hsa_circ_0000518 stimulates the malignant progression of hepatocellular carcinoma via regulating ITGA5 to activate the Warburg effect.

Studies have shown that the abnormal expression of circular RNA (circRNA) is inextricably linked to hepatocellular carcinoma (HCC). Recently, hsa_circ_0000518 (circ_0000518) was discovered in many cancer progressions. However, its function in HCC is still unclear. Through GEO database analysis combined with gene expression detection of HCC related clinical samples and cell lines, we identified that circ_0000518 was abnormally overexpressed in HCC. Cell and animal model experiments jointly indicated that circ_0000518 can stimulate HCC cell proliferation, migration, invasion and suppress apoptosis. Furthermore, we also found that knocking down the circ_0000518 could inhibit the Warburg effect in HCC cells. Mechanistically, circ_0000518 was found to be primarily localized in the cytoplasm, and sponge hsa-miR-326 (miR-326) promoted integrin alpha 5 (ITGA5) expression. In addition, circ_0000518 could enhance the stability of HuR-mediated ITGA5 mRNA, thereby activating the Warburg effect. In conclusion, this study elucidated that circ_0000518 was a cancer-promoting circRNA, which could enhance ITGA5 expression through competing endogenous RNAs (ceRNA) and RNA Binding Protein (RBP) mechanisms, thus facilitating the development of HCC. It provides a meaningful diagnostic and therapeutic target for HCC.

Silencing of circRPPH1 Inhibits the Progression of Non-Small-Cell Lung Cancer Through miR-326/ERBB4 Signal Axis.

Circular RNAs (circRNAs) play critical roles in the recurrence and progression of non-small-cell lung cancer (NSCLC). This study aimed to investigate the function and underlying mechanism of a novel circRNA (circRPPH1) in NSCLC. Localization of circRPPH1 was determined via FISH assay, while cell proliferation was assessed via CCK8 and colony formation assay. Cell migration and invasion were studied using transwell assay, while binding sites between miR-326 and circRPPH1 or ERBB4 were verified by luciferase reporter, RIP, and RNA pull-down assays. Moreover, xenograft assay was performed to verify the in vivo roles of circRPPH1. Results indicated that circRPPH1 was highly expressed in NSCLC tissues and cells, where circRPPH1 levels were predictive of poor prognosis. The malignant behavior of NSCLC cells was exacerbated by overexpressing circRPPH1, while opposite effects were observed when it was knocked down. Direct interaction between miR-326 and circRPPH1 or ERBB4 was confirmed in NSCLC cells, while rescue experiment results showed that circRPPH1 exerted an oncogenic role via miR-326-ERBB4 signal axis. Moreover, in vitro, growth of NSCLC cells was significantly attenuated following circRPPH1 depletion. The study concluded that circRPPH1 was involved in promoting NSCLC progression via the miR-326/ERBB4 axis, which provided a novel potential target for the diagnosis or treatment of NSCLC.

ZNF460-mediated circRPPH1 promotes TNBC progression through ITGA5-induced FAK/PI3K/AKT activation in a ceRNA manner.

BACKGROUND: Circular RNAs are highly stable regulatory RNAs that have been increasingly associated with tumorigenesis and progression. However, the role of many circRNAs in triple-negative breast cancer (TNBC) and the related mechanisms have not been elucidated. METHODS: In this study, we screened circRNAs with significant expression differences in the RNA sequencing datasets of TNBC and normal breast tissues and then detected the expression level of circRPPH1 by qRT‒PCR. The biological role of circRPPH1 in TNBC was then verified by in vivo and in vitro experiments. Mechanistically, we verified the regulatory effects between circRPPH1 and ZNF460 and between circRPPH1 and miR-326 by chromatin immunoprecipitation (ChIP), fluorescence in situ hybridization assay, dual luciferase reporter gene assay and RNA pull-down assay. In addition, to determine the expression of associated proteins, we performed immunohistochemistry, immunofluorescence, and western blotting. RESULTS: The upregulation of circRPPH1 in TNBC was positively linked with a poor prognosis. Additionally, both in vivo and in vitro, circRPPH1 promoted the biologically malignant behavior of TNBC cells. Additionally, circRPPH1 may function as a molecular sponge for miR-326 to control integrin subunit alpha 5 (ITGA5) expression and activate the focal adhesion kinase (FAK)/PI3K/AKT pathway. CONCLUSION: Our research showed that ZNF460 could promote circRPPH1 expression and that the circRPPH1/miR-326/ITGA5 axis could activate the FAK/PI3K/AKT pathway to promote the progression of TNBC. Therefore, circRPPH1 can be used as a therapeutic or diagnostic target for TNBC.

