Knockdown of circBFAR inhibits proliferation and glycolysis in gastric cancer by sponging miR-513a-3p/hexokinase 2 axis

GCBRGCN: Integration of ceRNA and RGCN to Identify Gastric Cancer Biomarkers

Gastric cancer (GC) is a prevalent malignancy, and the discovery of biomarkers plays a crucial role in the diagnosis and prognosis of GC. However, current strategies for identifying GC biomarkers often focus on a single ribonucleic acid (RNA) class, neglecting the potential for multiple RNA types to collectively serve as biomarkers with improved predictive capabilities. To bridge this gap, our study introduces the GC biomarker relation graph convolution neural network (GCBRGCN) model which integrates the competing endogenous RNA (ceRNA) network with GC clinical informations and whole transcriptomics data, leveraging the relational graph convolutional network (RGCN) to predict GC biomarkers. It demonstrates exceptional performance, surpassing traditional machine learning and graph neural network algorithms with an area under the curve (AUC) of 0.8172 in the task of predicting GC biomarkers. Our study identified three unreported potential novel GC biomarkers: CCNG1, CYP1B1, and CITED2. Moreover, FOXC1 and LINC00324 were characterized as biomarkers with significance in both prognosis and diagnosis. Our work offers a novel framework for GC biomarker identification, highlighting the critical role of multiple types RNA interaction in oncological research.

Novel insights into the circ_0003489/let-7b-5p/GLUT1 axis and its possible role in multiple myeloma

BACKGROUND

Circular RNAs (circRNAs) act as vital players in multiple myeloma (MM). Herein, we focused on the function of hsa_circ_0003489 (circ_0003489) in MM development and bortezomib (BTZ) resistance.

METHODS

Relative RNA levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Relative protein levels were evaluated by Western blotting or immunohistochemistry (IHC). The 5'-ethynyl-2'-deoxyuridine (EdU) and cell colony formation (CF) assays were conducted for cell proliferation. Cell counting kit-8 assay was used to evaluate the BTZ resistance. Flow cytometry analysis was performed for cell apoptosis analysis. Glycolysis was determined by detecting the levels of ECAR, glucose consumption, and lactate production. Dual-luciferase reporter and RNA pull-down assays were carried out to analyze the relationships of circ_0003489 with let-7b-5p microRNA and glucose transporter 1 (GLUT1) glucose transporter protein. Xenograft models were conducted to assess the function of circ_0003489 in vivo.

RESULTS

Indeed, as shown by qRT-PCR, bone marrow samples of MM patients showed an upregulation of circ_0003489 RNA in comparison to normal controls (P < 0.0001). In in vitro experiments in MM cells, silencing of circ_0003489 repressed cell proliferation, BTZ resistance, and glycolysis. Furthermore, blocking circ_0003489 facilitated in vitro the apoptosis of MM cells. In vivo experiments showed that silencing circ_0003489 decreased tumor formation. Signaling experiments demonstrated that circ_0003489 sponged let-7b-5p microRNA and negatively regulated let-7b-5p microRNA expression. Loss of let-7b-5p microRNA ameliorated circ_0003489 silencing-mediated effects on MM cell malignant behaviors and BTZ resistance. Moreover, we showed that GLUT1 glucose transporter was targeted by let-7b-5p mircoRNA. GLUT1 enhancement reversed the repressive impacts of let-7b-5p upregulation on MM cell malignant behaviors and BTZ resistance.

CONCLUSION

We suggest that circ_0003489 RNA knockdown inhibited MM progression and reversed BTZ-induced resistance of MM growth by let-7b-5p microRNA regulated function of GLUT1 glucose transporter.

CircFLNA facilitates gastric cancer cell proliferation and glycolysis via regulating SOX5 by sponging miR-1200

BACKGROUND AND STUDY AIMS

Circular RNAs (circRNAs) are important regulators for gastric cancer (GC) progression. Our study aims to investigate the role and mechanism of circFLNA in GC progression.

