Circular RNA circ-ITCH inhibits bladder cancer progression by sponging miR-17/miR-224 and regulating p21, PTEN expression

The function of circular RNAs in regulating Wnt/β-catenin signaling: An innovative therapeutic strategy for breast and gynecological cancers

Breast cancer (BC) and gynecological malignancies, including cervical, ovarian, and uterine cancers, are significant global health challenges due to their high prevalence, complex nature, and elevated mortality rates. Dysregulation of the Wnt/β-catenin signaling pathway is a common feature in gynecological malignancies, contributing to cancer cell growth, progression, migration, and metastasis. Recent studies have highlighted the pivotal role of non-coding RNAs (ncRNAs), particularly circular RNAs (circRNAs), in modulating the Wnt/β-catenin signaling pathway. Acting as sponges for microRNAs (miRNAs), circRNAs regulate key oncogenic and tumor-suppressive processes by influencing Wnt-related components. This research explores the role of circRNAs in breast and gynecological malignancies, focusing on their regulatory effects on the Wnt/β-catenin pathway. The findings reveal that circRNAs modulate critical cellular processes such as proliferation, apoptosis, autophagy, and metastasis, with potential implications for therapeutic interventions. Targeting circRNA-mediated dysregulation of Wnt signaling could offer novel strategies for improving diagnostic precision, treatment efficacy, and survival outcomes in breast and gynecological cancers.

RNA profiling and immunohistochemistry analyses of circRNAs in imatinib-resistant gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal sarcomas of the upper digestive tract. Imatinib is the first-line therapy for patients with metastatic or unresectable GISTs. However, the majority of GIST patients eventually develop imatinib resistance.

METHODS

To identify the factors that are responsible for imatinib resistance, we investigated the differentially expressed mRNAs and circRNAs in imatinib-naïve and imatinib-resistant GISTs via ceRNA microarrays. The expression levels of circ-BRIP1, circ-EPHB4 and their host genes were validated via quantitative real-time PCR analyses and formalin-fixed and paraffin-embedded (FFPE) tissue microarrays (TMAs).

RESULTS

We found that 107 mRNAs and 521 circRNAs were differentially expressed between imatinib-resistant and imatinib-naïve GIST tissue samples. Among them, circ-BRIP1, circ-EPHB4 and their host genes were upregulated in imatinib-resistant GISTs and associated with imatinib resistance, tumor relapse and progression, and metastasis in GIST patients. The expression level of EPHB4 was significantly greater in high-grade GISTs than in low-grade GISTs and was correlated with imatinib resistance.

CONCLUSIONS

Our results demonstrated that the circRNA in situ hybridization-immunohistochemistry could not only be applied to FFPE-TMAs for high-throughput analysis of circRNA expression in tumors but also suggested a possible role for circ-BRIP1, circ-EPHB4, and their host genes in the progression of GISTs.

Circ-NMNAT1 Drives Tumor Progression in Bladder Cancer by Modulating the miR-370-3p/ATXN2L Axis

The relationship between circular RNAs (circRNAs) and tumor growth and metastasis is increasingly well-established. In this study, we sought to shed light on circ-NMNAT1's potential molecular mechanisms in bladder cancer (BCa). circ-NMNAT1, miR-370-3p, and ATXN2L expression profiles were explored using RT-qPCR and/or Western blot techniques. Cell proliferation was detected by MTT and colony formation assay. Transwell assay was used to detect the migration and invasion ability of cells. Western Blot was used to detect the protein expression level of ATXN2L. The targeting relationship between miR-370-3p and circ-NMNAT1 or ATXN2L was confirmed by dual luciferase reporter gene and RIP assay. A xenograft tumor model was created to investigate circ-NMNAT1's function in BCa in vivo. The high expression of circ-NMNAT1 was measured in BCa. circ-NMNAT1 bound competitively to miR-370-3p and downregulated miR-370-3p expression. After knocking down circ-NMNAT1, the proliferation ability of EJ cells was significantly inhibited, and the number of cell colonies was (80.00 ± 7.10). The number of migrated and invaded cells was significantly reduced by (35.49 ± 0.05)% and (59.00 ± 0.04)%, respectively, after silencing circ-NMNAT1. In addition, downregulation of circ-NMNAT1 also significantly increased the apoptosis rate of EJ cells by (23.55 ± 2.95)%. Knockdown of miR-370-3p or overexpression of ATXN2L reduced the effect of circ-NMNAT1 silencing on BCa cells. The promoting effect of circ-NMNAT1 on BCa progression was further validated in vivo tumor models. The weight and volume of the tumor were significantly inhibited after circ-NMNAT1 knockdown, which were (87.50 ± 20.40) mg and (238.90 ± 21.38) mm3, respectively. Circ-NMNAT1 is highly expressed in BCa and promotes the proliferation, migration, and invasion of BCa cells by regulating the miR-370-3p/ATXN2L axis, thereby accelerating the progression of BCa. Our results suggest that circ-NMNAT1 may be a new therapeutic target for BCa.

Therapeutic potential of microRNA-506 in cancer treatment: mechanisms and therapeutic implications

Cancer is a complex and highly lethal disease marked by unchecked cell proliferation, aggressive behavior, and a strong tendency to metastasize. Despite significant advancements in cancer diagnosis and treatment, challenges such as early detection difficulties, drug resistance, and adverse effects of radiotherapy or chemotherapy continue to threaten patient survival. MicroRNAs (miRNAs) have emerged as critical regulators in cancer biology, with miR-506 being extensively studied and recognized for its tumor-suppressive effects across multiple cancer types. This review examines the regulatory mechanisms of miR-506 in common cancers, focusing on its role in the competing endogenous RNA (ceRNA) network and its effects on cancer cell proliferation, apoptosis, and migration. We also discuss the potential of miR-506 as a therapeutic target and its role in overcoming drug resistance in cancer treatment. Overall, these insights underscore the therapeutic potential of miR-506 and its promise in developing novel cancer therapies.

Circ-ITCH promotes the ubiquitination degradation of HOXC10 to facilitate osteogenic differentiation in disuse osteoporosis through stabilizing BRCA1 mRNA via IGF2BP2-mediated m6A modification

BACKGROUND

Osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) facilitated by mechanical loading is a promising therapy for disuse osteoporosis (DOP), however, it is difficult to implement mechanical loading for a majority of patients. Our study aims to identify circ-ITCH-mediated novel approach to facilitate osteogenic differentiation in DOP.

METHODS

A rat DOP model and human BM-MSCs under microgravity condition were generated as in vivo and in vitro models of DOP, respectively. The bone mineral density (BMD) and bone parameters were examined in rats. The histological changes of bones and mineralization were monitored by H&E, Alcian blue and Alizarin red S staining. Co-IP was employed to examine the ubiquitination of HOXC10 and the interaction between HOXC10 and BRCA1. The direct associations among circ-ITCH, IGFBP2 and BRCA1 mRNA were assessed by RIP, FISH and RNA pull-down assays.

RESULTS

Circ-ITCH was downregulated in rat model of DOP and BM-MSCs under microgravity stimulation. Circ-ITCH overexpression promoted osteogenic differentiation in BM-MSCs under microgravity condition. The altered bone parameters, such as BMD, trabecular number (Tb.N), trabecular separation (Tb.Sp), trabecular thickness (Tb.Th), and bone microstructure in DOP rats were rescued by circ-ITCH overexpression. Mechanistically, circ-ITCH enhanced the ubiquitination degradation of HOXC10 through enhancing BRCA1 mRNA stability. Circ-ITCH directly bound to IGF2BP2 protein to stabilize BRCA1 mRNA via m6A modification, thus facilitating osteogenic differentiation in BM-MSCs under microgravity condition.

CONCLUSION

Circ-ITCH stabilized BRCA1 mRNA via IGF2BP2-mediated m6A modification, thereby facilitating the ubiquitination degradation of HOXC10 to promote osteogenic differentiation in DOP.