MiR-326 sponges TET2 triggering imbalance of Th17/Treg differentiation to exacerbate pyroptosis of hepatocytes in concanavalin A-induced autoimmune hepatitis.

INTRODUCTION AND OBJECTIVES: MicroRNA-326 is abnormally expressed in autoimmune diseases, but its roles in autoimmune hepatitis (AIH) are unknown. In this study, we aimed to investigate the effect of miR-326 on AIH and the underlying mechanism. MATERIALS AND METHODS: Concanavalin A was administrated to induce AIH in mice and the expression levels of miR-326 and TET2 was evaluated by qRT-PCR and western blot, respectively. The percentages of Th17 and Treg cells were evaluated by flow cytometry and their marker proteins were determined by western blot and ELISA. The mitochondrial membrane potential (MMP) and ROS level were tested with the JC-1 kit and DCFH-DA assay. The binding relationships between miR-326 and TET2 were verified by dual-luciferase reporter assay. The liver tissues were stained by the HE staining. In vitro, AML12 cells were cocultured with mouse CD4+T cells. The expression levels of pyroptosis-related proteins were assessed by western blot. RESULTS: Concanavalin A triggered AIH and enhanced the expression level of miR-326 in mice. It increased both Th17/Treg ratio and the levels of their marker proteins. The expression of TET2 was decreased in AIH mice. Knockdown of miR-326 could decrease the levels of pyroptosis-related proteins, the ROS level and increase MMP. In mouse CD4+T cells, miR-326 sponged TET2 to release IL-17A. Coculture of AML12 cells with isolated CD4+T cells from miR-326 knockdown AIH mice could relieve pyroptosis. CONCLUSIONS: Knockdown of miR-326 exerted anti-pyroptosis effects via suppressing TET2 and downstream NF-κB signaling to dampen AIH. We highlighted a therapeutic target in AIH.

Downregulation of microRNA-326 enhances ZNF322A expression, transcriptional activity and tumorigenic effects in lung cancer.

Zinc finger protein ZNF322A is an oncogenic transcription factor. Overexpression of ZNF322A activates pro-metastasis, cancer stemness, and neo-angiogenesis-related genes to enhance lung cancer progression. However, the upstream regulator of ZNF322A is not well defined. Dysregulation of microRNAs (miRNAs) can mediate cancer cell growth, migration, and invasion to promote tumorigenesis. Here, we uncover the mechanism of miRNA-mediated transcriptional regulation in ZNF322A-driven oncogenic events. ZNF322A harbors several putative miRNA-binding sites in the 3'-untranslated region (UTR). We validated that miR-326 downregulated ZNF322A-3'-UTR luciferase activity and mRNA expression. Furthermore, miR-326 suppressed the expression of ZNF322A-driven cancer-associated genes such as cyclin D1 and alpha-adducin. Reconstitution experiments by ectopic overexpression of ZNF322A abolished miR-326-suppressed cancer cell proliferation and cell migration capacity. Moreover, miR-326 attenuated ZNF322A-induced tumor growth and lung tumor metastasis in vivo. Clinically, the expression of miR-326 negatively correlated with ZNF322A mRNA expression in surgically resected tissues from 120 non-small cell lung cancer (NSCLC) patients. Multivariate Cox regression analysis demonstrated that NSCLC patients with low miR-326/high ZNF322A profile showed poor overall survival. Our results reveal that the deregulated expression of miR-326 leads to hyperactivation of ZNF322A-driven oncogenic signaling. Targeting the miR-326/ZNF322A axis would provide new therapeutic strategies for lung cancer patients.

Lnc-HIBADH-4 Regulates Autophagy-Lysosome Pathway in Amyotrophic Lateral Sclerosis by Targeting Cathepsin D.

