The circINTS4/miR-146b/CARMA3 axis promotes tumorigenesis in bladder cancer

Deciphering the impact of circRNA-mediated autophagy on tumor therapeutic resistance: a novel perspective

Cancer therapeutic resistance remains a significant challenge in the pursuit of effective treatment strategies. Circular RNAs (circRNAs), a class of non-coding RNAs, have recently emerged as key regulators of various biological processes, including cancer progression and drug resistance. This review highlights the emerging role of circRNAs-mediated autophagy in cancer therapeutic resistance, a cellular process that plays a dual role in cancer by promoting both cell survival and death. Increasing evidence suggests that circRNAs can modulate autophagy pathways, thereby influencing the response of cancer cells to therapeutic agents. In this context, the intricate interplay between circRNAs, autophagy, and therapeutic resistance is explored. Various mechanisms are discussed through which circRNAs can impact autophagy, including direct interactions with autophagy-related genes, modulation of signaling pathways, and cross-talk with other non-coding RNAs. Furthermore, the review delves into specific examples of how circRNA-mediated autophagy regulation can contribute to resistance against chemotherapy and radiotherapy. Understanding these intricate molecular interactions provides valuable insights into potential strategies for overcoming therapeutic resistance in cancer. Exploiting circRNAs as therapeutic targets or utilizing them as diagnostic and predictive biomarkers opens new avenues for developing personalized treatment approaches. In summary, this review underscores the importance of circRNA-mediated autophagy in cancer therapeutic resistance and proposes future directions for research in this exciting and rapidly evolving field.

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.

Mechanisms of immune checkpoint inhibitors: insights into the regulation of circular RNAS involved in cancer hallmarks

Current treatment strategies for cancer, especially advanced cancer, are limited and unsatisfactory. One of the most substantial advances in cancer therapy, in the last decades, was the discovery of a new layer of immunotherapy approach, immune checkpoint inhibitors (ICIs), which can specifically activate immune cells by targeting immune checkpoints. Immune checkpoints are a type of immunosuppressive molecules expressed on immune cells, which can regulate the degree of immune activation and avoid autoimmune responses. ICIs, such as anti-PD-1/PD-L1 drugs, has shown inspiring efficacy and broad applicability across various cancers. Unfortunately, not all cancer patients benefit remarkably from ICIs, and the overall response rates to ICIs remain relatively low for most cancer types. Moreover, the primary and acquired resistance to ICIs pose serious challenges to the clinical application of cancer immunotherapy. Thus, a deeper understanding of the molecular biological properties and regulatory mechanisms of immune checkpoints is urgently needed to improve clinical options for current therapies. Recently, circular RNAs (circRNAs) have attracted increasing attention, not only due to their involvement in various aspects of cancer hallmarks, but also for their impact on immune checkpoints in shaping the tumor immune microenvironment. In this review, we systematically summarize the current status of immune checkpoints in cancer and the existing regulatory roles of circRNAs on immune checkpoints. Meanwhile, we also aim to settle the issue in an evidence-oriented manner that circRNAs involved in cancer hallmarks regulate the effects and resistance of ICIs by targeting immune checkpoints.

MicroRNA-146b protects kidney injury during urinary tract infections by modulating macrophage polarization

Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) can lead to severe kidney injury. However, the molecular mechanisms underlying the pathological process of kidney injury are still incompletely understood. In the present study, we demonstrate that microRNA-146b (miR-146b) deficiency aggravates kidney injury during UTIs caused by UPEC. In a mouse kidney infection model utilizing urosepsis isolate CFT073, we found that miR-146b expression significantly increased in the early stages of UPEC infection. Also, miR-146b-deficient mice displayed exacerbated inflammation in the kidney injury with severe M1 macrophage infiltration. Additionally, the results showed that miR-146b targeted interferon regulatory factor 5-regulated M1 macrophage polarization during UTIs. The results suggested that miR-146b contributed significantly to the control of kidney damage during UTIs, highlighting that miR-146b might be used as a novel therapeutic target for treating kidney injury during UTIs. IMPORTANCE Kidney injury during acute urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) is an important public health problem. However, how kidney injury develops during UPEC infection is still unclear. Although antibiotic therapy is currently an effective treatment for UTI, it cannot avoid kidney injury. MicroRNAs have gained extensive attention as essential molecules capable of regulating the autoimmune response. Among these, microRNA-146b (miR-146b) is involved in regulating inflammatory responses. In the present study, we demonstrated that miR-146b played an essential role in the development of kidney injury during UTIs caused by UPEC. The results showed that miR-146b may suppress M1 macrophage polarization and alleviate acute kidney injury. Furthermore, the miR-146b activator, agomir, in order to upregulate miR-146b, was effective in treating kidney damage by inhibiting the activation of M1 macrophages. In conclusion, our findings elucidated the mechanisms by which miR-146b alleviated kidney injury induced by UTIs, shed new light on the relationship between microRNA and bacterial infection, and provided a novel therapeutic target for treating this common bacterial infection.

