Construction and expression of circular RNA in vitro / 中国生物制品学杂志

@#Objective To construct encoding RNA that can be cyclized in vitro by using the permuted intron exon(PIE)strategy in the maturation process of eukaryotic mRNA,and transfect it into HEK-293T cells for expression.Methods The sequences of 5'and 3'cyclic arms with groupⅠcatalytic intron,the internal ribosome entry sites(IRES)of Coxsackievirus B3(CVB3)and the target gene were selected to construct the template plasmid. Linearization plasmid template obtained by PCR was used to synthesize linear RNA through in vitro transcription(IVT),which then started in vitro cyclization(IVC)by the addition of cyclization reagents to obtain circular RNA(circRNA). RNA cyclization was confirmed by agarose gel electrophoresis and ribonuclease R(RNase R)digestion. HEK-293T cells were transfected with circRNAs respectively carrying enhanced green fluorescent protein(EGFP),firefly luciferase(Fluc),and influenza virus hemagglutinin(HA)IVR-180 genes,to verify their expression with in vitro.Results With RNA cyclization,the main band of agarose gel electrophoresis became smaller and small fragments appeared. After RNase R digestion,only some circRNA bands remained.HEK-293T cells transfected with EGFP-circRNA showed significant green fluorescence under the fluorescence microscope.The Fluc expression values of HEK-293T cells transfected with Fluc-circRNA were on average 20 times higher than non cyclized RNA,and the relative light unit(RLU)scaled up with the increase of Fluc-circRNA transfection dose. Western blot analysis showed that HA protein was successfully expressed in HEK-293T cells transfected with HA-circRNA.Conclusion In this study,linear RNA was successfully cyclized in vitro and different proteins were expressed,which lays a foundation of the research of new influenza vaccines and mRNA vaccines.

Construction of competitive endogenous RNA network mediated by lung ischemia-reperfusion core genes / 器官移植

Objective To analyze the core genes of lung ischemia-reperfusion injury and construct a competitive endogenous RNA (ceRNA) network. Methods Original data of GSE145989 were downloaded from the Gene Expression Omnibus (GEO) database as the training set, and the GSE172222 and GSE9634 datasets were used as the validation sets, and the differentially-expressed genes (DEG) were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Protein-protein interaction (PPI) network was constructed, and the core genes were screened, and the diagnostic values of these core genes and the immune infiltration levels of immune cells were evaluated. The ceRNA network was constructed and validated. The targeted drugs based on ceRNA network were assessed. Results A total of 179 DEG were identified, including 61 down-regulated and 118 up-regulated genes. GO analysis showed that DEGs were associated with multiple biological processes, such as cell migration, differentiation and regulation, etc. They were correlated with cell components, such as vesicle membrane, serosa and membrane raft, etc. They were also associated with multiple molecular functions, such as chemokine receptor, G protein-coupled receptor, immune receptor activity and antigen binding, etc. KEGG pathway enrichment analysis revealed that DEG were involved in tumor necrosis factor (TNF), Wnt, interleukin (IL)-17 and nuclear factor (NF)-κB signaling pathways, etc. PPI network suggested that CD8A, IL2RG, STAT1, CD3G and SYK were the core genes of lung ischemia-reperfusion injury. The ceRNA network prompted that miR-146a-3p, miR-28-5p and miR-593-3p were related to the expression level of CD3G. The miR-149-3p, miR-342-5p, miR-873-5p and miR-491-5p were correlated with the expression level of IL-2RG. The miR-194-3p, miR-512-3p, miR-377-3p and miR-590-3p were associated with the expression level of SYK. The miR-590-3p and miR-875-3p were related to the expression level of CD8A. The miR-143-5p, miR-1231, miR-590-3p and miR-875-3p were associated with the expression level of STAT1. There were 13 targeted drugs for CD3G, 4 targeted drugs for IL-2RG, 28 targeted drugs for SYK and 3 targeted drugs for lncRNA MUC2. No targeted drugs were identified for CD8A, STAT1 and other ceRNA network genes. Conclusions CD8A, IL2RG, STAT1, CD3G and SYK are the core genes of lung ischemia-reperfusion injury. The research and analysis of these core genes probably contribute to the diagnosis of lung ischemia-reperfusion injury and providing novel research ideas and therapeutic targets.

