Hsa_circ_0069094 positively regulates the expression of oncogenic ZNF217 by competitively targeting miR-758–3p to promote the development of breast cancer

To investigate the functions and potential mechanisms of hsa_circ_0069094 in this cancer. The expression of hsa_circ_0069094, zinc finger protein 217 (ZNF217) and microRNA-758–3p (miR-758–3p) was detected by quantitative polymerase chain reaction (qPCR), and the protein level of ZNF217 was detected by western blot. Cell proliferation was assessed using cell counting kit-8 (CCK-8) assay and colony formation assay. Cell cycle progression and cell apoptosis were determined using flow cytometry assay. Cell invasion and cell migration were monitored using transwell assay and wound healing assay. The protein levels of apoptosis-related proteins were quantified by western blot. The putative relationship between miR-758–3p and hsa_circ_0069094 and ZNF217 was confirmed using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Xenograft model was constructed in mice to explore the role of hsa_circ_0069094 on solid tumor growth.Hsa_circ_0069094 and ZNF217 were highly expressed, while miR-758–3p was poorly expressed in tissues and cells of breast cancer. Hsa_circ_0069094 knockdown or ZNF217 knockdown inhibited cell proliferation, invasion and migration and induced cell apoptosis and cell cycle arrest in breast cancer cells. The inhibitory effects of hsa_circ_0069094 knockdown on cell malignant behaviors were abolished by ZNF217 overexpression. Hsa_circ_0069094 competed with ZNF217 for the binding site of miR-758–3p, and hsa_circ_0069094 positively regulated ZNF217 expression by competitively binding to miR-758–3p. Hsa_circ_0069094 knockdown also blocked solid tumor growth in mice. Collectively, Hsa_circ_0069094 played oncogenic effects in breast cancer by activating the expression of ZNF217 via competitively binding to miR-758–3p, which might be a novel strategy for breast cancer suppression.     

Elevated expression of circular RNA circ_0008450 predicts dismal prognosis in hepatocellular carcinoma and regulates cell proliferation,apoptosis, and invasion via sponging miR-548p

Hepatocellular carcinoma (HCC) is one of the most frequent malignancies and a main cause of global cancer mortality. In the past decade, circular RNAs (circRNAs) have been proved to play key roles in various cancers. Previously, circ_0008450 was identified upregulated in HCC tissues by high-throughput circRNA sequencing. In this study, quantitative real-time polymerase chain reaction was used to evaluate the expression level of circ_0008450 in human HCC tumor and corresponding nontumor tissue samples, and the association between circ_0008450 expression and clinicopathologic features of patients with HCC was also analyzed. After that, the functions of circ_0008450 in biological behaviors of HCC cells were determined by cell counting kit-8, colony formation, flow cytometry, and the transwell assays. The mechanism of circ_0008450 was explored by the bioinformatic analysis and dual-luciferase reporter assay. The expression of circ_0008450 is upregulated in HCC tissue specimens and cell lines. Patients with a high circ_0008450 expression usually bear a lower 5-year survival rate. Silencing of circ_0008450 in Huh-7 cells inhibited cell viability, migration, and invasion, whereas cell apoptosis was increased. Conversely, its overexpression in HepG2 cells leads to absolutely inverse results. In addition, circ_0008450 was proved to be a sponge of miR-548p. The oncogenic role of circ_0008450 was partially attributed to its suppression on miR-548p. This study implies a new target for the treatment of HCC.     

