Endogenous microRNA sponges: evidence and controversy

Integrated analysis of high‑throughput sequencing reveals the regulatory potential of hsa_circ_0035431 in HNSCC

Circular RNAs (circRNAs) are molecular sponges that are involved in regulation of multiple types of cancer. The present study aimed to screen and explore the key circRNA/microRNA (miRNA or miR)/mRNA interactions in head and neck squamous cell carcinoma (HNSCC) using bioinformatics. A total of six pairs of cancerous and adjacent healthy tissue were obtained from patients with HNSCC and genome-wide transcriptional sequencing was performed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on differentially expressed genes (DEGs). Moreover, expression levels of DEGs were verified in HNSCC cells and tissues using reverse transcription-quantitative (RT-q)PCR. A molecular regulatory network consisting of three circRNAs, seven miRNAs and seven mRNAs was constructed, resulting in identification of two signaling axes, hsa_circ_0035431/hsa-miR-940/fucosyltransferase 6 (FUT6) and hsa_circ_0035431/hsa-miR-940/cingulin-like 1 (CGNL1). FUT6 and CGNL1 were downregulated in HNSCC compared with adjacent healthy tissue and the expression levels of these genes were associated with tumor stage. Low FUT6 and CGNL1 expression levels were associated with lower overall survival rate and progression-free intervals in HNSCC. RT-qPCR demonstrated that hsa_circ_0035431, FUT6 and CGNL1 were downregulated in HNSCC cells and tissue and hsa-miR-940 was upregulated. Notably, these results were consistent with those obtained using high-throughput sequencing. In conclusion, hsa_circ_0035431 may participate in regulation of FUT6 and CGNL1 expression by sponging hsa-miR-940, thus, impacting the occurrence, development and prognosis of HNSCC.

Pan-cancer characterization of ncRNA synergistic competition uncovers potential carcinogenic biomarkers

Non-coding RNAs (ncRNAs) act as important modulators of gene expression and they have been confirmed to play critical roles in the physiology and development of malignant tumors. Understanding the synergism of multiple ncRNAs in competing endogenous RNA (ceRNA) regulation can provide important insights into the mechanisms of malignant tumors caused by ncRNA regulation. In this work, we present a framework, SCOM, for identifying ncRNA synergistic competition. We systematically construct the landscape of ncRNA synergistic competition across 31 malignant tumors, and reveal that malignant tumors tend to share hub ncRNAs rather than the ncRNA interactions involved in the synergistic competition. In addition, the synergistic competition ncRNAs (i.e. ncRNAs involved in the synergistic competition) are likely to be involved in drug resistance, contribute to distinguishing molecular subtypes of malignant tumors, and participate in immune regulation. Furthermore, SCOM can help to infer ncRNA synergistic competition across malignant tumors and uncover potential diagnostic and prognostic biomarkers of malignant tumors. Altogether, the SCOM framework (https://github.com/zhangjunpeng411/SCOM/) and the resulting web-based database SCOMdb (https://comblab.cn/SCOMdb/) serve as a useful resource for exploring ncRNA regulation and to accelerate the identification of carcinogenic biomarkers.

Long non-coding RNA Homeobox D gene cluster antisense growth-associated long noncoding RNA/microRNA-182-5p/Homeobox protein A10 alleviates postmenopausal osteoporosis via accelerating osteoblast differentiation of bone marrow mesenchymal stem cells

BACKGROUND

Studies have illuminated that long non-coding RNA (lncRNA) influences bone cell differentiation and formation. Nevertheless, whether lncRNA Homeobox D gene cluster antisense growth-associated long noncoding RNA (HAGLR) was implicated in postmenopausal osteoporosis (PMOP) was yet uncertain.

PURPOSE

The research was to explore HAGLR's role in the osteogenic differentiation (OD) process of bone marrow mesenchymal stem cells (BMSCs).

METHODS

BMSCs were isolated from mouse bone marrow tissues and identified by electron microscope and flow cytometry. HAGLR, microRNA (miR)-182-5p, and homeobox protein A10 (Hoxa10) levels in BMSCs were detected. Mouse BMSC OD process was induced, and calcium deposition and alkaline phosphatase content were analyzed, as well as expressions of runt-related transcription factor 2, osteopontin, and osteocalcin, and cell apoptosis. Bilateral ovaries were resected from mice to construct the ovariectomized model and bone mineral density, maximum bending stress, maximum load, and elastic modulus of the femur were tested, and the femur was histopathologically evaluated. Chondrocyte apoptosis in the articular cartilage of mice was analyzed. Analysis of the interaction of HAGLR, miR-182-5p with Hoxa10 was conducted.

RESULTS

HAGLR and Hoxa10 were down-regulated and miR-182-5p was elevated in PMOP patients. During the BMSC OD process, HAGLR and Hoxa10 levels were suppressed, while miR-182-5p was elevated. Promotion of HAGLR or suppression of miR-182-5p accelerated OD of BMSCs. Inhibition of miR-182-5p reversed the inhibitory effect of HAGLR on BMSC OD. In in vivo experiments, up-regulating HAGLR alleviated PMOP, while silencing Hoxa10 reversed the effects of upregulating HAGLR. HAGLR performed as a sponge for miR-182-5p, while miR-182-5p targeted Hoxa10.

CONCLUSION

In general, HAGLR boosted the OD process of BMSCs and relieved PMOP via the miR-182-5p/Hoxa10 axis. These data preliminarily reveal the key role of HAGLR in PMOP, and the research results have a certain reference for the treatment of PMOP.

The Intergenic Type LncRNA (LINC RNA) Faces in Cancer with In Silico Scope and a Directed Lens to LINC00511: A Step toward ncRNA Precision

BACKGROUND

Long intergenic non-coding RNA, is one type of lncRNA, exerting various cellular activities, as does ncRNA, including the regulation of gene expression and chromatin remodeling. The abnormal expression of lincRNAs can induce or suppress carcinogenesis.

MAIN BODY

LincRNAs can regulate cancer progression through different mechanisms and are considered as potential drug targets. Genetic variations such as single nucleotide polymorphisms (SNPs) in lincRNAs may affect gene expression and messenger ribonucleic acid (mRNA) stability. SNPs in lincRNAs have been found to be associated with different types of cancer, as well. Specifically, LINC00511 has been known to promote the progression of multiple malignancies such as breast cancer, colorectal cancer, lung cancer, hepatocellular carcinoma, and others, making it a promising cancer prognostic molecular marker.

CONCLUSION

LincRNAs have been proved to be associated with different cancer types through various pathways. Herein, we performed a comprehensive literature and in silico databases search listing lncRNAs, lincRNAs including LINC00511, lncRNAs' SNPs, as well as LINC00511 SNPs in different cancer types, focusing on their role in various cancer types and mechanism(s) of action.

Circ_0000396 suppresses the proliferation and inflammation of rheumatoid arthritis synovial fibroblasts by targeting miR-574-5p/RSPO1 axis

BACKGROUND

Circular RNAs (circRNAs) are important regulators on the onset and progression of rheumatoid arthritis (RA). Our purpose is to explore the role and underpin mechanism of circ_0000396 in RA progression.

METHODS

RA patients (n = 39) and healthy volunteers (n = 33) were recruited from the Affiliated Hospital of Shaanxi University of Chinese Medicine for the present work. Circ_0000396, microRNA-574-5p (miR-574-5p) and R-spondin 1 (RSPO1) RNA levels were analyzed by reverse transcription-quantitative polymerase chain reaction. Cell proliferation was analyzed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine (EDU) assay. Cell apoptosis was assessed by flow cytometry. Protein expression levels of proliferating cell nuclear antigen (PCNA), Cyclin D1, Cyclin E1, BCL2-associated × protein (Bax), B-cell lymphoma-2 (Bcl2), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and RSPO1 were detected by western blot assay. Enzyme-linked immunosorbent assay (ELISA) was conducted to analyze the secretion of pro-inflammatory cytokines including IL-1β and TNF-α. The interaction between miR-574-5p and circ_0000396 or RSPO1 was confirmed by dual-luciferase reporter assay and RNA-pull down assay.

RESULTS

Circ_0000396 expression was notably down-regulated in RA patients compared with healthy controls. Circ_0000396 overexpression suppressed the proliferation and inflammatory response and triggered the apoptosis of RA synovial fibroblasts (RASFs), accompanied by decreases in PCNA, Cyclin D1, Cyclin E1, Bcl2, IL-1β and TNF-α protein expression and an increase in Bax protein expression. Circ_0000396 acted as a molecular sponge for miR-574-5p, and circ_0000396 overexpression-mediated protective effects on RASFs dysfunction were largely reversed by the introduction of miR-574-5p mimics. miR-574-5p interacted with the 3' untranslated region (3'UTR) of RSPO1, and miR-574-5p negatively regulated RSPO1 expression in RASFs. Circ_0000396 could up-regulate the expression of RSPO1 by sponging miR-574-5p in RASFs. RSPO1 interference largely overturned circ_0000396 overexpression-mediated effects in RASFs.

CONCLUSION

Circ_0000396 restrained the proliferation and inflammation and induced the apoptosis of RASFs by mediating miR-574-5p/RSPO1 axis, which provided novel potential targets for RA treatment.

Under pressure-mechanisms and risk factors for orthodontically induced inflammatory root resorption: a systematic review

BACKGROUND

The application of orthodontic forces causes root resorption of variable severity with potentially severe clinical ramifications.

OBJECTIVE

To systematically review reports on the pathophysiological mechanisms of orthodontically induced inflammatory root resorption (OIIRR) and the associated risk factors based on in vitro, experimental, and in vivo studies.

SEARCH METHODS

We undertook an electronic search of four databases and a separate hand-search.

SELECTION CRITERIA

Studies reporting on the effect of orthodontic forces with/without the addition of potential risk factors on OIIRR, including (1) gene expression in in-vitro studies, the incidence root resorption in (2) animal studies, and (3) human studies.