Circular RNA circDCUN1D4 suppresses hepatocellular carcinoma development via targeting the miR-590-5p/ TIMP3 axis

Hepatocellular carcinoma (HCC) is a major global health concern, necessitating innovative therapeutic strategies. In this study, we investigated the functional role of circular RNA circDCUN1D4 in HCC progression and its potential therapeutic implications. It was found that HCC patients exhibiting higher levels of circDCUN1D4 demonstrated a more favorable survival rate. Furthermore, we revealed that circDCUN1D4 suppressed HCC cell proliferation, migration, and invasion. Mechanistically, circDCUN1D4 was identified as a sponge for miR-590-5p, leading to the downregulation of its downstream target, Tissue Inhibitor of Metalloproteinase 3 (TIMP3). Importantly, circDCUN1D4 administration through In vivo jet-PEI exhibited a robust inhibitory effect on tumor progression without causing notable toxicity in mice. Overall, our findings highlight circDCUN1D4 as a promising therapeutic candidate for HCC, unraveling its intricate regulatory role through the miR-590-5p/TIMP3 axis. This study contributes valuable insights into the potential clinical applications of circRNA-based therapies for HCC.

Circular RNAs: driving forces behind chemoresistance and immune evasion in bladder cancer

Bladder cancer (BCa) is characterized by recurring relapses and the emergence of chemoresistance, especially against standard treatments like cisplatin and gemcitabine. Despite its significance, the molecular mechanisms underlying chemoresistance in BCa remain elusive. Recent studies have revealed that circular RNAs (circRNAs) are pivotal regulators of cancer progression and chemoresistance. Through their function as miRNA sponges and protein sequesters, circRNAs modulate the expression of key genes, ultimately driving either drug resistance or sensitivity in BCa. The complex interplay between circRNAs and chemoresistance suggests that they may represent promising therapeutic targets for overcoming treatment resistance in patients with BCa. This review aims to summarize the current understanding of circRNAs' regulatory roles in chemoresistance and provide insights into their potential as therapeutic targets, particularly in the context of cisplatin and gemcitabine resistance. Furthermore, we explore how chemoresistance can also impact tumor immune evasion, thereby affecting the tumor microenvironment. Our findings may pave the way for the advancement of innovative treatment approaches for bladder cancer.

Hsa_circ_0002005 aggravates osteosarcoma by increasing cell proliferation, migration, and invasion

Emerging evidence suggests that circular RNAs (circRNAs), a class of non-coding RNAs, play a critical role in the progression of several cancers, including osteosarcoma (OS). In this study, we focused on a specific circRNA, hsa_circ_0002005, derived from the mesoderm-induced early response 1 family member 2 (MIER2) gene. We determined the expression levels of hsa_circ_0002005 in OS samples through the use of real-time quantitative polymerase chain reaction (RT-qPCR). To assess the effect of hsa_circ_0002005, we used lentiviral analysis and performed several assays including transwell migration, cell invasion, 5-ethynyl-2'-deoxyuridine assay (EdU), cell counting kit-8 (CCK-8), proliferation, colony formation, and western blotting. In addition, we investigated the delivery mechanism of hsa_circ_0002005 in nude mice and predicted the interaction network involving hsa_circ_0002005, microRNA (miRNA), and mRNAs through bioinformatics analysis. The results showed that hsa_circ_0002005 is overexpressed in OS tissues and cells and is derived from exons 2 to 7 of the MIER2 gene. Knockdown of hsa_circ_0002005 markedly reduced the proliferation, migration, and invasive capabilities of cells, as well as their metastatic potential. We discovered miRNAs that may engage with hsa_circ_0002005. Further mechanistic studies indicated that the suppression of hsa_circ_0002005 influenced the expression levels of proteins associated with the epithelial-mesenchymal transition (EMT), suggesting its regulatory role in EMT progression through modulation of cell proliferation, migration, and invasion.

Circular RNAs as key regulators in cancer hallmarks: New progress and therapeutic opportunities

Circular RNAs (circRNAs) have emerged as critical regulators in cancer biology, contributing to various cancer hallmarks, including cell proliferation, apoptosis, metastasis, and drug resistance. Defined by their covalently closed loop structure, circRNAs possess unique characteristics like high stability, abundance, and tissue-specific expression. These non-coding RNAs function through mechanisms such as miRNA sponging, interactions with RNA-binding proteins (RBPs), and modulating transcription and splicing. Advances in RNA sequencing and bioinformatics tools have enabled the identification and functional annotation of circRNAs across different cancer types. Clinically, circRNAs demonstrate high specificity and sensitivity in samples, offering potential as diagnostic and prognostic biomarkers. Additionally, therapeutic strategies involving circRNA mimics, inhibitors, and delivery systems are under investigation. However, their precise mechanisms remain unclear, and more clinical evidence is needed regarding their roles in cancer hallmarks. Understanding circRNAs will pave the way for novel diagnostic and therapeutic approaches, potentially improving patient outcomes.

Unleashing the power of urine‑based biomarkers in diagnosis, prognosis and monitoring of bladder cancer (Review)

Bladder cancer (BCa) is a prevalent malignant neoplasm of the urinary tract with high incidence rate, frequent recurrence and rapid disease progression. Conventional approaches for diagnosing, prognosticating and monitoring BCa often rely on invasive procedures such as cystoscopy and tissue biopsy, which are associated with high costs and low patient compliance for follow‑up. Liquid biopsies have advantages, such as being non‑invasive, real‑time, and reproducible, in obtaining diverse biomarkers derived from cellular, molecular, proteomic and genetic signatures in urine or plasma samples. Although plasma‑based biomarkers have been clinically validated, urine provides greater specificity for directly assessing biological materials from urological sources. The present review summarizes advancements and current limitations in urinary protein, genetic and epigenetic biomarkers for disease progression and treatment response of BC, compares performance and application scenarios of urine and blood biomarkers and explores how urinary biomarkers may serve as an alternative or complementary tool to traditional diagnostic methods. The integration of urine‑based or plasma‑based biomarkers into existing diagnostic workflows offers promising avenues for improving accuracy and efficiency of diagnosis in the management of BCa. Notably, the emergence of synthetic biomarkers and urine metabolites, combined with artificial intelligence or bioinformatic technologies, has promise in the screening of potential targets. Continued research and validation efforts are needed to translate these findings into routine clinical practice, ultimately improving patient outcomes and decreasing the burden of BCa.

Multiple roles of circular RNAs in prostate cancer: from the biological basis to potential clinical applications

Prostate cancer is an important health concern affecting men. Circular RNAs (circRNAs) play an important molecular biological role in regulating gene expression due to their unique structure. Studies have revealed the involvement of circRNAs in many human diseases. In prostate cancer, circRNAs can act as oncogenes or tumour suppressor genes and affect cancer cell proliferation, invasion, resistance to chemotherapy and, consequently, disease progression. Accordingly, prostate cancer-related circRNAs are expected to serve as new targets in early clinical diagnosis and targeted therapy, but the various roles of circRNAs in prostate cancer have not been fully elucidated. This article reviews the molecular pathological roles of circRNA in prostate cancer and explores its prospects as a translational medicine in clinical treatment and prognostic evaluation.

Non-Coding RNAs in Cancer: Structure, Function, and Clinical Application

We are on the brink of a paradigm shift in both theoretical and clinical oncology. Genomic and transcriptomic profiling, alongside personalized approaches that account for individual patient variability, are increasingly shaping discourse. Discussions on the future of personalized cancer medicine are mainly dominated by the potential of non-coding RNAs (ncRNAs), which play a prominent role in cancer progression and metastasis formation by regulating the expression of oncogenic or tumor suppressor proteins at transcriptional and post-transcriptional levels; furthermore, their cell-free counterparts might be involved in intercellular communication. Non-coding RNAs are considered to be promising biomarker candidates for early diagnosis of cancer as well as potential therapeutic agents. This review aims to provide clarity amidst the vast body of literature by focusing on diverse species of ncRNAs, exploring the structure, origin, function, and potential clinical applications of miRNAs, siRNAs, lncRNAs, circRNAs, snRNAs, snoRNAs, eRNAs, paRNAs, YRNAs, vtRNAs, and piRNAs. We discuss molecular methods used for their detection or functional studies both in vitro and in vivo. We also address the challenges that must be overcome to enter a new era of cancer diagnosis and therapy that will reshape the future of oncology.