PATIENTS AND METHODS

The levels of circFLNA, microRNA (miR)-1200 and SRY-box transcription factor 5 (SOX5) were examined using qRT-PCR. Flow cytometry, cell counting kit 8 assay and EdU assay were performed to measure cell proliferation and apoptosis. Cell glycolysis ability was assessed by examining glucose uptake and lactate produce. RNA interaction was determined using RNA pull-down assay and dual-luciferase reporter assay. Mice xenograft models were constructed to evaluate the regulation of circFLNA knockdown on GC tumor growth.

RESULTS

CircFLNA was upregulated in GC tissues. Functional experiments showed that circFLNA knockdown suppressed GC cell proliferation, inhibited glycolysis, and promoted apoptosis in vitro, as well as reduced GC tumor growth in vivo. CircFLNA sponged miR-1200, and miR-1200 targeted SOX5. MiR-1200 mimic reversed the promotion effect of circFLNA overexpression on GC cell growth and glycolysis, and SOX5 upregulation also abolished the inhibiting effect of miR-1200 mimic on GC cell growth and glycolysis.

CONCLUSION

Our data suggest that circFLNA might exert oncogenic role in GC development, which promoted GC proliferation and glycolysis through regulating miR-1200/SOX5 axis.

Exploring the impact of circRNAs on cancer glycolysis: Insights into tumor progression and therapeutic strategies

Cancer cells exhibit altered metabolic pathways, prominently featuring enhanced glycolytic activity to sustain their rapid growth and proliferation. Dysregulation of glycolysis is a well-established hallmark of cancer and contributes to tumor progression and resistance to therapy. Increased glycolysis supplies the energy necessary for increased proliferation and creates an acidic milieu, which in turn encourages tumor cells' infiltration, metastasis, and chemoresistance. Circular RNAs (circRNAs) have emerged as pivotal players in diverse biological processes, including cancer development and metabolic reprogramming. The interplay between circRNAs and glycolysis is explored, illuminating how circRNAs regulate key glycolysis-associated genes and enzymes, thereby influencing tumor metabolic profiles. In this overview, we highlight the mechanisms by which circRNAs regulate glycolytic enzymes and modulate glycolysis. In addition, we discuss the clinical implications of dysregulated circRNAs in cancer glycolysis, including their potential use as diagnostic and prognostic biomarkers. All in all, in this overview, we provide the most recent findings on how circRNAs operate at the molecular level to control glycolysis in various types of cancer, including hepatocellular carcinoma (HCC), prostate cancer (PCa), colorectal cancer (CRC), cervical cancer (CC), glioma, non-small cell lung cancer (NSCLC), breast cancer, and gastric cancer (GC). In conclusion, this review provides a comprehensive overview of the significance of circRNAs in cancer glycolysis, shedding light on their intricate roles in tumor development and presenting innovative therapeutic avenues.

CircRNAs: A promising target for intervention regarding glycolysis in gastric cancer

Gastric cancer is characterized by a high incidence and mortality rate, with therapeutic efficacy currently constrained by substantial limitations. Aerobic glycolysis in cancer constitutes a pivotal aspect of the reprogramming of energy metabolism in tumor cells and profoundly influences the malignant progression of cancer. CircRNAs, serving as stable endogenous RNA, have been shown to regulate downstream targets by sponging miRNAs, which in turn are involved in the regulation of multiple malignant behaviors in a variety of cancers through the CircRNA-miRNA axis, suggesting that CircRNAs could be used as potential therapeutic targets for cancer. In recent years, it has been shown that some CircRNAs can be involved in the regulation of GC glycolysis, therefore, this paper summarizes the notable roles of some important CircRNAs in the regulation of GC glycolysis in recent years, which may be useful for our understanding of GC progression and the development of new therapeutic strategies.

