Nuclear-cytoplasmic Fractionation Research Articles

GATAD1 is involved in sphingosylphosphorylcholine-attenuated myocardial ischemia-reperfusion injury by modulating myocardial fatty acid oxidation and glucose oxidation

Modulating the equilibrium between glucose metabolism and lipid metabolism represents highly promising novel strategies for therapy of myocardial ischemia/reperfusion (I/R) injury. Sphingosylphosphorylcholine (SPC), an intermediate metabolite of sphingolipids, has shown cardioprotective roles during myocardial infarction by regulating the activities of various transcript factors. Gene microarray revealed that SPC significantly upregulated the expression of GATA zinc finger domain protein 1 (GATAD1), which is a vital transcript factor affecting heart development and various heart diseases. However, it remains unclear whether SPC is involved in the regulation of cardiac fatty acid and glucose metabolism via GATAD1. In this study, we found that myocardium-specific Gatad1 knockout (Gatad1 CKO) significantly increased the myocardial infarct size, impaired cardiac function in I/R mice, and disrupted the protective effect of SPC on the hearts of I/R mice. Immunofluorescence experiment and western blot evaluation of the nuclear-cytoplasmic fractionation sample showed that GATAD1 acted as a transcription factor and was regulated by SPC. Double fluorescence reporting experiment and quantitative polymerase chain reaction (qPCR) revealed that GATAD1 could inhibit the expression of genes involved in fatty acid oxidation (FAO), i.e., acetyl-coenzyme A acyltransferase 2 (Acaa2) and medium-chain acyl-CoA dehydrogenase (Acadm), and promoted the expression of genes involved in glucose oxidation, i.e., pyruvate dehydrogenase E1 α subunit (Pdha1). Small interfering RNA (SiRNA) or overexpression strategies confirmed the pro-apoptotic roles of Acaa2 and Acadm and anti-apoptotic role of Pdha1 in cardiac myocytes challenged with I/R treatment. In summary, our findings suggest that SPC can be used as a candidate to prevent I/R injury by reshaping fatty acid and glucose metabolism. Transcription factor GATAD1 plays a crucial role in regulating fatty acid oxidation and glucose oxidation homeostasis and is involved in SPC-mediated cardioprotection during I/R of the heart. Our study identifies GATAD1 as a new therapeutic target for clinical treatment of myocardial I/R injury.

Study on the metastatic mechanism of LINC00115 in adenocarcinoma of the Esophagogastric junction.

Adenocarcinoma of the esophagogastric junction (AEG) is a common and deadly cancer, and an in-depth investigation of its molecular mechanisms of metastasis is crucial for discovering new therapeutic targets. This study explores the role of the long non-coding RNA (lncRNA) LINC00115 in AEG metastasis and its underlying mechanisms. Through the analysis of 108 pairs of AEG cancer tissues and matched adjacent tissues, we found a significant upregulation of LINC00115 in AEG tissues, closely associated with TNM staging and lymph node metastasis. Utilizing cell counting kit-8 (CCK-8) assays, colony formation experiments, wound healing assays, flow cytometry for apoptosis and cell cycle analysis, and Transwell assays, we have confirmed that LINC00115 significantly promotes proliferation, migration, and invasion of AEG cells in vitro. Animal experiments further validate the role of LINC00115 in promoting tumor growth and metastasis in vivo. Additionally, our nuclear-cytoplasmic fractionation experiments and RNA fluorescence in situ hybridization (FISH) reveal that LINC00115, along with its interacting protein KH-Type splicing regulatory protein (KHSRP), predominantly localizes to the cell nucleus. By conducting RNA pull-down assays and mass spectrometry (MS) analysis, we have identified a direct interaction between LINC00115 and KHSRP protein and further determined their binding sites through catRAPID and ENCORI databases. This study provides evidence of LINC00115 as a novel biomarker and potential therapeutic target for AEG and offers a fresh perspective on understanding the molecular mechanisms of AEG metastasis.

The miR-1269a/PCDHGA9/CXCR4/β-catenin pathway promotes colorectal cancer invasion and metastasis

BackgroundColorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. This research focuses on investigating the impact and underlying molecular mechanisms of protocadherin gamma subfamily A, 9 (PCDHGA9) on the invasion and metastasis of CRC, aiming to identify more precise molecular markers for the diagnosis and prognosis of CRC.MethodsPCDHGA9 expression was detected using quantitative real-time quantitative polymerase chain reaction (RT-qPCR) in 63 pairs of colorectal cancer tissues. Differential gene expression from high-throughput sequencing was analyzed using ingenuity pathway analysis (IPA) to explore the biological functions of PCDHGA9 and its potential regulated genes. Bioinformatics tools were employed to explore potential upstream regulatory microRNAs of PCDHGA9. Dual-luciferase assays were performed to demonstrate the regulation between PCDHGA9 and miR-1269a. Protein mass spectrometry suggested an interaction between PCDHGA9 and HOXA1. JASPAR predicted that HOXA1 may act as a transcription factor of CXCR4. Coimmunoprecipitation, dual-luciferase assays, and nuclear–cytoplasmic fractionation experiments confirmed the molecular mechanism involving PCDHGA9, CXCR4, HOXA1, and β-catenin. Transwell, wound healing, and western blot assays were conducted to confirm the impact of PCDHGA9, miR-1269a, and CXCR4 on the invasion, metastasis, and epithelial–mesenchymal transition (EMT) functions of CRC cells in in vitro experiments. A whole-body fluorescence imaging system was used to evaluate the combined impact of miR-1269a and PCDHGA9 on the invasion and metastasis of CRC in in vivo experiments.ResultsThe expression of PCDHGA9 was found to be lower in CRC tissues compared with their corresponding adjacent tissues. Low expression of PCDHGA9 potentially correlated with worse prognosis and increased chances of invasion and metastasis in CRC. miR-1269a was highly expressed in CRC tissues and acted as a negative regulator for PCDHGA9, promoting invasion, migration, and EMT of CRC cells. PCDHGA9’s interaction with HOXA1 downregulated CXCR4, a transcription factor, leading to accumulation of β-catenin and further promoting invasion, migration, and EMT of CRC cells.ConclusionsPCDHGA9, acting as a tumor suppressor, is downregulated by miR-1269a. The low level of PCDHGA9 activates the Wnt/β-catenin pathway by releasing its interaction with HOXA1, promoting the expression of CXCR4, and causing invasion, migration, and EMT in CRC.Graphical