CircPTK2 as a Valuable Biomarker and Treatment Target in Cancer

Circular RNA (CircRNA)s, a newly discovered type of noncoding RNAs, have been found to play a role in controlling the development and aggressiveness of tumors. Abnormal control of circRNA has been observed in various types of human cancers, including bladder cancer, hepatocellular carcinoma (HCC), breast cancer, and gastric cancer (GC). CircRNAs possess binding sites for microRNAs (miRNAs) and function as miRNA sponges in posttranscriptional regulation. This mechanism has been documented to influence the course of cancer. Significantly, among these putative circRNAs, circular RNA protein tyrosine kinase 2 (circPTK2) exhibited increased expression and displayed a substantial association with adverse clinical characteristics and a negative prognosis. The production of these transcripts occurs via a back-splicing mechanism. The enclosed conformation of circRNAs shields them from destruction and enhances their potential as biomarkers. Gaining insight into the molecular mechanisms involved in these processes would aid in the development of treatment approaches and the discovery of new tumor markers. This article provides a comprehensive assessment of the latest research on the biosynthesis and features of circRNAs. It examines the role of circPTK2 in the diagnosis, treatment, and prognosis evaluation of cancer.

hsa_circ_0001508 as a new gene that may promote breast cancer progression via the miR‑505‑3p/HMGB1, VGLL3 axis

Breast cancer (BC) is a malignant tumor, that damages the physical health of female patients. It is crucial to develop new treatment strategies for BC, as this disease significantly affects the quality of life of women in both developing and developed countries, despite the existence of effective treatment options to reduce mortality. Recently, several researchers have been studying circular RNAs (circRNAs) in BC due to their stability and sponge function. In the present study, a new circRNA, hsa_circ_0001508, was discovered using Gene Chip's prediction. This gene is important because it is novel in BC. However, due to financial constraints, the study was designed as a pilot study for future research. The present study included several common biomedical experimental techniques, such as reverse transcription-quantitative PCR, flow cytometry, cell counting, cell invasion, wound healing assay and western blotting. It also involves the use of DNA microarray (gene chip) and prediction of microRNA and mRNA interactions using bioinformatics tools such as TargetScan. The findings revealed that hsa_circ_0001508 exhibits carcinogenic properties that facilitate the progression of BC. Furthermore, potential binding sites were identified as crucial areas for future investigation.

AL161431.1 is identified as a biomarker for bladder cancer progression and immunotherapy response

LncRNA AL161431.1 is currently known as a factor that can promote epithelial-mesenchymal transition. However, its role in the prognosis, immune infiltration and progression of bladder cancer (BLCA)patients is still unclear. The expression of AL161431.1 is elevated in BLCA tissues compared to normal tissues according to the TCGA database. By combining this data with clinical information, patients with high AL161431.1 expression have more advanced clinicopathological stages and shorter survival periods. Furthermore, AL161431.1 was identified as an independent prognostic factor for bladder cancer. We further analyzed the differences in immune infiltration, tumor mutation burden (TMB), immune checkpoints, and sensitivity to immunotherapy between groups with different levels of AL161431.1 expression. Enrichment analysis demonstrated that AL161431.1 is associated with numerous immune signaling pathways. High expression of AL161431.1 in cancer tissues was confirmed by qRT-PCR. CCK8, transwell, and wound healing demonstrated the oncogenic effects of AL161431.1. In conclusion, AL161431.1 is associated with immune infiltration in bladder cancer and has the potential to become a biomarker for predicting the prognosis of BLCA.

Circ-ITCH inhibits bladder cancer progression through miR-184/FOXO3 axis

OBJECTIVE

This study aimed to explore the role of circ-ITCH in the progression of bladder cancer (BCa).

METHODS

Kaplan-Meier analysis was performed to evaluate the prognostic significance of miR-184 in bladder cancer. Clustering analysis compared miR-184 expression levels across various BCa cell lines. Cell Counting Kit-8 (CCK-8) and transwell assays were used to assess cell proliferation and migration. Dual-luciferase reporter assays were employed to examine the regulatory relationship among circ-ITCH, miR-184, and FOXO3. Western blot analysis was conducted to investigate the post-transcriptional regulation of the circ-ITCH/miR-184/FOXO3 axis.

RESULTS

The study demonstrated a correlation between elevated miR-184 expression and poor prognosis in bladder cancer. Compared to SV-HUC, a normal bladder tissue cell line, most BCa cell lines exhibited increased miR-184 expression. Additionally, miR-184 was found to promote BCa cell progression. Importantly, circ-ITCH was identified as a natural sponge for miR-184 in BCa. Overexpression of circ-ITCH in BCa significantly reduced miR-184 expression, thereby inhibiting cell proliferation and migration. Moreover, FOXO3, a target of miR-184, is regulated by circ-ITCH. The suppression of FOXO3 by miR-184 was counteracted by circ-ITCH, which diminished the tumor-promoting effects of miR-184.

CONCLUSIONS

This study underscores the pivotal role of the circ-ITCH/miR-184/FOXO3 axis in regulating BCa cell proliferation and migration. It introduces a potential therapeutic target for bladder cancer, suggesting that strategies like circ-ITCH overexpression and miR-184 inhibition could offer promising treatment options.

Circular RNA LMBR1 inhibits bladder cancer progression by enhancing expression of the protein ALDH1A3

Background

Circular RNAs (circRNAs) have been identified as playing an integral role in the development of bladder cancer (BC). However, the mechanism by which circRNAs operate in the chemical carcinogenesis of BC remains unclear.

Methods

To explore this mechanism, we used RNA high-throughput sequencing to identify differentially expressed circRNA in bladder epithelial cells and chemically induced malignant transformed BC cells. Subsequently, in vitro experiments were conducted to investigate the biological function and molecular mechanism of circLMBR1 in BC. Finally, animal experiments were conducted to examine the clinical relevance of circLMBR1 in vivo.

Results

Our profiling of circular RNA expression during cellular malignant transformation induced by chemical carcinogens identified a subset of circRNAs associated with cell transformation. We verified that the expression of circLMBR1 in bladder epithelial malignant transformed cells was decreased compared with control cells, as well as in BC tissues and bladder cell lines. Furthermore, circLMBR1 was seen to inhibit the proliferation, invasion, and migration of BC cells both in vitro and in vivo. Mechanistically, circLMBR1 was found to exert its antitumor effect by binding to the protein ALDH1A3.

Conclusions

Our findings have revealed that circLMBR1 inhibits the progression of BC cells by binding to ALDH1A3 and upregulating its expression. As such, circLMBR1 serves as a promising predictor of BC and may provide a novel therapeutic target for the treatment of BC.

CircRNA ITCH Inhibits Epithelial-Mesenchymal Transformation and Promotes Apoptosis in Papillary Thyroid Carcinoma via miR-106a-5p/JAZF1 Axis

Circular RNA ITCH (circ-ITCH) is implicated in papillary thyroid carcinoma (PTC) development. Nevertheless, the more detailed molecular mechanism remains uncovered. The transcriptional level of circ-ITCH was tested via quantitative real-time PCR. Transwell assay was introduced to assess the migrative and invasive abilities of cells. RNA interference technology was employed to reduce the level of circ-ITCH as well as JAZF1 in PTC cells. Western blot assay was utilized to reveal the content of JAZF1 and proteins related to epithelial-mesenchymal transformation (EMT) progression. Circ-ITCH was downregulated in PTC tissues as well as cells. Overexpression of circ-ITCH suppressed EMT, migration, invasion, facilitated apoptosis in PTC cells, while silencing circ-ITCH exhibited reversed effects. Additionally, miR-106a-5p was the target of circ-ITCH and negatively regulated through circ-ITCH. MiR-106a-5p mimic partly eliminated the influences of overexpressed circ-ITCH in PTC cells. Moreover, JAZF1 could interact with miR-106a-5p, then it was regulated via circ-ITCH. Silencing JAZF1 partially counteracted the role of circ-ITCH in PTC cells progress. This study uncovered that circ-ITCH suppressed the development of PTC cells at least partly by mediating miR-106a-5p/JAZF1 network.

Dihydroartemisinin enhances the radiosensitivity of breast cancer by targeting ferroptosis signaling pathway through hsa_circ_0001610

OBJECTIVE

This study aimed to elucidate how DHA enhances the radiosensitivity of BC and to explain its potential mechanisms of action.