DATA COLLECTION AND ANALYSIS

Potential hits underwent a two-step selection, data extraction, quality assessment, and systematic appraisal performed by duplicate examiners.

RESULTS

One hundred and eighteen articles met the eligibility criteria. Studies varied considerably in methodology, reporting of results, and variable risk of bias judgements.In summary, the variable evidence identified supports the notion that the application of orthodontic forces leads to (1) characteristic alterations of molecular expression profiles in vitro, (2) an increased rate of OIIRR in animal models, as well as (3) in human studies. Importantly, the additional presence of risk factors such as malocclusion, previous trauma, and medications like corticosteroids increased the severity of OIIRR, whilst other factors decreased its severity, including oral contraceptives, baicalin, and high caffeine.

CONCLUSIONS

Based on the systematically reviewed evidence, OIIRR seems to be an inevitable consequence of the application of orthodontic forces-with different risk factors modifying its severity. Our review has identified several molecular mechanisms that can help explain this link between orthodontic forces and OIIRR. Nevertheless, it must be noted that the available eligible literature was in part significantly confounded by bias and was characterized by substantial methodological heterogeneity, suggesting that the results of this systematic review should be interpreted with caution.

REGISTRATION

PROSPERO (CRD42021243431).

The NONRATT023402.2/rno-miR-3065-5p/NGFR axis affects levodopa-induced dyskinesia in a rat model of Parkinson's disease

Levodopa-induced dyskinesia (LID) is a common motor complication in Parkinson's disease. However, few studies have focused on the pathogenesis of LID at the transcriptional level. NONRATT023402.2, a long non-coding RNA (lncRNA) that may be related to LID was discovered in our previous study and characterized in rat models of LID. In the present study, NONRATT023402.2 was overexpressed by injection of adeno-associated virus (AAV) in striatum of LID rats, and 48 potential target genes, including nerve growth factor receptor (NGFR) were screened using next-generation sequencing and target gene predictions. The NONRATT023402.2/rno-miR-3065-5p/NGFR axis was verified using a dual luciferase reporter gene. Overexpression of NONRATT023402.2 significantly increased the abnormal involuntary movements (AIM) score of LID rats, activated the PI3K/Akt signaling pathway, and up-regulated c-Fos in the striatum. NGFR knockdown by injection of ShNGFR-AAV into the striatum of LID rats resulted in a significant decrease in the PI3K/Akt signaling pathway and c-Fos expression. The AIM score of LID rats was positively correlated with the expressions of NONRATT023402.2 and NGFR. A dual luciferase reporter assay showed that c-Fos, as a transcription factor, bound to the NONRATT023402.2 promoter and activated its expression. Together, the results showed that NONRATT023402.2 regulated NGFR expression via a competing endogenous RNA mechanism, which then activated the PI3K/Akt pathway and promoted c-Fos expression. This suggested that c-Fos acted as a transcription factor to activate NONRATT023402.2 expression, and form a positive feedback regulation loop in LID rats, thus, aggravating LID symptoms. NONRATT023402.2 is therefore a possible novel therapeutic target for LID.

Expression and function of CCN2-derived circRNAs in chondrocytes

Cellular communication network factor 2 (CCN2) molecules promote endochondral ossification and articular cartilage regeneration, and circular RNAs (circRNAs), which arise from various genes and regulate gene expression by adsorbing miRNAs, are known to be synthesized from CCN2 in human vascular endothelial cells and other types of cells. However, in chondrocytes, not only the function but also the presence of CCN2-derived circRNA remains completely unknown. In the present study, we investigated the expression and function of CCN2-derived circRNAs in chondrocytes. Amplicons smaller than those from known CCN2-derived circRNAs were observed using RT-PCR analysis that could specifically amplify CCN2-derived circRNAs in human chondrocytic HCS-2/8 cells. The nucleotide sequences of the PCR products indicated novel circRNAs in the HCS-2/8 cells that were different from known CCN2-derived circRNAs. Moreover, the expression of several Ccn2-derived circRNAs in murine chondroblastic ATDC5 cells was confirmed and observed to change alongside chondrocytic differentiation. Next, one of these circRNAs was knocked down in HCS-2/8 cells to investigate the function of the human CCN2-derived circRNA. As a result, CCN2-derived circRNA knockdown significantly reduced the expression of aggrecan mRNA and proteoglycan synthesis. Our data suggest that CCN2-derived circRNAs are expressed in chondrocytes and play a role in chondrogenic differentiation. Production and role of CCN2-derived RNAs in chondrocytes.

circEIF3I facilitates the recruitment of SMAD3 to early endosomes to promote TGF-β signalling pathway-mediated activation of MMPs in pancreatic cancer

BACKGROUND

Among digestive tract tumours, pancreatic ductal adenocarcinoma (PDAC) shows the highest mortality trend. Moreover, although PDAC metastasis remains a leading cause of cancer-related deaths, the biological mechanism is poorly understood. Recent evidence demonstrates that circular RNAs (circRNAs) play important roles in PDAC progression.

METHODS

Differentially expressed circRNAs in normal and PDAC tissues were screened via bioinformatics analysis. Sanger sequencing, RNase R and actinomycin D assays were performed to confirm the loop structure of circEIF3I. In vitro and in vivo functional experiments were conducted to assess the role of circEIF3I in PDAC. MS2-tagged RNA affinity purification, mass spectrometry, RNA immunoprecipitation, RNA pull-down assay, fluorescence in situ hybridization, immunofluorescence and RNA-protein interaction simulation and analysis were performed to identify circEIF3I-interacting proteins. The effects of circEIF3I on the interactions of SMAD3 with TGFβRI or AP2A1 were measured through co-immunoprecipitation and western blotting.

RESULTS

A microarray data analysis showed that circEIF3I was highly expressed in PDAC cells and correlated with TNM stage and poor prognosis. Functional experiments in vitro and in vivo revealed that circEIF3I accelerated PDAC cells migration, invasion and metastasis by increasing MMPs expression and activity. Mechanistic research indicated that circEIF3I binds to the MH2 domain of SMAD3 and increases SMAD3 phosphorylation by strengthening the interactions between SMAD3 and TGFβRI on early endosomes. Moreover, AP2A1 binds with circEIF3I directly and promotes circEIF3I-bound SMAD3 recruitment to TGFβRI on early endosomes. Finally, we found that circEif3i exerts biological functions in mice similar to those of circEIF3I in humans PDAC.

CONCLUSIONS

Our study reveals that circEIF3I promotes pancreatic cancer progression. circEIF3I is a molecular scaffold that interacts with SMAD3 and AP2A1 to form a ternary complex, that facilitates the recruitment of SMAD3 to early endosomes and then activates the TGF-β signalling pathway. Hence, circEIF3I is a potential prognostic biomarker and therapeutic target in PDAC.

Discovery of long non-coding RNAs in the liver fluke, Fasciola hepatica

Long non-coding (lnc)RNAs are a class of eukaryotic RNA that do not code for protein and are linked with transcriptional regulation, amongst a myriad of other functions. Using a custom in silico pipeline we have identified 6,436 putative lncRNA transcripts in the liver fluke parasite, Fasciola hepatica, none of which are conserved with those previously described from Schistosoma mansoni. F. hepatica lncRNAs were distinct from F. hepatica mRNAs in transcript length, coding probability, exon/intron composition, expression patterns, and genome distribution. RNA-Seq and digital droplet PCR measurements demonstrated developmentally regulated expression of lncRNAs between intra-mammalian life stages; a similar proportion of lncRNAs (14.2%) and mRNAs (12.8%) were differentially expressed (p<0.001), supporting a functional role for lncRNAs in F. hepatica life stages. While most lncRNAs (81%) were intergenic, we identified some that overlapped protein coding loci in antisense (13%) or intronic (6%) configurations. We found no unequivocal evidence for correlated developmental expression within positionally correlated lncRNA:mRNA pairs, but global co-expression analysis identified five lncRNA that were inversely co-regulated with 89 mRNAs, including a large number of functionally essential proteases. The presence of micro (mi)RNA binding sites in 3135 lncRNAs indicates the potential for miRNA-based post-transcriptional regulation of lncRNA, and/or their function as competing endogenous (ce)RNAs. The same annotation pipeline identified 24,141 putative lncRNAs in F. gigantica. This first description of lncRNAs in F. hepatica provides an avenue to future functional and comparative genomics studies that will provide a new perspective on a poorly understood aspect of parasite biology.

Antisense lncRNA-RP11-498C9.13 promotes bladder cancer progression by enhancing reactive oxygen species-induced mitophagy

BACKGROUND

Urinary system's most prevalent malignant tumor is bladder cancer. The enzyme pyrroline-5-carboxylate reductase 1 (PYCR1) has pro-tumorigenic characteristics. In the present study, the upstream and downstream regulatory mechanisms of PYCR1 in bladder cancer were investigated.

METHODS

The relationship between the expression of PYCR1 in bladder cancer and its prognosis was analyzed using a bioinformatics technique. Plasmid transfection and small interfering RNA were utilized to overexpress and silence genes, respectively. Utilizing MTT, colony formation, EdU, and transwell assays, the proliferation and invasiveness of bladder cancer cells were evaluated. Employing an RNA pull-down experiment and RNA immunoprecipitation, the relationship between RNAs was analyzed. Fluorescence in situ hybridization, immunohistochemistry, and western blotting were used to detect protein expression and localization. Flow cytometry was used to identify reactive species (ROS) expression in cells. Mitophagy was detected using immunofluorescence.

RESULTS

PYCR1 was highly expressed in bladder cancer tissue and was related with a poor prognosis for the patient. By binding to PYCR1, the antisense RNA lncRNA-RP11-498C9.13 prevented the degradation of PYCR1 and promoted its production. Down-regulation of lncRNA-RP11-498C9.13 and PYCR1 inhibited the proliferation and invasiveness of bladder cancer cells and decreased tumorigenesis. In addition, it was found that the lncRNA-RP11-498C9.13/PYCR1 axis promoted ROS generation and induced mitophagy in bladder cancer cells.