Prostate cancer cell-derived exosomes ZNF667-AS1 reduces TGFBR1 mRNA stability to inhibit Treg expansion and DTX resistance by binding to U2AF1

BackgroundDocetaxel (DTX) resistance attenuates anti-tumor effects of DTX on prostate cancer (mCRPC) and drug resistance was related to Treg expansion in tumors. ZNF667-AS1 played a suppressing role in various tumors and tumor-derived exosomes carry lncRNAs to participate in tumor progression. Here, the effects of ZNF667-AS1 on malignant characteristics and DTX resistance in PC and the effect and its underlying molecular mechanism of tumor-derived exosomes carrying ZNF667-AS1 on Treg expansion were investigated.MethodsThe identification of exosomes were determined using TEM, NTA and western blot. The abundance of genes and proteins were evaluated using IHC, RT-qPCR, western blot and FISH. Malignant phenotypes of PC cells were evaluated by means of Edu, scratch test, transwell, CCK-8 and flow cytometry. The percentage of CD4+CD25+Foxp3+ Tregs was detected using flow cytometry. The location of ZNF667-AS1 was detected using nuclear-cytoplasmic fractionation. The co-location of ZNF667-AS1 and U2AF1 protein was detected using IF-FISH assay. The interactions among ZNF667-AS1, TGFBR1 and U2AF1 were verified using RNA pull-down, RIP and dual luciferase activity.ResultsZNF667-AS1 expression in PC samples was lowered, which was negatively relative to poor prognosis and DTX resistance. ZNF667-AS1 overexpression inhibited malignant phenotypes of PC cells, tumor growth and DTX resistance. Besides, DTX resistant cell-derived exosomes expressed lower ZNF667-AS1 expression. Exosomes carrying exogenously high ZNF667-AS1 expression derived PC cells or serum of mice suppressed Treg expansion. On the mechanism, ZNF667-AS1 interacted with U2AF1 to destabilize TGFBR1 mRNA and reduce TGFBR1 expression in CD4+T cells.ConclusionZNF667-AS1 suppressed cell growth of PC cells, tumor growth of mice and DTX resistance to PC cells and exogenously high ZNF667-AS1 expression in tumor-derived exosomes destabilized TGFBR1 mRNA and reduce TGFBR1 expression through interacting with U2AF1, thus resulting in attenuated Treg expansion, which was related to DTX resistance.

Hsa_circ_0000825 promotes the progression of laryngeal squamous cell carcinoma by sponging miR-766 and interacting with ELAVL1

Emerging evidence suggests that circular RNAs (circRNAs) are involved in the regulation of tumourigenesis and progression of a variety of malignant tumours. In this study, we aimed to identify laryngeal squamous cell carcinoma (LSCC)-specific circRNAs and explore their biological functions and underlying molecular mechanisms. Employing microarray and qRT-PCR, hsa_circ_0000825 was found to be significantly increased in LSCC tissues versus para-cancerous tissues. High hsa_circ_0000825 expression was positively associated with advanced clinical stages, lymph node metastasis, and poor survival. Furthermore, the overexpression of hsa_circ_0000825 in TU177 and AMC-HN-8 cells promoted cell proliferation. Transwell assays showed enhanced migration and invasion of TU177 and AMC-HN-8 cells upon overexpression of hsa_circ_0000825. Conversely, the knockdown of hsa_circ_0000825 had the opposite effect. Xenograft tumours in BALB/c nude mice derived from hsa_circ_0000825-overexpressed TU177 cells showed greater volume and weight than those derived from control TU177 cells. Mechanistically, nuclear-cytoplasmic fractionation assay confirmed that hsa_circ_0000825 was mainly located in the cytoplasm of TU177 and AMC-HN-8 cells. The AGO2-RNA immunoprecipitation (RIP) assay revealed that hsa_circ_0000825 was significantly enriched in the AGO2-precipitated complex in both TU177 and AMC-HN-8 cells, suggesting that this circRNA may function via a competitive endogenous RNA (ceRNA) mechanism. Next, bioinformatics analysis, biotinylated-oligo pull-down assay and dual-luciferase reporter assay verified that miR-766 could be sponged by hsa_circ_0000825 and also target 3′UTR of HOXD10 mRNA. Moreover, miR-766 was shown to be involved in the pro-oncogenic effect of hsa_circ_0000825. This occurred via the mediation of hsa_circ_0000825-enhanced HOXD10 mRNA by the ceRNA mechanism in TU177 and AMC-HN-8 cells. Besides, RNA-binding protein (RBP) ELAVL1 interacted with hsa_circ_0000825 in TU177 and AMC-HN-8 cells, as revealed through bioinformatics analysis, biotinylated-oligo pull-down assays, and RIP assays. ELAVL1 knockdown decreased cell proliferation by 38 % and 34 % in hsa_circ_0000825-overexpressed TU177 and AMC-HN-8 cells (P < 0.05). Similarly, ELAVL1 was involved in the pro-migration and pro-invasion effects of hsa_circ_0000825 overexpression. In addition, comprehensive analysis of mRNA-seq in hsa_circ_0000825-overexpressed TU177 cells, as well as catRAPID and TCGA databases, suggested that ITGB2, HOXD10, and MTCL1 might be crucial downstream target mRNAs of ELAVL1 in LSCC, participating in the hsa_circ_0000825-ELAVL1 axis pro-oncogenic effect. Taken together, hsa_circ_0000825 plays a pro-oncogenic role in LSCC via the miR-766/HOXD10 axis and ELAVL1 and may serve as a promising specific biomarker and therapeutic target for LSCC.