Research progress on circular RNA in fundus oculi proliferative diseases / 中华实验眼科杂志

Fundus oculi proliferative diseases, such as choroidal neovascularization, diabetic retinopathy, and proliferative vitreoretinopathy, are characterized by cell proliferation and neovascularization.It can lead to damage to the ocular structure and visual acuity.Circular RNA (CircRNA) is a non-coding endogenous RNA, which has been confirmed to be involved in the pathophysiological process of many ophthalmic diseases by recent studies.Thus, circRNA may become a promising target of fundus oculi proliferative diseases.This review concluded the physiological function of circRNA and its role in the physiological and pathological process of diabetic retinopathy, proliferative vitreoretinopathy and glaucoma-related glia proliferation.

Effect of circRNA on breast cancer metastasis / 国际外科学杂志

Breast cancer is the most common malignant tumor in women, and metastasis is the main cause of death in breast cancer patients. Circular RNA (circRNA) is prevalent, abundant in organisms, and are characterized by their stable structure, conserved sequences, and specific expression. CircRNA have emerged as crucial regulators in diverse human cancers including breast cancer. Increasing evidence suggests that circRNA are aberrantly expressed in tissues and cell lines of breast cancer and involved in breast cancer metastasis. However, systematic knowledge regarding circRNA involvement in metastatic breast cancer remains unclear. This review outline functional circRNA associated with breast cancer metastasis and discuss their underlying mechanisms, providing new ideas for early prediction, diagnosis and treatment of breast cancer metastasis in the future.

Read-through circular RNA rt-circ-HS promotes hypoxia inducible factor 1α expression and renal carcinoma cell proliferation, migration and invasiveness / 北京大学学报(医学版)

OBJECTIVE@#To identify and characterize read-through RNAs and read-through circular RNAs (rt-circ-HS) derived from transcriptional read-through hypoxia inducible factor 1α (HIF1α) and small nuclear RNA activating complex polypeptide 1 (SNAPC1) the two adjacent genes located on chromosome 14q23, in renal carcinoma cells and renal carcinoma tissues, and to study the effects of rt-circ-HS on biological behavior of renal carcinoma cells and on regulation of HIF1α.@*METHODS@#Reverse transcription-polymerase chain reaction (RT-PCR) and Sanger sequencing were used to examine expression of read-through RNAs HIF1α-SNAPC1 and rt-circ-HS in different tumor cells. Tissue microarrays of 437 different types of renal cell carcinoma (RCC) were constructed, and chromogenic in situ hybridization (ISH) was used to investigate expression of rt-circ-HS in different RCC types. Small interference RNA (siRNA) and artificial overexpression plasmids were designed to examine the effects of rt-circ-HS on 786-O and A498 renal carcinoma cell proliferation, migration and invasiveness by cell counting kit 8 (CCK8), EdU incorporation and Transwell cell migration and invasion assays. RT-PCR and Western blot were used to exa-mine expression of HIF1α and SNAPC1 RNA and proteins after interference of rt-circ-HS with siRNA, respectively. The binding of rt-circ-HS with microRNA 539 (miR-539), and miR-539 with HIF1α 3' untranslated region (3' UTR), and the effects of these interactions were investigated by dual luciferase reporter gene assays.@*RESULTS@#We discovered a novel 1 144 nt rt-circ-HS, which was derived from read-through RNA HIF1α-SNAPC1 and consisted of HIF1α exon 2-6 and SNAPC1 exon 2-4. Expression of rt-circ-HS was significantly upregulated in 786-O renal carcinoma cells. ISH showed that the overall positive expression rate of rt-circ-HS in RCC tissue samples was 67.5% (295/437), and the expression was different in different types of RCCs. Mechanistically, rt-circ-HS promoted renal carcinoma cell proliferation, migration and invasiveness by functioning as a competitive endogenous inhibitor of miR-539, which we found to be a potent post-transcriptional suppressor of HIF1α, thus promoting expression of HIF1α.@*CONCLUSION@#The novel rt-circ-HS is highly expressed in different types of RCCs and acts as a competitive endogenous inhibitor of miR-539 to promote expression of its parental gene HIF1α and thus the proliferation, migration and invasion of renal cancer cells.