CONCLUSIONS

We demonstrated that lncRNA-RP11-498C9.13 promoted bladder cancer tumorigenesis by stabilizing the mRNA of PYCR1 and promoted ROS-induced mitophagy. The lncRNA-RP11-498C9.13/PYCR1/mitophagy axis was anticipated to be a significant therapeutic target for bladder cancer.

Linc-ROR Promotes EMT by Targeting miR-204-5p/SMAD4 in Endometriosis

Endometriosis (EMs) is a systemic and chronic disease with cancer-like feature, namely, distant implantation, which caused heavy healthy burden of nearly 200 million females. LncRNAs have been proved as new modulators in epithelial-mesenchymal transition (EMT) and EMs. Quantitative real-time PCR was conducted to measure the expression level of long intergenic non-protein coding RNA, regulator of reprogramming (Linc-ROR), and miR-204-5p in ectopic endometrium (n = 25), eutopic endometrium (n = 20), and natural control endometrium (n = 22). Overexpression of Linc-ROR, knockdown or overexpression of miR-204-5p in End1/E6E7 and Ishikawa cells, was conducted to detect the function of Linc-ROR and miR-204-5p in EMs. Furthermore, luciferase reports were used to confirm the combination of Linc-ROR and miR-204-5p and the combination between miR-204-5p and SMAD4. Cell-Counting Kit-8, EdU assay, transwell assays, and Western blotting were used to detect the function of Linc-ROR and miR-204-5p in EMs cancer-like behaviors and EMT process. Linc-ROR was up-regulated in ectopic endometrium. Overexpressed Linc-ROR promotes cell proliferation, invasion, and EMT process. Linc-ROR regulated the EMT process, cellular proliferation, and invasion of EMs via binding to miR-204-5p. In addition, overexpression of Linc-ROR up-regulated SMAD4, a target protein of miR-204-5p, with which regulated EMT process and cancer-like behaviors in EMs together. Linc-ROR/miR-204-5p/SMAD4 axis plays a vital role in regulation EMT process in EMs, which might become a novel therapeutic targets and powerful biomarkers in EMs therapy.

Circular RNAs: Emerging roles and new insights in human cancers

Circular RNAs (circRNAs) are single-stranded, covalently closed RNA molecules formed by mRNA exon back-splicing. Although the circRNA functions remain largely unknown, their currently known biological activities include: acting as competing endogenous RNA (ceRNA) to adsorb microRNA (miRNA), binding proteins, regulating transcription or splicing, and ability to be translated into proteins or peptides. A growing number of studies have found that many circRNAs are abnormally expressed in various cancers, and their dysregulation is highly correlated with tumor progression. Therefore, diagnosis and treatment using circRNAs as biomarkers and therapeutic targets, respectively, has gradually become an attractive research topic. In this review, we introduced the canonical biogenesis pathways and degradation mechanisms of circRNAs. In addition, we examined the biological functions of circRNAs in vivo. Finally, we discussed the current clinical applications and challenges faced by circRNA, and proposed future directions for this promising research field.

MIR663AHG as a competitive endogenous RNA regulating TGF-β-induced epithelial proliferation and epithelial-mesenchymal transition in benign prostate hyperplasia

Benign prostate hyperplasia (BPH) is the most commonly seen disease among aging males. Transforming growth factor(TGF)-β-mediated epithelial-mesenchymal transition (EMT) and epithelial overproliferation might be central events in BPH etiology and pathophysiology. In the present study, long noncoding RNA MIR663AHG, miR-765, and FOXK1 formed a competing endogenous RNAs network, modulating TGF-β-mediated EMT and epithelial overproliferation in BPH-1 cells. miR-765 expression was downregulated in TGF-β-stimulated BPH-1 cells; miR-765 overexpression ameliorated TGF-β-mediated EMT and epithelial overproliferation in BPH-1 cells. MIR663AHG directly targeted miR-765 and negatively regulated miR-765; MIR663AHG knockdown also attenuated TGF-β-induced EMT and epithelial overproliferation in BPH-1 cells, whereas miR-765 inhibition attenuated MIR663AHG knockdown effects on TGF-β-stimulated BPH-1 cells. miR-765 directly targeted FOXK1 and negatively regulated FOXK1. FOXK1 knockdown attenuated TGF-β-induced EMT and epithelial overproliferation and promoted autophagy in BPH-1 cells, and partially attenuated miR-765 inhibition effects on TGF-β-stimulated BPH-1 cells. In conclusion, this study provides a MIR663AHG/miR-765/FOXK1 axis modulating TGF-β-induced epithelial proliferation and EMT, which might exert an underlying effect on BPH development and act as therapeutic targets for BPH treatment regimens.

Going circular: history, present, and future of circRNAs in cancer

To date, thousands of highly abundant and conserved single-stranded RNA molecules shaped into ring structures (circRNAs) have been identified. CircRNAs are multifunctional molecules that have been shown to regulate gene expression transcriptionally and post-transcriptionally and exhibit distinct tissue- and development-specific expression patterns associated with a variety of normal and disease conditions, including cancer pathogenesis. Over the past years, due to their intrinsic stability and resistance to ribonucleases, particular attention has been drawn to their use as reliable diagnostic and prognostic biomarkers in cancer diagnosis, treatment, and prevention. However, there are some critical caveats to their utility in the clinic. Their circular shape limits their annotation and a complete functional elucidation is lacking. This makes their detection and biomedical application still challenging. Herein, we review the current knowledge of circRNA biogenesis and function, and of their involvement in tumorigenesis and potential utility in cancer-targeted therapy.

MiRNAs in Lung Adenocarcinoma: Role, Diagnosis, Prognosis, and Therapy

Lung cancer has emerged as a significant public health challenge and remains the leading cause of cancer-related mortality worldwide. Among various types of lung malignancies, lung adenocarcinoma (LUAD) stands as the most prevalent form. MicroRNAs (miRNAs) play a crucial role in gene regulation, and their involvement in cancer has been extensively explored. While several reviews have been published on miRNAs and lung cancer, there remains a gap in the review regarding miRNAs specifically in LUAD. In this review, we not only highlight the potential diagnostic, prognostic, and therapeutic implications of miRNAs in LUAD, but also present an inclusive overview of the extensive research conducted on miRNAs in this particular context.

Dysregulated microRNAs as a biomarker for diagnosis and prognosis of hepatitis B virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignancy with a high incidence and fatality rate worldwide. Hepatitis B virus (HBV) infection is one of the most important risk factors for its occurrence and development. Early detection of HBV-associated HCC (HBV-HCC) can improve clinical decision-making and patient outcomes. Biomarkers are extremely helpful, not only for early diagnosis, but also for the development of therapeutics. MicroRNAs (miRNAs), a subset of non-coding RNAs approximately 22 nucleotides in length, have increasingly attracted scientists' attention due to their potential utility as biomarkers for cancer detection and therapy. HBV profoundly impacts the expression of miRNAs potentially involved in the development of hepatocarcinogenesis. In this review, we summarize the current progress on the role of miRNAs in the diagnosis and treatment of HBV-HCC. From a molecular standpoint, we discuss the mechanism by which HBV regulates miRNAs and investigate the exact effect of miRNAs on the promotion of HCC. In the near future, miRNA-based diagnostic, prognostic, and therapeutic applications will make their way into the clinical routine.

LncRNA SNHG4 promotes prostate cancer cell survival and resistance to enzalutamide through a let-7a/RREB1 positive feedback loop and a ceRNA network

BACKGROUND

Prostate cancer threatens the health of men over sixty years old, and its incidence ranks first among all urinary tumors among men. Enzalutamide remains the first-line drug for castration-resistant prostate cancer, however, tumors inevitably become resistant to enzalutamide. Hence, it is of great importance to investigate the mechanisms that induce enzalutamide resistance in prostate cancer cells.

METHODS

Bioinformatic analyzing approaches were used to identified the over-expressed genes in prostate cancer tumor tissues from three GEO datasets. qRT-PCR, western blotting and immunochemistry/In situ hybridization staining assays were performed to assess the expression of SNHG4, RRM2, TK1, AURKA, EZH2 and RREB1. Cell cycle was measured by flow cytometry. CCK-8, plate colony formation and EdU assays were performed to assess the cell proliferation. Senescence-associated β-Gal assay was used to detect the cell senescence level. γ-H2AX staining assay was performed to assess the DNA damages of PCa cells. Luciferase reporter assay and RNA immunoprecipitation assay were performed to verify the RNA-RNA interactions. Chromatin immunoprecipitation assay was performed to assess the bindings between protein and genomic DNA.

RESULTS

We found that RRM2 and NUSAP1 are highly expressed in PCa tumors and significantly correlated with poor clinical outcomes in PCa patients. Bioinformatic analysis as well as experimental validation suggested that SNHG4 regulates RRM2 expression via a let-7 miRNA-mediated ceRNA network. In addition, SNHG4 or RRM2 knockdown significantly induced cell cycle arrest and cell senescence, and inhibited DNA damage repair and cell proliferation, and the effects can be partially reversed by let-7a knockdown or RRM2 reoverexpression. In vitro and in vivo experiments showed that SNHG4 overexpression markedly enhanced cell resistance to enzalutamide. RREB1 was demonstrated to transcriptionally regulate SNHG4, and RREB1 was also validated to be a target of let-7a and thereby regulated by the SNHG4/let-7a feedback loop.

CONCLUSION

Our study uncovered a novel molecular mechanism of lncRNA SNHG4 in driving prostate cancer progression and enzalutamide resistance, revealing the critical roles and therapeutic potential of RREB1, SNHG4, RRM2 and let-7 miRNAs in anticancer therapy.