Roles of non-coding RNAs in the metabolism and pathogenesis of bladder cancer

Bladder cancer (BC) is featured as the second most common malignancy of the urinary tract worldwide with few treatments leading to high incidence and mortality. It stayed a virtually intractable disease, and efforts to identify innovative and effective therapies are urgently needed. At present, more and more evidence shows the importance of non-coding RNA (ncRNA) for disease-related study, diagnosis, and treatment of diverse types of malignancies. Recent evidence suggests that dysregulated functions of ncRNAs are closely associated with the pathogenesis of numerous cancers including BC. The detailed mechanisms underlying the dysregulated role of ncRNAs in cancer progression are still not fully understood. This review mainly summarizes recent findings on regulatory mechanisms of the ncRNAs, long non-coding RNAs, microRNAs, and circular RNAs, in cancer progression or suppression and focuses on the predictive values of ncRNAs-related signatures in BC clinical outcomes. A deeper understanding of the ncRNA interactive network could be compelling framework for developing biomarker-guided clinical trials.

Recent advances in the understanding of urothelial tumorigenesis

INTRODUCTION

Patients with non-muscle-invasive bladder tumor suffer from disease recurrence following transurethral surgery even with intravesical pharmacotherapy, while muscle-invasive disease is often deadly. It is therefore critical to elucidate the underlying molecular mechanisms responsible for not only bladder tumor progression but also its tumorigenesis. Indeed, various molecules and/or signaling pathways have been suggested to contribute to the pathogenesis of bladder cancer.

AREAS COVERED

We summarize the progress during the last few years on the initiation or development, but not progression, of urothelial cancer. The clinical implications of these available data, including prognostic significance and possible application for the prevention of the recurrence of non-muscle-invasive bladder tumors, are also discussed.

EXPERT OPINION

Bladder cancer is a heterogeneous group of neoplasms. The establishment of personalized therapeutic options based on the molecular profile in each case should thus be considered. On that account, further accumulation of data on urothelial tumorigenesis is warranted to identify promising targets for the prevention of postoperative tumor recurrence or tumor development in otherwise high-risk patients.

Circ_0002476 regulates cell growth, invasion, and mtDNA damage in non-small cell lung cancer by targeting miR-1182/TFAM axis

BACKGROUND

Many circular RNAs (circRNAs) have been identified as potential targets for cancer therapy. However, the role of circ_0002476 in non-small cell lung cancer (NSCLC) progression has not been explored.

METHODS

The expression levels of circ_0002476, microRNA (miR)-1182, and mitochondrial transcription factor A (TFAM) were detected by quantitative real-time polymerase chain reaction. Cell functions were measured by cell counting kit 8 assay, EdU assay, colony formation assay, flow cytometry and transwell assay. Mitochondrial DNA (mtDNA) damage was assessed by measuring mtDNA copy number and transcript levels of ND1 and ATP6. Protein expression was examined by western blot. The interaction between miR-1182 and circ_0002476 or TFAM was detected by dual-luciferase reporter assay and RNA pull-down assay. Animal experiments were performed to explore circ_0002476 role in vivo. Exosomes (Exs) were extracted and identified by transmission electron microscopy and nanoparticle tracking analysis.

RESULTS

Circ_0002476 was overexpressed in NSCLC tissues and cells. Circ_0002476 knockdown suppressed NSCLC cell proliferation and invasion, while promoted apoptosis and mtDNA damage. Circ_0002476 could sponge miR-1182, and miR-1182 inhibitor reversed the influence induced by circ_0002476 knockdown. Moreover, TFAM was targeted by miR-1182, and miR-1182 hindered NSCLC cell progression by regulating TFAM. Additionally, circ_0002476 silencing could reduce NSCLC tumor growth by miR-1182/TFAM. Further analyzed showed that Exs were involved in the transport of circ_0002476 between cells.