Circ_0004015 silencing represses cisplatin chemoresistance and tumor progression by reducing KLF8 in a miR-198-dependent manner in non-small cell lung cancer

Circular RNA (circRNA) plays vital roles in diverse cancer progression, including non-small cell lung cancer (NSCLC). Herein, the role of circ_0004015 in regulating the sensitivity of NSCLC to cisplatin (DDP) is revealed. The RNA expression of circ_0004015, microRNA-198 (miR-198) and kruppel like factor 8 (KLF8) was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blot. The half maximal inhibitory concentration of DDP and cell proliferation were determined by cell counting kit-8 assay. Cell colony formation ability, migration, invasion and apoptosis were investigated by colony-forming assay, transwell assay and flow cytometry analysis, respectively. The effect of circ_0004015 knockdown on DDP sensitivity in vivo was demonstrated by mouse model assay. The interactions among circ_0004015, miR-198 and KLF8 were predicted by bioinformatics methods, and identified by mechanism assays. The expression of circ_0004015 and KLF8 was apparently upregulated, while miR-198 expression was downregulated in DDP-resistant NSCLC tissues and cells compared with control groups. Additionally, circ_0004015 silencing repressed DDP resistance, cell proliferation, migration and invasion, but induced cell apoptosis in DDP-resistant NSCLC cells. Circ_0004015 knockdown promoted the effect of DDP on tumor formation in vivo. Also, miR-198 inhibitors attenuated circ_0004015 depletion-mediated action though associating with circ_0004015. MiR-198 regulated DDP sensitivity and NSCLC progression by targeting KLF8. Furthermore, circ_0004015 modulated KLF8 expression through interaction with miR-198. Circ_0004015 conferred DDP resistance and promoted NSCLC progression by miR-198/KLF8 pathway, proving a potential target for studying DDP-mediated treatment of NSCLC.     

Circ_0025039 acts an oncogenic role in the progression of non-small cell lung cancer through miR-636-dependent regulation of CORO1C

Non-small cell lung cancer remains the leading cause of cancer-related death worldwide. Circular RNA plays vital roles in NSCLC progression. This study is designed to reveal the role of circ_0025039 in NSCLC cell malignancy. The RNA expression of circ_0025039, microRNA-636 (miR-636), and coronin 1C was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by Western blot analysis or immunohistochemistry assay. Cell proliferation, migration, invasion, tube formation ability, sphere formation capacity, and apoptosis were investigated by cell counting kit-8, 5-Ethynyl-29-deoxyuridine, transwell assay, tube formation assay, sphere formation assay, and flow cytometry analysis, respectively. Mouse model assay was conducted to reveal the effect of circ_0025039 silencing on tumor formation in vivo. The interaction between miR-636 and circ_0025039 or CORO1C was identified through dual-luciferase reporter and RNA pull-down assays. The expression of circ_0025039 and CORO1C was significantly increased, while miR-636 was decreased in NSCLC tissues and cells compared with controls. Circ_0025039 depletion repressed NSCLC cell proliferation, migration, invasion, tube-forming capacity, and sphere formation ability, but induced cell apoptosis. The neoplasm formation was repressed after circ_0025039 silencing. Additionally, circ_0025039 acted as a sponge for miR-636, which was found to target CORO1C. Importantly, the contribution of circ_0025039 to NSCLC progression was mediated by miR-636/CORO1C axis. Circ_0025039 silencing repressed NSCLC malignant progression by reducing CORO1C expression through miR-636, showing the possibility of circ_0025039 as a therapeutic target for NSCLC.

     

Circ_0079593 facilitates proliferation,metastasis, glucose metabolism and inhibits apoptosis in melanoma by regulating the miR-516b/GRM3 axis