High-density lipoprotein regulates angiogenesis by long non-coding RNA HDRACA

Normal high-density lipoprotein (nHDL) can induce angiogenesis in healthy individuals. However, HDL from patients with coronary artery disease undergoes various modifications, becomes dysfunctional (dHDL), and loses its ability to promote angiogenesis. Here, we identified a long non-coding RNA, HDRACA, that is involved in the regulation of angiogenesis by HDL. In this study, we showed that nHDL downregulates the expression of HDRACA in endothelial cells by activating WW domain-containing E3 ubiquitin protein ligase 2, which catalyzes the ubiquitination and subsequent degradation of its transcription factor, Kruppel-like factor 5, via sphingosine 1-phosphate (S1P) receptor 1. In contrast, dHDL with lower levels of S1P than nHDL were much less effective in decreasing the expression of HDRACA. HDRACA was able to bind to Ras-interacting protein 1 (RAIN) to hinder the interaction between RAIN and vigilin, which led to an increase in the binding between the vigilin protein and proliferating cell nuclear antigen (PCNA) mRNA, resulting in a decrease in the expression of PCNA and inhibition of angiogenesis. The expression of human HDRACA in a hindlimb ischemia mouse model inhibited the recovery of angiogenesis. Taken together, these findings suggest that HDRACA is involved in the HDL regulation of angiogenesis, which nHDL inhibits the expression of HDRACA to induce angiogenesis, and that dHDL is much less effective in inhibiting HDRACA expression, which provides an explanation for the decreased ability of dHDL to stimulate angiogenesis.

A potential therapeutic drug for osteoporosis: prospect for osteogenic LncRNAs

Long non-coding RNAs (LncRNAs) play essential roles in multiple physiological processes including bone formation. Investigators have revealed that LncRNAs regulated bone formation through various signaling pathways and micro RNAs (miRNAs). However, several problems exist in current research studies on osteogenic LncRNAs, including sophisticated techniques, high cost for in vivo experiment, as well as low homology of LncRNAs between animal model and human, which hindered translational medicine research. Moreover, compared with gene editing, LncRNAs would only lead to inhibition of target genes rather than completely knocking them out. As the studies on osteogenic LncRNA gradually proceed, some of these problems have turned osteogenic LncRNA research studies into slump. This review described some new techniques and innovative ideas to address these problems. Although investigations on osteogenic LncRNAs still have obtacles to overcome, LncRNA will work as a promising therapeutic drug for osteoporosis in the near future.

Exosomal non-coding RNAs in angiogenesis: Functions, mechanisms and potential clinical applications

Exosomes are extracellular vesicles that can be produced by most cells. Exosomes act as important intermediaries in intercellular communication, and participate in a variety of biological activities between cells. Non-coding RNAs (ncRNAs) usually refer to RNAs that do not encode proteins. Although ncRNAs have no protein-coding capacity, they are able to regulate gene expression at multiple levels. Angiogenesis is the formation of new blood vessels from pre-existing vessels, which is an important physiological process. However, abnormal angiogenesis could induce many diseases such as atherosclerosis, diabetic retinopathy and cancer. Many studies have shown that ncRNAs can stably exist in exosomes and play a wide range of physiological and pathological roles including regulation of angiogenesis. In brief, some specific ncRNAs can be enriched in exosomes secreted by cells and absorbed by recipient cells through the exosome pathway, thus activating relevant signaling pathways in target cells and playing a role in regulating angiogenesis. In this review, we describe the physiological and pathological functions of exosomal ncRNAs in angiogenesis, summarize their role in angiogenesis-related diseases, and illustrate potential clinical applications like novel drug therapy strategies and diagnostic markers in exosome research as inspiration for future investigations.

Long Noncoding RNAs in Taxane Resistance of Breast Cancer

Breast cancer is a common cancer in women and a leading cause of mortality. With the early diagnosis and development of therapeutic drugs, the prognosis of breast cancer has markedly improved. Chemotherapy is one of the predominant strategies for the treatment of breast cancer. Taxanes, including paclitaxel and docetaxel, are widely used in the treatment of breast cancer and remarkably decrease the risk of death and recurrence. However, taxane resistance caused by multiple factors significantly impacts the effect of the drug and leads to poor prognosis. Long noncoding RNAs (lncRNAs) have been shown to play a significant role in critical cellular processes, and a number of studies have illustrated that lncRNAs play vital roles in taxane resistance. In this review, we systematically summarize the mechanisms of taxane resistance in breast cancer and the functions of lncRNAs in taxane resistance in breast cancer. The findings provide insight into the role of lncRNAs in taxane resistance and suggest that lncRNAs may be used to develop therapeutic targets to prevent or reverse taxane resistance in patients with breast cancer.

Dysregulation of a lncRNA within the TNFRSF10A locus activates cell death pathways

TNFRSF10A (tumor necrosis factor receptor superfamily member 10A) encodes a cell surface receptor protein involved in apoptotic, necroptotic, and inflammatory pathways. Dysregulation of TNFRSF10A has been implicated in sensitization to apoptosis and to the development of multiple diseases, yet little is known of the AC100861.1 long noncoding RNA (lncRNA) that lies head-to-head with TNFRSF10A. Given its genomic positioning, we sought to investigate the function of AC100861.1, focusing on its potential relationship with TNFRSF10A and the role it may play in death receptor signaling. Using knockdown and overexpression strategies, we probed cell viability and examined transcript and protein-level changes in key genes involved in apoptosis, necroptosis, and inflammation. Decreased cell viability was observed upon TNFRSF10A overexpression, regardless of whether the cells were subjected to the chemical stressor tunicamycin. Similarly, overexpression of AC100861.1 led to increased cell death, with a further increase observed under conditions of cellular stress. Knockdown of TNFRSF10A increased cell death only when the cells were stressed, and AC100861.1 knockdown exhibited no effect on cell death. Neither knockdown nor overexpression of either of these genes greatly affected the expression of the other. Manipulating AC100861.1, however, led to marked changes in the expression of genes involved in necroptosis and inflammatory cell-signaling pathways. Additionally, RNA fluorescence in situ hybridization (RNA-FISH) revealed that the AC100861.1 transcript is localized primarily to the cytoplasm. Together, these data suggest that AC100861.1 may have a role in regulating necroptotic and inflammatory signaling pathways and that this function is separate from changes in TNFRSF10A expression. Given the importance of this genomic locus for cell survival, these data provide insight into the function of a poorly understood lncRNA with potential implications regarding disease pathology and treatment.

Circular RNA as a Novel Regulator and Promising Biomarker in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a prevalent metabolic and reproductive disorder that causes low fertility in females. Despite its detrimental effects on women's health, care for PCOS has been impeded by its undefined pathogenesis. Thus, there is an urgent need to explore novel biomarkers and therapeutic targets for the diagnosis and treatment of PCOS. Circular RNAs (circRNAs) are a class of noncoding RNAs with covalently closed cyclic structures, present in high abundance, and show development-stage specific expression patterns. Recent studies have demonstrated that circRNAs participate in PCOS progression by modulating various biological functions, including cell proliferation, apoptosis, and steroidogenesis. In addition, circRNAs are widely present in the follicular fluid of women with PCOS, indicating their potential as diagnostic biomarkers and therapeutic targets for PCOS. This review provides the current knowledge of circRNAs in PCOS, including their regulatory functions and molecular mechanisms, and explores their potential as diagnostic biomarkers and therapeutic targets.

Emerging roles of microRNAs in septic cardiomyopathy

As one of the serious complications of sepsis, septic cardiomyopathy has gained more and more attention, because of its high morbidity and mortality. With the in-depth study of septic cardiomyopathy, several methods have been adopted clinically but have poor therapeutic effects due to failure to find precise therapeutic targets. In recent years, microRNAs have been found to be related to the pathogenesis, diagnosis, and treatment of septic cardiomyopathy via regulating immunity and programmed cell death. This paper reviews the role of microRNAs in septic cardiomyopathy, aiming to provide new targets for the diagnosis and treatment of septic cardiomyopathy.

CircAFF1 Is a Circular RNA with a Role in Alveolar Rhabdomyosarcoma Cell Migration

Circular RNAs (circRNAs), covalently closed RNAs that originate from back-splicing events, participate in the control of several processes, including those that occur in the development of pathological conditions such as cancer. Hereby, we describe circAFF1, a circular RNA overexpressed in alveolar rhabdomyosarcoma. Using RH4 and RH30 cell lines, a classical cell line models for alveolar rhabdomyosarcoma, we demonstrated that circAFF1 is a cytoplasmatic circRNA and its depletion impacts cell homeostasis favouring cell migration through the downregulation of genes involved in cell adhesion pathways. The presented data underline the importance of this circular RNA as a new partial suppressor of the alveolar rhabdomyosarcoma tumour progression and as a putative future therapeutic target.

Long noncoding RNA (lncRNA) H19: An essential developmental regulator with expanding roles in cancer, stem cell differentiation, and metabolic diseases

Recent advances in deep sequencing technologies have revealed that, while less than 2% of the human genome is transcribed into mRNA for protein synthesis, over 80% of the genome is transcribed, leading to the production of large amounts of noncoding RNAs (ncRNAs). It has been shown that ncRNAs, especially long non-coding RNAs (lncRNAs), may play crucial regulatory roles in gene expression. As one of the first isolated and reported lncRNAs, H19 has gained much attention due to its essential roles in regulating many physiological and/or pathological processes including embryogenesis, development, tumorigenesis, osteogenesis, and metabolism. Mechanistically, H19 mediates diverse regulatory functions by serving as competing endogenous RNAs (CeRNAs), Igf2/H19 imprinted tandem gene, modular scaffold, cooperating with H19 antisense, and acting directly with other mRNAs or lncRNAs. Here, we summarized the current understanding of H19 in embryogenesis and development, cancer development and progression, mesenchymal stem cell lineage-specific differentiation, and metabolic diseases. We discussed the potential regulatory mechanisms underlying H19's functions in those processes although more in-depth studies are warranted to delineate the exact molecular, cellular, epigenetic, and genomic regulatory mechanisms underlying the physiological and pathological roles of H19. Ultimately, these lines of investigation may lead to the development of novel therapeutics for human diseases by exploiting H19 functions.