CONCLUSION

Taken together, our findings suggested that circ_0002476 might be a potential molecular target for NSCLC treatment.

The Role of Circular RNAs in the Carcinogenesis of Bladder Cancer

Circular RNAs (circRNAs) are a group of transcripts with enclosed configurations which can regulate gene expression. These transcripts have important roles in normal development and in the pathogenesis of disorders. Recent evidence has supported involvement of circRNAs in the development of bladder cancer. Several circRNAs such as circ_0058063, hsa-circRNA-403658, circPDSS1, circCASC15, circRNA-MYLK, and circRNA_103809 have been upregulated in bladder cancer samples. On the other hand, hsa_circ_0137606, BCRC-3, circFUT8, hsa_circ_001598, circSLC8A1, hsa_circ_0077837, hsa_circ_0004826, and circACVR2A are among downregulated circRNAs in bladder cancer. Numerous circRNAs have diagnostic or prognostic value in bladder cancer. In this review, we aim to outline the latest findings about the role of circRNAs in bladder cancer and introduce circRNAs for further investigations as therapeutic targets.

CircEAF2 counteracts Epstein-Barr virus-positive diffuse large B-cell lymphoma progression via miR-BART19-3p/APC/β-catenin axis

Background

Epstein-Barr virus (EBV) represents an important pathogenic factor of lymphoma and is significantly associated with poor clinical outcome of diffuse large B-cell lymphoma (DLBCL). Circular RNAs (circRNAs) play an essential role in lymphoma progression. However, the underlying mechanism of circRNA on DLBCL progression related to EBV remains largely unknown.

Methods

CircRNA was screened by high-throughput sequencing in tumor samples of 12 patients with DLBCL according to EBV infection status. Expression of circEAF2, as well as the relationship with clinical characteristics and prognosis, were further analyzed in tumor samples of 100 DLBCL patients using quantitative real-time PCR. Gain- and loss-of-function experiments were conducted to investigate the biological functions of circEAF2 both in vitro and in vivo. The underlying mechanism of circRNA on DLBCL progression were further determined by RNA sequencing, RNA pull down assay, dual-luciferase reporter assay, rescue experiments and western blotting.

Results

We identified a novel circRNA circEAF2, which was downregulated in EBV + DLBCL and negatively correlated with EBV infection and DLBCL progression. In EBV-positive B lymphoma cells, circEAF2 overexpression induced lymphoma cell apoptosis and sensitized lymphoma cells to epirubicin. As mechanism of action, circEAF2 specifically targeted EBV-encoded miR-BART19-3p, upregulated APC, and suppressed downstream β-catenin expression, resulting in inactivation of Wnt signaling pathway and inhibition of EBV + DLBCL cell proliferation. In EBV-positive B-lymphoma murine models, xenografted tumors with circEAF2 overexpression presented decreased Ki-67 positivity, increased cell apoptosis and retarded tumor growth.

Conclusions

CircEAF2 counteracted EBV + DLBCL progression via miR-BART19-3p/APC/β-catenin axis, referring circEAF2 as a potential prognostic biomarker. Therapeutic targeting EBV-encoded miRNA may be a promising strategy in treating EBV-associated lymphoid malignancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01458-9.

The Emerging Functions of Circular RNAs in Bladder Cancer

Simple Summary

The role of circular RNAs has made breakthroughs in understanding the mechanisms of tumor development. Bladder cancer has an increasing incidence, high recurrence rate, high metastatic potential, poor prognosis, and susceptibility to chemotherapy resistance. Thus, it is essential to identify molecules related to the tumorigenesis of bladder cancer. In this review, we summarize current knowledge about the expression of circular RNAs in bladder cancer and their implications in vesical carcinogenesis. We further discuss the limitations of existing studies and provide an outlook for future studies in the hopes of better revealing the association between circular RNAs and bladder cancer.

Abstract

Bladder cancer (BC) is among the top ten most common cancer types worldwide and is a serious threat to human health. Circular RNAs (circRNAs) are a new class of non-coding RNAs generated by covalently closed loops through back-splicing. As an emerging research hotspot, circRNAs have attracted considerable attention due to their high conservation, stability, abundance, and specificity of tissue development. Accumulating evidence has revealed different form of circRNAs are closely related to the malignant phenotype, prognosis and chemotherapy resistance of BC, suggesting that different circRNAs may be promising biomarkers and have therapeutic significance in BC. The intention of this review is to summarize the mechanisms of circRNA-mediated BC progression and their diagnostic and prognostic value as biomarkers, as well as to further explore their roles in chemotherapy resistance.

