The emerging roles and potential applications of circular RNAs in ovarian cancer: a comprehensive review

Extracellular vesicles-powered immunotherapy: Unleashing the potential for safer and more effective cancer treatment

Cancer treatment has seen significant advancements with the introduction of Onco-immunotherapies (OIMTs). Although some of these therapies have received approval for use, others are either undergoing testing or are still in the early stages of development. Challenges persist in making immunotherapy widely applicable to cancer treatment. To maximize the benefits of immunotherapy and minimize potential side effects, it's essential to improve response rates across different immunotherapy methods. A promising development in this area is the use of extracellular vesicles (EVs) as novel delivery systems. These small vesicles can effectively deliver immunotherapies, enhancing their effectiveness and reducing harmful side effects. This article discusses the importance of integrating nanomedicines into OIMTs, highlighting the challenges with current anti-OIMT methods. It also explores key considerations for designing nanomedicines tailored for OIMTs, aiming to improve upon existing immunotherapy techniques. Additionally, the article looks into innovative approaches like biomimicry and the use of natural biomaterial-based nanocarriers (NCs). These advancements have the potential to transform the delivery of immunotherapy. Lastly, the article addresses the challenges of moving OIMTs from theory to clinical practice, providing insights into the future of using advanced nanotechnology in cancer treatment.

circ_0006789 promotes cervical cancer development via the miR-615-5p/HSF1 axis

OBJECTIVE

Circular RNAs (circRNAs) are involved in the development of human cancers, including cervical cancer (CC). However, the role and mechanism of circ_0006789 (circSLC25A43) in CC are unclear. The purpose of this study was to investigate the functional role of circ_0006789 in CC.

METHODS

The expression of circ_0006789 in CC tissues and cell lines was examined by RT-qPCR. The characterization of circ_0006789 in CC cells was verified by subcellular localisation, actinomycin D assay, and RNase R assay. After circ_0006789 was knocked down in CC cell lines, the proliferation, apoptosis, migration and invasion of CC cells were assessed by CCK-8 method, flow cytometry, and Transwell assay. RIP assay, FISH assay, dual luciferase reporter gene assay and Western blot were used to investigate the regulatory mechanism between circ_0006789, miR-615-5p and heat shock factor 1 (HSF1).

RESULTS

circ_0006789 was upregulated in CC tissues and cell lines. CC cells were inhibited in their proliferation, migration, and invasion, as well as promoted to apoptosis when circ_0006789 was knocked down. It was found that circ_0006789 targeted miR-615-5p, and miR-615-5p expression was inversely correlated with circ_0006789 expression. Furthermore, HSF1 was a target gene of miR-615-5p. Furthermore, the suppressive effects on HeLa cells mediated by circ_0006789 knockdown were counter-balanced when miR-615-5p was knocked down and HSF1 was overexpressed. Mechanistically, circ_0006789 was found to promote CC development by reducing miR-615-5p and increasing HSF1 expressions.

CONCLUSION

circ_0006789 accelerates CC development via the miR-615-5p/HSF1 axis.

Long non-coding RNA LOXL1-AS1: a potential biomarker and therapeutic target in human malignant tumors

Long non-coding RNAs (lncRNAs) are transcripts that contain more than 200 nucleotides. Despite their inability to code proteins, multiple studies have identified their important role in human cancer through different mechanisms. LncRNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1), a newly discovered lncRNA located on human chromosome 15q24.1, has recently been shown to be involved in the occurrence and progression of various malignancies, such as colorectal cancer, gastric cancer, hepatocellular carcinoma, prostate cancer, non-small cell lung cancer, ovarian cancer, cervical cancer, breast cancer, glioma, thymic carcinoma, pancreatic carcinoma. LOXL1-AS1 acts as competitive endogenous RNA (ceRNA) and via sponging various miRNAs, including miR-374b-5p, miR-21, miR-423-5p, miR-589-5p, miR-28-5p, miR-324-3p, miR-708-5p, miR-143-3p, miR-18b-5p, miR-761, miR-525-5p, miR-541-3p, miR-let-7a-5p, miR-3128, miR-3614-5p, miR-377-3p and miR-1224-5p to promote tumor cell proliferation, invasion, migration, apoptosis, cell cycle, and epithelial-mesenchymal transformation (EMT). In addition, LOXL1-AS1 is involved in the regulation of P13K/AKT and MAPK signaling pathways. This article reviews the current understanding of the biological function and clinical significance of LOXL1-AS1 in human cancers. These findings suggest that LOXL1-AS1 may be both a reliable biomarker and a potential therapeutic target for cancers.