CircRNA7632 down-regulation alleviates endothelial cell dysfunction in Kawasaki disease via regulating IL-33 expression

Kawasaki disease (KD) is a form of idiopathic vasculitis frequently accompanied by coronary artery lesions, which involves endothelial dysfunction. Recent studies have demonstrated that circular RNAs (circRNAs) are implicated in many cardiovascular diseases. However, few studies have examined the role of circRNAs on endothelial dysfunction in KD. In this study, we investigated the role of circ7632 on endothelial-mesenchymal transition (EndoMT) in KD and then explored the underlying mechanism. Children diagnosed with KD and age-matched healthy controls (HC) were included. Sera samples were collected. Primary human umbilical vein endothelial cells (HUVECs) were obtained and incubated with 15% HC and KD serum for 48 h. The mRNA and protein expression of mesenchymal markers vimentin and α-smooth muscle actin (α-SMA) and endothelial marker zonula occludens-1 (ZO-1) in HUVECs transfected with plasmid-circ7632 and si-circ7632 were detected by RT-qPCR and Western blot analysis. CCK8, scratch test, and migration test were performed to examine the effect of circ7632 on the cell proliferation and migration. The circ7632 level was higher in HUVECs treated by KD serum than in HUVECs treated with HC serum. Overexpression of circ7632 significantly increased vimentin and α-SMA expression, decreased ZO-1 expression, and also decreased cell proliferation. Down-regulation of circ7632 expression got the opposite results. RNA-seq analysis, and confirmatory experiment displayed that down-regulation of circ7632 decreased IL-33 expression, and IL-33 silencing mitigated KD serum-mediated EndoMT. Our study revealed that circ7632 level was elevated in KD serum-treated HUVECs. Circ7632 down-regulation could alleviate EndoMT likely through decreasing IL-33 expression. The circ7632 may become a potential therapeutic target for KD.

Circ_0010235 confers cisplatin resistance in lung cancer by upregulating E2F7 through absorbing miR-379-5p

BACKGROUND

Cisplatin (DDP) treatment is one of the most predominant chemotherapeutic strategies for lung cancer patients. Circular RNAs (circRNAs) have been revealed to participate in the chemoresistance in lung cancer. Hence, the role and mechanism of circ_0010235 in cisplatin resistance in lung cancer was investigated.

METHODS

Expression levels of circ_0010235, microRNA (miR)-379-5p and E2F transcription factor 7 (E2F7) were analyzed using quantitative reverse transcription PCR (qRT-PCR) and western blot. Cell DDP sensitivity, proliferation, apoptosis, invasion, and migration were detected by cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine (EDU) assay, flow cytometry and western blot, respectively. The binding interaction was verified using dual-luciferase reporter assay. A murine xenograft model was established to investigate effects in vivo.

RESULTS

Circ_0010235 was highly expressed in DDP-resistant lung cancer tissues and cells. Knockdown of circ_0010235 elevated DDP sensitivity, constrained proliferation, invasion and migration as well as fostered apoptosis in DDP-resistant lung cancer cells. Moreover, circ_0010235 silencing boosted DDP sensitivity and impeded tumor growth in lung cancer in vivo. Mechanistically, circ_0010235 acted as a sponge for miR-379-5p to elevate the expression of its target E2F7. Rescue experiments showed that miR-379-5p inhibition attenuated circ_0010235 knockdown-evoked reduction on DDP resistance of DDP-resistant cancer cells. In addition, miR-379-5p re-expression elevated DDP sensitivity and suppressed the malignant phenotype of DDP-resistant lung cancer cells through miR-379-5p.

CONCLUSION

Circ_0010235 knockdown reduced DDP resistance and tumor growth via miR-379-5p/ E2F7 axis in lung cancer, suggesting an effective therapeutic target for lung cancer patients.

PCSK9 inhibitor attenuates atherosclerosis by regulating SNHG16/EZH2/TRAF5-mediated VSMC proliferation, migration, and foam cell formation

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor has been demonstrated to exert a great cardioprotection in cardiometabolic impairments, including atherosclerosis. However, its underlying mechanism remains not fully understood. This study focuses on uncovering the actions of PCSK9 inhibitor on the connection between atherosclerosis and vascular smooth muscle cell (VSMC) behaviors. qRT-PCR was utilized to detect the expression of SNHG16. Proliferation and migration of VSMC were characterized by Cell Counting Kit-8 and wound healing assays. The intracellular lipids and foam cell formation were assessed by Oil Red O staining, fluorescence image, and cholesterol quantification kit. Atherosclerosis in vivo was evaluated by imaging the atherosclerotic lesions, hematoxylin-eosin staining, Oil Red O staining and Masson staining. The interaction between SNHG16 with EZH2 and histone H3 lysine 27 trimethylation (H3K27me3) were investigated by fluorescence in situ hybridization, RNA immunoprecipitation, and chromatin immunoprecipitation assays. A ApoE-/- mice model was used to validate the role of PCSK9 inhibitor and SNHG16 for atherosclerosis. The protective regulation of PCSK9 inhibitor was observed both in high-fat diet (HFD)-fed mice and oxidized low-density lipoprotein (ox-LDL)-treated VSMC, as manifested in the decreased the atherosclerotic lesions in vivo, as well as the weakened cell proliferation, migration, and formation of foam cells in vitro. SNHG16 was identified to be a downstream effector of PCSK9 inhibitor-mediated biological functions, of which knockdown also significantly ox-LDL-treated VSMC proliferation, migration, and foam cell formation abilities. SNHG16 epigenetically suppressed TRAF5 via recruiting EZH2. Silencing of TRAF5 abolished the protective effects of SNHG16 knockdown on the pathogenesis of atherosclerosis. Collectively, PCSK9 inhibitor attenuated atherosclerosis by regulating SNHG16/EZH2/TRAF5 axis to impair the proliferation, migration, and foam cell formation of VSMC.

Discovery of long non-coding RNAs in Aspergillus flavus response to water activity, CO2 concentration, and temperature changes

Although the role of long non-coding RNAs (lncRNAs) in key biological processes in animals and plants has been confirmed for decades, their identification in fungi remains limited. In this study, we discovered and characterized lncRNAs in Aspergillus flavus in response to changes in water activity, CO₂ concentration, and temperature, and predicted their regulatory roles in cellular functions. A total of 472 lncRNAs were identified in the genome of A. flavus, consisting of 470 novel lncRNAs and 2 putative lncRNAs (EFT00053849670 and EFT00053849665). Our analysis of lncRNA expression revealed significant differential expression under stress conditions in A. flavus. Our findings indicate that lncRNAs in A. flavus, particularly down-regulated lncRNAs, may play pivotal regulatory roles in aflatoxin biosynthesis, respiratory activities, cellular survival, and metabolic maintenance under stress conditions. Additionally, we predicted that sense lncRNAs down-regulated by a temperature of 30 °C, osmotic stress, and CO₂ concentration might indirectly regulate proline metabolism. Furthermore, subcellular localization analysis revealed that up-and down-regulated lncRNAs are frequently localized in the nucleus under stress conditions, particularly at a water activity of 0.91, while most up-regulated lncRNAs may be located in the cytoplasm under high CO₂ concentration.

The lncRNA LETS1 promotes TGF-β-induced EMT and cancer cell migration by transcriptionally activating a TβR1-stabilizing mechanism

Transforming growth factor-β (TGF-β) signaling is a critical driver of epithelial-to-mesenchymal transition (EMT) and cancer progression. In SMAD-dependent TGF-β signaling, activation of the TGF-β receptor complex stimulates the phosphorylation of the intracellular receptor-associated SMADs (SMAD2 and SMAD3), which translocate to the nucleus to promote target gene expression. SMAD7 inhibits signaling through the pathway by promoting the polyubiquitination of the TGF-β type I receptor (TβRI). We identified an unannotated nuclear long noncoding RNA (lncRNA) that we designated LETS1 (lncRNA enforcing TGF-β signaling 1) that was not only increased but also perpetuated by TGF-β signaling. Loss of LETS1 attenuated TGF-β-induced EMT and migration in breast and lung cancer cells in vitro and extravasation of the cells in a zebrafish xenograft model. LETS1 potentiated TGF-β-SMAD signaling by stabilizing cell surface TβRI, thereby forming a positive feedback loop. Specifically, LETS1 inhibited TβRI polyubiquitination by binding to nuclear factor of activated T cells (NFAT5) and inducing the expression of the gene encoding the orphan nuclear receptor 4A1 (NR4A1), a component of a destruction complex for SMAD7. Overall, our findings characterize LETS1 as an EMT-promoting lncRNA that potentiates signaling through TGF-β receptor complexes.

The regulatory role and mechanism of lncTUG1 on cartilage apoptosis and inflammation in osteoarthritis

BACKGROUND

Long-stranded non-coding RNA TUG1 is lowly expressed in osteoarthritic chondrocytes. This study aimed to elucidate the role of TUG1 in osteoarthritic cartilage damage and the underlying mechanisms.

METHODS

Combined database analysis, using primary chondrocytes as well as the C28/I2 cell line, was performed by qRT-PCR, Western blotting, and immunofluorescence to determine the expression of TUG1, miR-144-3p, DUSP1, and other target proteins. Dual luciferase reporter gene and RIP to verify direct interaction of TUG1 with miR-144-3-p and miR-144-3-p with DUSP1, Annexin V-FITC/PI double staining to detect apoptosis. CCK-8 to detect cell proliferation. The biological significance of TUG1, miR-144-3p, and DUSP1 was assessed in vitro experiments using siRNA for TUG1, mimic and repressor for miR-144-3p, and overexpression plasmid for DUSP1. In this study, all data were subjected to a t-test or one-way analysis of variance with a p-value < 0.05 as the cutoff.