Amyotrophic lateral sclerosis (ALS) is the most prevalent and lethal class of severe motor neuron diseases (MND) with no efficacious treatment. The pathogenic mechanisms underlying ALS remain unclear. Nearly 90% of patients exhibit sporadic onset (sALS). Therefore, elucidating the pathophysiology of ALS is imperative. Long non-coding RNA (lncRNA) is a large class of non-coding RNAs that regulate transcription, translation, and post-translational processes. LncRNAs contribute to the pathogenesis of diverse neurodegenerative disorders and hold promise as targets for interference in the realm of neurodegeneration. However, the mechanisms of which lncRNAs are involved in ALS have not been thoroughly investigated. We identified and validated a downregulated lncRNA, lnc-HIBADH-4, in ALS which correlated with disease severity and overall survival. Lnc-HIBADH-4 acted as a "molecular sponge" regulating lysosomal function through the lnc-HIBADH-4/miR-326/CTSD pathway, thereby impacting autophagy-lysosome dynamics and the levels of cell proliferation and apoptosis. Therefore, this study discovered and revealed the role of lnc-HIBADH-4 in the pathogenesis of ALS. With further research, lnc-HIBADH-4 is expected to provide a new biomarker in the diagnosis and treatment of ALS.

LncRNA Gm28382 promotes lipogenesis by interacting with miR-326-3p to regulate ChREBP signaling pathway in NAFLD.

Long non-coding RNAs (lncRNAs) have been demonstrated to play vital roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). However, their biological roles and function mechanisms in NAFLD remain largely unknown. In this study, we found that Gm28382 may be a potential pathogenic lncRNA of NAFLD and highly expressed in NAFLD through RNA-seq. Overexpression of Gm28382 significantly enhanced the lipid accumulation in AML12 cells, whereas Gm28382 silencing reduced lipogenesis both in palmitic acid (PA)-induced AML12 cells and high fat diet (HFD)-induced mice. Then, bioinformatics were employed to speculate the potential interacting genes of Gm28382, and found that Gm28382 may regulate ChREBP expression through binding with miR-326-3p. Fluorescence in situ hybridization (FISH), dual luciferase reporter assay, immunofluorescence RNA pull-down and RNA immunoprecipitation (RIP) assays were used to validate the binding and targeting relationship of these genes, and we confirmed that Gm28382 competitively binds to miR-326-3p to increase ChREBP expression as a ceRNA. Mechanistically, overexpression of Gm28382 upregulated the ChREBP-mediated lipid synthesis signaling pathway, but the function was sabotaged by miR-326-3p deletion or ChREBP overexpression. Furthermore, in PA-challenged AML12 cells or HFD-induced mice, silencing of Gm28382 reversed the aberrant ChREBP signaling pathway and lipid accumulation, whereas ChREBP overexpression or liver-specific silencing of miR-326-3p blocked this function of Gm28382. Collectively, these findings reveal a critical role of Gm28382 in the promotion of lipogenesis in NAFLD by regulating the ChREBP signaling pathway through interaction with miR-326-3p, which could serve as a potential therapeutic target for NAFLD treatment.

Adhesion G Protein-Coupled Receptor G2 Promotes Hepatocellular Carcinoma Progression and Serves as a Neutrophil-Related Prognostic Biomarker.

Adhesion G protein-coupled receptor G2 (ADGRG2) is an orphan adhesion G protein-coupled receptor (GPCR), which performs a tumor-promoting role in certain cancers; however, it has not been systematically investigated in hepatocellular carcinoma (HCC). In the current study, we utilized multiple databases to analyze the expression and diagnostic and prognostic value of ADGRG2 in HCC and its correlation with immune infiltration and inflammatory factors. The function and upstream regulatory miRNA of ADGRG2 were validated through qPCR, Western blot, CCK8, wound healing, and dual luciferase assays. It turned out that ADGRG2 was significantly higher in HCC and had a poor survival rate, especially in AFP ≤ 400 ng/mL subgroups. Functional enrichment analysis suggested that ADGRG2 may be involved in cancer pathways and immune-related pathways. In vitro, siRNA-mediated ADGRG2 silencing could inhibit the proliferation and migration of Huh7 and HepG2 cells. There was a highly significant positive correlation between ADGRG2 and neutrophils. Moreover, NET-related genes were filtered and confirmed, such as ENO1 and S100A9. Meanwhile, the high expression of ADGRG2 was also accompanied by the highest number of inflammatory cytokines, chemokines, and chemokine receptors and good immunotherapy efficacy. Finally, AGDGR2 may be sensitive to two drugs (PIK-93 and NPK76-II-72-1) and can be targeted by miR-326. In conclusion, ADGRG2 may serve as a novel biomarker and drug target for HCC diagnosis, immunotherapy, and prognosis and was related to neutrophils and the inflammatory process of liver cancer development.