Brain-Derived Exosomal CircRNAs in Plasma Serve as Diagnostic Biomarkers for Acute Ischemic Stroke

Acute ischemic stroke (AIS), commonly known as stroke, is a debilitating condition characterized by the interruption of blood flow to the brain, resulting in tissue damage and neurological deficits. Early diagnosis is crucial for effective intervention and management, as timely treatment can significantly improve patient outcomes. Therefore, novel methods for the early diagnosis of AIS are urgently needed. Several studies have shown that bioactive molecules contained in extracellular vesicles, especially circRNAs, could be ideal markers for the diagnosis of many diseases. However, studies on the effects of exosomes and their circRNAs on the development and prognosis of AIS have not been reported extensively. Therefore, we explored the feasibility of using circRNAs in plasma brain-derived exosomes as biomarkers for AIS. By high-throughput sequencing, we first identified 358 dysregulated circRNAs (including 23 significantly upregulated circRNAs and 335 significantly downregulated circRNAs) in the plasma brain-derived exosomes of the brain infarct patient group compared to those of the noninfarct control group. Five upregulated circRNAs (hsa_circ_0007290, hsa_circ_0049637, hsa_circ_0000607, hsa_circ_0004808, and hsa_circ_0000097) were selected for further validation via Real-Time Quantitative Reverse Transcription PCR (qRT‒PCR) in a larger cohort based on the exclusion criteria of log2FC > 1, p < 0.05 and measurable expression. We found that the expression levels of hsa_circ_0007290, hsa_circ_0049637, hsa_circ_0000607, hsa_circ_0004808 and hsa_circ_0000097 were significantly upregulated in AIS patients and could serve as potential biomarkers for AIS with high specificity and sensitivity. Moreover, the expression levels of hsa_circ_0007290, hsa_circ_0049637, hsa_circ_0000607, hsa_circ_0004808 and hsa_circ_0000097 were also found to be positively correlated with National Institutes of Health Stroke Scale (NISS) and modified Rankin scale (mRS) scores, which indicated that the presence of these circRNAs in plasma brain-derived exosomes could also determine the progression of AIS.

circSNTB2 and CUL4A Induces Dysfunction of Nucleus Pulposus Cells by Competitively Binding miR-665

Circular RNA (circRNA) plays important roles in lumbar degenerative diseases. This study aimed to investigate the role of circSNTB2 in regulating the development of lumbar disc herniation (LDH) in vitro and in vivo. The abnormally expressed circSNTB2 in intervertebral disc degeneration (IDD) through bioinformatics analysis was identified, and verified in nucleus pulposus (NP) tissues of patients with LDH. NP cells were treated with TNF-α to mimic the LDH microenvironment. RT-qPCR was applied to determine levels of mRNA and microRNA (miRNA) in clinical samples and cells. We performed CCK-8, EdU, TUNEL and flow cytometric apoptosis assays to evaluate the proliferation and apoptosis of NP cells. The predicted the miRNAs and downstream target genes were verified with the help of luciferase reporter gene and RNA pull-down experiments. Finally, we established an LDH rat model to further verify the role of circSNTB2 in vivo. circSNTB2 was significantly up-regulated in the NP tissues of LDH group and TNF-α -treated NP cells. miR-665 binds to circSNTB2 and cullin 4A (CUL4A) is the downstream target gene of miR-665. Knockdown of circSNTB2 promoted NP cells proliferation and inhibited apoptosis, which was reversed by down-regulation of miR-665. In addition, up-regulated CUL4A reversed the effects of over-expressed miR-665 on proliferation and apoptosis of NP cells. Meanwhile, results of in vivo experiments demonstrated that knocking down circSNTB2 alleviated LDH-induced thermo-mechanical pain and NP injury. In summary, circSNTB2 regulates the proliferation and apoptosis of NP by mediating miR-665 regulation of CUL4A, which provides a reliable idea for targeted therapy of LDH.