LncRNA TRPM2-AS promotes endometrial carcinoma progression and angiogenesis via targeting miR-497-5p/SPP1 axis

BackgroundAnti-angiogenic therapy has become one of the effective treatment methods for tumors. Long noncoding RNAs (lncRNAs) are emerging as important regulators of tumorigenesis and angiogenesis in EC. However, the underlying mechanisms of lncRNA TRPM2-AS in EC are still not clear.MethodsWe screened the differently expressed lncRNAs that were highly associated with poor prognosis and angiogenesis of EC by bioinformatics analysis, and constructed a ceRNA network based on the prognostic lncRNAs. The subcellular localization of TRPM2-AS was determined by fluorescence in situ hybridization (FISH) and nuclear cytoplasmic fractionation assay. CCK-8, EdU, transwell, western blot, qRT-PCR and endothelial tube formation assay were used to evaluate the effects of TRPM2-AS on the proliferation, invasion, migration of EC cells and angiogenesis. The targeted microRNA (miRNA) of TRPM2-AS was predicted by bioinformatic methods. The interaction between TRPM2-AS and miR497-5p, miR497-5p and SPP1 were analyzed by RNA immunoprecipitation and dual-luciferase reporter assay. A subcutaneous tumor model was used to explore TRPM2-AS’s function in vivo. CIBERSORT was used to analyze the correlation between TRPM2-AS and immune cell immersion in EC.ResultsWe found that the expression of TRPM2-AS and SPP1 was aberrantly upregulated, while miR-497-5p expression was significantly downregulated in EC tissues and cells. TRPM2-AS was closely correlated with the angiogenesis and poor prognosis in EC patients. Mechanistically, TRPM2-AS could sponge miR-497-5p to release SPP1, thus promoting the proliferation, invasion and migration of EC cells and angiogenesis of HUVECs. Knockdown of TRPM2-AS in xenograft mouse model inhibited tumor proliferation and angiogenesis in vivo. In addition, TRPM2-AS plays a vital role in regulating the tumor immune microenvironment of EC, overexpression of TRPM2-AS in EC cells stimulated the polarization of M2 macrophages and angiogenesis through secreting SPP1 enriched exosomes.ConclusionThe depletion of TRPM2-AS inhibits the oncogenicity of EC by targeting the miR-497-5p/SPP1 axis. This study offers a better understanding of TRPM2-AS’s role in regulating angiogenesis and provides a novel target for EC treatment.

A novel protein FNDC3B-267aa encoded by circ0003692 inhibits gastric cancer metastasis via promoting proteasomal degradation of c-Myc.

Gastric cancer (GC) ranks fifth in global cancer incidence and third in mortality rate among all cancer types. Circular RNAs (circRNAs) have been extensively demonstrated to regulate multiple malignant biological behaviors in GC. Emerging evidence suggests that several circRNAs derived from FNDC3B play pivotal roles in cancer. However, the role of circFNDC3B in GC remains elusive. We initially screened circFNDC3B with translation potential via bioinformatics algorithm prediction. Subsequently, Sanger sequencing, qRT-PCR, RNase R, RNA-FISH and nuclear-cytoplasmic fractionation assays were explored to assess the identification and localization of circ0003692, a circRNA derived from FNDC3B. qRT-PCR and ISH were performed to quantify expression of circ0003692 in human GC tissues and adjacent normal tissues. The protein-encoding ability of circ0003692 was investigated through dual-luciferase reporter assay and LC/MS. The biological behavior of circ0003692 in GC was confirmed via in vivo and in vitro experiments. Additionally, Co-IP and rescue experiments were performed to elucidate the interaction between the encoded protein and c-Myc. We found that circ0003692 was significantly downregulated in GC tissues. Circ0003692 had the potential to encode a novel protein FNDC3B-267aa, which was downregulated in GC cells. We verified that FNDC3B-267aa, rather than circ0003692, inhibited GC migration in vitro and in vivo. Mechanistically, FNDC3B-267aa directly interacted with c-Myc and promoted proteasomal degradation of c-Myc, resulting in the downregulation of c-Myc-Snail/Slug axis. Our study revealed that the novel protein FNDC3B-267aa encoded by circ0003692 suppressed GC metastasis through binding to c-Myc and enhancing proteasome-mediated degradation of c-Myc. The study offers the potential applications of circ0003692 or FNDC3B-267aa as therapeutic targets for GC.

