental factors may serve as contributing factors for many pediatric malignancies, the underlying mechanisms are yet unknown. Long non-coding RNAs (lncRNAs) are a group of transcripts with longer than 200 nucleotides that lack the coding capacity. However, increasing evidence indicates that lncRNAs play vital regulatory roles in cancer initiation and development in both adults and children. In particular, many lncRNAs are stable in cancer patients' body fluids such as blood and urine, suggesting that they could be used as novel biomarkers. In support of this notion, lncRNAs have been identified in liquid biopsy samples from pediatric cancer patients. In this review, we look at the regulatory functions and underlying processes of lncRNAs in the initiation and progression of children cancer and discuss the potential of lncRNAs as biomarkers for early detection. We hope that this article will help researchers explore lncRNA functions and clinical applications in pediatric cancers.

Cellular functions and molecular mechanisms of ubiquitination in osteosarcoma

Although some advances have been made in the treatment of osteosarcoma in recent years, surgical resection remains the mainstream treatment. Initial and early diagnosis of osteosarcoma could be very difficult to achieve due to the insufficient sensitivity for the means of examination. The distal metastasis of osteosarcoma also predicts the poor prognosis of osteosarcoma. In order to solve this series of problems, people begin to discover a new method of diagnosing and treating osteosarcoma. Ubiquitination, as an emerging posttranslational modification, has been shown to be closely related to osteosarcoma in studies over the past decades. In general, this review describes the cellular functions and molecular mechanisms of ubiquitination during the development of osteosarcoma.

A ubiquitin-related gene signature for predicting prognosis and constructing molecular subtypes in osteosarcoma

Background: Ubiquitination is medicated by three classes of enzymes and has been proven to involve in multiple cancer biological processes. Moreover, dysregulation of ubiquitination has received a growing body of attention in osteosarcoma (OS) tumorigenesis and treatment. Therefore, our study aimed to identify a ubiquitin-related gene signature for predicting prognosis and immune landscape and constructing OS molecular subtypes.

Methods: Therapeutically Applicable Research to Generate Effective Treatments (TARGET) was regarded as the training set through univariate Cox regression, Lasso Cox regression, and multivariate Cox regression. The GSE21257 and GSE39055 served as the validation set to verify the predictive value of the signature. CIBERSORT was performed to show immune infiltration and the immune microenvironment. The NMF algorithm was used to construct OS molecular subtypes.

Results: In this study, we developed a ubiquitin-related gene signature including seven genes (UBE2L3, CORO6, DCAF8, DNAI1, FBXL5, UHRF2, and WDR53), and the gene signature had a good performance in predicting prognosis for OS patients (AUC values at 1/3/5 years were 0.957, 0.890, and 0.919). Multivariate Cox regression indicated that the risk score model and prognosis stage were also independent prognostic prediction factors. Moreover, analyses of immune cells and immune-related functions showed a significant difference in different risk score groups and the three clusters. The drug sensitivity suggested that IC50 of proteasome inhibitor (MG-132) showed a notable significance between the risk score groups (p < 0.05). Through the NMF algorithm, we obtained the three clusters, and cluster 3 showed better survival outcomes. The expression of ubiquitin-related genes (CORO6, UBE2L3, FBXL5, DNAI1, and DCAF8) showed an obvious significance in normal and osteosarcoma tissues.

Conclusion: We developed a novel ubiquitin-related gene signature which showed better predictive prognostic ability for OS and provided additional information on chemotherapy and immunotherapy. The OS molecular subtypes would also give a useful guide for individualized therapy.