Promising roles of non-exosomal and exosomal non-coding RNAs in the regulatory mechanism and as diagnostic biomarkers in myocardial infarction / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Non-exosomal non-coding RNAs (non-exo-ncRNAs) and exosomal ncRNAs (exo-ncRNAs) have been associated with the pathological development of myocardial infarction (MI). Accordingly, this analytical review provides an overview of current MI studies on the role of plasma non-exo/exo-ncRNAs. We summarize the features and crucial roles of ncRNAs and reveal their novel biological correlations via bioinformatics analysis. The following contributions are made: (1) we comprehensively describe the expression profile, competing endogenous RNA (ceRNA) network, and "pre-necrotic" biomarkers of non-exo/exo-ncRNAs for MI; (2) functional enrichment analysis indicates that the target genes of ncRNAs are enriched in the regulation of apoptotic signaling pathway and cellular response to chemical stress, etc.; (3) we propose an updated and comprehensive view on the mechanisms, pathophysiology, and biomarker roles of non-exo/exo-ncRNAs in MI, thereby providing a theoretical basis for the clinical management of MI.

Role of ceRNA network in inflammatory cells of rheumatoid arthritis / 中南大学学报(医学版)

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease caused by inflammatory cells. Various inflammatory cells involved in RA include fibroblast-like synoviocytes, macrophages, CD4+T-lymphocytes, B lymphocytes, osteoclasts and chondrocytes. The close interaction between various inflammatory cells leads to imbalance of immune response and disorder of the expression of mRNA in inflammatory cells. It helps to drive production of pro-inflammatory cytokines and stimulate specific antigen-specific T- and B-lymphocytes to produce autoantibodies which is an important pathogenic factor for RA. Competing endogenous RNA (ceRNA) can regulate the expression of mRNA by competitively binding to miRNA. The related ceRNA network is a new regulatory mechanism for RNA interaction. It has been found to be involved in the regulation of abnormal biological processes such as proliferation, apoptosis, invasion and release of inflammatory factors of RA inflammatory cells. Understanding the ceRNA network in 6 kinds of RA common inflammatory cells provides a new idea for further elucidating the pathogenesis of RA, and provides a theoretical basis for the discovery of new biomarkers and effective therapeutic targets.

Recent Research Progress on CircRNA in Hematological Malignancies--Review / 中国实验血液学杂志

Most hematological tumors have high-grade malignancy and low cure rate, requiring new molecular markers for detection and evaluation. Circular RNAs (circRNAs) are a class of non-coding RNAs with covalently closed-loop structures, which participate in gene transcription and translation by binding to microRNAs and proteins. In recent years, with the deepening research on circRNAs, circRNAs have been found to play an important role in hematological malignancies. In this review, the latest research progress on the function and molecular mechanism of circRNAs in hematological malignancies was systematically summarized, and it was found that circRNAs may be potential new biomarkers and therapeutic targets in hematological malignancies.

Intervention effect of Chuanxiong-Chishao herb pair on circRNA/lncRNA expression profile in a myocardial infarction-atherosclerosis model / 中国中药杂志