The Roles of CircRNAs in Bladder Cancer: Biomarkers, Tumorigenesis Drivers, and Therapeutic Targets

Bladder cancer (BCa) is the most prevalent malignancy of the urinary system. Circular RNAs (circRNAs), a novel subtype of non-coding RNAs, play a crucial role in physiological and developmental processes. CircRNAs mainly function as regulators of splicing process and transcription, microRNA sponges, and protein brackets. Recent advances in understanding the pathogenesis of BCa have led to the identification of an abundance of dysregulated circRNAs associated with BCa. These aberrantly expressed circRNAs eventually lead to abnormalities in biological, genetic, and epigenetic information. In this review, we introduce the potential of circRNAs as biomarkers for BCa diagnosis and prognosis. Notably, diverse mechanisms have been proposed for circRNAs driving carcinogenesis, including increasing cell proliferation, promoting invasive and migratory capacity, enhancing endothelial–mesenchymal transition, sustaining stemness, and enabling resistance to chemotherapy. Importantly, a full understanding of circRNA mechanisms is needed to mine promising therapeutic approaches for targeting BCa. In this paper, we present the latest advances in circRNAs and systemically summarize the characteristics and mechanisms of circRNAs in BCa, providing potential perspectives for BCa treatment.

Circular RNA circGLIS3 promotes bladder cancer proliferation via the miR-1273f/SKP1/Cyclin D1 axis

Extensive research confirmed that circRNA can play a regulatory role in various stages of tumors by interacting with various molecules. Identifying the differentially expressed circRNA in bladder cancer and exploring its regulatory mechanism on bladder cancer progression are urgent. In this study, we screened out a circRNA-circGLIS3 with a significant upregulation trend in both bladder cancer tissues and cells. Bioinformatics prediction results showed that circGLIS3 may be involved in multiple tumor-related pathways. Function gain and loss experiments verified circGLIS3 can affect the proliferation, migration, and invasion of bladder cancer cells in vitro. Moreover, silencing circGLIS3 inhibited bladder cancer cell growth in vivo. Subsequent research results indicated circGLIS3 regulated the expression of cyclin D1, a cell cycle–related protein, and cell cycle progression. Mechanically, circGLIS3 upregulates the expression of SKP1 by adsorbing miR-1273f and then promotes cyclin D1 expression, ultimately promoting the proliferation of bladder cancer cells. In summary, our study indicates that circGLIS3 plays an oncogene role in the development of bladder cancer and has potential to be a candidate for bladder cancer.

Upregulation of miR-146b promotes porcine ovarian granulosa cell apoptosis by attenuating CYP19A1

MicroRNAs (miRNAs) are 21- to 24-nucleotide long small noncoding RNAs, which play an important role in follicular atresia and granulosa cell (GC) apoptosis in the mammalian ovary. Here, we report that miR-146b, a conserved and ovary-enriched miRNA, modulates estradiol (E2) secretion, GC apoptosis, and follicular atresia in pigs. Genome-wide analysis and quantitative real-time PCR revealed that miR-146b was significantly upregulated during follicular atresia, and fluorescence-activated cell sorting showed that miR-146b functioned as a proapoptotic factor to induce GC apoptosis. MicroRNA-mRNA network analysis and luciferase reporter assays showed that CYP19A1, the pivotal enzyme for E2 synthesis signaling, was directly targeted by miR-146b. Furthermore, miR-146b interacted with the 3'untranslated region of CYP19A1 to prevent translation, thereby regulating CYP19A1-mediated E2 secretion and GC apoptosis. However, miR-146b was not regulated by the transcription factor SMAD4 or oxidative stress, both of which are critical regulators of CYP19A1. We, thus, conclude that miR-146b is a novel epigenetic factor regulating GC functions, follicular development, and female reproduction.

Knockdown of circular RNA circZNF652 remits LPS-induced inflammatory damage by regulating miR-181a

BACKGROUND

Infantile pneumonia (IP) is a usual disease in infants and young children. The function and underlying mechanism of circZNF652 on lipopolysaccharide (LPS)-triggered inflammatory damage in WI-38 cells were detected in this article.