METHODS

The circular structure of hsa_circ_0001610 was confirmed by Sanger sequencing, RNase R treatment, RT-PCR analysis using gDNA or cDNA. Cellular localization of hsa_circ_0001610 and microRNA-139-5p (miR-139-5p) was detected by fluorescence in situ hybridization. Cell counting kit-8 assay, wound healing and colony formation tests for assessing cell proliferation, while flow cytometry was utilized to estimate cell cycle progression and apoptosis. Reactive oxygen species and malondialdehyde experiments were conducted to validate ferroptosis of BC cells. The expression of ncRNAs and mRNAs was quantified via qRT-PCR, and protein expression was analyzed using Western blot. The effects of hsa_circ_0001610 and DHA on radiosensitivity of BC in vivo were studied by establishing BC mice model.

RESULTS

In vivo and in vitro experimental results indicate that DHA promotes ferroptosis of BC cells at least partly by inhibiting hsa_circ_0001610/miR-139-5p/SLC7A11 pathway, thereby enhancing the radiosensitivity of BC cells.

CONCLUSIONS

Our findings showed that DHA can induce ferroptosis of BC cells by down-regulation of hsa_circ_0001610, thus enhancing radiosensitivity, suggesting a promising therapeutic strategy for enhancing BC radiosensitivity that is worthy of further exploration.

Emerging roles of noncoding RNAs in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic lung disease with limited treatment options and efficacy. Evidence suggests that IPF arises from genetic, environmental, and aging-related factors. The pathogenic mechanisms of IPF primarily involve dysregulated repeated microinjuries to epithelial cells, abnormal fibroblast/myofibroblast activation, and extracellular matrix (ECM) deposition, but thus far, the exact etiology remains unclear. Noncoding RNAs (ncRNAs) play regulatory roles in various biological processes and have been implicated in the pathophysiology of multiple fibrotic diseases, including IPF. This review summarizes the roles of ncRNAs in the pathogenesis of IPF and their potential as diagnostic and therapeutic targets.

Extracellular vesicle-mediated delivery of miR-766-3p from bone marrow stromal cells as a therapeutic strategy against colorectal cancer

OBJECTIVE

As colorectal cancer (CRC) remains one of the leading causes of cancer-related deaths, understanding novel therapeutic mechanisms is crucial. This research focuses on the role of extracellular vesicles (EVs) from bone marrow stromal cells (BMSCs) in delivering miR-766-3p to CRC cells, targeting the MYC/CDK2 signaling axis.

METHODS

Differentially expressed genes between BMSCs-EVs and CRC were identified using the Gene Expression Omnibus database. miR-766-3p target genes were predicted via TargetScan and RNAInter, with protein interactions analyzed using the STRING database. The analysis included RT-qPCR and Western blot on samples from 52 CRC patients. Characterization of BMSCs-EVs was followed by their functional assessment on CRC cell lines and the normal colon cell line CCD-18CO, evaluating cellular uptake, proliferation, migration, invasion, and apoptosis.

RESULTS

miR-766-3p was confirmed in BMSCs-EVs and found underexpressed in CRC. BMSCs-EVs transported miR-766-3p to CRC cells, inhibiting their proliferation, migration, and invasion while promoting apoptosis. miR-766-3p targeted MYC, leading to decreased CDK2 transcription. Overexpression of MYC in HCT-116 cells counteracted these effects. In vivo studies showed that BMSCs-EVs carrying miR-766-3p hindered tumor growth.

CONCLUSION

The study demonstrates the efficacy of BMSCs-EVs in delivering miR-766-3p to CRC cells, leading to the suppression of the MYC/CDK2 signaling pathway and hindering cancer progression.

Circular RNAs: Novel Players in Cancer Mechanisms and Therapeutic Strategies

Circular RNAs (circRNAs) are a novel class of noncoding RNAs that have emerged as pivotal players in gene regulation. Our understanding of circRNAs has greatly expanded over the last decade, with studies elucidating their biology and exploring their therapeutic applications. In this review, we provide an overview of the current understanding of circRNA biogenesis, outline their mechanisms of action in cancer, and assess their clinical potential as biomarkers. Furthermore, we discuss circRNAs as a potential therapeutic strategy, including recent advances in circRNA production and translation, along with proof-of-concept preclinical studies of cancer vaccines.

The role of circular RNA during the urological cancer metastasis: exploring regulatory mechanisms and potential therapeutic targets

Metastasis is a major contributor to treatment failure and death in urological cancers, representing an important biomedical challenge at present. Metastases form as a result of cancer cells leaving the primary site, entering the vasculature and lymphatic vessels, and colonizing clones elsewhere in the body. However, the specific regulatory mechanisms of action underlying the metastatic process of urological cancers remain incompletely elucidated. With the deepening of research, circular RNAs (circRNAs) have been found to not only play a significant role in tumor progression and prognosis but also show aberrant expression in various tumor metastases, consequently impacting tumor metastasis through multiple pathways. Therefore, circRNAs are emerging as potential tumor markers and treatment targets. This review summarizes the research progress on elucidating how circRNAs regulate the urological cancer invasion-metastasis cascade response and related processes, as well as their role in immune microenvironment remodeling and circRNA vaccines. This body of work highlights circRNA regulation as an emerging therapeutic target for urological cancers, which should motivate further specific research in this regard.

The importance of the circRNA/Wnt axis in gliomas: Biological functions and clinical opportunities

Gliomas are among the most common cancers in the central nervous system, arising through various signaling pathways. One significant pathway is Wnt signaling, a tightly regulated process that plays a crucial role in gliomagenesis and development. The current study aims to explore the relationship between circular RNAs (circRNAs) and the Wnt/β-catenin signaling pathway in gliomas, considering the growing recognition of circRNAs in disease pathogenesis. A comprehensive review of recent research was conducted to investigate the roles of circRNAs in gliomas, focusing on their expression patterns and interactions with the Wnt signaling pathway. The analysis included studies examining circRNAs' function as microRNA sponges and their impact on glioma biology. The findings reveal that circRNAs are differentially expressed in gliomas and significantly influence the occurrence, growth, and metastasis of these tumors. Specifically, circRNAs interact with the Wnt signaling pathway, affecting glioma development and progression. This interaction highlights the importance of circRNAs in glioma pathophysiology. Understanding the regulatory network involving circRNAs and Wnt signaling offers valuable insights into glioma pathophysiology. CircRNAs hold promise as diagnostic and prognostic biomarkers and may serve as targets for novel therapeutic strategies in glioma treatment.

Unraveling the crosstalk: circRNAs and the wnt signaling pathway in cancers of the digestive system

Circular RNA (circRNA) is a unique type of noncoding RNA molecule characterized by its closed-loop structure. Functionally versatile, circRNAs play pivotal roles in gene expression regulation, protein activity modulation, and participation in cell signaling processes. In the context of cancers of the digestive system, the Wnt signaling pathway holds particular significance. Anomalous activation of the Wnt pathway serves as a primary catalyst for the development of colorectal cancer. Extensive research underscores the notable participation of circRNAs associated with the Wnt pathway in the progression of digestive system tumors. These circRNAs exhibit pronounced dysregulation across esophageal cancer, gastric cancer, liver cancer, colorectal cancer, pancreatic cancer, and cholangiocarcinoma. Furthermore, the altered expression of circRNAs linked to the Wnt pathway correlates with prognostic factors in digestive system tumors. Additionally, circRNAs related to the Wnt pathway showcase potential as diagnostic, therapeutic, and prognostic markers within the realm of digestive system tumors. This comprehensive review outlines the interplay between circRNAs and the Wnt signaling pathway in cancers of the digestive system. It seeks to provide a comprehensive perspective on their association while delving into ongoing research that explores the clinical applications of circRNAs associated with the Wnt pathway.

Bladder cancer: non-coding RNAs and exosomal non-coding RNAs

Bladder cancer (BCa) is a highly prevalent type of cancer worldwide, and it is responsible for numerous deaths and cases of disease. Due to the diverse nature of this disease, it is necessary to conduct significant research that delves deeper into the molecular aspects, to potentially discover novel diagnostic and therapeutic approaches. Lately, there has been a significant increase in the focus on non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), due to their growing recognition for their involvement in the progression and manifestation of BCa. The interest in exosomes has greatly grown due to their potential for transporting a diverse array of active substances, including proteins, nucleic acids, carbohydrates, and lipids. The combination of these components differs based on the specific cell and its condition. Research indicates that using exosomes could have considerable advantages in identifying and forecasting BCa, offering a less invasive alternative. The distinctive arrangement of the lipid bilayer membrane found in exosomes is what makes them particularly effective for administering treatments aimed at managing cancer. In this review, we have tried to summarize different ncRNAs that are involved in BCa pathogenesis. Moreover, we highlighted the role of exosomal ncRNAs in BCa.