Many studies confirm that circular RNA (circRNA) plays an important regulatory role in the malignant progression of cancer, including melanoma. However, the role of a novel circRNA, circ_0079593, in melanoma is unclear. The expression levels of circ_0079593 and miR-516b were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was measured by cell counting kit-8 (CCK-8) assay, and cell migration and invasion were evaluated using transwell assay. Meanwhile, western blot (WB) analysis was employed to determine the levels of proliferation and metastasis-related proteins, as well as metabotropic glutamate receptor 3 (GRM3) protein. Furthermore, cell apoptosis was tested by detecting the cell apoptosis rate and Caspase-3 activity. The glucose consumption and lactate production of cells were measured to evaluate cell glucose metabolism. Moreover, dual-luciferase reporter assay and biotin-labeled RNA pull-down assay were used to confirm the interaction between miR-516b and circ_0079593 or GRM3. In addition, mice xenograft models were constructed to explore the effect of circ_0079593 on melanoma tumor growth in vivo. Our results discovered that circ_0079593 was highly expressed in melanoma, and its silencing suppressed melanoma cell proliferation, migration, invasion, glucose metabolism and promoted apoptosis. Moreover, we found that circ_0079593 could serve as a sponge of miR-516b, and miR-516b could target GRM3 in melanoma. The rescue experiments revealed that both miR-516b inhibitor and GRM3 overexpression could reverse the inhibition effect of circ_0079593 knockdown on melanoma progression. Additionally, in vivo experiments also revealed that circ_0079593 interference suppressed melanoma tumor growth. Our study concluded that circ_0079593 accelerated melanoma progression via upregulating GRM3 by sponging miR-516b, which suggested that circ_0079593 had the potential to be a new therapeutic biomarker for melanoma.

     

Long intergenic noncoding RNA 00641 inhibits breast cancer cell proliferation,migration, and invasion by sponging miR-194-5p

Long noncoding RNAs have an essential role in the tumorigenesis of breast cancer (BC). Nonetheless, the consequences of long intergenic noncoding RNA 00641 (LINC00641) in BC remain unidentified. This study shows that LINC00641 expression level was decreased in BC tissues. LINC00641 expression level was negatively related to tumor size, lymph-node metastasis, as well as clinical stage. LINC00641 overexpression inhibited cell proliferation, migration, and invasion but stimulated apoptosis in BC cells. LINC00641 overexpression also remarkably reduced BC growth and metastasis in vivo. LINC00641 acts as a competitive endogenous RNA to sponge miR-194-5p. miR-194-5p level was higher in BC tissues and cells compared with normal-adjacent tissues and normal breast epithelial cell. miR-194-5p expression was negatively correlated with LINC00641 expression in BC tissues. miR-194-5p overexpression reversed the effects of LINC00641 on cell proliferation, cycle, apoptosis, migration, as well as invasion. In conclusion, LINC00641 inhibits BC cell proliferation, migration, as well as invasion by sponging miR-194-5p.     

ANXA2P2/miR-9/LDHA axis regulates Warburg effect and affects glioblastoma proliferation and apoptosis

BackgroundAerobic glycolysis is a unique tumor cell phenotype considered as one of the hallmarks of cancer. Aerobic glycolysis can accelerate tumor development by increasing glucose uptake and lactate production. In the present study, lactate dehydrogenase A (LDHA) is significantly increased within glioma tissue samples and cells, further confirming the oncogenic role of LDHA within glioma.MethodsHematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were applied for histopathological examination. The protein levels of LDHA, transporter isoform 1 (GLUT1), hexokinase 2 (HK2), phosphofructokinase (PFK) in target cells were detected by Immunoblotting. The predicted miR-9 binding to lncRNA Annexin A2 Pseudogene 2 (ANXA2P2) or the 3′ untranslated region (UTR) of LDHA was verified using Luciferase reporter assay. Cell viability or apoptosis were examined by MTT assay or Flow cytometry. Intracellular glucose and Lactate levels were measured using glucose assay kit and lactate colorimetric assay kit.ResultsThe expression of ANXA2P2 showed to be dramatically upregulated within glioma tissue samples and cells. Knocking down ANXA2P2 within glioma cells significantly inhibited cell proliferation and aerobic glycolysis, as manifested as decreased lactate and increased glucose in culture medium, and downregulated protein levels of glycolysis markers, GLUT1, HK2, PFK, as well as LDHA. miR-9 was predicted to target both lncRNA ANXA2P2 and LDHA. The overexpression of miR-9 suppressed the cell proliferation and aerobic glycolysis of glioma cells. Notably, miR-9 could directly bind to LDHA 3′UTR to inhibit LDHA expression and decrease the protein levels of LDHA. ANXA2P2 competitively targeted miR-9, therefore counteracting miR-9-mediated repression on LDHA. Within tissues, miR-9 exhibited a negative correlation with ANXA2P2 and LDHA, respectively, whereas ANXA2P2 and LDHA exhibited a positive correlation with each other.ConclusionsIn conclusion, ANXA2P2/miR-9/LDHA axis modulates the aerobic glycolysis progression in glioma cells, therefore affecting glioma cell proliferation.     