Novel players in the development of chemoresistance in ovarian cancer: ovarian cancer stem cells, non-coding RNA and nuclear receptors

Ovarian cancer (OC) ranks as the fifth leading factor for female mortality globally, with a substantial burden of new cases and mortality recorded annually. Survival rates vary significantly based on the stage of diagnosis, with advanced stages posing significant challenges to treatment. OC is primarily categorized as epithelial, constituting approximately 90% of cases, and correct staging is essential for tailored treatment. The debulking followed by chemotherapy is the prevailing treatment, involving platinum-based drugs in combination with taxanes. However, the efficacy of chemotherapy is hindered by the development of chemoresistance, both acquired during treatment (acquired chemoresistance) and intrinsic to the patient (intrinsic chemoresistance). The emergence of chemoresistance leads to increased mortality rates, with many advanced patients experiencing disease relapse shortly after initial treatment. This review delves into the multifactorial nature of chemoresistance in OC, addressing mechanisms involving transport systems, apoptosis, DNA repair, and ovarian cancer stem cells (OCSCs). While previous research has identified genes associated with these mechanisms, the regulatory roles of non-coding RNA (ncRNA) and nuclear receptors in modulating gene expression to confer chemoresistance have remained poorly understood and underexplored. This comprehensive review aims to shed light on the genes linked to different chemoresistance mechanisms in OC and their intricate regulation by ncRNA and nuclear receptors. Specifically, we examine how these molecular players influence the chemoresistance mechanism. By exploring the interplay between these factors and gene expression regulation, this review seeks to provide a comprehensive mechanism driving chemoresistance in OC.

Modifying CAR-T cells with anti-checkpoints in cancer immunotherapy: A focus on anti PD-1/PD-L1 antibodies

Chimeric antigen receptor-modified T (CAR-T) are genetically engineered cells to express tumor-specific antigens revolutionizing the treatment of hematologic malignancies. The hostile tumor microenvironment (TME) remains a challenge for CAR-T cell therapy in solid tumors. As a solution, combinational therapy with immune checkpoint inhibitors (ICIs) is shown to improve the safety and efficacy of CAR-T cell therapy. To avoid side effects related to the application of ICIs in combinational therapy, engineering CARs to express tumor-specific antigens may help improvement of clinical outcomes. Those CARs expressing single chain variable fragments (scFvs) or nanobodies against immune checkpoint stimulatory or inhibitory molecules, such as the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling axis are being extensively studied in various clinical trials. In this review, we discuss the significance of anti-PD-(L)1 scFv-expressing CAR-T cells in the treatment of human cancers, describing current challenges and potential strategies to overcome such predicaments in the area of cancer immunotherapy.

The Circular RNA circFOXK2 Enhances the Tumorigenesis of Non-Small Cell Lung Cancer Through the miR-149-3p/IL-6 Axis

Circular RNAs (circRNAs) are the non-coding types of RNAs and are thoughts to be linked with human cancer progression. circFOXK2 is believed to be associated with cancers, however, the molecular mechanisms of circFOXK2 in non-small cell lung cancer (NSCLC) are still unclear. Here we firstly reported that circFOXK2 enhances the tumorigenesis of NSCLC through the miR-149-3p/IL-6 axis. The expression of circFOXK2, microRNA-149-3p (miR-149-3p) and IL-6 were assessed by qRT-PCR and western blot. Transwell, colony formation, wound healing, and CCK-8 assays were used to elucidate NSCLC cells' proliferation, migration, and invasion. MiR-149-3p interaction with circFOXK2 was confirmed by dual-luciferase reporter gene assay (DLRGA). Furthermore, the biological effect of circFOXK2 on NSCLC progression was detected by tumor xenograft assay. CircFOXK2 were upregulated in NSCLC tissues and cells, miR-149-3p were downregulated in NSCLC tissues and cells. In addition, circFOXK2 stimulated NSCLC cell proliferation, migration and invasion in vitro. Mechanical analysis indicated that circFOXK2 modulated IL-6 via miR-149-3p sponging. Furthermore, circFOXK2 overexpression promoted tumor growth in vivo. Overall, this research verified that circFOXK2 enhances the tumorigenesis of NSCLC through the miR-149-3p/IL-6 axis.