Has_circ_0002360 promotes the progression of lung adenocarcinoma by activating miR-762 and regulating PODXL expression

Background

Circular RNAs (circRNAs) have been found to be linked to cancer progression and metastasis, but there is not much known about their connection to lung adenocarcinoma (LAC). In the previous study reported by our group, has_circ_0002360 was highly expressed in LAC tissues. The goal of this study was to investigate the potential impact of has_circ_0002360 in LAC.

Methods

Bioinformatics software, TargetScan, and miRanda were used to study the interactions of RNAs. Luciferase reporter assays further confirmed their relationship. The relative expression of has_circ_0002360 in 122 patients and four cell lines of the lung were obtained using real-time qualitative polymerase chain reaction (qRT-PCR). The target gene podocalyxin-like (PODXL) expression was confirmed by immunohistochemistry (IHC) in ten pairs of clinical samples. Then, cell counting kit-8 (CCK8), wound healing, and transwell experiments were applied to examine cell growth, migration, and infection-induced cell invasion. LAC cell lines were infected, and the process was monitored by examination of the related epithelial-mesenchymal transition (EMT) proteins.

Results

The resulting data indicated that has_circ_0002360 and PODXL were overexpressed in LAC tissues, whereas miR-762 expression was repressed. The reduction of has_circ_0002360 or upregulation of miR-762 mitigated the proliferation, migration, invasion of LAC cells. Mechanistically, has_circ_0002360 upregulated PODXL expressions by targeting miR-762 to promote LAC progression.

Conclusions

In general, the has_circ_0002360/miR-762/PODXL axis affected the progress of LAC. The results of our study identified has_circ_0002360 as a novel oncogenic RNA in LAC.

CircRNA as an Achilles heel of cancer: characterization, biomarker and therapeutic modalities

Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs characterized by their lack of 5' caps and 3' poly(A) tails. These molecules have garnered substantial attention from the scientific community. A wide range of circRNA types has been found to be expressed in various tissues of the human body, exhibiting unique characteristics such as high abundance, remarkable stability, and tissue-specific expression patterns. These attributes, along with their detectability in liquid biopsy samples such as plasma, position circRNAs an ideal choice as cancer diagnostic and prognostic biomarkers. Additionally, several studies have reported that the functions of circRNAs are associated with tumor proliferation, metastasis, and drug resistance. They achieve this through various mechanisms, including modulation of parental gene expression, regulation of gene transcription, acting as microRNA (miRNA) sponges, and encoding functional proteins. In recent years, a large number of studies have focused on synthesizing circRNAs in vitro and delivering them to tumor tissue to exert its effects in inhibit tumor progression. Herein, we briefly discuss the biogenesis, characteristics, functions, and detection of circRNAs, emphasizing their clinical potential as biomarkers for cancer diagnosis and prognosis. We also provide an overview the recent techniques for synthesizing circRNAs and delivery strategies, and outline the application of engineered circRNAs in clinical cancer therapy.

A comprehensive review of the PTEN/PI3K/Akt axis in multiple myeloma: From molecular interactions to potential therapeutic targets

Phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) signaling pathways contribute to the development of several cancers, including multiple myeloma (MM). PTEN is a tumor suppressor that influences the PI3K/Akt/mTOR pathway, which in turn impacts vital cellular processes like growth, survival, and treatment resistance. The current study aims to present the role of PTEN and PI3K/Akt/mTOR signaling in the development of MM and its response to treatment. In addition, the molecular interactions in MM that underpin the PI3K/Akt/mTOR pathway and address potential implications for the development of successful treatment plans are also discussed in detail. We investigate their relationship to both upstream and downstream regulators, highlighting new developments in combined therapies that target the PTEN/PI3K/Akt axis to overcome drug resistance, including the use of PI3K and mitogen-activated protein kinase (MAPK) inhibitors. We also emphasize that PTEN/PI3K/Akt pathway elements may be used in MM diagnosis, prognosis, and therapeutic targets.

Advances in CircRNAs in the Past Decade: Review of CircRNAs Biogenesis, Regulatory Mechanisms, and Functions in Plants

Circular RNA (circRNA) is a type of non-coding RNA with multiple biological functions. Whole circRNA genomes in plants have been identified, and circRNAs have been demonstrated to be widely present and highly expressed in various plant tissues and organs. CircRNAs are highly stable and conserved in plants, and exhibit tissue specificity and developmental stage specificity. CircRNAs often interact with other biomolecules, such as miRNAs and proteins, thereby regulating gene expression, interfering with gene function, and affecting plant growth and development or response to environmental stress. CircRNAs are less studied in plants than in animals, and their regulatory mechanisms of biogenesis and molecular functions are not fully understood. A variety of circRNAs in plants are involved in regulating growth and development and responding to environmental stress. This review focuses on the biogenesis and regulatory mechanisms of circRNAs, as well as their biological functions during growth, development, and stress responses in plants, including a discussion of plant circRNA research prospects. Understanding the generation and regulatory mechanisms of circRNAs is a challenging but important topic in the field of circRNAs in plants, as it can provide insights into plant life activities and their response mechanisms to biotic or abiotic stresses as well as new strategies for plant molecular breeding and pest control.

Non-coding RNAs as therapeutic targets in cancer and its clinical application

Cancer genomics has led to the discovery of numerous oncogenes and tumor suppressor genes that play critical roles in cancer development and progression. Oncogenes promote cell growth and proliferation, whereas tumor suppressor genes inhibit cell growth and division. The dysregulation of these genes can lead to the development of cancer. Recent studies have focused on non-coding RNAs (ncRNAs), including circular RNA (circRNA), long non-coding RNA (lncRNA), and microRNA (miRNA), as therapeutic targets for cancer. In this article, we discuss the oncogenes and tumor suppressor genes of ncRNAs associated with different types of cancer and their potential as therapeutic targets. Here, we highlight the mechanisms of action of these genes and their clinical applications in cancer treatment. Understanding the molecular mechanisms underlying cancer development and identifying specific therapeutic targets are essential steps towards the development of effective cancer treatments.

CircUGGT2 downregulation by METTL14-dependent m6A modification suppresses gastric cancer progression and cisplatin resistance through interaction with miR-186-3p/MAP3K9 axis

Chemoresistance is a major therapeutic challenge in advanced gastric cancer (GC). N6-methyladenosine (m6A) RNA modification has been shown to play fundamental roles in cancer progression. However, the underlying mechanisms by which m6A modification of circRNAs contributes to GC and chemoresistance remain unknown. We found that hsa_circ_0030632 (circUGGT2) was a predominant m6A target of METTL14, and METTL14 knockdown (KD) reduced circUGGT2 m6A levels but increased its mRNA levels. The expression of circUGGT2 was markedly increased in cisplatin (DDP)-resistant GC cells. CircUGGT2 KD impaired cell growth, metastasis and DDP-resistance in vitro and in vivo, but circUGGT2 overexpression prompted these effects. Furthermore, circUGGT2 was validated to sponge miR-186-3p and upregulate MAP3K9 and could abolish METTL14-caused miR-186-3p upregulation and MAP3K9 downregulation in GC cells. circUGGT2 negatively correlated with miR-186-3p expression and harbored a poor prognosis in patients with GC. Our findings unveil that METTL14-dependent m6A modification of circUGGT2 inhibits GC progression and DDP resistance by regulating miR-186-3p/MAP3K9 axis.