METHODS

WI-38 cells were induced by dosages of LPS to construct inflammatory injury model. WI-38 cell viability and apoptosis were detected by CCK-8 assay and flow cytometry, respectively. CircZNF652 and miR-181a levels were changed and detected by cell transfection and qRT-PCR. The levels of apoptosis and JNK/p38 and NF-κB pathways-related proteins, as well as the level of Cox-2 were detected by western blot. Finally, the concentrations of inflammatory factors were detected by ELISA.

RESULTS

LPS induced inflammatory injury showing as notably decreased the viability, while increased the numbers of apoptotic cells, as well as the levels of apoptosis and inflammatory factors in a dose dependent way. Besides, LPS inducement remarkably enhanced the expression of circZNF652. However, knockdown of circZNF652 remitted LPS-triggered inflammatory damage and restrained NF-κB and JNK/p38 pathways. Moreover, circZNF652 knockdown promoted miR-181a expression. Whereas, miR-181a inhibition markedly relieved circZNF652 knockdown-induced impacts.

CONCLUSION

Knockdown of circZNF652 remitted LPS-triggered WI-38 cells inflammatory damage through deactivation of NF-κB and JNK/p38pathways by up-regulating miR-181a.

Circular RNAs and Bladder Cancer

Bladder cancer (BC) is the most common urinary system malignancy and is a serious threat to human health. Circular RNAs (circRNAs) are members of a newly defined class of noncoding RNAs (ncRNAs) that can regulate gene expression at the transcriptional or posttranscriptional level. Studies have shown that circRNAs are related to the clinicopathological characteristics, prognosis, and chemosensitivity of BC, and basic research has further confirmed that changes in the expression of circRNAs in BC are closely related to various tumor biological functions. CircRNAs promote tumor development by interacting with miRNAs to regulate transcription factors and both classical and nonclassical tumor signaling pathways. The nonclassical signaling pathways are related to cell cycle progression, epithelial–mesenchymal transition (EMT), extracellular matrix maintenance, and tumor stem cell maintenance. In this article, the relationships between circRNAs and the clinical characteristics of BC are reviewed, and the molecular mechanisms by which circRNAs promote tumor development are explored.

Expression Profiles of CircRNA and mRNA in Lacrimal Glands of AQP5-/- Mice With Primary Dry Eye

Purpose: This work aimed to identify differentially expressed circular RNAs (circRNAs) and elucidate their potential function in aquaporin 5 (AQP5) knockout (AQP5^–/–) mice with the primary dry eye phenotype.

Methods: A slit lamp examination was performed on AQP5^–/– mice to assess corneal epithelial defects using fluorescein sodium staining. Hematoxylin–eosin staining and transmission electron microscopy analysis were performed to identify structural changes in lacrimal gland epithelial cells due to AQP5 deficiency. The expression profiles of circRNA and messenger RNA (mRNA) were determined by a microarray analysis. The selected circRNA was verified by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to predict the biological functions and the potential pathways of parental genes involved in lacrimal gland epithelial cell changes. According to the bioinformatics analysis of identified circRNAs, we predicted a circRNA–miRNA–mRNA network of phagosomes.

Results: The AQP5^–/– mice spontaneously exhibit dry eye symptoms, wherein the AQP5 deficiency changes the structure of lacrimal gland epithelial cells. The analysis revealed that, compared to AQP5^+/+ mice, 30 circRNAs in the lacrimal glands of AQP5^–/– mice were differentially expressed (fold change ≥ 2.0, p < 0.05). Nine upregulated circRNAs were identified using qRT-PCR, and nine upregulated validated circRNAs, 40 altered microRNAs (miRNAs), and nine upregulated mRNAs were identified through a network analysis. The KEGG analysis showed that these nine target genes were expressed in phagosomes.

Conclusion: The AQP5^–/– mice have primary and stable dry eye phenotypes from birth. We identified differently expressed circRNAs in the lacrimal glands of AQP5^–/– and AQP5^+/+ mice, predicting a circRNA–miRNA–mRNA network of phagosomes. CircRNA likely plays an important role in lacrimal gland epithelial cell pathogenesis. Therefore, it is reasonable to use circRNA as a potential therapeutic agent for the treatment of dry eyes.