RESULTS

TUG1 expression was closely associated with osteoarthritic chondrocyte damage, and knockdown of TUG1 significantly promoted chondrocyte apoptosis and inflammation. In the present study, we found that TUG1 inhibited chondrocyte apoptosis and inflammation by competitively binding miR-144-3p, deregulating the negative regulatory effect of miR-144-3p on DUSP1, promoting DUSP1 expression, and inhibiting the p38 MAPK signaling pathway.

CONCLUSIONS

In conclusion, our study clarifies the role of the ceRNA regulatory network of TUG1/miR-144-3p/DUSP1/P38 MAPK in OA cartilage injury and provides an experimental and theoretical basis for genetic engineering tools to promote articular cartilage repair.

Identification of immunity-related lncRNAs and construction of a ceRNA network of potential prognostic biomarkers in acute myeloid leukemia

Objective: Using bioinformatics analyses, this study aimed to identify lncRNAs related to the immune status of acute myeloid leukemia (AML) patients and ascertain the potential impact in immunity-related competing endogenous RNA (ceRNA) networks on AML prognosis. Methods: AML-related RNA-seq FPKM data, AML-related miRNA expression microarray data, and gene sets associated with immunity-related pathways were, respectively, obtained from the TCGA, GEO, and ImmReg databases. An immunity-related ceRNA network was then constructed according to the predicted interactions between AML-related mRNAs, lncRNAs, and miRNAs. After performing LASSO and multivariate Cox regression analyses, lncRNAs in the ceRNA network were used to establish an AML prognostic model. According to mutual regulatory relationships and consistent trends of expression among candidate ceRNAs, two ceRNA subnetworks related to the AML prognostic model were determined. Finally, the correlation between the expression levels of mRNAs, lncRNAs, and miRNAs in each ceRNA subnetwork and immune cell infiltration (assessed by combining the ESTIMATE and CIBERSORT methods and ssGSEA) was analyzed. Results: A total of 424 immunity-related differentially expressed (IR-DE) mRNAs (IR-DEmRNAs), 191 IR-DElncRNAs, and 69 IR-DEmiRNAs were obtained, and a ceRNA network of 20 IR-DElncRNAs, 6 IR-DEmRNAs, and 3 IR-DEmiRNAs was established. Univariate Cox regression analysis was conducted on 20 IR-DElncRNAs, and 7 of these were identified to be significantly correlated with the overall survival (OS) time in AML patients. Then, two IR-DElncRNAs (MEG3 and HCP5) were screened as independent OS-related factors by LASSO and multivariable Cox regression analyses, and a prognostic model was constructed to evaluate the survival risk in AML patients. Survival analyses indicated that the OS of patients was often poor in the high-risk group. Additionally, from this model, two ceRNA regulatory pathways, namely, MEG3/miR-125a-5p/SEMA4C and HCP5/miR-125b-5p/IL6R, which were potentially involved in the immune regulation of AML prognosis were identified. Conclusion: lncRNAs HCP5 and MEG3 may act as key ceRNAs in the pathogenesis in AML by regulating immune cell representation as part of the regulatory lncRNA-miRNA-mRNA axes. The candidate mRNAs, lncRNAs, and miRNAs included in the ceRNA network identified here may serve as useful prognostic biomarkers and immunotherapeutic targets for AML.

Plumbing mysterious RNAs in "dark genome" for the conquest of human diseases

Next-generation sequencing has revealed that less than 2% of transcribed genes are translated into proteins, with a large portion transcribed into noncoding RNAs (ncRNAs). Among these, long noncoding RNAs (lncRNAs) represent the largest group and are pervasively transcribed throughout the genome. Dysfunctions in lncRNAs have been found in various diseases, highlighting their potential as therapeutic, diagnostic, and prognostic targets. However, challenges, such as unknown molecular mechanisms and nonspecific immune responses, and issues of drug specificity and delivery present obstacles in translating lncRNAs into clinical applications. In this review, we summarize recent publications that have explored lncRNA functions in human diseases. We also discuss challenges and future directions for developing lncRNA treatments, aiming to bridge the gap between functional studies and clinical potential and inspire further exploration in the field.

PVT1 alleviates hypoxia-induced endothelial apoptosis by enhancing autophagy via the miR-15b-5p/ATG14 and miR-424-5p/ATG14 axis

Endothelial dysfunction plays a crucial role in the pathogenesis of vascular disease. Long noncoding RNA (lncRNA) and microRNA (miRNA) play important roles in various cellular processes and are involved in several vascular endothelial cells (VECs) biological processes, including cell growth, migration, autophagy, and apoptosis. The functions of plasmacytoma variant translocation 1 (PVT1) in VECs have been progressively investigated in recent years, mainly with regard to proliferation and migration of endothelial cells (ECs). However, the mechanism underlying the regulation of autophagy and apoptosis in human umbilical vein endothelial cells (HUVEC) by PVT1 remains unclear. The present study showed that PVT1 knockdown accelerated apoptosis induced by oxygen and glucose deprivation (OGD) through suppression of cellular autophagy. Bioinformatic prediction of PVT1 target miRNAs revealed that PVT1 interacts with miR-15b-5p and miR-424-5p. The study further showed that miR-15b-5p and miR-424-5p inhibit the functions of autophagy related 14 (ATG14) and suppress cellular autophagy. The results showed that PVT1 can function as a competing endogenous RNA (ceRNA) of miR-15b-5p and miR-424-5p and promote cellular autophagy by competitive binding, which down-regulates apoptosis. The results showed that PVT1 can function as a competing endogenous RNA (ceRNA) of miR-15b-5p and miR-424-5p and promote cellular autophagy through competitive binding, which down-regulates apoptosis. The study provides insight into a novel therapeutic target that may be explored in the future for the treatment of cardiovascular disease.

Competing endogenous RNA (ceRNA) in a non-model animal: Non-coding RNAs respond to heat stress in rainbow trout (Oncorhynchus mykiss) through ceRNA-regulated mechanisms

BACKGROUND

Rainbow trout (Oncorhynchus mykiss) is a typical cold-water fish. With global warming and extreme heat, high summer temperatures are the biggest threat to rainbow trout farming. Rainbow trout initiate stress defense mechanisms in response to thermal stimuli, and competing endogenous RNA (ceRNA) regulation of target genes (mRNAs) mediated by non-coding RNAs (microRNAs [miRNAs], long non-coding RNAs) may be the main strategy for responding to thermal stimuli and enhancing adaptation.

RESULTS

We screened the LOC110485411-novel-m0007-5p-hsp90ab1 ceRNA relationship pairs for affect heat stress in rainbow trout and validated their targeting relationships and functions based on preliminary high-throughput sequencing analysis results. The transfection of exogenous novel-m0007-5p mimics and inhibitors into primary rainbow trout hepatocytes effectively bound and inhibited the target genes hsp90ab1 and LOC110485411 without significant effects on hepatocyte viability, proliferation, and apoptosis. The inhibitory effect of novel-m0007-5p overexpression on hsp90ab1 and LOC110485411 under heat stress was time-efficient. Similarly, small interfering RNAs (siRNAs) affected hsp90ab1 mRNA expression by silencing LOC110485411 expression time-efficiently.

CONCLUSIONS

In conclusion, we found that in rainbow trout, LOC110485411 and hsp90ab1 can bind competitively to novel-m0007-5p via 'sponge adsorption' and that interference with LOC110485411 affects hsp90ab1 expression. These results provide potential for anti-stress drug screening in rainbow trout.

Hsa_circ_0003528 promotes cell malignant transformation and immune escape via increasing oncogene PDL1 through sponging miR-511-3p in non-small cell lung cancer

BACKGROUND

Accumulating evidence suggests that circular RNAs (circRNAs) play important regulatory roles in non-small cell lung cancer (NSCLC). At present, we aimed to explore the regulatory role of has_circ_0003528 (circ_0003528) in NSCLC.

METHODS

Alterations of circ_0003528 expression in NSCLC samples and cell lines were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Impacts of circ_0003528 on NSCLC cell malignant transformation were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell invasion, and tube formation assays. Epithelial-mesenchymal transition (EMT)-related markers were detected with western blotting. Pro-inflammatory cytokines were detected by Enzyme-linked immunosorbent assay (ELISA). The regulation mechanism of circ_0003528 was verified by dual-luciferase reporter and RNA pull-down assays. The tumorigenesis role of circ_0003528 was verified by animal experiments.

RESULTS

Higher levels of circ_0003528 were obtained in NSCLC samples and cell lines, and patients with high circ_0003528 expression had a worse prognosis. Silence of circ_0003528 decreased xenograft growth in mouse models and induced cell apoptosis and repressed cell viability, proliferation, invasion, EMT, angiogenesis, and immune escape in NSCLC cells in vitro. Mechanistically, circ_0003528 controlled programmed cell death ligand 1 (PDL1) expression through interaction with miR-511-3p. The inhibiting impacts of circ_0003528 knockdown on NSCLC cell malignant transformation and immune escape were weakened after miR-511-3p silencing. Moreover, PDL1 overexpression partially counteracted miR-511-3p upregulation-mediated suppression on NSCLC cell malignant transformation and immune escape.

CONCLUSIONS

Circ_0003528 facilitated NSCLC cell malignant transformation and immune escape through regulation of the miR-511-3p/PDL1 axis, highlighting the oncogenic role of circ_0003528 in NSCLC.