CircAGFG1 Promotes Ovarian Cancer Progression Through the miR-409-3 p/ZEB1 Axis

OBJECTIVES

Circular RNAs (circRNAs) serve a crucial regulatory role in ovarian cancer (OC). Circular RNA ArfGAP with FG repeats 1 (circAGFG1) has been shown to be involved in promoting the progression of several cancers, containing triple-negative breast cancer, esophageal cancer and colorectal cancer. However, the function of circAGFG1 in OC is unclear.

METHODS

Quantitative real-time reverse transcription PCR (RT-qPCR) was conducted to determine the expression levels of circAGFG1 and miR-409-3p. The proliferation and metastasis of cells were determined by colony formation assays, EdU assays, transwell assays and wound healing assays. In addition, a dual-luciferase reporter assay was performed to validate the mechanism between circAGFG1, miR-409-3p, and ZEB1.

RESULTS

Our data suggested that circAGFG1 was significantly overexpressed in OC tissues compared to normal ovarian epithelial tissues. Overexpression of circAGFG1 was correlated with intraperitoneal metastasis, tumor recurrence and advanced stage. Additionally, circAGFG1 overexpression revealed a poor prognosis in OC patients. Knockdown of circAGFG1 suppressed the proliferation, invasion and migration of OC cells. Mechanistically, circAGFG1 acted as a sponge of miR-409-3p to enhance the expression level of zinc finger E-box binding homeobox 1 (ZEB1), thereby conferring OC cell proliferation, invasion and migration. Importantly, re-expression of ZEB1 effectively reversed the effects of circAGFG1 knockdown on OC cells.

CONCLUSIONS

In summary, our study indicated that circAGFG1 may act as a prognostic biomarker and potential therapeutic target for patients with OC.

A review focusing on the role of pyroptosis in prostate cancer

As one of the types of programmed cell death, pyroptosis has become a focus of research in recent years. Numerous studies have shown that pyroptosis plays a regulatory role in tumor cell invasiveness, differentiation, proliferation, and metastasis. It has been demonstrated that pyroptosis is involved in the regulation of signaling pathways implicated in the pathogenesis of prostate cancer (PCa). Furthermore, the loss of expression of pyroptosis-related genes in PCa has been reported, and pyroptosis-related genes have demonstrated a considerable ability in predicting the prognosis of PCa. Therefore, the potential role of pyroptosis in regulating the development of PCa warrants further investigation and attention. In this review, we summarize the basics of the role of pyroptosis and also discuss research into the mechanisms of action associated with pyroptosis in PCa. It is hoped that by exploring the potential of the pyroptosis pathway in intervening in PCa, it will provide a viable direction for the diversification of PCa treatment.

The role of circRNAs in regulation of drug resistance in ovarian cancer

Ovarian cancer is one of the female reproductive system tumors. Chemotherapy is used for advanced ovarian cancer patients; however, drug resistance is a pivotal cause of chemotherapeutic failure. Hence, it is critical to explore the molecular mechanisms of drug resistance of ovarian cancer cells and to ameliorate chemoresistance. Noncoding RNAs (ncRNAs) have been identified to critically participate in drug sensitivity in a variety of human cancers, including ovarian cancer. Among ncRNAs, circRNAs sponge miRNAs and prevent miRNAs from regulation of their target mRNAs. CircRNAs can interact with DNA or proteins to modulate gene expression. In this review, we briefly describe the biological functions of circRNAs in the development and progression of ovarian cancer. Moreover, we discuss the underneath regulatory molecular mechanisms of circRNAs on governing drug resistance in ovarian cancer. Furthermore, we mention the novel strategies to overcome drug resistance via targeting circRNAs in ovarian cancer. Due to that circRNAs play a key role in modulation of drug resistance in ovarian cancer, targeting circRNAs could be a novel approach for attenuation of chemoresistance in ovarian cancer.