This study aimed to explore the intervention effect of Chuanxiong-Chishao herb pair(CX-CS) on a myocardial infarction-atherosclerosis(MI-AS) mouse model and investigate its effect on the expression profile of circular RNAs(circRNAs)/long non-coding RNAs(lncRNAs) in ischemic myocardium and aorta. Sixty male ApoE~(-/-) mice were randomly assigned to a model group, high-, medium-, and low-dose CX-CS groups(7.8, 3.9, and 1.95 g·kg~(-1)), and a positive drug group(metoprolol 26 mg·kg~(-1) and simvastatin 5.2 mg·kg~(-1)), with 12 mice in each group. Male C57BL/6J mice were assigned to the sham group. The mice in the model group and the groups with drug intervention were fed on a high-fat diet for 10 weeks, followed by anterior descending coronary artery ligation. After that, the mice were fed on a high-fat diet for another two weeks to induce the MI-AS model. The mice in the sham group received normal feed, followed by sham surgery without coronary artery ligation. Mice in the groups with drug intervention received CX-CS or positive drug by gavage for four weeks from the 9th week of high-fat feeding, and those in the model group and the sham group received an equal volume of normal saline. Whole transcriptome sequencing was performed on the heart and aorta tissues of the medium-dose CX-CS group, the model group, and the sham group after administration. The results showed that the medium-and high-dose CX-CS groups showed improved cardiac function and reduced myocardial fibrosis area, and the medium-dose CX-CS group showed significantly reduced plaque area. CX-CS treatment could reverse the expression of circRNA＿07227 and circRNA＿11464 in the aorta of AS model and circRNA expression(such as circRNA＿11505) in the heart of the MI model. Differentially expressed circRNAs between the CX-CS-treated mice and the model mice were mainly enriched in lipid synthesis, lipid metabolism, lipid transport, inflammation, and angiogenesis in the aorta, and in angiogenesis, blood pressure regulation, and other processes in the heart. CX-CS treatment could reverse the expression of lncRNAs such as ENSMUST00000162209 in the aorta of the AS model and TCONS＿00002123 in the heart of the MI model. Differentially expressed lncRNAs between the CX-CS-treated mice and model mice were mainly enriched in lipid metabolism, angiogenesis, autophagy, apoptosis, and iron death in the aorta, and in angiogenesis, autophagy, and iron death in the heart. In summary, CX-CS can regulate the expression of a variety of circRNAs and lncRNAs, and its intervention mechanism in coronary heart disease may be related to the regulation of angiogenesis and inflammation in ischemic myocardium, as well as lipid metabolism, lipid transport, inflammation, angiogenesis in AS aorta.

circSNRK alleviates ischemia-reperfusion injury in renal tubular epithelial cell by up-regulating Akt pathway / 器官移植

Objective To investigate the role and mechanism of circular RNA SNRK (circSNRK) in ischemia-reperfusion injury (IRI). Methods A hypoxia-reoxygenation (IRI) cell model was established. The expression level of circSNRK after IRI treatment and the effect of overexpression of circSNRK on cell proliferation and apoptosis were detected. The targets of circSNRK were identified. HK2 cells were divided into the blank group (Mock group), IRI group, control plasmid+IRI group (IRI+NC group), human circSNRK overexpression+IRI group (IRI+circSNRK group), human circSNRK overexpression+IRI+protein kinase B (Akt) inhibitor group (IRI+circSNRK+MK2206 group) and control plasmid group (NC group). Cell proliferation and apoptosis were detected in the Mock, IRI, IRI+NC and IRI+circSNRK groups. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the target of circSNRK were carried out. The expression levels of CDKN1A, Akt, B-cell lymphoma (Bcl)-2, cysteinyl aspartate specific proteinase (Caspase)-9 messenger RNA (mRNA), and those of p21, Bcl-2, Caspase-9, Akt and p-Akt proteins were detected in the Mock, IRI, IRI+NC and IRI+circSNRK groups, respectively. Cell proliferation and apoptosis were determined in the NC, IRI+NC, IRI+circSNRK and IRI+circSNRK+MK2206 groups. Results Compared with the Mock group, the expression level of circSNRK was lower, and cell proliferation capability of HK2 cells was decreased and cell apoptosis was increased in the IRI group. In the IRI+circSNRK group, cell proliferation capability was higher, whereas cell apoptosis was lower than those in the IRI+NC group. circSNRK could act on 648 targets through 51 microRNAs (miRNAs). GO enrichment analysis revealed that the targets of circSNRK were mainly enriched in biological processes (such as cell process and biological regulation), cell components (such as cell parts, cells and extracellular parts), and molecular functions (such as binding, binding proteins and enzymes). KEGG enrichment analysis showed that the targets of circSNRK were mainly enriched in cancer signaling pathway, phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway, miRNA in cancer and other related signaling pathways. Compared with the Mock group, the relative expression levels of CDKN1A and Caspase-9 mRNA were higher, the expression level of miR-99a-5p RNA was higher and the relative expression levels of Akt and Bcl-2 mRNA were lower in the IRI group. Compared with the IRI+NC group, the relative expression levels of CDKN1A and Caspase-9 mRNA were lower, those of Akt and Bcl-2 mRNA were higher, and the expression level of miR-99a-5p RNA was lower in the IRI+circSNRK group, and the differences were statistically significant (all P < 0.05). Compared with the Mock group, the expression levels of p21 and Caspase-9 proteins were higher, while those of p-Akt, Akt and Bcl-2 proteins were lower in the IRI group. Compared with the IRI+NC group, the expression levels of p21 and Caspase-9 proteins were lower, whereas those of p-Akt, Akt and Bcl-2 proteins were higher in the IRI+circSNRK group. The miR-99a-5p binding sites were observed in circSNRK and Akt. Compared with the NC group, cell proliferation capability was declined in the IRI+NC group. Compared with the IRI+NC group, cell proliferation capability was elevated in the IRI+circSNRK group. Compared with the IRI+circSNRK group, cell proliferation capability was declined in the IRI+circSNRK+MK2206 group (all P < 0.05). The cell apoptosis level in the IRI+NC group was higher than that in the NC group. The cell apoptosis level in the IRI+circSNRK group was lower compared with that in the IRI+NC group. The cell apoptosis level in the IRI+circSNRK+MK2206 group was higher than that in the IRI+circSNRK group. Conclusions Under IRI conditions, circSNRK may affect the proliferation and apoptosis of HK2 cells probably via the Akt signaling pathway.