CircATP13A1 (hsa_circ_0000919) promotes cell proliferation and metastasis and inhibits cell apoptosis in pancreatic ductal adenocarcinoma via the miR-186/miR-326/HMGA2 axis: implications for novel therapeutic targets.

Pancreatic ductal adenocarcinoma (PDAC) is a notoriously aggressive malignancy with a survival rate of merely 9%. The prognosis in patients with PDAC is relatively poor, particularly in patients with advanced distant metastases. However, the mechanisms of PDAC progression remain elusive. Circular RNAs (circRNAs) have been implicated in the development of various malignancies, including PDAC. Therefore, this study aimed to investigate how a novel circRNA, circATP13A1, regulates PDAC progression. We used the GEO database to determine circATP13A1 expression levels in cancer and adjacent cells and employed the limma package of R software to identify differentially expressed circRNAs. We detected the expression of circATP13A1, miR-186, and miR-326 using qRT-PCR and investigated the effect of circATP13A1 on cell proliferation, migration, invasion, and apoptosis in vitro using the Cell Counting Kit-8 (CCK-8), the transwell migration assay, and the flow cytometry assay. We then performed RNA pull-down assay, RNA immunoprecipitation (RIP), and Western blot to verify the interaction between circATP13A1, miR-186, miR-326, and HMGA2. Moreover, we used a naked mice model to determine how circATP13A1 affects tumor growth and progression in vivo. Loss and gain of function analyses revealed that circATP13A1 upregulation promotes cell proliferation, migration, invasion and tumor growth both in vitro and in vivo, which results in PDAC progression and poor prognosis in patients. CircATP13A1 knockdown significantly impaired cell proliferation and migration of PDAC cell lines. Additionally, circATP13A1 knockdown significantly increased the expression of miR-186 and miR-326, while reducing the expression of HMGA2 (P < 0.05), indicating that miR-186 and miR-326 are downstream targets of circATP13A1. Rescue experiments support the interactions between circATP13A1, miR-186, miR-326, and HMGA2. In conclusion, we demonstrated that circATP13A1 sponges the miR-186/miR-326/HMGA2/axis, acting as an oncogene to promote PDAC development.

MiR-326-mediated overexpression of NFIB offsets TGF-ß induced epithelial to mesenchymal transition and reverses lung fibrosis.

Idiopathic Pulmonary Fibrosis (IPF) is a progressively fatal and incurable disease characterized by the loss of alveolar structures, increased epithelial-mesenchymal transition (EMT), and aberrant tissue repair. In this study, we investigated the role of Nuclear Factor I-B (NFIB), a transcription factor critical for lung development and maturation, in IPF. Using both human lung tissue samples from patients with IPF, and a mouse model of lung fibrosis induced by bleomycin, we showed that there was a significant reduction of NFIB both in the lungs of patients and mice with IPF. Furthermore, our in vitro experiments using cultured human lung cells demonstrated that the loss of NFIB was associated with the induction of EMT by transforming growth factor beta (TGF-ß). Knockdown of NFIB promoted EMT, while overexpression of NFIB suppressed EMT and attenuated the severity of bleomycin-induced lung fibrosis in mice. Mechanistically, we identified post-translational regulation of NFIB by miR-326, a miRNA with anti-fibrotic effects that is diminished in IPF. Specifically, we showed that miR-326 stabilized and increased the expression of NFIB through its 3'UTR target sites for Human antigen R (HuR). Moreover, treatment of mice with either NFIB plasmid or miR-326 reversed airway collagen deposition and fibrosis. In conclusion, our study emphasizes the critical role of NFIB in lung development and maturation, and its reduction in IPF leading to EMT and loss of alveolar structures. Our study highlights the potential of miR-326 as a therapeutic intervention for IPF. The schema shows the role of NFIB in maintaining the normal epithelial cell characteristics in the lungs and how its reduction leads to a shift towards mesenchymal cell-like features and pulmonary fibrosis. A In normal lungs, NFIB is expressed abundantly in the epithelial cells, which helps in maintaining their shape, cell polarity and adhesion molecules. However, when the lungs are exposed to factors that induce pulmonary fibrosis, such as bleomycin, or TGF-ß, the epithelial cells undergo epithelial to mesenchymal transition (EMT), which leads to a decrease in NFIB. B The mesenchymal cells that arise from EMT appear as spindle-shaped with loss of cell junctions, increased cell migration, loss of polarity and expression of markers associated with mesenchymal cells/fibroblasts. C We designed a therapeutic approach that involves exogenous administration of NFIB in the form of overexpression plasmid or microRNA-326. This therapeutic approach decreases the mesenchymal cell phenotype and restores the epithelial cell phenotype, thus preventing the development or progression of pulmonary fibrosis.