Navigating the genomic instability mine field of osteosarcoma to better understand implications of non-coding RNAs

Osteosarcoma is one of the most genomically complex cancers and as result, it has been difficult to assign genomic aberrations that contribute to disease progression and patient outcome consistently across samples. One potential source for correlating osteosarcoma and genomic biomarkers is within the non-coding regions of RNA that are differentially expressed. However, it is unsurprising that a cancer classification that is fraught with genomic instability is likely to have numerous studies correlating non-coding RNA expression and function have been published on the subject. This review undertakes the formidable task of evaluating the published literature of noncoding RNAs in osteosarcoma. This is not the first review on this topic and will certainly not be the last. The review is organized with an introduction into osteosarcoma and the epigenetic control of gene expression before reviewing the molecular function and expression of long non-coding RNAs, circular RNAs, and short non-coding RNAs such as microRNAs, piwi RNAs, and short-interfering RNAs. The review concludes with a review of the literature and how the biology of non-coding RNAs can be used therapeutically to treat cancers, especially osteosarcoma. We conclude that non-coding RNA expression and function in osteosarcoma is equally complex to understanding the expression differences and function of coding RNA and proteins; however, with the added lens of both coding and non-coding genomic sequence, researchers can begin to identify the patterns that consistently associate with aggressive osteosarcoma.

Oncogenic lncRNA ZNFX1 antisense RNA 1 promotes osteosarcoma cells proliferation and metastasis by stabilizing serine and arginine‑rich splicing factor 3

Recent studies have demonstrated that lncRNAs play an important role in cancers, particularly osteosarcoma. ZFAS1 is a newly identified and characterized lncRNA linked to a variety of cancers. The role of ZFAS1 in osteosarcoma is mainly unknown. This study discovered that ZFAS1 was upregulated in osteosarcoma patient tissues, which correlates with elevated SRSF3 protein levels. Higher levels of ZFAS1 or SRSF3 were linked to a poor prognosis of osteosarcoma. ZFAS1 knockdown decreased SRSF3 protein levels but had a negligible effect on SRSF3 mRNA expression. Further research indicated that ZFAS1 could bind to the SRSF3 protein directly and prevent degrading. Functional studies revealed that ZFAS1 knockdown inhibited osteosarcoma cell proliferation as measured by the CCK-8 assay, colony formation assay, and Ki-67 immunofluorescence staining. Furthermore, ZFAS1 knockdown reduced the expression of PCNA, CDK1, CDK4, and CDK6, increasing p53 and p16. IT has also been observed that ZFAS1 knockdown inhibited osteosarcoma cell migration and invasion as measured by the wound healing assay and the trans-well assay with or without Matrigel.

Furthermore, exogenous SRSF3 expression in ZFAS1-depleted osteosarcoma cells restored SRSF3 expression while simultaneously inhibiting cell proliferation and metastasis. Our findings show that ZFAS1 plays an essential role in osteosarcoma progression by stabilizing the SRSF3 protein. Our study provides novel insight into the role of ZFAS1 in osteosarcoma. ZFAS1 has the potential to be used as a prognostic biomarker as well as a therapeutic target in the treatment of osteosarcoma.

Acidic Tumor Microenvironment Promotes Pancreatic Cancer through miR-451a/MEF2D Axis

Pancreatic cancer (PC), as a highly malignant and aggressive solid tumor, is common in the digestive system. The acidic microenvironment is one of the critical markers of cancer. Nonetheless, there are few studies on how the acidic microenvironment affects the development of PC. This study focused on investigating the specific molecular mechanisms of the acidic microenvironment in PC. In our study, qRT-PCR was conducted for examining microRNA (miR)-451a and myocyte enhancer factor 2D (MEF2D) expressions in PANC-1 cells. Then, detailed functional effects of an acidic environment on miR-451a and MEF2D in PANC-1 cells were detected by CCK-8, colony formation, flow cytometry, wound healing, transwell, mitochondrial functionality measurement, JC-1 staining, DCFH-DA staining, and sphere formation assays. The relationship between miR-451a and MEF2D was confirmed by luciferase reporter analysis. Under acidic conditions, the increase of proliferation, migration, and invasion of PANC-1 cells was observed. Moreover, the mitochondrial oxidative respiration-related gene miR-451a was reduced in acidic conditions. In addition, we found that, in PANC-1 cells under an acidic environment, miR-451a overexpression enhanced oxygen consumption, mitochondrial membrane potential (MMP) loss, and ROS generation and inhibited proliferation, migration, invasion, and stemness via sponging MEF2D. In a word, our results revealed that the acidic microenvironment regulated PC progression by affecting the miR-451a/MEF2D axis, indicating a novel avenue for the future treatment of PC.