Advances on Senescence-associated secretory phenotype regulated by circular RNAs in tumors

The components that comprise the senescence-associated secretory phenotype (SASP) include growth factors, proteases, chemokines, cytokines, and bioactive lipids. It drives secondary aging and disrupts tissue homeostasis, ultimately leading to tissue repair and regeneration loss. It has a two-way regulatory effect on tumor cells, resisting cancer occurrence and promoting its progression. A category of single-stranded circular non-coding RNA molecules known as circular RNAs (circRNAs) carries out a series of cellular activities, including sequestering miRNAs and modulating gene editing and expression. Research has demonstrated that a large number of circRNAs exhibit aberrant expression in pathological settings, and play a part in the onset and progress of cancer via modulating SASP factors. However, the research related to SASP and circRNAs in tumors is still in its infancy at this stage. This review centers on the bidirectional modulation of SASP and the role of circRNAs in regulating SASP factors across different types of tumors. The aim is to present novel perspectives for the diagnosis and therapeutic management of malignancies.

Circular RNAs in Cell Cycle Regulation of Cancers

Cancer has been one of the most problematic health issues globally. Typically, all cancers share a common characteristic or cancer hallmark, such as sustaining cell proliferation, evading growth suppressors, and enabling replicative immortality. Indeed, cell cycle regulation in cancer is often found to be dysregulated, leading to an increase in aggressiveness. These dysregulations are partly due to the aberrant cellular signaling pathway. In recent years, circular RNAs (circRNAs) have been widely studied and classified as one of the regulators in various cancers. Numerous studies have reported that circRNAs antagonize or promote cancer progression through the modulation of cell cycle regulators or their associated signaling pathways, directly or indirectly. Mostly, circRNAs are known to act as microRNA (miRNA) sponges. However, they also hold additional mechanisms for regulating cellular activity, including protein binding, RNA-binding protein (RBP) recruitment, and protein translation. This review will discuss the current knowledge of how circRNAs regulate cell cycle-related proteins through the abovementioned mechanisms in different cancers.

N6-Methyladenosine reader HNRNPC-mediated downregulation of circITCH prevents miR-224-3p sequestering and contributes to tumorigenesis in nasopharyngeal carcinoma

BACKGROUND

N6-Methyladenosine (m6A) RNA methylation modulators are implicated in nasopharyngeal carcinoma (NPC). Circular RNAs (circRNAs) stimulate/inhibit the development of NPC by sponging microRNAs (miRNAs). Herein, m6A modifications affecting the circRNA/miRNA axis in NPC were explored.

METHODS

Twenty prognostic m6A RNA methylation regulators were identified from 504 head/neck squamous cell carcinoma and 44 normal samples from The Cancer Genome Atlas (TCGA). Differentially expressed miRNAs were screened from the TCGA and Gene Expression Omnibus (GEO) databases. RNA-binding protein (RBP)-circRNA and circRNA-miRNA interactive pairs were verified using RBPmap and RNAhybrid, respectively. The RBP/circRNA/miRNA network was constructed using Cytoscape. Furthermore, CircITCH (hsa_circ_00059948), HNRNPC, and miR-224-3p expressions were detected by western blotting and quantitative polymerase chain reaction. The role of circITCH in NPC was examined using apoptosis, scratch wound healing, transwell invasion, and cell counting kit-8 assays. Finally, CircITCH-miR-224-3p and circITCH-HNRNPC interactions were assessed by dual-luciferase reporter and RNA-immunoprecipitation (RIP) assays, respectively.

RESULTS

Bioinformatics analysis revealed that high pathological grade, late-stage tumors, and low survival were associated with increased HNRNPC expression. MiR-224-3p was upregulated in NPC and sequestered by circITCH. Construction of the RBP/circRNA/miRNA network highlighted the HNRNPC/circITCH/miR-224-3p axis. In vitro experiments demonstrated decreased circITCH expression and increased HNRNPC and miR-224-3p expressions in NPC. In NPC cells overexpressing circITCH, HNRNPC and miR-224-3p expressions were significantly decreased. Dual-luciferase assays demonstrated a targeting relationship between circITCH and miR-224-3p, and RIP assays demonstrated interaction of HNRNPC targets with circITCH.

CONCLUSION

CircITCH overexpression inhibited NPC progression by sequestering miR-224-3p, and HNRNPC reduced circITCH expression through direct interaction.

Whole transcriptome sequencing identifies a competitive endogenous RNA network that regulates the immunity of bladder cancer

Several types of non-coding RNAs such as circRNAs, lncRNAs, and miRNAs have been identified to regulate mRNAs through the mechanism known as the competitive endogenous RNA (ceRNA) network. To explore the role of the ceRNA regulatory network in the immune microenvironment of bladder cancer, whole-transcriptome sequencing of bladder tumor and its peritumoral tissues from 38 bladder cancer patients, with a total of 63 samples, was performed to screen differentially expressed circ-, lnc-, mi-, and mRNAs to construct a circ/lnc-mi-mRNA regulatory network with pruning algorithms. We excavated a key immune-related gene BDNF to build the final ceRNA network as hsa-miR-107 sponged by hsa-circ-000211, AC108488.1, and LINC00163. Finally, a meta-analysis of 7 public datasets demonstrated that low expression of BDNF and high expression of hsa-miR-107 were associated with longer survival. Our study identified a ceRNA regulatory network as a potentially new prognostic marker and molecular therapeutic target of bladder cancer.

Autophagy flux in bladder cancer: Cell death crosstalk, drug and nanotherapeutics

Autophagy, a self-digestion mechanism, has emerged as a promising target in the realm of cancer therapy, particularly in bladder cancer (BCa), a urological malignancy characterized by dysregulated biological processes contributing to its progression. This highly conserved catabolic mechanism exhibits aberrant activation in pathological events, prominently featured in human cancers. The nuanced role of autophagy in cancer has been unveiled as a double-edged sword, capable of functioning as both a pro-survival and pro-death mechanism in a context-dependent manner. In BCa, dysregulation of autophagy intertwines with cell death mechanisms, wherein pro-survival autophagy impedes apoptosis and ferroptosis, while pro-death autophagy diminishes tumor cell survival. The impact of autophagy on BCa progression is multifaceted, influencing metastasis rates and engaging with the epithelial-mesenchymal transition (EMT) mechanism. Pharmacological modulation of autophagy emerges as a viable strategy to impede BCa progression and augment cell death. Notably, the introduction of nanoparticles for targeted autophagy regulation holds promise as an innovative approach in BCa suppression. This review underscores the intricate interplay of autophagy with cell death pathways and its therapeutic implications in the nuanced landscape of bladder cancer.

Potential molecular biomarkers for the diagnosis and prognosis of bladder cancer

Bladder cancer (BC) is a common malignant tumor of urinary system, which can be divided into muscle-invasive BC (MIBC) and nonmuscle-invasive BC (NMIBC). The number of BC patients has been gradually increasing currently. At present, bladder tumours are diagnosed and followed-up using a combination of cystoscopic examination, cytology and histology. However, the detection of early grade tumors, which is much easier to treat effectively than advanced stage disease, is still insufficient. It frequently recurs and can progress when not expeditiously diagnosed and monitored following initial therapy for NMIBC. Treatment strategies are totally different for different stage diseases. Therefore, it is of great practical significance to study new biomarkers for diagnosis and prognosis. In this review, we summarize the current state of biomarker development in BC diagnosis and prognosis prediction. We retrospectively analyse eight diagnostic biomarkers and eight prognostic biomarkers, in which CK, P53, PPARγ, PTEN and ncRNA are emphasized for discussion. Eight molecular subtype systems are also identified. Clinical translation of biomarkers for diagnosis, prognosis, monitoring and treatment will hopefully improve outcomes for patients. These potential biomarkers provide an opportunity to diagnose tumors earlier and with greater accuracy, and help identify those patients most at risk of disease recurrence.

hsa_circ_0000092 promotes hepatocellular carcinoma progression through up-regulating HN1 expression by binding to microRNA-338-3p

Circular RNAs (circRNAs) have been identified in diverse cancers for their role in regulating multiple cellular processes by antagonizing microRNAs (miRNAs or miRs). However, the role of circRNA hsa_circ_0000092 in hepatocellular carcinoma (HCC) still remains enigmatic. Therefore, we aimed to investigate the specific mechanism of hsa_circ_0000092 in HCC. Differentially expressed circRNAs associated to HCC were initially analysed. The expression of hsa_circ_0000092, miR-338-3p and HN1 in HCC tissues and cell lines was examined. Next, the interaction among hsa_circ_0000092, miR-338-3p and HN1 was determined by dual-luciferase reporter, RNA pull-down and northern blot assays. Subsequently, a series of mimic, inhibitor or siRNA plasmids were delivered into HCC cells to validate the effects of hsa_circ_0000092, miR-338-3p and HN1 in controlling cell proliferation, migration, invasion and angiogenesis in vitro. Furthermore, the role of hsa_circ_0000092 in tumour growth of HCC in vivo was assessed with hsa_circ_0000092 depleted with siRNA. The hsa_circ_0000092/miR-338-3p/HN1 axis was predicted to participate in the development of HCC. hsa_circ_0000092 and HN1 were highly expressed while miR-338-3p was poorly expressed in HCC tissues and cell lines. hsa_circ_0000092 could competitively bind to miR-338-3p to up-regulate HN1 expression. Moreover, depleted hsa_circ_0000092 or elevated miR-338-3p was shown to suppress HCC cell proliferation, migration, invasion and angiogenesis in vitro via down-regulation of HN1. Furthermore, silencing hsa_circ_0000092 was demonstrated to suppress tumour growth in HCC in vivo. The results of this study suggested that hsa_circ_0000092 impaired miR-338-3p-mediated HN1 inhibition to aggravate the development of HCC, indicating that hsa_circ_0000092 is a potential candidate marker and therapeutic target for HCC.