An updated database of virus circular RNAs provides new insights into the biogenesis mechanism of the molecule

Virus circular RNAs (circRNA) have been reported to be extensively expressed and play important roles in viral infections. Previously we build the first database of virus circRNAs named VirusCircBase which has been widely used in the field. This study significantly improved the database on both the data quantity and database functionality: the number of virus circRNAs, virus species, host organisms was increased from 46440, 23, 9 to 60859, 43, 22, respectively, and 1902 full-length virus circRNAs were newly added; new functions were added such as visualization of the expression level of virus circRNAs and visualization of virus circRNAs in the Genome Browser. Analysis of the expression of virus circRNAs showed that they had low expression levels in most cells or tissues and showed strong expression heterogeneity. Analysis of the splicing of virus circRNAs showed that they used a much higher proportion of non-canonical back-splicing signals compared to those in animals and plants, and mainly used the A5SS (alternative 5' splice site) in alternative-splicing. Most virus circRNAs have no more than two isoforms. Finally, human genes associated with the virus circRNA production were investigated and more than 1000 human genes exhibited moderate correlations with the expression of virus circRNAs. Most of them showed negative correlations including 42 genes encoding RNA-binding proteins. They were significantly enriched in biological processes related to cell cycle and RNA processing. Overall, the study provides a valuable resource for further studies of virus circRNAs and also provides new insights into the biogenesis mechanisms of virus circRNAs.

Defining new biomarkers for overcoming therapeutical resistance in cervical cancer using lncRNA

Despite improvements in cervical cancer diagnosis and treatment, the prognosis for cervical cancer patients remains dismal due to the development of drug resistance, metastasis, and invasion resulting leading to treatment failure. Long non-coding RNAs (lncRNAs), a class of RNA transcripts have been reported in mediating carcinogenesis as well as drug, and radio-resistance in tumor cells. These lncRNAs regulate various cancer hallmarks and contribute to the development of therapeutic resistance. They regulates multiple signalling pathways, recruits polycomb group, function as miRNA sponge and scaffolds. Additionally, lncRNAs can act as oncogenes or tumor suppressors in cervical cancer. This comprehensive review outlines the biogenesis of lncRNA and its role in cancer development. It delves into the mechanisms through which various lncRNAs mediate chemoresistance and radioresistance in cervical cancer. By shedding into the light of mechanism, this review will also aids researchers in understanding lncRNAs as biomarkers and latest advancements in clinically targeting them with the help of Artificial Intelligence for overcoming chemoresistance and radioresistance, thereby improving cervical cancer treatment.

The role of microRNAs in the pathophysiology of human central nervous system: A focus on neurodegenerative diseases

microRNAs (miRNAs) are suggested to play substantial roles in regulating the development and various physiologic functions of the central nervous system (CNS). These include neurogenesis, cell fate and differentiation, morphogenesis, formation of dendrites, and targeting non-neural mRNAs. Notably, deregulation of an increasing number of miRNAs is associated with several neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and CNS tumors. They are particularly known to affect the amyloid β (Aβ) cleavage and accumulation, tau protein homeostasis, and expression of alpha-synuclein (α-syn), Parkin, PINK1, and brain-derived neurotrophic factor (BDNF) that play pivotal roles in the pathogenesis of neurodegenerative diseases. These include miR-16, miR-17-5p, miR-20a, miR-106a, miR-106b, miR-15a, miR-15b, miR-103, miR-107, miR-298, miR-328, miR-195, miR-485, and miR-29. In CNS tumors, several miRNAs, including miR-31, miR-16, and miR-21 have been identified to modulate tumorigenesis through impacting tumor invasion and apoptosis. In this review article, we have a look at the recent advances on our knowledge about the role of miRNAs in human brain development and functions, neurodegenerative diseases, and their clinical potentials.