Cuproptosis-related lncRNAs as potential biomarkers of AML prognosis and the role of lncRNA HAGLR/miR-326/CDKN2A regulatory axis in AML.

Acute myeloblastic leukemia (AML) is the most prevalent form of AML in adults. Despite the availability of various treatment options, including radiotherapy and chemotherapy, many patients fail to respond to treatment or relapse. Copper is a necessary cofactor for all organisms; however, it turns toxic when concentrations reach a certain threshold maintained by homeostatic systems that have been conserved through evolution. However, the mechanism through which excess copper triggers cell death remains unknown. In this study, data on long non-coding RNAs (lncRNAs) related to cuproptosis were retrieved from publicly available databases. LASSO and univariate and multivariate Cox regression analyses were performed to establish an lncRNA model associated with cuproptosis specific to AML. To investigate the risk model, the Kaplan-Meier curve, principal component analysis, functional enrichment analysis, and nomographs were employed. The underlying clinicopathological characteristics were determined, and drug sensitivity predictions against the model were identified. Six cuproptosis-related lncRNA-based risk models were identified as the independent prognostic factors. By regrouping patients using a model-based method, we were able to more accurately differentiate patients according to their responses to immunotherapy. In addition, prospective compounds targeting AML subtypes have been identified. Using qRT-PCR, we examined the expression levels of six cuproptosis-associated lncRNAs in 30 clinical specimens. The cuproptosis-associated lncRNA risk-scoring model developed herein has implications in monitoring AML prognosis and in the clinical prediction of the response to immunotherapy. Furthermore, we identified and verified the ceRNA of the cuproptosis-related lncRNA HAGLR/miR-326/CDKN2A regulatory axis using bioinformatic tools. HAGLR is highly expressed in AML and AML cell lines. HAGLR inhibition significantly reduced the proliferation of AML cells and promoted apoptosis. Elesclomol promotes the degradation of CDKN2A and inhibits the proliferation of AML cells. Elesclomol combined with si-HAGLR inhibited the AML progression of AML both in vitro and in vivo.

MicroRNA-326 negatively regulates CD155 expression in lung adenocarcinoma.

Treatment with immune checkpoint inhibitors induces a durable response in some patients with non-small-cell lung cancer, but eventually gives rise to drug resistance. Upregulation of CD155 expression is implicated as one mechanism of resistance to programmed death receptor-1 (PD-1)/PD-1 ligand (PD-L1) inhibitors, and it is therefore important to characterize the mechanisms underlying regulation of CD155 expression in tumor cells. The aim of this study was to identify microRNAs (miRNAs) that might regulate CD155 expression at the posttranscriptional level in lung cancer. Comprehensive miRNA screening with target prediction programs and a dual-luciferase reporter assay identified miR-346, miR-328-3p, miR-326, and miR-330-5p as miRNAs that bind to the 3'-UTR of CD155 mRNA. Forced expression of these miRNAs suppressed CD155 expression in lung cancer cell lines. Immunohistochemical staining of CD155 in tissue specimens from 57 patients with lung adenocarcinoma revealed the median tumor proportion score for CD155 to be 68%. The abundance of miR-326 in these specimens with a low level of CD155 expression was significantly greater than in specimens with a high level (p < 0.005). Our results thus suggest that miR-326 negatively regulates CD155 expression in lung adenocarcinoma and might therefore play a role in the development of resistance to PD-1/PD-L1 inhibitors.

Regulation of tumorigenesis and ferroptosis in non-small cell lung cancer by a novel BBOX1-AS1/miR-326/PROM2 axis.