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

LncRNA EPIC1 promotes proliferation and inhibits apoptosis of gallbladder cancer cells by interacting with LET

INTRODUCTION AND OBJECTIVES

Long non-coding RNA (lncRNA) EPIC1 (epigenetically-induced lncRNA1) is likely involved in human cancer by promoting cell cycle progression. Our study was carried out to investigate the involvement of EPIC1 in gallbladder cancer (GBC).

METHODS

Expression levels of EPIC1 in two types of tissues (GBC and paracancerous) and plasma were measured by performing qPCR. GBC-SD and SGC-996 cells were transfected with low expression in tumor (LET) and EPIC1 expression vectors.

RESULTS

The present study found that EPIC1 was upregulated in tumor tissues than in paracancerous tissues of GBC patients, and plasma levels of EPIC1 were significantly correlated with levels of EPIC1 in tumor tissues. LncRNA LET was downregulated in tumor tissues than in paracancerous tissues and was inversely correlated with EPIC1 in both tumor tissues and paracancerous tissues. Overexpression of EPIC1 led to downregulated LET, and LET overexpression also mediated the downregulation of EPIC1. EPIC1 led to accelerated GBC cell proliferation and inhibited apoptosis. Overexpression of LET played opposites roles. In addition, LET overexpression attenuated the effects of EPIC1 overexpression on cancer cell proliferation and apoptosis.

CONCLUSIONS

LncRNA EPIC1 promoted proliferation and inhibited apoptosis of GBC cells by interacting with LET.

LncRNA EPIC1 promotes tumor angiogenesis via activating the Ang2/Tie2 axis in non-small cell lung cancer

AIMS

Non-small cell lung cancer (NSCLC) is considered a highly fatal tumor. Importantly, angiogenesis is critical for tumor progression. Long non-coding RNAs (lncRNAs), which are untranslatable, control cell functions through different pathways. lncRNA EPIC1 has been reported to promote cell viability, cell cycle progression, and invasion. However, the relationship between EPIC1 and tumor angiogenesis remains an enigma. We explored the role of EPIC1 in tumor angiogenesis in NSCLC.

MATERIALS AND METHODS

First, EPIC1 expression was analyzed using the GEPIA database and was further verified using qPCR in tumor tissues from patients with NSCLC and NSCLC cell lines. Next, EPIC1 function was detected using loss-of-function and gain-of-function assays. Moreover, EdU staining, flow cytometry, and channel formation assays were performed to assess HUVEC proliferation and channel the formation in the NSCLC-HUVEC transwell co-culture system.

KEY FINDINGS

EPIC1 expression was significantly upregulated in NSCLC tissues and cell lines. Furthermore, the overexpression of EPIC1 in NSCLC cells stimulated HUVEC channel formation and proliferation by activating Ang2/Tie2 signaling, and the opposite results were obtained when EPIC1 was silenced in NSCLC cells. The density of new blood vessels was simultaneously increased by EPIC1 overexpression in vivo, using CAM angiogenesis model and a nude mouse tumor model. Finally, all these experimental findings could be established in the samples from patients with NSCLC. We postulate that EPIC1 promotes tumor angiogenesis by activating the Ang2/Tie2 axis in NSCLC.

SIGNIFICANCE

Elucidating the molecular and cellular mechanisms of EPIC1 in tumor angiogenesis provides a novel perspective on NSCLC clinical therapy.

Long non‑coding RNA PCAT6 promotes the development of osteosarcoma by increasing MDM2 expression