Circular RNA circTRAPPC6B Enhances IL-6 and IL-1β Expression and Repolarizes Mycobacteria Induced Macrophages from M2- to M1-Like Phenotype by Targeting miR-892c-3p

Mycobacterium tuberculosis (Mtb) infection elicits macrophage polarization into M2 phenotype to block the host's protective immune response. However, it remains unclear how Mtb regulates macrophage polarization. Recent studies have suggested that noncoding RNA may play a role in macrophage polarization. In this study, we investigated the potential involvement of circTRAPPC6B, a circular RNA that is downregulated in tuberculosis (TB) patients, in regulating macrophage polarization. We found that Mtb infection downregulated M1-related IL-6 and IL-1β while highly expressed M2-related CCL22 and CD163. Overexpressed circTRAPPC6B had switched Mtb-infected macrophages from M2- to M1-like phenotype, accompanied by upregulation of IL-6 and IL-1β. Meanwhile overexpressed circTRAPPC6B significantly inhibited Mtb growth in macrophages. Our findings suggest that circTRAPPC6B may regulate macrophage polarization by targeting miR-892c-3p, which is highly expressed in TB patients and M2-like macrophages. And miR-892c-3p inhibitor decreased intracellular Mtb growth in macrophages. Thus, TB-inhibited circTRAPPC6B could specifically induce IL-6 and IL-1β expression to switch/antagonize Mtb-induced macrophage polarization from M2- to M1-like phenotype by targeting miR-892c-3p, leading to enhanced host clearance of Mtb. Our results reveal a potential role for circTRAPPC6B in regulating macrophage polarization during Mtb infection and provide new insights into the molecular mechanisms underlying host defense against Mtb.

The role of long non-coding RNAs in the development of adipose cells

In recent times, the rising prevalence of obesity and its associated comorbidities have had a severe impact on human health and social progress. Therefore, scientists are delving deeper into the pathogenesis of obesity, exploring the role of non-coding RNAs. Long non-coding RNAs (lncRNAs), once regarded as mere "noise" during genome transcription, have now been confirmed through numerous studies to regulate gene expression and contribute to the occurrence and progression of several human diseases. LncRNAs can interact with protein, DNA, and RNA, respectively, and participate in regulating gene expression by modulating the levels of visible modification, transcription, post-transcription, and biological environment. Increasingly, researchers have established the involvement of lncRNAs in regulating adipogenesis, development, and energy metabolism of adipose tissue (white and brown fat). In this article, we present a literature review of the role of lncRNAs in the development of adipose cells.

MITA Promotes Macrophage Proinflammatory Polarization and Its circRNA-Related Regulatory Mechanism in Recurrent Miscarriage

MITA (also called STING), a master regulator of DNA-mediated innate immune activation, is a potential therapeutic target for viral infection and virus-related diseases. The circRNA-mediated ceRNA network plays important roles in gene regulation and may contribute to many human diseases. However, the relationship between MITA and recurrent miscarriage (RM) and its circRNA-related regulatory mechanisms remain unclear. In this study, we validated that the decidual M1/M2 ratio was upregulated in RM patients, suggesting the vital roles of decidual macrophages in the pathogenesis of RM. We found that MITA was highly expressed in decidual macrophages of RM patients and validated that MITA could promote apoptosis and macrophage proinflammatory polarization in THP-1-derived macrophage (TDM) cells. Using circRNA sequencing and bioinformatic analysis, we screened out a novel circRNA (circKIAA0391) that is overexpressed in decidual macrophages of RM patients. Mechanistically, we found that circKIAA0391 could promote the apoptosis and proinflammatory polarization of TDM cells by sponging the miR-512-5p/MITA axis. This study provides a theoretical basis for further understanding the impact of MITA on macrophages and its circRNA-related regulatory mechanisms, which may have a crucial immunomodulatory function in the pathophysiology of RM.

Constructing ferroptosis-related competing endogenous RNA networks and exploring potential biomarkers correlated with immune infiltration cells in asthma using combinative bioinformatics strategy

BACKGROUND

Asthma is a common chronic respiratory disease worldwide. Recent studies have revealed the critical effects of the ceRNA network and ferroptosis on patients with asthma. Thus, this study aimed to explore the potential ferroptosis-related ceRNA network, investigate the immune cell infiltration level in asthma through integrated analysis of public asthma microarray datasets, and find suitable diagnostic biomarkers for asthma.

METHODS

First, three asthma-related datasets which were downloaded from the Gene Expression Omnibus (GEO) database were integrated into one pooled dataset after correcting for batch effects. Next, we screened differentially expressed lncRNAs (DElncRNAs) between patients and healthy subjects, constructed a ceRNA network using the StarBase database and screened ferroptosis-related genes from the predicted target mRNAs for Disease Ontology (DO), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. We also performed Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA) on the batch effect-corrected mRNA expression profile. Then, Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to screen potential diagnostic biomarkers, and the diagnostic efficacy was assessed using a receiver operating characteristic (ROC) curve. Finally, we determined the proportion of 22 immune cells in patients with asthma using CIBERSORT and investigated the correlation between key RNAs and immune cells.

RESULTS

We obtained 19 DElncRNAs, of which only LUCAT1 and MIR222HG had corresponding target miRNAs. The differentially expressed ferroptosis-related genes were involved in multiple programmed cell death-related pathways. We also found that the mRNA expression profile was primarily enriched in innate immune system responses. We screened seven candidate diagnostic biomarkers for asthma using LASSO regression (namely, BCL10, CD300E, IER2, MMP13, OAF, TBC1D3, and TMEM151A), among which the area under the curve (AUC) value for CD300E and IER2 were 0.722 and 0.856, respectively. Finally, we revealed the infiltration ratio of different immune cells in asthma and found a correlation between LUCAT1, MIR222HG, CD300E, and IER2 with some immune cells.

CONCLUSION

This study explored a potential lncRNA-miRNA-mRNA regulatory network and its underlying diagnostic biomarkers (CD300E and IER2) in asthma and identified the immune cells most associated with them, providing possible diagnostic markers and immunotherapeutic targets for asthma.

Circular RNA circDLG1 contributes to HCC progression by regulating the miR-141-3p/WTAP axis

This study aims to explore novel and reliable biomarkers for predicting hepatocellular carcinoma (HCC) prognosis. Circular RNAs (circRNAs) were determined by analysis of human circRNA arrays and quantitative reverse transcription polymerase reactions. To test for an interaction between circDLG1, we used luciferase reporter assays, RNA immunoprecipitation, and fluorescence in situ hybridization assays that were employed to test the interaction between circDLG1, miR-141-3p, and WTAP. q-RT-PCR and western blot were used to evaluate the target regulation of miR-141-3p and WTAP. shRNA-mediated knockdown of circDLG1, proliferation, migration, and invasion experiment of metastasis were used to evaluate the function of circDLG. CircDLG1 rather than lining DLG1 was upregulated in HCC tissues, from HCC patients as well as HCC cell lines compared to normal controls. circDLG1 high expression in HCC patients was correlated with shorter overall survival. Knockdown of circDLG1 and miR-141-3p mimic could inhibit the tumorigenesis of HCC cells in vivo and in vitro. Importantly, we demonstrated that circDLG1 could act as a sponge of miR-141-3p to regulate the expression of WTAP, and further suppress the tumorigenesis of HCC cells. Our study reveals that circDLG1 can serve as a novel potential circulating biomarker for the detection of HCC. circDLG1 participates in the progression of HCC cells by sponging miR-141-3p with WTAP, providing new insight into the treatment of HCC.

Non-coding RNA-based therapeutics in cancer therapy: An emphasis on Wnt/β-catenin control

Non-coding RNA transcripts are RNA molecules that have mainly regulatory functions and they do not encode proteins. microRNAs (miRNAs), lncRNAs and circRNAs are major types of this family and these epigenetic factors participate in disease pathogenesis, especially cancer that their abnormal expression may lead to cancer progression. miRNAs and lncRNAs possess a linear structure, whereas circRNAs possess ring structures and high stability. Wnt/β-catenin is an important factor in cancer with oncogenic function and it can increase growth, invasion and therapy resistance in tumors. Wnt upregulation occurs upon transfer of β-catenin to nucleus. Interaction of ncRNAs with Wnt/β-catenin signaling can determine tumorigenesis. Wnt upregulation is observed in cancers and miRNAs are able to bind to 3'-UTR of Wnt to reduce its level. LncRNAs can directly/indirectly regulate Wnt and in indirect manner, lncRNAs sponge miRNAs. CircRNAs are new emerging regulators of Wnt and by its stimulation, they increase tumor progression. CircRNA/miRNA axis can affect Wnt and carcinogenesis. Overall, interaction of ncRNAs with Wnt can determine proliferation rate, migration ability and therapy response of cancers. Furthermore, ncRNA/Wnt/β-catenin axis can be utilized as biomarker in cancer and for prognostic applications in patients.

lncRNA AC005224.4/miR-140-3p/SNAI2 regulating axis facilitates the invasion and metastasis of ovarian cancer through epithelial-mesenchymal transition

BACKGROUND

Ovarian cancer is one of the most widespread malignant diseases of the female reproductive system worldwide. The plurality of ovarian cancer is diagnosed with metastasis in the abdominal cavity. Epithelial-mesenchymal transition (EMT) exerts a vital role in tumor cell metastasis. However, it remains unclear whether long non-coding RNA (lncRNA) are implicated in EMT and influence ovarian cancer cell invasion and metastasis. This study was designed to investigate the impacts of lncRNA AC005224.4 on ovarian cancer.

METHODS

LncRNA AC005224.4, miR-140-3p, and snail family transcriptional repressor 2 ( SNAI2 ) expression levels in ovarian cancer and normal ovarian tissues were determined using real-time quantitative polymerase chain reaction (qRT-PCR). Cell Counting Kit-8 (CCK-8) and Transwell (migration and invasion) assays were conducted to measure SKOV3 and CAOV-3 cell proliferation and metastasis. E-cadherin, N-cadherin, Snail, and Vimentin contents were detected using Western blot. Nude mouse xenograft assay was utilized to validate AC005224.4 effects in vivo . Dual-luciferase reporter gene assay confirmed the targeted relationship between miR-140-3p and AC005224.4 or SNAI2 .