Dysregulation of long non-coding RNAs (lncRNAs) is associated with the tumorigenesis and ferroptosis of non-small cell lung cancer (NSCLC). BBOX1 antisense RNA 1 (BBOX1-AS1) functions as an oncogenic driver in NSCLC. Here, we aim to investigate the regulation effect and underlying mechanism of BBOX1-AS1 in NSCLC progression and ferroptosis. RNA expression was detected by quantitative real-time PCR (qRT-PCR), and protein expression was measured by immunoblotting. Cell growth was assessed by CCK-8 and colony formation assays. Transwell assay was applied to evaluate cell invasion and migration. RNA pull-down and dual-luciferase reporter assays were applied to verify the relationship between miR-326 and BBOX1-AS1 or prominin 2 (PROM2). The role of BBOX1-AS1 in NSCLC tumorigenicity was also analyzed by xenograft assays. Silencing BBOX1-AS1 or PROM2 impeded NSCLC cell growth, migration, and invasion. Silencing BBOX1-AS1 induced cell apoptosis and ferroptosis. BBOX1-AS1 up-regulated PROM2 expression, and re-expression of PROM2 reversed the effects of BBOX1-AS1 depletion on cell malignant phenotypes and ferroptosis. BBOX1-AS1 post-transcriptionally modulated PROM2 expression by sponging miR-326. MiR-326 was validated as a mediator of BBOX1-AS1 in regulating NSCLC cell malignant phenotypes and ferroptosis. Additionally, BBOX1-AS1 deficiency in vivo resulted in the suppression of xenograft tumor growth. Together, our study defines a novel BBOX1-AS1/miR-326/PROM2 axis in regulating NSCLC malignant progression and ferroptosis, offering new evidence for the oncogenic role of BBOX1-AS1 in NSCLC. These findings may provide a basis for the future usage of targeting BBOX1-AS1 in NSCLC treatment.

RUSC1-AS1 promotes the malignant progression of breast cancer depending on the regulation of the miR-326/XRCC5 pathway.

BACKGROUND: Many long noncoding RNAs (lncRNAs) are the key regulators for cancer progression, including breast cancer (BC). RUSC1 antisense 1 (RUSC1-AS1) has been found to be highly expressed in BC, but its role and potential molecular mechanism in BC remain to be further elucidated. METHODS: Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was utilized to measure RUSC1-AS1, microRNA (miR)-326 and X-ray repair cross-complementing group 5 (XRCC5) expression. Cell proliferation, metastasis, cell cycle, apoptosis and angiogenesis were determined by cell counting kit-8, colony formation, transwell, flow cytometry and tube formation assays. Protein expression was detected by western blot analysis. The targeted relationship between miR-326 and RUSC1-AS1 or XRCC5 was validated using dual-luciferase reporter assay and RIP assay. Xenograft models were constructed to uncover the effect of RUSC1-AS1 on BC tumorigenesis. RESULTS: RUSC1-AS1 was upregulated in BC, and its downregulation suppressed BC proliferation, metastasis, cell cycle, angiogenesis, and tumor growth. MiR-326 was confirmed to be sponged by RUSC1-AS1, and its inhibitor reversed the regulation of RUSC1-AS1 silencing on BC progression. XRCC5 could be targeted by miR-326. Overexpression of XRCC5 reversed the inhibitory impacts of miR-326 on BC progression. CONCLUSION: RUSC1-AS1 could serve as a sponge of miR-326 to promote BC progression by targeting XRCC5, suggesting that RUSC1-AS1 might be a target for BC treatment.

MiR-326 regulates cell proliferation and apoptosis in fibroblast-like synoviocytes in rheumatoid arthritis.

The dysregulation of microRNAs plays a critical role in the development of rheumatoid arthritis (RA). This study aims to explore the functional significance of miR-326 in RA. The RT-qPCR results showed that miR-326 was downregulated in synovial tissues of RA patients and RA fibroblast-like synoviocytes (RA-FLS). We found that miR-326 could target and reduce the expression of inhibitor of DNA binding 1 (Id1). MTT assay and flow cytometry were conducted to explore the biological function of miR-326. Our data revealed that the upregulation of miR-326 suppressed cell proliferation and induced apoptosis in RA-FLS. In collagen-induced arthritis mice, intraarticular injection of lentivirus carrying miR-326 overexpression vectors could reduce the arthritis score and attenuate synovial inflammation and cartilage destruction. We also found that long non-coding RNA-Ewing sarcoma-associated transcript 1 (lncRNA-EWSAT1) was significantly increased in RA synovial tissues and RA-FLS. The RNA immunoprecipitation and RNA pull-down assay indicated that lncRNA-EWSAT1 directly bound and negatively regulated the expression of miR-326. Knockdown of lncRNA-EWSAT1 could upregulate miR-326 expression and attenuate its proliferation inhibition and apoptosis induction effect in RA-FLS.  In conclusion, the lncRNA-EWSAT1/miR-326 axis might provide a novel therapeutic target in the treatment of RA.