Wnt5a/β-catenin-mediated epithelial-mesenchymal transition: a key driver of subretinal fibrosis in neovascular age-related macular degeneration

BackgroundNeovascular age-related macular degeneration (nAMD), accounts for up to 90% of AMD-associated vision loss, ultimately resulting in the formation of fibrotic scar in the macular region. The pathogenesis of subretinal fibrosis in nAMD involves the process of epithelial–mesenchymal transition (EMT) occurring in retinal pigment epithelium (RPE). Here, we aim to investigate the underlying mechanisms involved in the Wnt signaling during the EMT of RPE cells and in the pathological process of subretinal fibrosis secondary to nAMD.MethodsIn vivo, the induction of subretinal fibrosis was performed in male C57BL/6J mice through laser photocoagulation. Either FH535 (a β-catenin inhibitor) or Box5 (a Wnt5a inhibitor) was intravitreally administered on the same day or 14 days following laser induction. The RPE-Bruch's membrane-choriocapillaris complex (RBCC) tissues were collected and subjected to Western blot analysis and immunofluorescence to examine fibrovascular and Wnt-related markers. In vitro, transforming growth factor beta 1 (TGFβ1)-treated ARPE-19 cells were co-incubated with or without FH535, Foxy-5 (a Wnt5a-mimicking peptide), Box5, or Wnt5a shRNA, respectively. The changes in EMT- and Wnt-related signaling molecules, as well as cell functions were assessed using qRT-PCR, nuclear-cytoplasmic fractionation assay, Western blot, immunofluorescence, scratch assay or transwell migration assay. The cell viability of ARPE-19 cells was determined using Cell Counting Kit (CCK)-8.ResultsThe in vivo analysis demonstrated Wnt5a/ROR1, but not Wnt3a, was upregulated in the RBCCs of the laser-induced CNV mice compared to the normal control group. Intravitreal injection of FH535 effectively reduced Wnt5a protein expression. Both FH535 and Box5 effectively attenuated subretinal fibrosis and EMT, as well as the activation of β-catenin in laser-induced CNV mice, as evidenced by the significant reduction in areas positive for fibronectin, alpha-smooth muscle actin (α-SMA), collagen I, and active β-catenin labeling. In vitro, Wnt5a/ROR1, active β-catenin, and some other Wnt signaling molecules were upregulated in the TGFβ1-induced EMT cell model using ARPE-19 cells. Co-treatment with FH535, Box5, or Wnt5a shRNA markedly suppressed the activation of Wnt5a, nuclear translocation of active β-catenin, as well as the EMT in TGFβ1-treated ARPE-19 cells. Conversely, treatment with Foxy-5 independently resulted in the activation of abovementioned molecules and subsequent induction of EMT in ARPE-19 cells.ConclusionsOur study reveals a reciprocal activation between Wnt5a and β-catenin to mediate EMT as a pivotal driver of subretinal fibrosis in nAMD. This positive feedback loop provides valuable insights into potential therapeutic strategies to treat subretinal fibrosis in nAMD patients.

Stabilization of KPNB1 by deubiquitinase USP7 promotes glioblastoma progression through the YBX1-NLGN3 axis

BackgroundGlioblastoma (GBM) is the most common malignant tumor of the central nervous system. It is an aggressive tumor characterized by rapid proliferation, diffuse tumor morphology, and poor prognosis. Unfortunately, current treatments, such as surgery, radiotherapy, and chemotherapy, are unable to achieve good outcomes. Therefore, there is an urgent need to explore new treatment targets. A detailed mechanistic exploration of the role of the nuclear pore transporter KPNB1 in GBM is lacking. This study demonstrated that KPNB1 regulated GBM progression through a transcription factor YBX1 to promote the expression of post-protrusion membrane protein NLGN3. This regulation was mediated by the deubiquitinating enzyme USP7.MethodsA tissue microarray was used to measure the expression of KPNB1 and USP7 in glioma tissues. The effects of KPNB1 knockdown on the tumorigenic properties of glioma cells were characterized by colony formation assays, Transwell migration assay, EdU proliferation assays, CCK-8 viability assays, and apoptosis analysis using flow cytometry. Transcriptome sequencing identified NLGN3 as a downstream molecule that is regulated by KPNB1. Mass spectrometry and immunoprecipitation were performed to analyze the potential interaction between KPNB1 and YBX1. Moreover, the nuclear translocation of YBX1 was determined with nuclear-cytoplasmic fractionation and immunofluorescence staining, and chromatin immunoprecipitation assays were conducted to study DNA binding with YBX1. Ubiquitination assays were performed to determine the effects of USP7 on KPNB1 stability. The intracranial orthotopic tumor model was used to detect the efficacy in vivo.ResultsIn this study, we found that the nuclear receptor KPNB1 was highly expressed in GBM and could mediate the nuclear translocation of macromolecules to promote GBM progression. Knockdown of KPNB1 inhibited the progression of GBM, both in vitro and in vivo. In addition, we found that KPNB1 could regulate the downstream expression of Neuroligin-3 (NLGN3) by mediating the nuclear import of transcription factor YBX1, which could bind to the NLGN3 promoter. NLGN3 was necessary and sufficient to promote glioma cell growth. Furthermore, we found that deubiquitinase USP7 played a critical role in stabilizing KPNB1 through deubiquitination. Knockdown of USP7 expression or inhibition of its activity could effectively impair GBM progression. In vivo experiments also demonstrated the promoting effects of USP7, KPNB1, and NLGN3 on GBM progression. Overall, our results suggested that KPNB1 stability was enhanced by USP7-mediated deubiquitination, and the overexpression of KPNB1 could promote GBM progression via the nuclear translocation of YBX1 and the subsequent increase in NLGN3 expression.ConclusionThis study identified a novel and targetable USP7/KPNB1/YBX1/NLGN3 signaling axis in GBM cells.