Bibliometric and visualized analysis of global research on microRNAs in gastric cancer: from 2013 to 2023

Gastric cancer (GC) imposes a heavy burden on global public health, and microRNAs (miRNAs) play a crucial role in the diagnosis and treatment of GC. Therefore, it is necessary to clarify the hotspots and frontiers in the field of miRNAs in GC to guide future research. A total of 2,051 publications related to miRNAs in GC from January 2013 to December 2023 were searched from the Web of Science Core Collection database. CiteSpace was used to identify research hotspots and delineate developmental trends. In the past decade, China, Nanjing Medical University, and Ba Yi were the most contributing research country, institute, and author in this field, respectively. The role of miRNAs as biomarkers in GC, the mechanism of miRNAs in the progression of GC, and the impact of the mutual effects between miRNAs and Helicobacter pylori on GC have been regarded as the research hotspots. The mechanisms of miRNAs on glucose metabolism and the application of the roles of circular RNAs as miRNA sponges in GC treatment will likely be frontiers. Overall, this study called for strengthened cooperation to identify targets and therapeutic regimes for local specificity and high-risk GC types, and to promote the translation of research results into clinical practice.

circRPS19 affects HK2‑mediated aerobic glycolysis and cell viability via the miR‑125a‑5p/USP7 pathway in gastric cancer

Despite advances in diagnosis and treatment, gastric cancer (GC) remains a refractory disease, which limits overall survival. Therefore, it is key to identify novel targets to develop more effective and precise treatment. Circular RNAs (circRNAs) serve essential roles in the process of various human cancers. Through analyzing GSE83521 dataset, the present study identified a novel circRNA derived from ribosomal protein S19 (circRPS19), which was considered a potential treatment target for GC. Results of RT‑qPCR indicated that circRPS19 was upregulated in GC compared with normal gastric epithelial cells. Loss‑of function assays revealed that silencing of circRPS19 suppressed proliferation and aerobic glycolysis but increased apoptosis of GC cells. circRPS19 upregulated ubiquitin‑specific processing protease 7 (USP7) expression by sponging microRNA (miR)‑125a‑5p. circRPS19 stabilized hexokinase 2 (HK2) protein by USP7‑mediated deubiquitination of HK2. In vivo experiments confirmed that circRPS19 promoted GC progression and aerobic glycolysis. Taken together, circRPS19 induced aerobic glycolysis of GC cells by stabilizing HK2 protein via the miR‑125a‑5p/USP7 axis and thus promoting the progression of GC. These findings suggested that circRPS19 served a critical role in the progression of GC and may be a novel therapeutic target for GC.

The Crosstalk and Clinical Implications of CircRNAs and Glucose Metabolism in Gastrointestinal Cancers

The majority of glucose in tumor cells is converted to lactate despite the presence of sufficient oxygen and functional mitochondria, a phenomenon known as the "Warburg effect" or "aerobic glycolysis". Aerobic glycolysis supplies large amounts of ATP, raw material for macromolecule synthesis, and also lactate, thereby contributing to cancer progression and immunosuppression. Increased aerobic glycolysis has been identified as a key hallmark of cancer. Circular RNAs (circRNAs) are a type of endogenous single-stranded RNAs characterized by covalently circular structures. Accumulating evidence suggests that circRNAs influence the glycolytic phenotype of various cancers. In gastrointestinal (GI) cancers, circRNAs are related to glucose metabolism by regulating specific glycolysis-associated enzymes and transporters as well as some pivotal signaling pathways. Here, we provide a comprehensive review of glucose-metabolism-associated circRNAs in GI cancers. Furthermore, we also discuss the potential clinical prospects of glycolysis-associated circRNAs as diagnostic and prognostic biomarkers and therapeutic targets in GI cancers.

Investigations into the impact of non-coding RNA on the sensitivity of gastric cancer to radiotherapy

Non-coding RNAs (ncRNAs) are a newly discovered functional RNA different from messenger RNA, which can participate in regulating the occurrence and development of tumors. More and more research results show that ncRNAs can participate in the regulation of gastric cancer (GC) radiotherapy response, and its mechanism may be related to its effect on DNA damage repair, gastric cancer cell stemness, cell apoptosis, activation of epidermal growth factor receptor signaling pathway, etc. This article summarizes the relevant mechanisms of ncRNAs regulating the response to radiotherapy in gastric cancer, which will be directly important for the introduction of ncRNAs particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) into clinical medicine as biomarkers and therapeutic targets.