microRNA-146b promotes neuroblastoma cell growth through targeting NUMB

Accumulating evidence has demonstrated that the abnormal expression of microRNA (miRNA/miR) serves a crucial role in the development of numerous types of human cancer, including neuroblastoma (NB). The present study aimed to investigate the expression levels and biological roles of miR-146b in NB. miR-146b expression levels in NB cell lines and human umbilical vein endothelial cells (HUVECs) were analyzed using reverse transcription-quantitative PCR, and the regulatory effects of miR-146b on NB cell proliferation, invasion and apoptosis in vitro were investigated using CCK-8 assay, transwell invasion assay and flow cytometry. In addition, bioinformatics analysis, western blotting and dual-luciferase reporter assays were used to determine whether NUMB was a target gene of miR-146b. miR-146b expression levels were increased in NB cell lines compared with HUVECs. The knockdown of miR-146b using a miR-146b inhibitor significantly inhibited NB cell proliferation and invasion, but promoted cell apoptosis in vitro. Furthermore, it was revealed that miR-146b promoted NB cell proliferation through targeting NUMB. In conclusion, miR-146b was suggested to serve as an oncogene, at least in part, through directly targeting NUMB, which indicated that miR-146b may be a potential therapeutic target for NB treatment.

Tumor-suppressor microRNA-139-5p restrains bladder cancer cell line ECV-304 properties via targeting Connexin 43

Background:

In our previous paper, we demonstrated that Connexin 43 (CX43) was highly expressed in bladder cancer (BC) tissues. But the molecular mechanism about microRNAs (miRNAs) regulation upstream of CX43 in BC has not been well elucidated and remains to be further studied. MicroRNA-139-5p (miR-139-5p) is a tumor suppressor in progression of multifarious cancers including BC. Nevertheless, the underlying mechanisms of CX43/miR-139-5p in tumorigenesis of BC are still not well illustrated. The specific objective of our study was to inquiry the effect of CX43/miR-139-5p on BC progression and its underlying mechanism.

Methods:

The bioinformatics analysis softwares were applied to predict the miRNAs in the upstream of CX43. First, the expression levels of miR-139-5p in BC tissues (tumor) and paracancer tissues (normal) were investigated using the data from The Cancer Genome Atlas database. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression level of miR-139-5p in three human BC cell lines 5637, T24, ECV-304 and a human bladder epithelial immortalized cell line SV-HUC-1 (normal control). Then si-CX43, si-control, miR-139-5p mimic, and its negative control (NC) were transfected into BC cell line ECV-304. The relationship of miR-139-5p and CX43 was analyzed by dual-luciferase reporter assay. The qRT-PCR and Western blotting were used to test the mRNA and protein expression level of CX43. The proliferation of ECV-304 and T24 cells were examined by cell counting kit-8. The migration and invasion of ECV-304 cells were tested by transwell assay. To determine whether miR-139-5p would affect cell proliferation, migration and invasion by targeting CX43, we executed the rescue assay. The comparison between two groups was analyzed by Student's t test, and comparisons among multiple samples were performed by one-way analysis of variance and a Bonferroni post hoc test.

Results:

The expression of miR-139-5p was remarkably down-regulated in BC tissues (tumor vs. normal, 2.286 ± 0.017 vs. 3.211 ± 0.034, t = 11.540, P < 0.0001) and cell lines (P < 0.01 in all BC cell lines). Besides, we also indicated that over-expression of miR-139-5p reduced the proliferation of ECV-304 (P = 0.001) and T24 cells (P = 0.005). Moreover, miR-139-5p over-expression weakened the invasion (P = 0.001) and migration (P = 0.001) of ECV-304 cells. Furthermore, the relative luciferase activity of CX43-wild type construct was distinctly lessened by up-regulation of miR-139-5p (miR-139-5p mimic NC vs. miR-139-5p mimic, 0.916 ± 0.063 vs. 0.356 ± 0.048, t = 7.085, P = 0.002), nevertheless the activity of CX43-mutant type construct was untouched (miR-139-5p mimic NC vs. miR-139-5p mimic, 0.918 ± 0.057 vs. 0.878 ± 0.039, t = 0.577, P = 0.595). Finally, the rescue assay revealed that CX43 deletion enhanced the depressor effect of miR-139-5p on ECV-304 cell proliferation (P < 0.01), invasion (P = 0.028), and migration (P = 0.014).

Conclusion:

MiR-139-5p, as a tumor-suppressor, repressed cell proliferation, invasion, and migration in BC, which might be achieved by regulating CX43.