CircRNA-regulated glucose metabolism in ovarian cancer: an emerging landscape for therapeutic intervention

Ovarian cancer (OC) has the highest mortality rate among female reproductive system tumours, with limited efficacy of traditional treatments and 5-year survival rates that rarely exceed 40%. Circular RNA (circRNA) is a stable endogenous circular RNA that typically regulates protein expression by binding to downstream miRNA. It has been demonstrated that circRNAs play an important role in the proliferation, migration, and glucose metabolism (such as the Warburg effect) of OC and can regulate the expression of glucose metabolism-related proteins such as GLUT1 and HK2, promoting anaerobic glycolysis of cancer cells, increasing glucose uptake and ATP production, and affecting energy supply and biosynthetic substances to support tumour growth and invasion. This review summarises the formation and characteristics of circRNAs and focuses on their role in regulating glucose metabolism in OC cells and their potential therapeutic value, providing insights for identifying new therapeutic targets.

Knockdown of ZNF280A inhibits cell proliferation and promotes cell apoptosis of bladder cancer

OBJECTIVE

ZNF280A is a member of the zinc finger protein family, whose role in human cancers is little known and rarely reported. This study aimed to investigate the role of ZNF280A in bladder cancer.

METHODS

Immunohistochemical analysis was performed to detect the expression of ZNF280A in clinical samples. ZNF280A knockdown cell models were constructed by transfection of shRNA-expressing lentivirus. MTT assay and flow cytometry were performed for detecting cell proliferation, apoptosis and cycle. Wound healing and Transwell assays were operated to detect cell migration. Western blotting and Human Apoptosis Antibody Microarray were used to measure expression of related proteins. A mouse xenograft model was constructed for in vivo study.

RESULTS

Our study demonstrated that ZNF280A was up-regulated in bladder cancer tissues compared with normal tissues, whose high expression was significantly correlated with advanced malignant grade. Knockdown of ZNF280A inhibited cell proliferation and cell migration, promoted cell apoptosis and G1/G2 phase arrest. The tumor growth in vivo was also proved to be inhibited by ZNF280A. Moreover, ZNF280A may promote bladder cancer through regulation of MAPK9, Cyclin D1 and the Akt pathway.

CONCLUSIONS

In this study, ZNF280A was shown as a potential tumor promoter and prognosis indicator for bladder cancer. Targeting ZNF280A may be a promising strategy for the development of novel bladder cancer treatment.

Circular RNA cVIM promotes hepatic stellate cell activation in liver fibrosis via miR-122-5p/miR-9-5p-mediated TGF-β signaling cascade

Hepatic stellate cell (HSC) activation is considered as a central driver of liver fibrosis and effective suppression of HSC activation contributes to the treatment of liver fibrosis. Circular RNAs (circRNAs) have been reported to be important in tumor progression. However, the contributions of circRNAs in liver fibrosis remain largely unclear. The liver fibrosis-specific circRNA was explored by a circRNA microarray and cVIM (a circRNA derived from exons 4 to 8 of the vimentin gene mmu_circ_32994) was selected as the research object. Further studies revealed that cVIM, mainly expressed in the cytoplasm, may act as a sponge for miR-122-5p and miR-9-5p to enhance expression of type I TGF-β receptor (TGFBR1) and TGFBR2 and promotes activation of the TGF-β/Smad pathway, thereby accelerating the progression of liver fibrosis. Our results demonstrate a vital role for cVIM in promoting liver fibrosis progression and provide a fresh perspective on circRNAs in liver fibrosis.

EIF4A3-mediated biogenesis of circSTX6 promotes bladder cancer metastasis and cisplatin resistance

BACKGROUND

Cisplatin (CDDP)-based chemotherapy is a standard first-line treatment for metastatic bladder cancer (BCa) patients, and chemoresistance remains a major challenge in clinical practice. Circular RNAs (circRNAs) have emerged as essential regulators in carcinogenesis and cancer progression. However, the role of circRNAs in mediating CDDP chemosensitivity has yet to be well elucidated in BCa.

METHODS

CircSTX6 (hsa_circ_0007905) was identified by mining the public circRNA datasets and verified by Sanger sequencing, agarose gel electrophoresis, RNase R treatment and qRT-PCR assays. Then, function experiments were performed to evaluate the effects of circSTX6 on BCa metastasis. Luciferase reporter assay, RNA pull-down, RNA immunoprecipitation (RIP), RNA stability assay, Fluorescence in situ hybridization (FISH) and Immunofluorescence (IF) were conducted to evaluate the interaction among circSTX6, miR-515-3p, PABPC1 and SUZ12. Animal experiments were performed to explore the function of circSTX6 in tumor metastasis and CDDP sensitivity.

RESULTS

We identified that circSTX6 was significantly upregulated in clinical samples and cells of BCa. Functionally, circSTX6 promoted cell migration and invasion both in vitro and in vivo. Mechanistically, circSTX6 could act as a miR-515-3p sponge and abolish its effect on SUZ12. Moreover, circSTX6 was confirmed to increase the stability of SUZ12 mRNA by interacting with a mRNA stabilizer PABPC1 and subsequently promote the expression of SUZ12. Importantly, silencing of circSTX6 improved the chemosensitivity of CDDP-resistant bladder cancer cells to CDDP. Furthermore, in vivo analysis supported that knockdown of circSTX6 attenuated CDDP resistance in BCa tumors.

CONCLUSION

These studies demonstrate that circSTX6 plays a pivotal role in BCa metastasis and chemoresistance, and has potential to serve as a therapeutic target for treatment of BCa.

The ceRNA Mechanism of lncRNA MEG3/miR-21-5p/SPRY2 in Cell Proliferation and Apoptosis in Bladder Cancer

Bladder cancer (BC) is the second most common genitourinary malignancy. Long noncoding RNA (lncRNA) is implicated in BC progression. This study delved into the underlying mechanism of lncRNA MEG3 in BC. Bioinformatics analysis predicted the expression of lncRNA MEG3, its association with the survival of BC patients, its subcellular localization, and its binding sites with miR-21-5p. Differentially expressed genes (DEGs) in the GSE13507 chip were analyzed using GEOexplorer, downstream targets of miR-21-5p were predicted from databases, and the overlapping genes were analyzed by the website Venny2.1 (https://bioinfogp.cnb.csic.es/tools/venny/index.html); their impacts on patient survival were analyzed by the Starbase database. The expression of SPRY2 and TGFBI associated with patient survival was analyzed in TCGA. RT-qPCR and western blot were performed to detect levels of MEG3, miR-21-5p, and SPRY2 in BC/SV-HUC-1 cells. Malignant biological behaviors of BC cells were detected using CCK8, flow cytometry, and Transwell assays. RNA pull-down and dual-luciferase assays were employed to verify the binding relationship of miR-21-5p with MEG3 and SPRY2. MEG3 was found to be lowly expressed in BC cells and mainly distributed in the cytoplasm. Over-expression of MEG3 was found to inhibit BC cell activity, promote apoptosis, and reduce invasion and migration. miR-21-5p was found to be highly expressed in BC cells, and its down-regulation was found to inhibit the malignant behavior of BC cells. Over-expression of miR-21-5p was found to reverse the effect of pcDNA3.1-MEG3 on BC cells. MEG3 was found to competitively bind to miR-21-5p as a ceRNA to promote SPRY2 levels. LncRNA MEG3 promotes SPRY2 expression by competitively binding to miR-21-5p, thereby inhibiting proliferation and promoting apoptosis of BC cells.