Circular RNA circ_0034642 elevates BATF3 expression and promotes cell proliferation and invasion through miR-1205 in glioma

Growing evidence indicates that circular RNA (circRNA) plays an important role in the regulation of tumor biological behaviors. In this study, we aimed to explore the role of a novel circRNA, circ_0034642, in glioma. qRT-PCR was conducted to evaluate the levels of circ_0034642 in glioma tissues and cells. In addition, the clinical severity and prognostic role of circ_0034642 were illustrated. Functionally, loss and gain-of function assays were performed by CCK-8, colony-forming, flow cytometric and transwell experiments in glioma cells. Moreover, luciferase reporter assay was used to detect the mechanism of circ_0034642. Circ_0034642 was upregulated in glioma tissues and cell lines. Overexpressed circ_0034642 was correlated with adverse phenotypes in the patients with glioma. In addition, circ_0034642 could be regarded as a prognostic predictor for glioma patients. Moreover, circ_0034642 could promote cell proliferation, migratory and invasive capacities and inhibit cell apoptosis. For the mechanism investigation, circ_0034642 was proved to be a sponge of miR-1205, and miR-1205 could regulate BATF3 expression via targeting 3′UTR of BATF3. Rescue assays also illustrated that the oncogenic function of circ_0034642 is partly attributed to its modulation on miR-1205/BATF3 axis. Collectively, circ_0034642/miR-1205/BATF3 pathway may play an important role in glioma.     

MicroRNA-216b targets HK2 to potentiate autophagy and apoptosis of breast cancer cells via the mTOR signaling pathway

Patients suffering from breast cancer (BC) still have a poor response to treatments, even though early detection and improved therapy have contributed to a reduced mortality. Recent studies have been inspired on the association between microRNAs (miRs) and therapies of BC. The current study set out to investigate the role of miR-216b in BC, and further analyze the underlining mechanism. Firstly, hexokinase 2 (HK2) and miR-216b were characterized in BC tissues and cells by RT-qPCR and Western blot assay. In addition, the interaction between HK2 and miR-216b was analyzed using dual luciferase reporter assay. BC cells were further transfected with a series of miR-216b mimic or inhibitor, or siRNA targeting HK2, so as to analyze the regulatory mechanism of miR-216b, HK2 and mammalian target of rapamycin (mTOR) signaling pathway, and to further explore their regulation in BC cellular behaviors. The results demonstrated that HK2 was highly expressed and miR-216b was poorly expressed in BC cells and tissues. HK2 was also verified as a target of miR-216b with online databases and dual luciferase reporter assay. Functionally, miR-216b was found to be closely associated with BC progression via inactivating mTOR signaling pathway by targeting HK2. Moreover, cell viability, migration and invasion were reduced as a result of miR-216b upregulation or HK2 silencing, while autophagy, cell cycle arrest and apoptosis were induced. Taken together, our findings indicated that miR-216b down-regulates HK2 to inactivate the mTOR signaling pathway, thus inhibiting the progression of BC. Hence, this study highlighted a novel target for BC treatment.     