CircUBE3B High Expression Participates in Sevoflurane-Induced Human Hippocampal Neuron Injury via Targeting miR-326 and Regulating MYD88 Expression.

The clinical application of Sevoflurane (Sevo) brings about non-negligible neuron injury, leading to postoperative cognitive dysfunction (POCD). However, related pathogenesis is complex and not fully established. We aimed to disclose the role of circRNA UBE3B (circUBE3B) in neuron injury induced by Sevo. Cell viability and apoptosis were determined by CCK-8 and flow cytometry experiments. Inflammation production was monitored by ELISA. The expression of circUBE3B, miR-326, and myeloid differentiation factor 88 (MYD88) mRNA was assessed by quantitative real-time PCR (qPCR). Apoptosis-associated markers and MYD88 protein were quantified by western blot. The putative binding site between miR-326 and circUBE3B or MYD88 was verified by a dual-luciferase reporter experiment, and their binding was validated by a pull-down assay. Sevo treatment weakened cell viability and promoted cell apoptosis and inflammatory response. CircUBE3B expression was elevated in Sevo-treated neurons. Sevo-induced neuron injury was alleviated by circUBE3B downregulation but aggravated by circUBE3B overexpression. MiR-326 was targeted by circUBE3B, and miR-326 inhibition recovered neuron injury that was repressed by circUBE3B absence in Sevo-treated neurons. MiR-326 interacted with MYD88. MiR-326 enrichment attenuated Sevo-induced neuron injury, while these effects were reversed by MYD88 overexpression. CircUBE3B dysregulation was involved in Sevo-induced human hippocampal neuron injury via targeting the miR-326/MYD88 network.

Circ_0008717 Sponges miR-326 to Elevate GATA6 Expression to Promote Breast Cancer Tumorigenicity.

Circular RNAs (circRNAs) have been reported to paly roles in the progression and management of breast cancers (BC). This work aimed to detect the role and mechanism of circ_0008717 in BC tumorigenesis. Expression levels of genes and proteins were evaluated by quantitative real-time polymerase chain reaction and western blot. In vitro assays were conducted using cell counting kit-8, colony formation, transwell, tube formation, and flow cytometry assays, respectively. The interaction between miR-326 and circ_0008717 or GATA6 (GATA Binding Protein six) was confirmed by bioinformatics analysis, and dual-luciferase reporter assay and RNA immunoprecipitation assay. The murine xenograft models were established to perform in vivo assay. Circ_0008717 and GATA6 were highly expressed, while miR-326 was lowly expressed in BC tissues and cells. Functionally, knockdown of circ_0008717 not only suppressed breast cancer cell proliferation, angiogenesis, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro, but also hindered tumor growth and EMT process in vivo. Mechanistically, Circ_0008717 directly bound to miR-326, which targeted GATA6. Rescue experiments showed that miR-326 reversed the anticancer action of circ_0008717 knockdown on BC cells. Moreover, miR-326 restoration repressed BC cell growth and metastasis, which were attenuated by GATA6 overexpression. In addition, we also observed that circ_0008717 could regulate GATA6 expression by sponging miR-326. Circ_0008717 promoted breast cancer growth and metastasis through miR-326/GATA6 axis, revealing a potential therapeutic target for breast cancer treatment.

Circ_0082182 upregulates the NFIB level via sponging miR-326 to promote oxaliplatin resistance and malignant progression of colorectal cancer cells.

Circular RNAs (circRNAs) are key regulators in tumor metastasis and drug resistance. This study was designed to investigate circ_0082182 function and mechanism in oxaliplatin (OXA) resistance and cancer progression of colorectal cancer (CRC). The circ_0082182, microRNA-326 (miR-326), and nuclear factor I B (NFIB) levels were quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell sensitization was analyzed by Cell Counting Kit-8 assay. The proliferation ability was determined via EdU assay, and apoptosis was measured by flow cytometry. Transwell assay and wound healing assay were performed to assess cell invasion and migration. The protein level was examined through Western blot. The binding interaction was conducted via dual-luciferase reporter assay. Xenograft tumor assay was used to explore the circ_0082182 function in vivo. The circ_0082182 level was upregulated in OXA-resistant CRC samples and cells. Downregulation of circ_0082182 suppressed OXA resistance, proliferation, invasion, and migration but promoted apoptosis of OXA-resistant CRC cells. Circ_0082182 acted as a sponge for miR-326. The regulatory role of circ_0082182 was ascribed to the miR-326 sponging function. MiR-326 directly targeted NFIB to impede OXA resistance and cancer progression in CRC cells. NFIB level was regulated by circ_0082182 via sponging miR-326. Circ_0082182 promoted tumor growth in OXA-resistant xenograft tumor model through mediating the miR-326/NFIB axis. These data suggested that circ_0082182 elevated the NFIB expression to regulate OXA resistance and CRC progression by absorbing miR-326.