Progress of the effect of circular RNA on the sensitivity to chemotherapy drugs in colorectal cancer / 肿瘤研究与临床

The pathogenesis of colorectal cancer involves a variety of molecules and genes, among which circular RNA (circRNA) has received extensive attention in regulating the development and progression of tumors and mediating drug resistance. circNRA has been identified as tumor promoters or tumor suppressors that influence the sensitivity to chemotherapy drugs and mediate the onset and metastasis of colorectal cancer. The influence of circRNA on the drug resistance sensitivity of conventional chemotherapy has become a new direction for the research of anti-tumor chemotherapy drugs. This paper discusses the biological characteristics of circRNA and introduces the relationship between circRNA and the sensitivity to chemotherapy drugs in colorectal cancer.

Effect of circular RNA hsa_circZDHHC21_004 on the proliferation of the human small intestinal epithelial cells HIEC-6 exposed to 60Co γ-rays / 中华放射医学与防护杂志

Objective:To study the influence of circular RNA hsa_circZDHHC21_004 on the proliferation of human small intestinal epithelial cells HIEC-6 after 60Co γ-rays exposure. Methods:HIEC-6 cells were exposed to 60Co γ-rays at 0, 5, 10, and 15 Gy with a dose rate of 1 Gy/min. The expression level of hsa_circZDHHC21_004 in the irradiated HIEC-6 cell was detected. Hsa_circZDHHC21_004 was knocked-down to investigate the influences of hsa_circZDHHC21_004 on the proliferation of irradiated HIEC-6 cells by CCK-8 assay and colony formation assay. Results:The expression level of hsa_circZDHHC21_004 in HIEC-6 cells was upregulated by (1.00±0.24), (1.34±0.28), (1.85±0.31), and (2.80±0.64) times of control after 0, 5, 10, and 15 Gy irradiation, respectively and there were significant difference between 10 or 15 Gy group and 0 Gy group ( F=10.86, P=0.008). Knockdown of hsa_circZDHHC21_004 significantly increased the proliferation rate of HIEC-6 cells at 24, 48, and 72 h after 10 Gy irradiation compared with non-irradiated control ( t=-6.25, -5.83, -7.75, P < 0.001). Under 2 and 5 Gy irradiation, the clone formation rates of the hsa_circZDHHC21_004 knockdown cells were significantly higher than those of the control ( t=-7.45, -8.83, P<0.01). Conclusions:Hsa_circZDHHC21_004 is increased after irradiation and influenced the proliferation of irradiated HIEC-6 cells.

Effects of circular RNA-SEC31A on the invasion and migration of pancreatic cancer cells and molecular mechanism / 中华胰腺病杂志