Circ_0005615 promotes cervical cancer cell growth and metastasis by modulating the miR-138-5p/KDM2A axis

Cervical cancer (CC) is a highly fatal gynecological malignancy due to its high metastasis and recurrence rate. Circular RNA (circRNA) has been regarded as a regulator of CC. However, the underlying molecular mechanism of circ_0005615 in CC remains unclear. The levels of circ_0005615, miR-138-5p, and lysine demethylase 2A (KDM2A) were measured using qRT-PCR or western blot. Cell proliferation was assessed by Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine, and colony formation experiments. Cell invasion and migration were tested by transwell assay and wound healing assay. Flow cytometry and Caspase-Glo 3/7 Assay kit were used to analyze cell apoptosis. The expression of proliferation-related and apoptosis-related markers was detected by western blot. The binding relationships among circ_0005615, miR-138-5p, and KDM2A were verified by dual-luciferase reporter assay or RNA immunoprecipitation assay. Xenograft assay was applied to detect the effect of circ_0005615 in vivo. Circ_0005615 and KDM2A were upregulated, while miR-138-5p was downregulated in CC tissues and cells. Circ_0005615 knockdown retarded cell proliferation, migration, and invasion, while promoting apoptosis. Besides, circ_0005615 sponged miR-138-5p, and miR-138-5p could target KDM2A. miR-138-5p inhibitor reversed the regulation of circ_0005615 knockdown on CC cell growth and metastasis, and KDM2A overexpression also abolished the inhibitory effect of miR-138-5p on CC cell growth and metastasis. In addition, we also discovered that circ_0005615 silencing inhibited CC tumor growth in vivo. Circ_0005615 acted as a tumor promoter in CC by regulating the miR-138-5p/KDM2A pathway.     

Circ_0011058 facilitates proliferation,angiogenesis and radioresistance in papillary thyroid cancer cells by positively regulating YAP1 via acting as miR-335-5p sponge

BackgroundCircular RNAs (circRNAs) are reported to be associated with multiple biological processes in human cancers. However, there are still numerous circRNAs whose functions remain unclear. The aim of this study was to investigate the role of circ_0011058 in papillary thyroid cancer (PTC).MethodsQuantitative real-time PCR (qPCR) was utilized to detect the expression of circ_0011058, microRNA-335-5p (miR-335-5p) and Yes-associated Protein 1 (YAP1). Cell proliferation was detected using cell counting kit-8 (CCK-8) assay and EdU assay. Cell apoptosis was detected by flow cytometry assay. Angiogenesis ability was assessed using tube formation assay. The expression of angiogenesis-related proteins and YAP1 protein was detected by western blot. Radioresistance was examined using colony formation assay. The binding relationship between miR-335-5p and circ_0011058 or YAP1 was verified by dual-luciferase reporter assay, pull-down assay and RIP assay. Xenograft models were constructed to ensure the role of circ_0011058.ResultsCirc_0011058 expression was aberrantly elevated in PTC tissues and cells. The downregulation of circ_0011058 suppressed proliferation, angiogenesis and radioresistance in PTC cells. MiR-335-5p was defined as a target of circ_0011058, and miR-335-5p inhibition reversed the effects of circ_0011058 downregulation. In addition, YAP1 was a target of miR-335-5p, and circ_0011058 positively regulated YAP1 expression by targeting miR-335-5p. MiR-335-5p restoration inhibited proliferation, angiogenesis and radioresistance in PTC cells, while YAP1 overexpression abolished these effects. Animal study showed that circ_0011058 knockdown inhibited tumor growth in vivo.ConclusionCirc_0011058 promoted PTC cell proliferation, angiogenesis and radioresistance by upregulating YAP1 via acting as miR-335-5p sponge.     

Circular RNA circ_0079593 indicates a poor prognosis and facilitates cell growth and invasion by sponging miR-182 and miR-433 in glioma