Circular circRANGAP1 Contributes to Non-small Cell Lung Cancer Progression by Increasing COL11A1 Expression Through Sponging miR-653-5p

Numerous studies have discovered that hsa_circ_0063526 (also known as circRANGAP1) is an oncogenic circular RNA (circRNA) in some human tumors, including non-small cell lung cancer (NSCLC). However, the concrete molecular mechanism of circRANGAP1 involved in NSCLC is not completely elucidated. CircRANGAP1, microRNA-653-5p (miR-653-5p), and Type XI collagen (COL11A1) contents were determined via real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferative ability, migration, and invasion were measured using 5-ethynyl-2'-deoxyuridine (EdU), colony formation, wound healing, and transwell assays. E-cadherin, N-cadherin, Vimentin, and COL11A1 protein levels were detected via western blot assay. After Starbase software prediction, the binding between miR-653-5p and circRANGAP1 or COL11A1 was verified using a dual-luciferase reporter assay. Besides, the role of circRANGAP1 on tumor cell growth was analyzed using a xenograft tumor model in vivo. Increased circRANGAP1 and COL11A1, and reduced miR-653-5p were found in NSCLC tissues and cell lines. Furthermore, circRANGAP1 absence might hinder NSCLC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Mechanically, circRANGAP1 functioned as a sponge of miR-653-5p to increase COL11A1 expression. In vivo experiments illustrated that circRANGAP1 knockdown repressed tumor growth. CircRANGAP1 silencing might suppress NSCLC cell malignant biological behaviors, at least in part, through the miR-653-5p/COL11A1 axis. These results provided a promising strategy for treating NSCLC malignancies.

Circular RNA in Multiple Sclerosis: Pathogenicity and Potential Biomarker Development: A Systematic Review

Multiple sclerosis (MS) is a complex autoimmune disorder of the CNS that affects millions of people worldwide. The causes of the disease remain unknown despite extensive efforts to understand it. CircRNAs are a unique class of endogenous non-coding RNA that are abundant, stable, conserved, and specifically expressed molecules, making them a promising biomarker of diseases. This review investigates the role of circRNA in MS pathogenicity and their potential as a biomarker through a comprehensive literature search conducted in 8 scientific databases. The studies found that there are differentially expressed circRNAs in MS patients compared to healthy controls (HC), and this difference is even more pronounced in different MS subtypes. Enrichment of circRNAs in linkage disequilibrium (LD) blocks that harbor MS-associated SNPs suggests that these SNPs manipulate the levels of circRNAs in the surrounding area, contributing to disease pathogenicity. While circRNA shows promise as an indicator or biomarker for MS disease pathology, further research is needed to fully explore its potential and impact on human biology.

microRNA-184 in the landscape of human malignancies: a review to roles and clinical significance

MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) with a short length of 19-22 nucleotides. miRNAs are posttranscriptional regulators of gene expression involved in various biological processes like cell growth, apoptosis, and angiogenesis. miR-184 is a well-studied miRNA, for which most studies report its downregulation in cancer cells and tissues and experiments support its role as a tumor suppressor inhibiting malignant biological behaviors of cancer cells in vitro and in vivo. To exert its functions, miR-184 affects some signaling pathways involved in tumorigenesis like Wnt and β-catenin, and AKT/mTORC1 pathway, oncogenic factors (e.g., c-Myc) or apoptotic proteins, such as Bcl-2. Interestingly, clinical investigations have shown miR-184 with good performance as a prognostic/diagnostic biomarker for various cancers. Additionally, exogenous miR-184 in cell and xenograft animal studies suggest it as a therapeutic anticancer target. In this review, we outline the studies that evaluated the roles of miR-184 in tumorigenesis as well as its clinical significance.

Revolutionizing colorectal cancer treatment: unleashing the potential of miRNAs in targeting cancer stem cells

Colorectal cancer (CRC) is a significant contributor to cancer mortality worldwide, and the presence of cancer stem cells (CSC) represents a major challenge for achieving effective treatment. miRNAs have emerged as critical regulators of gene expression, and recent studies have highlighted their role in regulating stemness and therapeutic resistance in CRC stem cells. This review highlights the mechanisms of CSC development, therapy resistance and the potential of miRNAs as therapeutic targets for CRC. It emphasizes the promise of miRNAs as a novel approach to CRC treatment and calls for further research to explore effective miRNA-based therapies and strategies for delivering miRNAs to CSCs in vivo.