CircBFAR correlates with poor prognosis and promotes laryngeal squamous cell cancer progression through miR-31-5p/COL5A1 axis

Introduction

Laryngeal squamous cell cancer (LSCC) is a highly malignant tumor originating from the respiratory system. Circular RNAs have been reported to be associated with the treatment and prognosis of a variety of cancers, including LSCC.

Methods

The expression of circBFAR, miR-31-5p, and collagen type V alpha 1 chain (COL5A1) in LSCC tissues and cells was detected by quantitative real-time polymerase chain reaction. Cell counting kit 8 and 5-Ethynyl-2'-deoxyuridine assays were used to detect cell proliferation. Wound healing assay and transwell assay were used to test cell migration and invasion, respectively. The protein expression in LSCC cells was detected with western blot. The relationships between miR-31-5p and circBFAR or COL5A1 were identified by dual-luciferase reporter assay, RNA-pull down assay, and immunoprecipitation assay. The effect of circBFAR on tumor growth in vivo was detected by tumor xenograft mice experiment. The protein expression of COL5A1 and KI-67 in LSCC tissues was measured by immunohistochemistry assay.

Results

CircBFAR was increased in LSCC tissues and cells, and was related to advanced clinical stage and overall survival of LSCC patients. The cell viability and proliferation were inhibited by circBFAR knockdown and silencing of circBFAR blocked migration and invasion of LSCC cells. CircBFAR knockdown suppressed cell tube formation, and the protein expression of KI-67, matrix metallopeptidase 2 (MMP2), and vascular endothelial growth factor A (VEGFA) in LSCC cells. MiR-31-5p was the target of circBFAR, and the inhibitory effects of circBFAR deficiency on viability, proliferation, migration, invasion, tube formation and the protein expression of KI-67, MMP2, and VEGFA in LSCC cells were rescued by miR-31-5p downregulation. COL5A1 was negatively regulated by miR-31-5p, and was boosted in LSCC tissues and cells. COL5A1 overexpression reversed the inhibitory effects of miR-31-5p on LSCC cells. CircBFAR insufficiency hindered tumor growth in vivo.

Conclusion

CircBFAR, miR-31-5p, and COL5A1 in LSCC progression might provide novel therapeutic targets for LSCC clinical intervention.

Hexokinase 2 promoted cell motility and proliferation by activating Akt1/p-Akt1 in human ovarian cancer cells

Background

Recently, increasing evidence has indicated that elevation of Hexokinase 2 (HK2) plays an important role in several cancers on regulating cell motility and growth. However, its role on regulating cell EMT in human ovarian cancer still less to known.

Methods

The transwell and wound-healing assay were used to detect the effective of HK2 on regulating motility of ovarian cancer cells. Real Time PCR and Western Blotting were used to explore the changing of EMT-related proteins in HK2-modified cells. The clonogenic formation, cell growth curves and MTT assays were used to evaluate the effective of HK2 on regulating cell proliferation in HK2-modified cells. The flow cytometry was used to detect the differences in the distribution of cells in the cell cycle between the HK2-modified cells and their control cells. The correlation of HK2 and Akt1/p-Akt1 was explored by using Western Blotting, Akt1 inhibitor (MK2206) and transient transfection of an Akt1 recombinant plasmid. The potential correlation between HK2 and EMT-related proteins in human ovarian cancer tissues and OV (ovarian serous cystadenocarcinoma) was confirmed by using Pearson correlation analysis and TIMER 2.0.