Glioma is one of the major global health problems, including in China. Circular RNAs (circRNAs) have been increasingly identified and characterized in almost every aspect of biology, especially in cancer biology. This research desires to explore the functions and mechanism of a novel circRNA, circ_0079593, on regulating glioma progression. Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to measure the relative expression of circ_0079593, which was upregulated in matched cancerous tissues from 60 patients and four cell lines of glioma. A higher level of circ_0079593 in glioma specimens was linked to larger tumor size, higher WHO grade, and worse survival rate for patients with glioma. Moreover, circ_0079593 can be deemed as an independent prognostic predictor for glioma patients analyzed by multivariate method. Cell counting kit-8, flow cytometric, wound healing, and transwell experiments were used to evaluate cell growth, apoptosis, migration, and invasion influenced by circ_0079593 knockdown/overexpression. Exogenous downregulation of circ_0079593 expression significantly suppressed glioma cell proliferation by increasing cell apoptosis in vitro, and retarded the migratory and invasive potential. Ectopic expressed circ_0079593 could induce the opposite effects. Mechanistically, bioinformatics analysis, qRT-PCR, and dual-luciferase reporter assays showed that microRNA 182 (miR-182) and miR-433 could be sponged and negatively regulated by circ_0079593. Further, rescue assays demonstrated that the biological functions of circ_0079593 are dependent on its inhibition of miR-182 and miR-433. Collectively, the present work indicates that circ_0079593 may be used as an effective prognostic marker and therapeutic target for glioma.     

circ_0000267靶向miR-198对急性淋巴细胞白血病细胞KOCL44增殖和凋亡的影响

目的探讨circ_0000267对急性淋巴细胞白血病（ALL）KOCL44细胞增殖和凋亡的影响及其作用机制。 方法选择ALL细胞株KOCL44为研究对象,分别将小干扰RNA （siRNA）阴性对照（si-NC）、circ_0000267 siRNA （si-circ_0000267）、微小RNA （miRNA）阴性对照（miR-NC）、miR-198模拟物（miR-198）、circ_0000267 siRNA+miRNA抑制剂阴性对照（si-circ_0000267+anti-miR-NC）和circ_0000267 siRNA+miR-198抑制剂（si-circ_0000267+anti-miR-198）转染细胞,48 h后通过RT-qPCR检测细胞circ_0000267和miR-198相对表达水平,采用CCK-8法检测KOCL44细胞的增殖水平,流式细胞术实验检测KOCL44细胞的凋亡水平,Western blot检测KOCL44细胞Ki-67、Bcl-2和Bax蛋白表达水平,通过双荧光素酶报告实验验证circ_0000267和miR-198靶向关系。两组间比较采用独立样本t检验。 结果与健康志愿者比较,ALL患者circ_0000267表达水平（1.00±0.06比3.19±0.21）上调,miR-198表达水平（1.00±0.07比0.41±0.03）下调,差异有统计学意义（P < 0.05）。敲低circ_0000267或者过表达miR-198可抑制KOCL44细胞增殖（0.68±0.05比0.32±0.02、0.69±0.06比0.39±0.03）、Ki-67 （0.84±0.06比0.37±0.03、0.85±0.06比0.45±0.04）和Bcl-2蛋白表达（0.63±0.05比0.22±0.02、0.65±0.04比0.29±0.02）,促进细胞凋亡[（6.53±0.51）﹪比（24.29±2.06）﹪、（7.38±0.57）﹪比（20.03±1.66）﹪]和Bax蛋白表达（0.31±0.03比0.77±0.04、0.30±0.02比0.71±0.04）,差异有统计学意义（P < 0.05）。双荧光素酶报告实验验证circ_0000267可以靶向miR-198表达,干扰miR-198表达可以逆转抑制circ_0000267表达对KOCL44细胞的增殖和凋亡的作用,差异有统计学意义（P < 0.05）。 结论circ_0000267通过调控miR-198抑制ALL细胞增殖,并促进凋亡,为临床治疗ALL提供新的依据。     

Hsa_circ_0009910 promotes carcinogenesis by promoting the expression of miR-449a target IL6R in osteosarcoma