Differential circular RNA expression profiling during osteogenic differentiation in human adipose-derived stem cells

Aim: Circular RNAs (circRNAs) are essential for stem cell differentiation. This study aimed to investigate their exact mechanism of action in human adipose-derived stem cell (hADSC) osteogenesis. Materials & methods: Isolated hADSCs were cultured in growth medium or osteogenic medium, then total RNA was extracted for circRNA microarray, hierarchical cluster, gene ontology, regulating pathway and circRNA–miRNA–mRNA network analyses. Results: A total of 171 circRNAs were upregulated and 119 were downregulated in induced groups compared with those in noninduced groups. Eight circRNAs, 40 miRNAs and 342 mRNAs were selected to construct a competing circRNA-miRNA-mRNA network. Conclusion: These findings may provide novel insight into altered and specific circRNAs that might function as competing endogenous RNAs in hADSCs during osteogenic differentiation.

CARD10 promotes the progression of renal cell carcinoma by regulating the NF‑κB signaling pathway

Previous studies have demonstrated that the expression of CARD10 is closely associated with the occurrence of tumors, and its role is mainly to promote tumor progression by activating the transcription factor NF-κB. However, the signaling pathway in renal cancer remains unclear. The objective of the present study was to investigate the ability of caspase recruitment domain 10 (CARD10) to regulate the NF-κB signaling pathway and promote the progression of renal cell carcinoma (RCC). Expression of CARD10 in ACHN, 786-O and HK-2 cells was evaluated via western blot analysis, as was the epidermal growth factor (EGF)-induced activation of NF-κB signaling pathway-related proteins in cells. The expression of CARD10 was inhibited by CARD10 short hairpin RNA transfection. Cell cycle analysis and MTT assays were used to evaluate cell proliferation. Cell apoptosis was analyzed via flow cytometry. The invasion of renal cell lines was detected via Transwell cell migration and invasion assays in vitro. The results showed that CARD10 expression was significantly higher in RCC cells than in normal renal tubular epithelial cells. CARD10 silencing inhibited the proliferation, invasion and migration of RCC cells. EGF stimulation upregulated the activation of the NF-κB pathway in RCC cells. Inhibition of CARD10 expression inhibited NF-κB activation in RCC cells. Taken together, these data suggested that CARD10 promotes the progression of renal cell carcinoma by regulating the NF-κB signaling pathway. Thus, this indicated that CARD10 may be a novel therapeutic target in RCC.

Caspase recruitment domain family member 10 regulates carbamoyl phosphate synthase 1 and promotes cancer growth in bladder cancer cells

Bladder cancer, which can be divided into non‐muscle‐invasive and muscle‐invasive bladder cancer, is the most common urinary cancer in the United States. Caspase recruitment domain family member 10 (CARD10), also named CARD‐containing MAGUK protein 3 (CARMA3), is a member of the CARMA family and may activate the nuclear factor kappa B (NF‐κB) pathway. We utilized RNA sequencing and metabolic mass spectrometry to identify the molecular and metabolic feature of CARD10. The signalling pathway of CARD10 was verified by Western blotting analysis and functional assays. RNA sequencing and metabolic mass spectrometry of CARD10 knockdown identified the metabolic enzyme carbamoyl phosphate synthase 1 (CPS1) in the urea cycle as the downstream gene regulated by CARD10. We confirmed that CARD10 affected cell proliferation and nucleotide metabolism through regulating CPS1. We indicated that CARD10 promote bladder cancer growth via CPS1 and maybe a potential therapeutic target in bladder cancer.

Current Status of Functional Studies on Circular RNAs in Bladder Cancer and their Potential Role as Diagnostic and Prognostic Biomarkers: A Review

Worldwide, bladder cancer represents the ninth most common malignancy and is the 13^th cause of cancer-associated death. Although surgery combined with chemotherapy and radiotherapy has improved patient outcomes, the prognosis remains poor for most patients with muscle-invasive bladder cancer. The exact mechanisms and critical regulators of bladder cancer remain unknown. Circular RNAs (circRNAs) are a distinct type of endogenous non-coding RNA. Recent studies have shown that circRNAs participate in many processes, including proliferation, invasion, migration, and apoptosis in multiple types of malignancy, including bladder cancer. Some circRNAs are dysregulated in bladder cancer and play essential roles in cancer progression. Importantly, some circRNAs may serve as diagnostic and prognostic biomarkers for bladder cancer. This review aims to summarize the findings from recent studies that have focused on the roles of human circRNAs in bladder cancer and discusses the clinical roles for circRNAs, including their potential roles as diagnostic or prognostic biomarkers.