The Circular RNA Circ_0085494 Regulates Prostate Cancer Progression Through NRBP1/miR-497-5p Axis

Aberrant expression of circular RNA (circRNA) is closely linked to the progression of various human cancers, including prostate cancer (PCa). In this research, we aimed to investigate the biological role of and mechanisms of circ_0085494 in PCa. The quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to detect circ_0085494, miR-497-5p, and nuclear receptor binding protein 1 (NRBP1) mRNA expression in PCa tissues and cell lines. Subsequently, colony formation, cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays were performed to evaluate PCa cell proliferation, migration, and invasion. Western blot assay was applied for assessing the protein levels. Dual-luciferase reporter and RNA pull-down assays were implemented for verifying the association between miR-497-5p and circ_0085494 or NRBP1. The role of circ_0085494 in vivo was measured by establishing a mice xenograft model. Circ_0085494 was highly expressed in PCa tissues and cells, and its absence suppressed PCa cell proliferation, migration, and invasion. Circ_0085494 impacts NRBP1 content by adsorbing miR-497-5p. Meanwhile, the repression of circ_0085494 absence on tumor growth in vivo was validated. Our finding revealed that circ_0085494 downregulation might repress PCa tumor progression through in part regulating the miR-497-5p/NRBP1 pathway.

A methylation- and immune-related lncRNA signature to predict ovarian cancer outcome and uncover mechanisms of chemoresistance

Tumor-associated lncRNAs regulated by epigenetic modification switches mediate immune escape and chemoresistance in ovarian cancer (OC). However, the underlying mechanisms and concrete targets have not been systematically elucidated. Here, we discovered that methylation modifications played a significant role in regulating immune cell infiltration and sensitizing OC to chemotherapy by modulating immune-related lncRNAs (irlncRNAs), which represent tumor immune status. Through deep analysis of the TCGA database, a prognostic risk model incorporating four methylation-related lncRNAs (mrlncRNAs) and irlncRNAs was constructed. Twenty-one mrlncRNA/irlncRNA pairs were identified that were significantly related to the overall survival (OS) of OC patients. Subsequently, we selected four lncRNAs to construct a risk signature predictive of OS and indicative of OC immune infiltration, and verified the robustness of the risk signature in an internal validation set. The risk score was an independent prognostic factor for OC prognosis, which was demonstrated via multifactorial Cox regression analysis and nomogram. Moreover, risk scores were negatively related to the expression of CD274, CTLA4, ICOS, LAG3, PDCD1, and PDCD1LG2 and negatively correlated with CD8+, CD4+, and Treg tumor-infiltrating immune cells. In addition, a high-risk score was associated with a higher IC50 value for cisplatin, which was associated with a significantly worse clinical outcome. Next, a competing endogenous RNA (ceRNA) network and a signaling pathway controlling the infiltration of CD8+ T cells were explored based on the lncRNA model, which suggested a potential therapeutic target for immunotherapy. Overall, this study constructed a prognostic model by pairing mrlncRNAs and irlncRNAs and revealed the critical role of the FTO/RP5-991G20.1/hsa-miR-1976/MEIS1 signaling pathway in regulating immune function and enhancing anticancer therapy.

Non-coding RNA's prevalence as biomarkers for prognostic, diagnostic, and clinical utility in breast cancer

Noncoding RNAs (ncRNAs), which make up a significant portion of the mammalian transcriptome and plays crucial regulatory roles in expression of genes and other biological processes, have recently been found. The most extensively researched of the sncRNAs, microRNAs (miRNAs), have been characterized in terms of their synthesis, roles, and significance in the tumor development. Its crucial function in the stem cell regulation, another class of sncRNAs known as aspirRNAs, has attracted attention in cancer research. The investigations have shown that long non-coding RNAs have a crucial role in controlling developmental stages, such as mammary gland development. Additionally, it has been discovered that lncRNA dysregulation precedes the development of several malignancies, including breast cancer. The functions of sncRNAs (including miRNAs and piRNAs) and lncRNAs in the onset and development of the breast cancer are described in this study. Additionally, future perspectives of various ncRNA-based diagnostic, prognostic, and therapeutic approaches also discussed.