LINC00926 promotes progression of renal cell carcinoma via regulating miR-30a-5p/SOX4 axis and activating IFNγ-JAK2-STAT1 pathway

The role of long non-coding RNA (lncRNA) in the progression of renal cell carcinoma (RCC) remains further study. Whether lncRNA may be used to predict the immunotherapy efficacy of RCC is less studied. In this study, LINC00926 was found to be mainly located in cytoplasm by FISH and RNA nuclear-cytoplasmic fractionation. Downregulation of LINC00926 in RCC cell lines inhibited the progression and metastasis of RCC cells. RNA pull-down assay and dual-luciferase reporter assay demonstrated that LINC00926 functioned as miR-30a-5p sponge to facilitate SOX4 expression. LINC00926 overexpression in BALB/c mice enhanced PD-L1 surface expression and resulted in immune escape. Mechanistic investigations showed that LINC00926 competitively bound to Lyn, leading to the inhibition of CBL-mediated ubiquitination and degradation, and stabilized Lyn, contributing to the activation of IFNγ-JAK2-STAT1 signaling pathway. Moreover, LINC00926, together with PD-L1 or PD-1 expression, may predict the overall survival in RCC patients. Therefore, LINC00926 has the potential to be a novel therapeutic target and a biomarker to predict ICB immunotherapy response in RCC.

Discovery of ligustrazine and chalcone derivatives as novel viral nucleoprotein nuclear export inhibitors against influenza viruses.

Influenza viruses pose a significant threat to human health worldwide due to seasonal epidemics and occasional global pandemics. These viruses can cause severe upper respiratory tract infections that contribute to high morbidity and mortality rates. The emergence of drug-resistant influenza viruses has created the need for the development of novel broad-spectrum antivirals. Here, we present a novel anti-influenza agent with new targets and mechanisms of action to address this problem. Our findings led to the discovery of a novel influenza virus inhibitor, a ligustrazine derivative known as A9. We have found that it exhibits broad-spectrum antiviral properties against influenza A and B viruses (IAV and IBV, respectively), including oseltamivir-resistant strain. Through multiple bioassays such as time-of-addition assay, indirect immunofluorescence assay, and nuclear-cytoplasmic fractionation assay, we demonstrated that A9 inhibits the nuclear export of the viral ribonucleoprotein (vRNP). Furthermore, escape mutant analyses and affinity studies determined by surface plasmon resonanceindicated that A9 specifically targets the nucleoprotein.In addition, four chalcone derivatives developed from A9 (B14, B29, B31, and B32), were found to effectively inhibit the replication of influenza virus through the same mechanism of action. In this manuscript we highlight A9 and its four derivatives as potential leads for the treatment of IAV and IBV infections, and their unique and novel mechanism of action probable benefit the field of anti-influenza drug discovery.

CircNFATC3 promotes the proliferation of gastric cancer through binding to IGF2BP3 and restricting its ubiquitination to enhance CCND1 mRNA stability

BackgroundInsulin like growth factor II mRNA binding protein 3 (IGF2BP3) is an RNA binding protein with multiple roles in regulation of gene expression at the post-transcriptional level and is implicated in tumorigenesis and progression of numerous cancers including gastric cancer (GC). Circular RNAs (circRNAs) are a diverse endogenous noncoding RNA population that have important regulatory roles in cancer. However, circRNAs that regulate the expression of IGF2BP3 in GC is largely unknown.MethodsCircRNAs that bound to IGF2BP3 were screened in GC cells using RNA immunoprecipitation and sequencing (RIP-seq). The identification and localization of circular nuclear factor of activated T cells 3 (circNFATC3) were identified using Sanger sequencing, RNase R assays, qRT-PCR, nuclear-cytoplasmic fractionation and RNA-FISH assays. CircNFATC3 expression in human GC tissues and adjacent normal tissues were measured by qRT-PCR and ISH. The biological role of circNFATC3 in GC was confirmed by in vivo and in vitro experiments. Furthermore, RIP, RNA-FISH/IF, IP and rescue experiments were performed to uncover interactions between circNFATC3, IGF2BP3 and cyclin D1 (CCND1).ResultsWe identified a GC-associated circRNA, circNFATC3, that interacted with IGF2BP3. CircNFATC3 was significantly overexpressed in GC tissues and was positively associated with tumor volume. Functionally, the proliferation of GC cells decreased significantly after circNFATC3 knockdown in vivo and in vitro. Mechanistically, circNFATC3 bound to IGF2BP3 in the cytoplasm, which enhanced the stability of IGF2BP3 by preventing ubiquitin E3 ligase TRIM25-mediated ubiquitination, thereby enhancing the regulatory axis of IGF2BP3-CCND1 and promoting CCND1 mRNA stability.ConclusionsOur findings demonstrate that circNFATC3 promotes GC proliferation by stabilizing IGF2BP3 protein to enhance CCND1 mRNA stability. Therefore, circNFATC3 is a potential novel target for the treatment of GC.