Osteosarcoma is a severe malignant tumor. Several studies indicated that lncRNA prostate cancer-associated transcript 6 (PCAT6) promoted the development of multiple types of cancers. Studies have also revealed that MDM2 could aggravate tumor symptoms inhibiting P53 expression. However, whether lncRNA PCAT6 could affect the proliferation and metastasis of osteosarcoma cells by regulating P53 expression is unclear. The present study established lncRNA PCAT6-overexpressing osteosarcoma cells. Cell Counting Kit-8, wound healing and Transwell assays were performed to detect the change in proliferation, migration and invasion of these cells, respectively. Subsequently, E3 ubiquitin-protein ligase Mdm2 (MDM2), P53 and P21 expression were determined using western blotting. Finally, MDM2 expression was inhibited and the proliferation, migration and invasion of these cells was determined again. The present study found that the proliferation, migration and invasion of osteosarcoma cells increased following overexpression of lncRNA PCAT6. MDM2 expression was upregulated while the levels of P53 and P21 decreased following overexpression of lncRNA PCAT6. However, the proliferation, migration and invasion of osteosarcoma cells were inhibited following MDM2 knockdown. Additionally, P53 and P21 was rescued following MDM2 knockdown. To conclude, lncRNA PCAT6 promoted the proliferation, migration and invasion of osteosarcoma cells by promoting the expression of MDM2 and suppressing the expression of P53 and P21.

LncRNA GATA3-AS1 facilitates tumour progression and immune escape in triple-negative breast cancer through destabilization of GATA3 but stabilization of PD-L1

OBJECTIVES

Long non-coding RNAs (lncRNAs) have been demonstrated as crucial regulators in cancer, but whether they are involved in the immune response of cancer cells remains largely undiscovered. GATA3-AS1 is a novel lncRNA that was upregulated in breast cancer (BC) according to online databases. However, its role in triple-negative breast cancer (TNBC) was elusive.

METHODS

GATA3-AS1 expression in BC tissues and adjacent normal tissues was obtained from online databases. Loss-of-function assays were designed and conducted to verify the functional role of GATA3-AS1 in TNBC cells. Bioinformatic analysis and mechanism experiments were applied to explore the downstream molecular mechanism of GATA3-AS1. Similarly, the upstream mechanism which led to the upregulation of GATA3-AS1 in TNBC cells was also investigated.

RESULTS

GATA3-AS1 was markedly overexpressed in TNBC tissues and cells. Knockdown of GATA3-AS1 suppressed TNBC cell growth and enhanced the resistance of TNBC cells to immune response. GATA3-AS1 induced the deubiquitination of PD-L1 through miR-676-3p/COPS5 axis. GATA3-AS1 destabilized GATA3 protein by promoting GATA3 ubiquitination.

CONCLUSION

GATA3-AS1 contributed to TNBC progression and immune evasion through stabilizing PD-L1 protein and degrading GATA3 protein, offering a new target for the treatment of TNBC.

Research progress regarding the role of long non-coding RNAs in osteosarcoma

Osteosarcoma is a malignant tumor that occurs in children and adolescents. Although treatments for osteosarcoma have improved, the likelihood of survival remains low for most patients with metastasis and recurrence. Elucidating the mechanism underlying the development of osteosarcoma and chemotherapy resistance will be important to improve diagnosis and treatment. Long non-coding RNAs (lncRNAs), which are longer than 200 nucleotides in length and do not encode for proteins, have been shown to play a regulatory role in the occurrence and development of osteosarcoma, and are expected to serve as biomarkers and molecular targets. This review discusses the progress in the study of the role of lncRNAs in osteosarcoma, and highlights the recent developments in this field.

MEF2D upregulation protects neurons from oxygen-glucose deprivation/re-oxygenation-induced injury by enhancing Nrf2 activation

Accumulating evidence suggests that myocyte enhancer factor 2D (MEF2D) is a pro-survival factor for neurons. However, whether MEF2D is involved in protecting neurons from cerebral ischemia/reperfusion injury remains unknown. The current study was designed to investigate the exact role and mechanism of MEF2D in regulating oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced neuronal injury, an in vitro model used to study cerebral ischemia/reperfusion injury. MEF2D expression was significantly induced in neurons in response to OGD/R injury. Functional analysis demonstrated that MEF2D upregulation significantly rescued the decreased viability of OGD/R-injured neurons and suppressed OGD/R-induced apoptosis and reactive oxygen species (ROS) production. By contrast, MEF2D knockdown increased the sensitivity of neurons to OGD/R-induced injury. Moreover, MEF2D overexpression increased the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and enhanced the activation of Nrf2 antioxidant signaling. However, Nrf2 knockdown partially blocked the MEF2D-mediated neuroprotective effect in OGD/R-exposed neurons. Overall, these results reveal that MEF2D overexpression attenuates OGD/R-induced injury by enhancing Nrf2-mediated antioxidant signaling. These findings suggest that MEF2D may serve as a neuroprotective target with a potential application for treatment of cerebral ischemia/reperfusion injury.