RESULTS

AC005224.4 and SNAI2 upregulation and miR-140-3p downregulation were observed in ovarian cancer tissues and cells. Silencing of AC005224.4 observably moderated SKOV3 and CAOV-3 cell proliferation, migration, invasion, and EMT process in vitro and impaired the tumorigenesis in vivo . miR-140-3p was a target of AC005224.4 and its reduced expression level was mediated by AC005224.4. miR-140-3p mimics decreased the proliferation, migration, and invasion of ovarian cancer cells. SNAI2 was identified as a novel target of miR-140-3p and its expression level was promoted by either AC005224.4 overexpression or miR-140-3p knockdown. Overexpression of SNAI2 also facilitated ovarian cancer cell viability and metastasis.

CONCLUSION

AC005224.4 was confirmed as an oncogene via sponging miR-140-3p and promoted SNAI2 expression, contributing to better understanding of ovarian cancer pathogenesis and shedding light on exploiting the novel lncRNA-directed therapy against ovarian cancer.

Pathogenesis of psoriasis via miR-149-5p/AKT1axis by long noncoding RNA BLACAT1

BACKGROUND

Psoriasis is a chronic, complicated, and recurrent inflammatory skin disease, whose precise molecular mechanisms need to be further explored. The lncRNA bladder cancer-associated transcript 1 (BLACAT1) is aberrantly expressed in many cancers and associated with cellular hyperproliferation and may play a role in the pathogenesis of psoriasis. Thus, this study aimed at identifying the primary mechanism associated with BLACAT1 in psoriasis pathogenesis.

MATERIALS AND METHODS

Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was performed to detect the expression of BLACAT1 in psoriasis tissues. Cell proliferation and apoptosis were assessed using cell counting kit-8 and apoptosis assays, respectively. In vivo experiments and histopathological examinations were performed to investigate the effects of BLACAT1 on psoriasis. Dual-luciferase Reporter and RNA immunoprecipitation assays were used to evaluate the relationship among BLACAT1 and miR-149-5p and AKT1.

RESULTS

BLACAT1 was upregulated in psoriasis tissues. Overexpression exacerbated the clinical manifestation of psoriasis and increased the epidermal thickness in imiquimod-induced mice. BLACAT1 could promote proliferation and inhibit apoptosis of keratinocytes. Further studies demonstrated that BLACAT1 positively regulated AKT1 expression, functioning as a competing endogenous RNA (ceRNA) by sponging miR-149-5p.

CONCLUSIONS

The combination of lncRNA BLACAT1 and miR-149-5p regulates AKT1 expression and promotes psoriasis formation thus may provide a new direction for psoriasis treatment.

Endothelial plasticity across PTEN and Hippo pathways: A complex hormetic rheostat modulated by extracellular vesicles

Vascularization is a multifactorial and spatiotemporally regulated process, essential for cell and tissue survival. Vascular alterations have repercussions on the development and progression of diseases such as cancer, cardiovascular diseases, and diabetes, which are the leading causes of death worldwide. Additionally, vascularization continues to be a challenge for tissue engineering and regenerative medicine. Hence, vascularization is the center of interest for physiology, pathophysiology, and therapeutic processes. Within vascularization, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and Hippo signaling have pivotal roles in the development and homeostasis of the vascular system. Their suppression is related to several pathologies, including developmental defects and cancer. Non-coding RNAs (ncRNAs) are among the regulators of PTEN and/or Hippo pathways during development and disease. The purpose of this paper is to review and discuss the mechanisms by which exosome-derived ncRNAs modulate endothelial cell plasticity during physiological and pathological angiogenesis, through the regulation of PTEN and Hippo pathways, aiming to establish new perspectives on cellular communication during tumoral and regenerative vascularization.

lncfos/miR-212-5p/CASP7 Axis-Regulated miR-212-5p Protects the Brain Against Ischemic Damage

miR-212-5p has been reported to be involved in many biological processes. However, the role of miR-212-5p in ischemic stroke remains unclear. This study explored the biological role and potential mechanism of miR-212-5p in ischemic stroke by investigating the lncfos/miR-212-5p/CASP7 axis. A total of 32 patients with ischemic stroke and 32 age- and sex-matched healthy controls (HCs) were enrolled in this study. In addition, 336 rats were used in this study. The rats were subjected to middle cerebral artery occlusion (MCAO) and intracerebroventricular injection of a microRNA (miRNA) agomir, a miRNA antagomir, a short hairpin RNA (shRNA) lentiviral vector, or a negative control. The neurological deficit score was calculated; the infarct volume was measured; histopathological assays were performed; the neuronal apoptosis rate was determined; and the lncfos, miR-212-5p, and CASP7 expression levels in the peri-infarct area were assessed. In this study, we found that the expression level of miR-212-5p was significantly downregulated in the peri-infarct area and blood of the MCAO model rats and the blood of patients with ischemic stroke. A double-luciferase experiment showed that CASP7 was a direct target gene of miR-212-5p and that miR-212-5p was a target miRNA of lncfos. Lateral ventricular injection of the miR-212-5p agomir effectively inhibited the apoptosis induced by ischemic brain damage, reduced the infarct volume, attenuated the neurological deficit symptoms, and downregulated the expression of CASP7 in the peri-infarct area of the MCAO model rats. Suppressing lncfos with sh-fos led to the upregulated expression of miR-212-5p and played a neuroprotective role in the rat MCAO models. We concluded that miR-212-5p plays a neuroprotective role in ischemic stroke and that its function is regulated by the lncfos/miR-212-5p/CASP7 axis. Moreover, miR-212-5p may be a potential biomarker and therapeutic target for ischemic stroke.

Circular RNA circ_0008896 contributes to oxidized low-density lipoprotein-induced aortic endothelial cell injury via targeting miR-188-3p/NOD2 axis

We aimed to investigate the role and mechanism of circ_0008896 in Atherosclerosis (AS) by using oxidized low-density lipoprotein (ox-LDL)-induced human aortic endothelial cell (HAECs). Levels of genes and proteins were measured by quantitative real-time PCR and Western blot. Functional experiments, including enzyme-linked immunosorbent assay analysis, cell counting kit-8, 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, tube formation assays and the detection of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) generation, were performed to investigate the role of circ_0008896 on ox-LDL-induced HAEC damage. Circ_0008896 was increased in AS patients and ox-LDL-stimulated HAECs. Functionally, circ_0008896 knockdown reversed ox-LDL-induced inflammatory response, oxidative stress, apoptosis as well as arrest of proliferation and angiogenesis in HAECs in vitro. Mechanistically, circ_0008896 functioned as a sponge for miR-188-3p to relieve the repression of miR-188-3p on its target NOD2. A series of rescue experiments showed that miR-188-3p inhibition attenuated the protective effects of circ_0008896 knockdown on ox-LDL-stimulated HAECs, and NOD2 overexpression abolished the beneficial action of miR-188-3p in the suppression of inflammatory response and oxidative stress, and the promotion of cell growth and angiogenesis in HAECs under ox-LDL treatment. Circ_0008896 silencing attenuates ox-LDL-induced inflammatory response, oxidative stress, and growth arrest in HAECs in vitro, adding further understanding for the pathogenesis of AS.

The β-catenin-LINC00183-miR-371b-5p-Smad2/LEF1 axis promotes adult T-cell lymphoblastic lymphoma progression and chemoresistance

BACKGROUND

High-intensity chemotherapy regimens are often used in adult T-cell lymphoblastic lymphoma (T-LBL) patients. Nevertheless, the response rate remains unsatisfactory due to emergence of chemoresistance. Growing evidence has shown that long non-coding RNAs (lncRNAs) are involved in tumor progression and chemoresistance. Herein, we investigated the potential role of lncRNAs in T-LBLs.

METHODS

RNAseq was used to screen and identify candidate lncRNAs associated with T-LBL progression and chemoresistance. Luciferase reporter assay was used to examine the binding of miR-371b-5p to the 3'UTR of Smad2 and LEF1, and the binding of TCF-4/LEF1 to the promoter of LINC00183. Chromatin immunoprecipitation assay was undertaken to analyze the connection between LEF1 and the LINC00183 promoter region. RNA immunoprecipitation assays were used to explore the mechanism whereby LINC00183 regulated miR-371b-5p. MTT and flow cytometry assays were used to measure apoptosis of T-LBL cells.

RESULTS

LINC00183 was upregulated in T-LBL progression and chemoresistant tissues in both the Sun Yat-sen University Cancer Center dataset and the First Affiliated Hospital of Anhui Medical University dataset. High expression of LINC00183 was correlated with poorer overall survival and progression-free survival of T-LBL patients compared to those with low expression of LINC00183. Furthermore, miR-371b-5p was negatively regulated by LINC00183. In vivo and in vitro assays showed that LINC00183-mediated T-LBL chemoresistance depended on miR-371b-5p expression. The direct binding of miR-371b-5p to Smad2 and LEF1 was verified by luciferase assays. It was shown that TCF4/LEF1 could bind to the LINC00183 promoter site and increase its transcript level. Downregulation of miR-371b-5p led to increased expression of Smad2/LEF1, and in turn increased LINC00183 expression. Additionally, phospho-Smad2 promotes nuclear translocation of β-catenin, LINC00183 downregulation decreased chemoresistance induced by β-catenin and TGF-β1 in T-LBL cells.

CONCLUSION

We unraveled a β-catenin-LINC00183-miR-371b-5p-Smad2/LEF1 feedback loop that promotes T-LBL progression and chemoresistance, indicating that LINC00183 may serve as a potential therapeutic target in T-LBLs.