Circular RNAs (circRNAs) have recently shown capabilities as gene regulators in mammals. Some of them interact with microRNAs (miRNAs) and function as sponges to affect related miRNAs' activities. In this study, the molecular function of circRNA_0009910 and its potential downstream miRNA targets were explored. The expression levels of hsa_circ_0009910 were found to be overexpressed in osteosarcoma (OS) cells. Knockdown of circ_0009910 induced cell proliferation inhibition, cell cycle arrest, and apoptosis in OS cells. The target miRNA was predicted to be miR-449a, whose expression was downregulated in OS cells. Inhibition of miR-449a abolished the effect of circ_0009910 knockdown on cell growth and apoptosis. The expression of miR-449a were found to be negatively correlated with that of circ_0009910 in OS tissues. Direct interaction of circ_0009910 and miR-449a was confirmed through dual-luciferase assays. Moreover, IL6R was predicted as a potential target of miR-449a. Overexpression of miR-449a decreased the mRNA and protein levels of IL6R. Restoration of IL6R impaired the miR-449a induced inhibition of cell proliferation, cell cycle arrest, and apoptosis. The mRNA expression of IL6R was inversely correlated with miR-449a in OS tissues. In addition, JAK1/STAT3 signaling pathway was regulated by circ_0009910/miR-449a/IL6R axis. Taken together, we suggested that circ_0009910 acted as a sponge of miR-449a and upregulated miR-449a functional target IL6R, thereby contributed to carcinogenesis of OS.     

Circ_0003423 Alleviates ox-LDL-Induced Human Brain Microvascular Endothelial Cell Injury via the miR-589-5p/TET2 Network

Brain microvascular endothelial cells (BMECs) injury is one of the main causes of cerebrovascular diseases. Circular RNA (circRNA) has been found to be involved in the regulation of cerebrovascular diseases progression. However, the role and mechanism of circ_0003423 in cerebrovascular diseases is still unclear. In our study, oxidized low density lipoprotein (ox-LDL)-induced HBMEC-IM cells were used to construct cerebrovascular cell injury model in vitro. Quantitative real-time PCR was used to determine the expression levels of circ_0003423, miR-589-5p and Ten-eleven translocation 2 (TET2). The interactions between miR-589-5p and circ_0003423 or TET2 were confirmed by dual-luciferase reporter assay, RIP assay and RNA pull-down assay. Cell viability, angiogenesis and apoptosis were measured using cell counting kit 8 assay, tube formation assay and flow cytometry. Cell oxidative stress was evaluated by detecting the levels of reactive oxygen species and lactate dehydrogenase. The protein levels were examined by western blot analysis. Our results showed that circ_0003423 was a downregulated circRNA in ox-LDL-induced HBMEC-IM cells. In the terms of mechanism, circ_0003423 was found to be a sponge of miR-589-5p. Function analysis showed that circ_0003423 overexpression could relieve ox-LDL-induced HBMEC-IM cell injury, and this effect could be reversed by miR-589-5p mimic. In addition, TET2 was confirmed to be a target of miR-589-5p, and its overexpression could alleviate ox-LDL-induced HBMEC-IM cell injury. Moreover, the rescue experiments also confirmed that TET2 silencing could abolish the inhibition effect of anti-miR-589-5p on ox-LDL-induced HBMEC-IM cell injury. In summary, our data showed that circ_0003423 alleviated ox-LDL-induced HBMEC-IM cells injury through regulating the miR-589-5p/TET2 axis.

     

Circ_0001178 regulates miR-382/VEGFA axis to facilitate hepatocellular carcinoma progression

Circular RNAs (circRNAs) have been reported to regulate the gene expression through sponging corresponding microRNAs in multiple malignant tumors, including hepatocellular carcinoma (HCC). Up to now, the effects of circ_0001178 in HCC are barely known. In our current work, we tested circ_0001178 expression in HCC tissues and HCC cells and found it was greatly elevated. Then, we evaluated the function of circ_0001178 on HCC cell proliferation. We found HepG2 and Huh-7 cell proliferation was repressed after circ_0001178 shRNA was infected into the cells. Moreover, flow cytometry evidenced that HepG2 and Huh-7 cell apoptosis was markedly triggered and cell cycle was arrested. Meanwhile, it was shown that HCC cell migration and invasion capacity were markedly inhibited by loss of circ_0001178. Knockdown of circ_0001178 restrained HCC tumor growth in vivo. Then, miR-382 was predicted and confirmed as the target of circ_0001178. Circ_0001178 was demonstrated to modulate miR-382 expression negatively. The effect of circ_0001178 on HCC tumor was rescued by miR-382 overexpression. Furthermore, vascular epithelial growth factor A (VEGFA) is identified in various cancers. Currently, VEGFA was proved to be the downstream target of miR-382. To conclude, this research revealed that circ_0001178 induced HCC progression via modulating miR-382 and VEGFA axis.     