Results

In ovarian cancer cells, overexpressing of HK2 enhanced cell motility by inducing of EMT-related proteins, such as CDH2, fibronectin, MMP9, ZEB1, ZEB2 and vimentin. Moreover, overexpressing of HK2 promoted cell growth by reducing p21 and p27 expression in ovarian cancer cells. Further studies demonstrated that this promotion of cell motility and growth by HK2 was probably a result of it activating of Akt1 (p-Akt1) in ovarian cancer cells. Additionally, the positive correlation between HK2 and p-Akt1, fibronectin, MMP9 expression in human ovarian cancer samples was verified by using Pearson correlation analysis. The positive correlation between HK2 and CDH2, fibronectin, MMP9, ZEB1, ZEB2 and vimentin in OV (ovarian serous cystadenocarcinoma) was confirmed by using TIMER 2.0.

Conclusion

This study demonstrated that HK2 could induce EMT-related proteins and reduce cell cycle inhibitor by activating Akt1 in human ovarian cancer cells, subsequently enhancing cell motility and growth, suggesting that HK2 participate in the malignant process of ovarian cancer by interacting with Akt1.

circDNMT1 Promotes Malignant Progression of Gastric Cancer Through Targeting miR-576-3p/Hypoxia Inducible Factor-1 Alpha Axis

BACKGROUND

Circular RNAs (circRNAs) regulate multiple malignant behaviors of various types of cancer. The role of circDNMT1, a newly identified circRNA, remains unknown in gastric cancer (GC). This study aimed to elucidate the underlying mechanisms of circDNMT1 in regulating GC progression.

METHODS

microRNA (miRNA) and circRNA expression was detected by quantitative real-time PCR. Western blotting was performed to measure hypoxia inducible factor-1 alpha (HIF-1α) protein expression. Sanger sequencing, gel electrophoresis and fluorescence in situ hybridization were performed to identify the presence of circDNMT1. The clinicopathological features and overall survival of patients were analyzed based on circDNMT1 expression. The proliferation, migration and invasion of GC cells were determined by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, wound healing and transwell assays. Glycolysis of GC cells was detected based on the levels of glucose uptake, the lactate acid, ATP and pyruvic acid production and the extracellular acidification and oxygen consumption rates. The binding sites between miR-576-3p and circDNMT1 or HIF-1α were predicted by online bioinformatic tools and were validated using RNA pull-down and luciferase reporter assays. Xenograft models were established to determine the effects of the circDNMT1/miR-576-3p/HIF-1α axis on GC growth and metastasis in vivo.

RESULTS

circDNMT1 was successfully identified and shown to be overexpressed in GC tissues and cell lines. The expression levels of circDNMT1 were correlated with pathological T stage, pathological TNM stage and shorter survival time of GC patients. circDNMT1 knockdown inhibited the proliferation, migration, invasion and glycolysis of GC cells. circDNMT1 functioned as an oncogenic factor by sponging miR-576-3p. HIF-1α was negatively regulated by miR-576-3p via binding its mRNA 3' untranslated region. circDNMT1 promoted malignant behaviors and metabolic reprogramming of GC by targeting the miR-576-3p/HIF-1α axis both in vitro and in vivo.

CONCLUSION

These findings demonstrated that circDNMT1 knockdown inhibited GC proliferation, migration, invasion and glycolysis through sponging miR-576-3p/HIF-1α axis. circDNMT1 may be a novel target for GC treatment.