Long Noncoding RNA ACTA2-AS1 Inhibits Cell Growth and Facilitates Apoptosis in Gastric Cancer by Binding with miR-6720-5p to Regulate ESRRB.

Gastric cancer (GC) is a common malignant tumor, posing a great threat to human's health and life. Previous studies have suggested aberrant expression of long non-coding RNAs (lncRNAs) in GC. This study elucidated the effects of lncRNA ACTA2-AS1 on the biological characteristics of GC. Gene expression in stomach adenocarcinoma (STAD) samples compared with normal tissues and the correlation between gene expression and prognosis of STAD patients were analyzed using bioinformatic tools. Gene expression at protein and mRNA levels in GC and normal cells was tested by western blotting and RT-qPCR. The subcellular localization of ACTA2-AS1 in AGS and HGC27 cells was identified by nuclear-cytoplasmic fractionation and FISH assay. EdU, CCK-8, flow cytometry analysis, TUNEL staining assays were conducted to evaluate the role of ACTA2-AS1 and ESRRB on GC cellular behaviors. The binding relationship among ACTA2-AS1, miR-6720-5p and ESRRB was verified by RNA pulldown, luciferase reporter assay and RIP assay. LncRNA ACTA2-AS1 was underexpressed in GC tissues and cell lines. ACTA2-AS1 elevation suppressed GC cell proliferation and induced apoptosis. Mechanistically, ACTA2-AS1 directly bound to miR-6720-5p and subsequently promoted the expression of target gene ESRRB in GC cells. Furthermore, ESRRB knockdown reversed the influence of ACTA2-AS1 overexpression on GC proliferation and apoptosis. ACTA2-AS1 plays an antioncogenic role in GC via binding with miR-6720-5p to regulate ESRRB expression.

Fuzheng Kang-Ai inhibits NSCLC cell proliferation via regulating hsa_circ_0048091/hsa-miR-378g/ARRDC3 pathway

BackgroundCurrent treatments for lung cancer have their own deficiencies, such as severe adverse effect. Therefore, more safe and effective drugs are needed. PurposeFuzheng Kang-Ai (FZKA for short) has been applied as an adjuvant treatment in advanced Non-Small Cell Lung Cancer (NSCLC) patients for decades in China, showing a definitive effect with minimal toxicities. However, the underlying mechanism is yet to be identified. Study designBoth in vitro and in vivo experiments were performed in this study to identify the exact mechanism by which FZKA inhibits NSCLC cell proliferation. MethodsMTT and CCK-8 assays were used to detect cell viability. Xenograft model was performed for in vivo experiments. CircRNA and miRNA sequencing were used to find the differentially expressed circRNAs and miRNAs, respectively. qRT-PCR was performed to check the expression levels of circRNA, miRNA and mRNA. BaseScope was carried out to observe the expression of circRNA in situ. Actinomycin D and RNase R experiments were done to show the stability of circRNA. Nuclear-cytoplasmic fractionation and FISH were used to identify the localization of circRNA and miRNA. Pull-down, RIP, and luciferase activity assays were performed to show the biding ability of circRNA, miRNA and target proteins. Flow cytometry was done to observe cell apoptosis. Western blot and IHC were done to detect the protein expression. TCGA database was used to analyze the survival rate. ResultsFZKA inhibits NSCLC cell proliferation both in vitro and in vivo. Hsa_circ_0048091 and hsa-miR-378g were the most differentially expressed circRNA and miRNA, respectively, after FZKA treatment. Silencing hsa_circ_0048091 and overexpressing hsa-miR-378g promoted cell proliferation and reversed the inhibition effect of FZKA on NSCLC, respectively. Hsa-miR-378g was sponged by hsa_circ_0048091, and the overexpression of miR-378g reversed the inhibition effect of hsa_ circ_0048091 on NSCLC. ARRDC3, as a target of hsa-miR-378g, was increased by FZKA treatment. Silencing ARRDC3 reversed both the inhibition effect of FZKA and miR-378g inhibitor on NSCLC. ConclusionThis study, for the first time, has established the function of hsa_circ_0048091, hsa- miR-378g, and ARRDC3 in lung cancer. It also shows that FZKA inhibits NSCLC cell proliferation through hsa_circ_0048091/hsa-miR-378g/ARRDC3 pathway, uncovering a novel mechanism by which FZKA controls human NSCLC cell growth.