Recent insights into the roles of circular RNAs in human brain development and neurologic diseases

Circular RNAs (circRNAs) are a novel class of non-coding RNAs. They are single-stranded RNA transcripts characterized with a closed loop structure making them resistant to degrading enzymes. Recently, circRNAs have been suggested with regulatory roles in gene expression involved in controlling various biological processes. Notably, they have demonstrated abundance, dynamic expression, back-splicing events, and spatiotemporally regulation in the human brain. Accordingly, they are expected to be involved in brain functions and related diseases. Studies in animals and human brain have revealed differential expression of circRNAs in brain compartments. Interestingly, contributing roles of circRNAs in the regulation of central nervous system (CNS) development have been demonstrated in a number of studies. It has been proposed that circRNAs play role in substantial neurological functions like neurotransmitter-associated tasks, neural cells maturation, and functions of synapses. Furthermore, 3 main pathways have been identified in association with circRNAs's host genes including axon guidance, Wnt signaling, and transforming growth factor beta (TGF-β) signaling pathways, which are known to be involved in substantial functions like migration and differentiation of neurons and specification of axons, and thus play role in brain development. In this review, we have an overview to the biogenesis, biological functions of circRNAs, and particularly their roles in human brain development and the pathogenesis of neurodegenerative diseases including Alzheimer's diseases, multiple sclerosis, Parkinson's disease and brain tumors.

Role of circular RNAs in retinoblastoma

Retinoblastoma (RB), the most common malignant retinal tumor among children under 3 years old, is lethal if left untreated. Early diagnosis, together with timely and effective treatment, is important to improve retinoblastoma-related outcomes. Circular RNAs (circRNAs), a new class of non-coding RNAs with the capacity to regulate cellular activities, have great potential in retinoblastoma diagnosis and treatment. Recent studies have identified circular RNAs that regulate multiple cellular processes involved in retinoblastoma, including cell viability, proliferation, apoptosis, autophagy, migration, and invasion. Six circular RNAs (circ-FAM158A, circ-DHDDS, circ-E2F3, circ-TRHDE, circ-E2F5, and circ-RNF20) promote disease progression and metastasis in retinoblastoma and function as oncogenic factors. Other circular RNAs, such as circ-TET1, circ-SHPRH, circ-MKLN1, and circ-CUL2, play tumor suppressive roles in retinoblastoma. At present, the studies on the regulatory mechanism of circular RNAs in retinoblastoma are not very clear. The purpose of this review is to summarize recent studies on the functional roles and molecular mechanisms of circular RNAs in retinoblastoma and highlight novel strategies for retinoblastoma diagnosis, prognosis, and treatment.

Circular RNAs in Epithelial Ovarian Cancer: From Biomarkers to Therapeutic Targets

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer, and more than 70% of patients are diagnosed at advanced stages. Despite the application of surgery and chemotherapy, the prognosis remains poor due to the high relapse rate. It is urgent to identify novel biomarkers and develop novel therapeutic strategies for EOC. Circular RNAs (circRNAs) are a class of noncoding RNAs generated from the "back-splicing" of precursor mRNA. CircRNAs exert their functions via several mechanisms, including acting as miRNA sponges, interacting with proteins, regulating transcription, and encoding functional proteins. Recent studies have identified many circRNAs that are dysregulated in EOC and may be used as diagnostic and prognostic markers. Increasing evidence has revealed that circRNAs play a critical role in ovarian cancer progression by regulating various cellular processes, including proliferation, apoptosis, metastasis, and chemosensitivity. The circRNA-based therapy may be a novel strategy that is worth exploring in the future. Here, we provide an overview of EOC and circRNA biogenesis and functions. We then discuss the dysregulations of circRNAs in EOC and the possibility of using them as diagnostic/prognostic markers. We also summarize the role of circRNAs in regulating ovarian cancer development and speculate their potential as therapeutic targets.