Targeting epigenetic deregulations for the management of esophageal carcinoma: recent advances and emerging approaches

Ranking from seventh in incidence to sixth in mortality, esophageal carcinoma is considered a severe malignancy of food pipe. Later-stage diagnosis, drug resistance, and a high mortality rate contribute to its lethality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two main histological subtypes of esophageal carcinoma, with squamous cell carcinoma alone accounting for more than eighty percent of its cases. While genetic anomalies are well known in esophageal cancer, accountability of epigenetic deregulations is also being explored for the recent two decades. DNA methylation, histone modifications, and functional non-coding RNAs are the crucial epigenetic players involved in the modulation of different malignancies, including esophageal carcinoma. Targeting these epigenetic aberrations will provide new insights into the development of biomarker tools for risk stratification, early diagnosis, and effective therapeutic intervention. This review discusses different epigenetic alterations, emphasizing the most significant developments in esophageal cancer epigenetics and their potential implication for the detection, prognosis, and treatment of esophageal carcinoma. Further, the preclinical and clinical status of various epigenetic drugs has also been reviewed.

The emerging role of circRNAs on skeletal muscle development in economical animals

CircRNAs are a novel type of closed circular molecules formed through a covalent bond lacking a 5'cap and 3' end tail, which mainly arise from mRNA precursor. They are widely distributed in plants and animals and are characterized by stable structure, high conservativeness in cells or tissues, and showed the expression specificity at different stages of development in different tissues. CircRNAs have been gradually attracted wide attention with the development of RNA sequencing, which become a new research hotspot in the field of RNA. CircRNAs play an important role in gene expression regulation. Presently, the related circRNAs research in the regulation of animal muscle development is still at the initial stage. In this review, the formation, properties, biological functions of circRNAs were summarized. The recent research progresses of circRNAs in skeletal muscle growth and development from economic animals including livestock, poultry and fishes were introduced. Finally, we proposed a prospective for further studies of circRNAs in muscle development, and we hope our research could provide new ideas, some theoretical supports and helps for new molecular genetic markers exploitation and animal genetic breeding in future.

Decrypting the circular RNAs does a favor for us: Understanding, diagnosing and treating diabetes mellitus and its complications

Circular RNAs (circRNAs), a novel type of single-stranded noncoding RNAs with a covalently closed loop structure, are generated in a circular conformation via non-canonical splicing or back-splicing events. Functionally, circRNAs have been elucidated to soak up microRNAs (miRNAs) and RNA binding proteins (RBPs), serve as protein scaffolds, maintain mRNA stability, and regulate gene transcription and translation. Notably, circRNAs are strongly implicated in the regulation of β-cell functions, insulin resistance, adipocyte functions, inflammation as well as oxidative stress via acting as miRNA sponges and RBP sponges. Basic and clinical studies have demonstrated that aberrant alterations of circRNAs expressions are strongly associated with the initiation and progression of diabetes mellitus (DM) and its complications. Here in this review, we present a summary of the biogenesis, transportation, degradation and functions of circRNAs, and highlight the recent findings on circRNAs and their action mechanisms in DM and its complications. Overall, this review should contribute greatly to our understanding of circRNAs in DM pathogenesis, offering insights into the further perspectives of circRNAs for DM diagnosis and therapy.

CircRNA itchy E3 ubiquitin protein ligase improves mitochondrial dysfunction in sepsis-induced acute kidney injury by targeting microRNA-214-3p/ATP-binding cassette A1 axis

BACKGROUND

Circular RNAs (circRNAs) are promising biomarkers and therapeutic targets for acute kidney injury (AKI). In this study, we investigated the mechanism by which circRNA itchy E3 ubiquitin protein ligase (circ-ITCH) regulates sepsis-induced AKI.

METHODS

A sepsis-induced AKI mouse model was created using LPS induction and circ-ITCH overexpression. Circ-ITCH levels were confirmed via RT-qPCR. Kidney tissue changes were examined through various stains and TUNEL. Enzyme-linked immunosorbent assay (ELISA) gauged oxidative stress and inflammation. Mitochondrial features were studied with electron microscopy. RT-qPCR and western blotting assessed mitochondrial function parameters. Using starBase, binding sites between circ-ITCH and miR-214-3p, as well as miR-214-3p and ABCA1, were predicted. Regulatory connections were proven by dual-luciferase assay, RT-qPCR, and western blotting.

RESULTS

Circ-ITCH expression was downregulated in LPS-induced sepsis mice. Overexpression of circ-ITCH ameliorates indicators of renal function (serum creatinine [SCr], blood urea nitrogen [BUN], neutrophil gelatinase-associated lipocalin [NGAL], and kidney injury molecule-1 [Kim-1]), reduces renal cell apoptosis, mitigates oxidative stress markers (reactive oxygen species [ROS] and malondialdehyde [MDA]), and diminishes inflammatory markers (interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF-α]). Moreover, circ-ITCH overexpression alleviated mitochondrial damage and dysfunction. Furthermore, circ-ITCH acts as a sponge for miR-214-3p, thereby upregulating ABCA1 expression. In addition, the miR-214-3p inhibitor repressed oxidative stress, inflammation, and mitochondrial dysfunction, which was reversed by circ-ITCH knockdown. Further cellular analysis in HK-2 cells supported these findings, highlighting the protective role of circ-ITCH against sepsis-induced AKI, particularly through the miR-214-3p/ABCA1 axis.

CONCLUSION

The novel circ-ITCH/miR-214-3p/ABCA1 pathway plays an essential role in the regulation of oxidative stress and mitochondrial dysfunction in sepsis-induced AKI.

Cancer quiescence: non-coding RNAs in the spotlight

Cancer quiescence reflects the ability of cancer cells to enter a reversible slow-cycling or mitotically dormant state and represents a powerful self-protecting mechanism preventing cancer cell 'damage' from hypoxic conditions, nutrient deprivation, immune surveillance, and (chemo)therapy. When stress conditions are restrained, and tumor microenvironment becomes beneficial, quiescent cancer cells re-enter cell cycle to facilitate tumor spread and cancer progression/metastasis. Recent studies have highlighted the dynamic role of regulatory non-coding RNAs (ncRNAs) in orchestrating cancer quiescence. The elucidation of regulatory ncRNA networks will shed light on the quiescence-proliferation equilibrium and, ultimately, pave the way for new treatment options. Herein, we have summarized the ever-growing role of ncRNAs upon cancer quiescence regulation and their impact on treatment resistance and modern cancer therapeutics.

An efficient circRNA-miRNA interaction prediction model by combining biological text mining and wavelet diffusion-based sparse network structure embedding

MOTIVATION

Accumulating clinical evidence shows that circular RNA (circRNA) plays an important regulatory role in the occurrence and development of human diseases, which is expected to provide a new perspective for the diagnosis and treatment of related diseases. Using computational methods can provide high probability preselection for wet experiments to save resources. However, due to the lack of neighborhood structure in sparse biological networks, the model based on network embedding and graph embedding is difficult to achieve ideal results.

RESULTS

In this paper, we propose BioDGW-CMI, which combines biological text mining and wavelet diffusion-based sparse network structure embedding to predict circRNA-miRNA interaction (CMI). In detail, BioDGW-CMI first uses the Bidirectional Encoder Representations from Transformers (BERT) for biological text mining to mine hidden features in RNA sequences, then constructs a CMI network, obtains the topological structure embedding of nodes in the network through heat wavelet diffusion patterns. Next, the Denoising autoencoder organically combines the structural features and Gaussian kernel similarity, finally, the feature is sent to lightGBM for training and prediction. BioDGW-CMI achieves the highest prediction performance in all three datasets in the field of CMI prediction. In the case study, all the 8 pairs of CMI based on circ-ITCH were successfully predicted.

AVAILABILITY

The data and source code can be found at https://github.com/1axin/BioDGW-CMI-model.