Long non-coding RNA LINC01480 is activated by Foxo3a and promotes hydroquinone-induced TK6 cell apoptosis by inhibiting the PI3K/AKT pathway

Long non-coding RNAs (lncRNAs) have been shown to play a critical role in the damage caused to the body by environmental exogenous chemicals; however, few studies have explored their effects during exposure to benzene and its metabolite, hydroquinone (HQ). An emerging lncRNA, LINC01480, was found to be associated with the immune microenvironment of some cancers, but its specific function remains unknown. Therefore, this study aimed to investigate the role of LINC01480 in HQ-induced apoptosis. The biological function of LINC01480 was investigated through gain-of-function and loss-of-function experiments. Mechanically, nuclear-cytoplasmic fractionation experiment, chromatin immunoprecipitation (ChIP), dual-luciferase reporter assay, and rescue experiments were performed. In this study, when TK6 cells were treated with HQ (0, 5, 10, and 20 μM) for 12, 24, 48, and 72 h, the expression of LINC01480 was increased in a dose-dependent manner. Meanwhile, the phosphorylation levels of PI3K and AKT decreased, and apoptosis increased. As compared to the control group, HQ-induced apoptosis was significantly reduced, and the relative survival rate of TK6 cells increased after silencing LINC01480, while overexpression of LINC01480 further sensitized TK6 cells to HQ-induced apoptotic cell death. LINC01480 negatively regulated the PI3K/AKT pathway in TK6 cells, and the apoptosis-inhibiting effect of LINC01480 silencing was reversed after inhibition of the PI3K/AKT pathway. In addition, ChIP and the dual-luciferase reporter assays showed that the transcription factor Foxo3a promoted LINC01480 transcription by directly binding to the promoter regions − 149 to − 138 of LINC01480. Moreover, short-term HQ exposure promoted the expression of Foxo3a. From these findings, we can conclude that LINC01480 is activated by Foxo3a, and promotes HQ-induced apoptosis by inhibiting the PI3K/AKT pathway, suggesting that LINC01480 might become a possible target for therapeutic intervention of HQ-induced toxicity.

Long Noncoding RNA PCGEM1 Facilitates Tumor Growth and Metastasis of Osteosarcoma by Sponging miR-433-3p and Targeting OMA1.

Osteosarcoma (OS) is regarded as one of the most common malignant bone tumors, mainly occurring in children and adolescents with high mortality. The dysregulation of lncRNAs is reported to regulate tumor development and be closely related to patient prognosis. Nevertheless, the role of long noncoding RNAs (lncRNAs) prostate-specific transcript 1 (PCGEM1) in OS remains uncharacterized. The current study aimed to explore the role of PCGEM1 in OS. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to examine the expression of PCGEM1 in OS cell lines. CCK-8, colony formation, Transwell, and western blotting analyses were applied to measure OS cell viability, proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) after PCGEM1 downregulation. Nuclear-cytoplasmic fractionation, RNA pulldown, RNA immunoprecipitation (RIP), luciferase reporter assays were performed to verify the relationship among PCGEM1, miR-433-3p. and OMA1 in OS. The xenograft tumor models were established to evaluate the effect of PCGEM1 on tumor growth of OS. In this study, we discovered that PCGEM1 knockdown inhibited cell proliferation, migration, invasion and EMT in OS (P < 0.05). Additionally, PCGEM1 directly bound to miR-433-3p (P < 0.01). OMA1 was confirmed to be a target gene of miR-433-3p (P < 0.05), positively regulated by PCGEM1 but negatively regulated by miR-433-3p. Rescue assays further verified that overexpression of OMA1 reversed the PCGEM1 knockdown-mediated inhibitory effect on the malignant phenotype in OS cells (P < 0.05). Moreover, knockdown of PCGEM1 inhibited tumor growth and metastasis in vivo (P < 0.05). Overall, PCGEM1 mediated tumor growth and metastasis of OS by sponging miR-433-3p and regulating OMA1, which might provide an innovative strategy for OS diagnosis or treatment.

Inhibition of YAP Sensitizes the Selumetinib Treatment for Neurofibromatosis Type 1 Related Plexiform Neurofibroma

Background: Targeted therapy of Neurofibromatosis type 1 (NF1) related plexiform neurofibroma (pNF) aiming at MEK molecule has not demonstrated a convincing result for complete disease inhibition, probably due to other signal pathways crosstalk. Our previous study revealed an increased nuclear translocation of YAP molecule in NF1 related pNF. Herein, we decided to further investigate the therapeutic relations of YAP interference during the MEK treatment against NF1 related pNF. Methods: By means of selumetinib (MEK-inhibitor), RNA-sequencing was firstly performed to identify the changes of signal pathways in pNF Schwann cells, which was probably related to YAP regulation. Nuclear-cytoplasmic fractionation and western blotting were performed to show the intracellular YAP changes under selumetinib treatment. Thirdly, a series of in vitro assays were performed including flow cytometry, CCK-8, and colony/sphere formation under dual treatment of selumetinib and verteporfin (YAP-inhibitor). In addition, Chou-Talalay method was adopted to evaluate the synergistic inhibiting effects of such drug combination. Xenograft study was also used to detect the combining effects in vivo. Results: RNA-sequencing revealed that selumetinib treatment might be associated with the undesirable activation of Hippo pathway in NF1 related pNF tumor cells, which might reduce its pharmaceutic effects. Next, nuclear-cytoplasmic fractionation and further studies demonstrated that selumetinib could promote the nuclear translocation and transcriptional activation of YAP in vitro, which might cause the aforementioned resistance to selumetinib treatment. Additionally, when combined treatments were performed based on verteporfin and selumetinib, synergistic effects were observed on cytotoxicity of NF1 related pNF tumor cells in vitro and in vivo xenograft models. Conclusion: YAP inhibition can effectively sensitize NF1 related pNF tumor cells to selumetinib. Dual targeting of YAP and MEK might be a promising therapeutic strategy for treating NF1 related pNF.