SP1-induced PROX1-AS1 contributes to tumor progression by regulating miR-326/FBXL20 axis in colorectal cancer.

Long noncoding RNAs (lncRNAs) play pivotal roles in cancers by regulating tumorigenesis and metastasis. LncRNA PROX1-AS1 has been reported to be involved in tumor progression, however, its role in colorectal cancer (CRC) remains ambiguous. Based on TCGA and GTEx databases, we found that the expression of PROX1-AS1 was upregulated in CRC tissues and cells. Bioinformatics analysis revealed that high PROX1-AS1 expression was associated with poor overall survival. Functionally, PROX1-AS1 knockdown suppressed CRC cell proliferation, migration, and invasion in vitro, as well as inhibiting tumor growth in vivo. Mechanistically, PROX1-AS1 was identified to act as a miR-326 sponge by luciferase reporter and RIP assay. Meanwhile, we found that the transcription factor SP1 activated PROX1-AS1/miR-32/FBXL20 axis, thereby promoting CRC progression. Our data demonstrated that PROX1-AS1 served as a promising prognostic biomarker for CRC, and the potential mechanism was unraveled.

Correlation between serum miR-124, miR-146a and miR-326 and pregnancy outcome in patients with hypothyroidism during pregnancy / 中华内分泌外科杂志

Objective:To exploring the correlation between the expression levels of microRNA-124 (miR-124), miR-146a, and miR-326 in serum of patients with gestational hypothyroidism and thyroid function and adverse pregnancy outcomes.Methods:Patients who came to our hospital for gestational hypothyroidism treatment from Jun. 2017 to Jun. 2019 were selected as the observation group ( n=121), while the control group was pregnant women who came to our hospital for normal pregnancy during the same period ( n=120). Quantitative real time PCR (RT-qPCR) was used to detect the serum expression levels of miR-124, miR-146a, and miR-326. The serum thyroid hormone (TSH), free triiodothyronine (FT3), free T4 (FT4), thyroid peroxidase antibody (TPOAb), thyroid hormone receptor antibodies (TRAb) were compared. The levels of thyroid microsomal antibody (TMAb) and anti-thyroid autoantibodies (TGAb) were different. Spearman and Pearson correlation analysis were used to explore the correlation between the expression of miR-124, miR-146a and miR-326 and the indicators of thyroid hormone. Chi-square was used to examine the correlation between the levels of miR-124, miR-146a and miR-326 and adverse pregnancy outcomes after treatment. Results:Compared with the control group of healthy pregnant women, the observation group showed an upregulation of miR-146a (0.98 ± 0.12 vs 2.71 ± 0.34) and miR-326 (1.09 ± 0.22 vs 2.11 ± 0.32) serum expression, while the expression of miR-124 was down regulated (1.46 ± 0.23 vs 0.56 ± 0.10), with statistically significant differences ( P<0.05). The TSH, TGAb, TRAb, TMAb, and TPOAb in the observation group were higher than those in the control group, while FT3 and FT4 were lower than those in the control group ( P<0.05). After treatment, FT4, TGAb and TPOAb levels were significantly different between miR-124, miR-146a and miR-326 high expression groups and low expression groups ( P < 0.05). The expression level of miR-124 was significantly positively correlated with FT3 and FT4, and significantly negatively correlated with TSH, TGAb, TRAb, TMAb and TPOAb, while the expression level of miR-146a and miR-326 was significantly negatively correlated with FT3 and FT4. It was positively correlated with TSH, TGAb, TRAb, TMAb and TPOAb ( P < 0.05) . Conclusion:MiR-124, miR-146a, and miR-326 can be used as predictive factors for the efficacy evaluation of gestational hypothyroidism and adverse pregnancy outcomes.