Objective:To determine the expression of circular RNA-SEC31A(circSEC31A) in pancreatic cancer and investigate the effects on the invasion and migration of pancreatic cancer cells and the underlying molecular mechanism.Methods:Differentially expressed circRNAs between pancreatic cancer cells (BXPC-3, PANC1, CaPan-2, SW1990) and human normal pancreatic cells (HPDE) were identified by qRT-PCR. Then, two cell lines with high circSEC31A expression were selected to conduct next experiments. According to the sequence of the back-splicing site in circSEC31A, siRNAs for downregulation of circSEC31A were designed and transfected by liposome to silence circSEC31A in pancreatic cancer cells, and grouped as followed siR-circSEC31A#1 and siR-circSEC31A#2. Meanwhile, siR-NC group transfected with non-specific siRNA served as control. Transwell assays and wound healing assays were operated to evaluate the functional role of circSEC31A on the invasion and migration of pancreatic cancer cells. RNA Pull-down assay with circSEC31A probe and oligo control probe was used to screen the miRNA combining with circSEC31A and the effects of miRNA on cell invasion and migration of pancreatic cancer cells were validated. The effect of miR-200c-3p and circSEC31A silencing on the expression of PDK1 mRNA was identified by qRT-PCR. The protein expression of PDK1, downstream Akt and p-Akt after circSEC31A silencing was verified by Western blotting assays.Results:The relative expression level of circSEC31A in HPDE (1.000±0.120) was obviously lower than that in BXPC-3 (1.920±0.130), SW1990 (2.93±0.528), PANC1 (4.557±0.692) and CaPan-2 (5.247±0.194), and all the differences were statistically significant ( P<0.001). Compared with the PANC1 siR-NC group (1301.3±94.6) and CaPan-2 siR-NC group (1835.0±70.1) per 100 high power field, transwell assays showed that the numbers of invasive pancreatic cancer cells was highly decreased in PANC1 siR-circSEC31A#1 group (727.3±92.9), siR-circSEC31A#2 group (792.0±18.1), CaPan-2 siR-circSEC31A#1 group (718.0±90.6), siR-circSEC31A#2 group (692.7±84.8). Wound healing assays showed that silencing circSEC31A decreased the wound healing rate of pancreatic cancer cells in PANC1 siR-circSEC31A#1 group (20.667±3.215)%, siR-circSEC31A#2 group (20.000±4.583)%, CaPan-2 siR-circSEC31A#1 group (28.000±8.185)%, siR-circSEC31A#2 group (29.667±5.686)%, compared with the PANC1 siR-NC group (55.000±4.359)% and CaPan-2 siR-NC group (69.000±3.606)%. RNA Pull-down assays showed that compared with PANC1 oligo probe group (1.000±0.091) and CaPan-2 oligo probe group (1.000±0.153), miR-200c-3p was significantly enriched in the PANC1 circSEC31A probe group (2.237±0.175) and CaPan-2 circSEC31A probe group (2.166±0.156). Compared with PANC1 siR-NC group (939.3±57.0) and CaPan-2 siR-NC group (786.7±51.5) per 100 high power field, the numbers of invasive pancreatic cancer cells were up-regulated in PANC1 siR-miR-200c-3p group (1206.0±99.1) and CaPan-2 siR-miR-200c-3p group (1838.0±105.7), while the low numbers of invasive pancreatic cancer cells were observed in PANC1 siR-miR-200c-3p+ siR-circSEC31A group (932.7±116.4) and CaPan-2 siR-miR-200c-3p+ siR-circSEC31A group (785.3±58.8). Compared with PANC1 siR-NC group (1.000±0.103) and CaPan-2 siR-NC group (1.000±0.107), the relative expression of PDK1 mRNA in PANC1 siR-miR-200c-3p group (1.898±0.159) and CaPan-2 siR-miR-200c-3p group (2.102±0.337) was upregulated. Furthermore, the expression of PDK1 mRNA was decreased in the siR-miR-200c-3p+ siR-circSEC31A group (0.980±0.070, 1.015±0.079). Western blot assays showed that the expression of PDK1 protein in PANC1 siR-NC group, siR-circSEC31A#1 group, siR-circSEC31A#2 group was 0.767±0.086, 0.281±0.191, 0.333±0.062 and in CaPan-2 siR-NC group, siR-circSEC31A#1 group, siR-circSEC31A#2 group was 0.712±0.038, 0.353±0.061, 0.308±0.018. The expression of p-Akt protein in PANC1 siR-NC group and siR-circSEC31A group was 0.741±0.050, 0.114±0.027, 0.139±0.041. In addition, p-Akt protein expression in CaPan-2 siR-NC group and siR-circSEC31A group was 0.823±0.052, 0.141±0.045, 0.280±0.089. PDK1 and p Akt expression in siR circSEC31A group was obviously lower than those in sir NC group. All the differences between either groups above were statistically significant ( P<0.05). Conclusions:circSEC31A is upregulated in pancreatic cancer cells, which facilitates the invasion and metastasis of pancreatic cancer cells via miR-200c-3p/PDK1/Akt signaling pathway, supporting that circSEC31A may function as a new diagnostic and therapeutic target for pancreatic cancer patients.