Circular RNAs Acting as miRNAs’ Sponges and Their Roles in Stem Cells

Circular RNAs (circRNAs), a novel type of endogenous RNAs, have become a subject of intensive research. It has been found that circRNAs are important players in cell differentiation and tissue homeostasis, as well as disease development. Moreover, the expression of circRNAs is usually not correlated with their parental gene expression, indicating that they are not only a steady-state by-product of mRNA splicing but a product of variable splicing under novel regulation. Sequence conservation analysis has also demonstrated that circRNAs have important non-coding functions. CircRNAs exist as a covalently closed loop form in mammalian cells, where they regulate cellular transcription and translation processes. CircRNAs are built from pre-messenger RNAs, and their biogenesis involves back-splicing, which is catalyzed by spliceosomes. The splicing reaction gives rise to three different types of intronic, exotic and exon–intron circular RNAs. Due to higher nuclease stability and longer half lives in cells, circRNAs are more stable than linear RNAs and have enormous clinical advantage for use as diagnostic and therapeutic biomarkers for disease. In recent years, it has been reported that circRNAs in stem cells play a crucial role in stem cell function. In this article, we reviewed the general feature of circRNAs and the distinct roles of circRNAs in stem cell biology, including regulation of stem cell self-renewal and differentiation. CircRNAs have shown unique expression profiles during differentiation of stem cells and could serve as promising biomarkers of these cells. As circRNAs play pivotal roles in stem cell regulation as well as the development and progression of various diseases, we also discuss opportunities and challenges of circRNA-based treatment strategies in future effective therapies for promising clinical applications.

Circular RNA circBFAR promotes glioblastoma progression by regulating a miR-548b/FoxM1 axis

Glioblastoma multiforme (GBM) is the most common and aggressive type of tumor of the primary nervous system. Treatment options for GBM include surgery, chemotherapy, and radiation therapy; however, the clinical outcomes are poor, with a high rate of recurrence. An increasing number of studies have shown that circular RNAs (circRNAs) serve important roles in several types of cancer. Gene Expression Omnibus (GEO) database was utilized to identify the differentially expressed circRNAs and their biological functions. Then, we detected the circular RNA bifunctional apoptosis regulator (circBFAR) was significantly increased in three GEO datasets. However, the role of circBFAR has not been reported in GBM. In this study, the expression of circBFAR was significantly increased both in GBM tissues or cell lines and was negatively correlated with overall survival in patients with GBM. Knockdown of circBFAR inhibited proliferation and invasion both in vitro and in vivo. Increased expression of circBFAR resulted in a reduction of miR-548b expression in glioma cells. A luciferase reporter and RIP assay indicated that miR-548b was a direct target of circBFAR, and miR-548b may negatively regulate the expression of FoxM1. Rescue experiments showed that overexpression of FoxM1 could counter the effect of circBFAR silencing on the proliferation and invasion of glioma cell lines. Moreover, we identified that circBFAR regulates FoxM1 by interacting with miR-548b in glioma cells. In conclusion, the present study demonstrated that a circBFAR/miR-548b/FoxM1 axis regulates the development of GBM and highlights potentially novel therapeutic targets for the treatment of GBM.

Circular RNA Circ-0002570 Accelerates Cancer Progression by Regulating VCAN via MiR-587 in Gastric Cancer

BACKGROUND

Circular RNAs (circRNAs) are closely associated with the occurrences and progress of gastric cancer (GC). We aimed to delve into the function and pathological mechanism of Circular RNA-0002570 (circ-0002570) in GC progression.

METHODS

CircRNAs differentially expressed in GC were screened using bioinformatics technology. The expression of circ-0002570 was detected in GC specimens and cells via qRT-PCR, and the prognostic values of circ-0002570 were determined. The functional roles of circ-0002570 on proliferation, migration, and invasion in GC cells were explored in vitro and in vivo. Interaction of circ-0002570, miR-587, and VCAN was confirmed by dual-luciferase reporter assays, Western blotting, and rescue experiments.

RESULTS

Circ-0002570 expression was distinctly increased in GC tissues compared to adjacent normal specimens, and GC patients with higher circ-0002570 expressions displayed a short survival. Functionally, knockdown of circ-0002570 resulted in the inhibition of cell proliferation, migration, and invasion, and suppressed tumor growth in vivo. Mechanistically, miR-587 was sponged by circ-0002570. VCAN expression in NSCLC was directly inhibited by miR-587. Overexpression of circ-0002570 prevented VCAN from miR-587-mediated degradation and thus facilitated GC progression.

CONCLUSION

The circ-0002570-miR-587-VCAN regulatory pathway promoted the progression of GC. Our findings provided potential new targets for the diagnosis and therapy of GC.