miR-497-5p inhibits tumor cell growth and invasion by targeting SOX5 in non–small-cell lung cancer

MicroRNAs plays an important role in the ccurrence and development of non–small-cell lung cancer (NSCLC). miR-497-5p has been reported to function as a tumor suppressor in various cancers. However, the role of miR-497-5p in NSCLC remains poorly understood. In this study, we aimed to investigate the biological role and potential molecular mechanism of miR-497-5p in NSCLC. Our results showed that the messenger RNA (mRNA) expression level of miR-497-5p was notably downregulated in human NSCLC tissues and cell lines. miR-497-5p overexpression remarkably inhibited NSCLC cell proliferation and increased cell apoptosis in A549 and H460 cells, whereas inhibition of miR-497-5p had an opposite effect. The ability of cell migration and invasion was inhibited by miR-497-5p overexpression but was increased by miR-497-5p inhibition. Moreover, our findings indicated that SOX5 was a direct target of miR-497-5p. The protein and mRNA expression levels of SOX5 in A549 cells were remarkably inhibited by miR-497-5p overexpression but was upregulated by miR-497-5p inhibition. Furthermore, SOX5 overexpression notably reversed the effect of miR-497-5p mimic on NSCLC cell proliferation, cell apoptosis, cell migration, and invasion. Taken together, these results indicated that miR-497-5p overexpression inhibited NSCLC cell proliferation, migration and invasion, and induced cell apoptosis through inhibiting SOX5 gene expression. It was conceivable that miR-497-5p might serve as a potential molecular target for NSCLC treatment.     

Circ_0004712 promotes endometriotic epithelial cell proliferation,migration and invasion by regulating miR-488-3p/ROCK1 axis in vitro

Recent evidence indicates that circular RNAs (circRNAs) play crucial regulatory roles in the pathogenesis and development of endometriosis. Circ_0004712 was found to be differentially expressed in endometriosis. However, the detailed function and mechanism of circ_0004712 in endometriosis are still unclear. Quantitative real-time polymerase chain reaction and Western blot were used for the detection of circ_0004712, miR-488-3p and ROCK1 (Rho Associated Coiled-Coil Containing Protein Kinase 1) levels. In vitro experiments in endometrial endothelial cells were performed by cell counting kit-8, EdU, transwell, wound healing assays, and flow cytometry, respectively. The molecular mechanism of circ_0004712 function was investigated using bioinformatics target predication, dual-luciferase reporter, and RNA immunoprecipitation (RIP) assays. The expression of circ_0004712 was higher in endometriotic endometrial tissues and epithelial cells. Knockdown of circ_0004712 suppressed cell proliferation, migration, invasion, EMT process and induced apoptosis in ectopic endometrial epithelial cells in vitro. Mechanistically, circ_0004712 acted as a ceRNA to sponge miR-488-3p, thus elevating the expression of ROCK1, which was confirmed to be a target of miR-488-3p. Rescue experiments suggested that miR-488-3p inhibition reversed the inhibitory effects of circ_0004712 silencing on cell growth and metastasis. Moreover, miR-488-3p restoration restrained the proliferation and metastasis in ectopic endometrial epithelial cells, which were attenuated by ROCK1 overexpression. Circ_0004712 knockdown suppressed the proliferation and metastasis of ectopic endometrial epithelial cells via miR-488-3p/ROCK1 axis in vitro, suggesting a new insight into the pathogenesis of endometriosis.