Regulation of Glial Function by Noncoding RNA in Central Nervous System Disease / 神经科学通报·英文版

Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.

Circular RNA circRSF1 binds to HuR to promote radiation-induced inflammatory phenotype in hepatic stellate cells / 南方医科大学学报

OBJECTIVE@#To investigate whether circular RNA circRSF1 regulates radiation-induced inflammatory phenotype of hepatic stellate cells (HSCs) by binding to HuR protein and repressing its function.@*METHODS@#Human HSC cell line LX2 with HuR overexpression or knockdown was exposed to 8 Gy X-ray irradiation, and the changes in the expression of inflammatory factors (IL-1β, IL-6 and TNF-α) were detected by qRT-PCR. The expressions of IκBα and phosphorylation of NF-κB were detected with Western blotting. The binding of circRSF1 to HuR was verified by RNA pull-down assay and RNA-binding protein immunoprecipitation (RIP). The expressions of inflammatory factors, IκBα and the phosphorylation of NF-κB were detected after modifying the interaction between circRSF1 and HuR.@*RESULTS@#Knockdown of HuR significantly up- regulated the expressions of IL-1β, IL-6 and TNF-α, decreased IκBα expression and promoted NF-κB phosphorylation in irradiated LX2 cells, whereas overexpression of HuR produced the opposite changes (P < 0.05). Overexpression or knockdown of circRSF1 did not significantly affect the expression of HuR. RNA pull-down and RIP experiments confirmed the binding between circRSF1 and HuR. Overexpression of circRSF1 significantly reduced the binding of HuR to IκBα and down-regulated the expression of IκBα (P < 0.05). Overexpression of circRSF1 combined with HuR overexpression partially reversed the up-regulation of the inflammatory factors, down-regulated IκBα expression and increased phosphorylation of NFκB in LX2 cells, while the opposite effects were observed in cells with knockdown of both circRSF1 and HuR (P < 0.05).@*CONCLUSION@#circRSF1 reduces IκBα expression by binding to HuR to promote the activation of NF-κB pathway, thereby enhancing radiation- induced inflammatory phenotype of HSCs.

Differential expression analysis of circular RNA in human retinal vascular endothelial cells induced by high glucose / 中华实验眼科杂志

Objective:To investigate the differential expression profile of circular RNA (circRNA) in high glucose-cultured human retinal vascular endothelial cells (HRVECs).Methods:HRVECs were divided into high glucose group, normal control group and hypertonic control group, and were cultured in 25 mmol/L glucose medium, 5.5 mmol/L glucose medium and 19.5 mmol/L mannitol+ 5.5 mmol/L glucose medium for 24 hours accordingly.The differentially expressed circRNA molecules between high glucose group and normal control group were screened by circRNA microarray analysis.The expression of the most significant differentially expressed circRNAs in different groups was verified by real-time quantitative PCR.The possible microRNA (miRNA) targets were analyzed through the Circular RNA Interactome database.Results:It was found that 448 circRNAs were differentially expressed (FC≥1.5 or FC≤0.67, P<0.05) in high glucose-cultured HRVECs, among which 182 were up-regulated and 266 were down-regulated.The top 3 significantly up-regulated circRNAs were hsa_circ_0002938, hsa_circ_0008036, and hsa_circ_0001946, and the top 3 significantly down-regulated circRNAs were hsa_circ_0035277, hsa_circ_0008344, and hsa_circ_0001874.Compared with normal control group and hypertonic control group, the relative expressions of top 3 up-regulated circRNAs were significantly enhanced and the relative expressions of top 3 down-regulated circRNAs were significantly reduced in high glucose group, showing statistically significant differences (all at P<0.05).No significant difference was found in the differentially expressed circRNAs between normal control group and hypertonic control group (all at P>0.05). Conclusions:CircRNAs are differentially expressed in high glucose-cultured HRVECs, and the differentially expressed circRNAs may be involved in the regulatory mechanism of diabetic retinopathy.