CircDUSP1 regulates tumor growth, metastasis, and paclitaxel sensitivity in triple-negative breast cancer by targeting miR-761/DACT2 signaling axis.

Triple-negative breast cancer TNBC) is a malignant tumor with high incidence and high mortality that threaten the health of women worldwide. Circular RNAs (circRNAs) are a new class of noncoding RNAs that participate in the biological processes of various tumors, but the regulatory roles of circRNAs in TNBC have not been fully elucidated.In this study, the expression and characterization of circDUSP1 was detected via quantitative real-time PCR, nuclear-cytoplasmic fractionation assay, and fluorescence in situ hybridization. Then, in vitro and in vivo functional experiments were performed to evaluate the effects of circDUSP1 in TNBC. The interaction among circDUSP1, miR-761, DACT2 were confirmed by dual luciferase reporter assay, RNA pull-down, and RNA immunoprecipitation experiments.We identified the circRNA named circDUSP1 that was inversely correlated with tumorigenesis and progression in TNBC. Overexpression of circDUSP1 significantly attenuated cell proliferation, migration, invasion, and epithelial-mesenchymal transition, while increased the sensitivity of TNBC cells to paclitaxel. In-depth mechanism analysis indicated that circDUSP1 acts as an endogenous sponge of miR-761 to reduce its suppression on target gene DACT2 expression in TNBC. Upregulation of miR-761 or downregulation of DACT2 partially reversed the biological process of TNBC and the prognosis of paclitaxel affected by circDUSP1.Taken together, our findings revealed a role for the regulation of the miR-761/DACT2 axis by circDUSP1 in the biological process of TNBC. These results provided new insights into the biological mechanism and targeted therapy of TNBC.

Circ_0002099 is a novel molecular therapeutic target for bladder cancer.

Bladder cancer (BLCA) acts as one of the most common malignant tumors in the urinary system without ideal therapy. We performed the present study to explore the role and mechanism of Circ_0002099 in BLCA progression. RNase R treatment assay and actinomycin D treatment assay were used to confirm the circular structure of Circ_0002099. Nuclear-cytoplasmic fractionation assay and fluorescence in situ hybridization (FISH) were used to indicatethe subcellular localization of Circ_0002099. The CCK-8 assay, colony formation assay, wound-healing assay, Transwell assay, and animal experiment were used to reveal the facilitative effect of Circ_0002099 on BLCA both in vitro and in vivo. Furthermore, bioinformatic analysis, western blot analysis, FISH,and dual-luciferase reporter assay were conducted to demonstrate the role of Circ_0002099 in BLCA progression. The results indicated that Circ_0002099 was significantly upregulated in BLCA and could enhance the progression of BLCA in vivo and in vitro. Furthermore, dual-luciferase reporter assay and FISHassay revealed that Circ_0002099 could regulate miR-217-5p/miR-103a-3p/Kirsten RAS (KRAS) axis in BLCA. In addition, rescue experiments confirmed that miR-217-5p/miR-103a-3p could rescue the facilitative effect of Circ_0002099 on BLCA progression. Moreover, FUS(FUSed in sarcoma)was identified to regulate the Circ_0002099-miR-217-5p/miR-103a-3p/KRAS axis in BLCA progression. The present study suggested that FUS-medicated Circ_0002099 could promote the epithelial-mesenchymal transitionprocess in BLCA progression via miR-217-5p/miR-103a-3p/KRAS axis-WNT/β-catenin axis. It could be a promising prognostic biomarker and therapeutic target for BLCA.

Circ0001470 Acts as a miR-140-3p Sponge to Facilitate the Progression of Embryonic Development through Regulating PTGFR Expression.

Embryonic implantation and development are vital in early pregnancy and assisted reproduction. Circular RNAs (circRNAs) are involved in the two physiological processes and thus regulate animal reproduction. However, their specific regulatory functions and mechanisms remain unclear. Here, a novel circ0001470, originating from the porcine GRN gene, differentially expressed on day 18 versus day 32 of gestation in Meishan and Yorkshire pigs was screened. The circularization characteristic of circ0001470 was identified based on divergent primer amplification, Sanger sequencing, RNase digestion, and RNA nuclear-cytoplasmic fractionation. Functionally, circ0001470 can promote cell proliferation and cycle progression of endometrial epithelial cells (EECs) and also inhibit apoptosis of EECs using CCK-8 assays and flow cytometry analyses. Mechanistically, bioinformatics database prediction, luciferase screening, RNA immunoprecipitation (RIP), RNA-pull down, and FISH co-localization experiments revealed that the circ0001470 acted as a competing endogenous RNA (ceRNA) through sponging miR-140-3p to regulate downstream PTGFR expression. Moreover, in vivo assays revealed that mmu_circGRN promoted embryonic development by affecting the expression of PTGFR, which can activate the MAPK reproduction pathway and facilitate pregnancy maintenance. This study enriched our understanding of circRNAs in embryo implantation and development by deciding the fate of EECs.