Long Non-coding RNA EPIC1 Promotes Cell Proliferation and Motility and Drug Resistance in Glioma

Evidence has revealed that long non-coding RNAs (lncRNAs) are involved in carcinogenesis and tumor progression. lncRNAs play an important role in regulation of numerous cellular processes including cell proliferation, apoptosis, cell cycle, differentiation, and motility. Several studies have demonstrated that lncRNA EPIC1 governs cell growth, cell cycle, migration, invasion, and drug resistance in human malignancies. However, the role of EPIC1 and its underlying molecular mechanisms in glioma have not been investigated. In this study, we determined the function of EPIC1 in glioma cells via upregulation or downregulation of EPIC1. We further dissected the mechanism of EPIC1-mediated tumor progression in glioma. Our results showed that inhibition of EPIC1 suppressed cell viability, induced apoptosis, inhibited cell invasion, and increased cell sensitivity to temozolomide in glioma cells. Consistently, overexpression of EPIC1 exhibited the opposite effects in glioma cells. Moreover, our data suggest that EPIC1 exerts its biological functions via targeting Cdc20 in glioma cells. In line with this, overexpression of Cdc20 reversed the EPIC1-mediated tumor progression in glioma cells. Therefore, targeting EPIC1 might be a useful approach for glioma treatment.

LncRNA EPIC1 downregulation mediates hydrogen peroxide-induced neuronal cell injury

Excessive oxidative stress causes neuronal cell injury. Long non-coding RNA (LncRNA) EPIC1 (Lnc-EPIC1) is a MYC-interacting LncRNA. Its expression and potential functions in hydrogen peroxide (H₂O₂)-stimulated neuronal cells are studied. In SH-SY5Y neuronal cells and primary human neuron cultures, H₂O₂ downregulated Lnc-EPIC1 and key MYC targets (Cyclin A1, CDC20 and CDC45). Ectopic overexpression of Lnc-EPIC1 increased expression of MYC targets and significantly attenuated H₂O₂-induced neuronal cell death and apoptosis. Contrarily, Lnc-EPIC1 siRNA potentiated neuronal cell death by H₂O₂. MYC knockout by CRISPR/Cas9 method also facilitated H₂O₂-induced SH-SY5Y cell death. Significantly, MYC knockout abolished Lnc-EPIC1-induced actions in H₂O₂-stimulated neuronal cells. Together, these results suggest that Lnc-EPIC1 downregulation mediates H₂O₂-induced neuronal cell death.

The long noncoding RNA ZFAS1 promotes the progression of glioma by regulating the miR-150-5p/PLP2 axis

Numerous studies have reported that long noncoding RNA (lncRNA) dysregulation is involved in the progression of many malignant tumors, including glioma. The lncRNA ZNFX1 antisense RNA 1 (ZFAS1) plays an oncogenic role in various malignant tumors, such as gastric cancer and hepatocellular carcinoma. However, the underlying molecular mechanism of ZFAS1 in glioma has not been fully clarified. In this study, we found that the expression of ZFAS1 was upregulated in both glioma tissues and cell lines. Functional experiments revealed that ZFAS1 promoted glioma proliferation, migration and invasion, and increased resistance to temozolomide in vitro. By using online databases, RNA pull-down assays and luciferase reporter assays, ZFAS1 was demonstrated to act as a sponge of miR-150-5p. Furthermore, proteolipid protein 2 (PLP2) was shown to be the functional target of miR-150-5p. Rescue experiments revealed that ZFAS1 regulated the expression of PLP2 by sponging miR-150-5p. Finally, a xenograft tumor assay demonstrated that ZFAS1 promoted glioma growth in vivo. Our results showed that ZFAS1 promoted glioma malignant progression by regulating the miR-150-5p/PLP2 axis, which may provide a potential therapeutic target for the treatment of glioma.