Analysis and prospects of a new component circular RNA in breast milk / 中华实用儿科临床杂志

Breast milk contains a variety of bioactive components, which play a vital role in disease prevention and treatment.Among them, circular RNA(circRNA), which is a closed ring structure formed by covalent bonds, has aroused interest because of its conservation and stability.Pediatric researchers should attach importance to studies on circRNA in breast milk, as they may bring new inspiration for breast milk functions.In this article, characteristics and functions of circRNA in breast milk will be investigated, and its research and prospects will be discussed.

Research progress of circRNA in silicosis fibrosis / 环境与职业医学

Silicosis is a chronic progressive pulmonary fibrosis disease that seriously endangers the occupational health of workers. There is no effective treatment at present. It is urgent to find effective therapeutic targets and use molecular markers to intervene the process of silicosis fibrosis. As a new type of non-coding RNA, circular RNA (circRNA) has the characteristics of stable structure, long half-life, high conservation, and is specifically expressed in different species, tissues, diseases, and developmental stages, and has potential value and application prospects as a biomarker. In recent years, the regulatory role of circRNA in the occurrence and development of human diseases has become a research hotspot. Some circRNAs have been found to associate with the pathogenesis of silicosis. This article briefly described the biological characteristics and functions of circRNA, focused on the reported relationship between circRNA and pathogenesis of silicosis, summarized the current research progress of circRNA-mediated pathogenesis of silicosis, and then put forward potential directions and suggestions for further research on targeting circRNA in the diagnosis and treatment of silicotic fibrosis.

Whole blood circular RNA hsa_circ_0002171 serves as a potential diagnostic biomarker for human adenovirus pneumonia in children

Severe pneumonia related to human adenoviruses (HAdVs) has a high lethality rate in children and its early diagnosis and treatment remain a major challenge. Circular RNAs (circRNAs) are novel long noncoding RNAs that play important roles in gene regulation and disease pathogenesis. To investigate the roles of circRNAs in HAdV pneumonia, we analyzed the circRNA profiles of healthy children and children with HAdV pneumonia, including both mild and severe cases, and identified 139 significantly upregulated circRNAs in children with HAdV pneumonia vs healthy controls and 18 significantly upregulated circRNAs in children with severe HAdV pneumonia vs mild HAdV pneumonia. In particular, hsa_circ_0002171 was differentially expressed in both groups and might thus be useful as a diagnostic biomarker of HAdV pneumonia and severe HAdV pneumonia. To identify the underlying mechanisms of circRNAs in HAdV pneumonia, we analyzed the transcriptome of children with HAdV pneumonia and established a circRNA-mRNA regulatory network. Enrichment analysis of differentially expressed target mRNAs demonstrated that the differentially expressed genes between healthy controls and HAdV pneumonia patients were mainly involved in RNA splicing while the differentially expressed genes between children with mild and severe HAdV pneumonia were mainly involved in regulating lymphocyte activation. Receiver operating characteristic (ROC) curve analysis suggested that hsa_circ_0002171 had a significant value in the diagnosis of HAdV pneumonia and of severe HAdV pneumonia. Taken together, the circRNA expression profile was altered in children with HAdV pneumonia. These results demonstrated that hsa_circ_0002171 is a potential diagnostic biomarker of HAdV pneumonia.

Research progress on the role of circular RNA in eye diseases / 国际眼科杂志(Guoji Yanke Zazhi)

@#Circular RNA(circRNA)is a single-stranded covalently closed RNA molecule produced by reverse splicing, which is an evolutionarily conserved and stable transcript, and widely exists in various eukaryotic cells. CircRNA is more stable and conserved than linear transcripts because of the absence of 5'cap and 3'polyadenylation tail in circRNA. A variety of bioactive processes are regulated by circRNA, such as cell differentiation, proliferation, angiogenesis and cell apoptosis. CircRNAs were shown to be key regulators of various diseases, especially cancers, neurodegenerative and cardiovascular. Recently, with the rapid development of RNA high-throughput sequencing technology, accumulating evidence shows that there are multiple differentially expressed circRNAs in ocular tissues and they play important roles in initiation, progression, and prognosis of diverse ocular diseases, such as glaucoma, cataract, retinopathy, ocular tumors and ocular immunologic diseases. In this article, the research on the relationship between circRNA and ophthalmic diseases in the recent years is briefly reviewed, and the purpose is to provide reference for its clinical treatment and prognosis.