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_0001461靶向抑制miR-30a-5p对骨肉瘤细胞增殖和凋亡的影响

摘要 目的：探讨circ_0001461对骨肉瘤细胞增殖和凋亡的影响及调控机制。方法：采用实时荧光定量聚合酶反应（qRT-PCR）检测检测circ_0001461在骨肉瘤组织和细胞中的表达水平。在U2OS和HOS细胞中转染sh-NC和sh-circ_0001461后,采用CCK8检测细胞增殖情况,流式细胞术检测细胞凋亡情况,qRT-PCR检测增殖相关分子Ki-67 mRNA的表达水平,Western Blot检测凋亡相关分子Cleaved-caspase-3蛋白的表达水平。采用双荧光素酶报告基因检测circ_0001461和miR-30a-5p的结合情况。结果：circ_0001461在骨肉瘤组织中的表达水平明显高于癌旁正常组织（P<0.05）,circ_0001461在骨肉瘤细胞U2OS和HOS中的表达水平均明显高于成骨细胞NHOst（P<0.05）。低表达circ_0001461能够抑制骨肉瘤细胞U2OS和HOS的增殖和增殖相关分子Ki-67的表达（P<0.05）;促进骨肉瘤细胞U2OS和HOS的凋亡和凋亡相关分子Cleaved-caspase-3蛋白的表达（P<0.05）。双荧光素酶结果显示circ_0001461能够靶向结合miR-30a-5p。低表达circ_0001461能够促进miR-30a-5p的表达（P<0.05）,circ_0001461和miR-30a-5p在骨肉瘤组织中的表达呈负相关（P<0.05）。在U2OS细胞中共转染sh-circ_0001461和miR-30a-5p mimics后能够进一步加强单独转染sh-circ_0001461对U2OS细胞增殖和凋亡的影响（P<0.05）;在HOS细胞中共转染sh-circ_0001461和miR-30a-5p inhibitors后能够逆转单独转染sh-circ_0001461对U2OS细胞增殖和凋亡的影响（P>0.05）。结论：circ_0001461在骨肉瘤组织和细胞中明显高表达,低表达circ_0001461能够靶向促进miR-30a-5p的表达进而抑制骨肉瘤细胞增殖和促进细胞凋亡。     

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_0015756 promotes ovarian cancer progression via the miR-145–5p/PSAT1 axis

Circular RNA (circRNA) have been shown to exert vital functions in the pathological progressions of ovarian cancer (OC). Herein, this study aimed to investigate the role and mechanisms of circ_0015756 in OC progression. Levels of circ_0015756, microRNA (miR)? 145–5p and phosphoserine aminotransferase 1 (PSAT1) were detected using quantitative real-time polymerase chain reaction, Western blot or immunohistochemistry assays. Cell proliferation, apoptosis, migration and invasion were determined using cell counting kit-8, 5-Ethynyl-2′-Deoxyuridine (Edu) incorporation, flow cytometry, transwell and Western blot assays. The binding interaction between miR-145–5p and circ_0015756 or PSAT1 was confirmed by bioinformatics prediction and dual-luciferase reporter assay. Tumor formation assay in nude mice was performed to determine the tumor growth in vivo. Circ_0015756 was highly expressed in OC tissues and cells. Knockdown of circ_0015756 suppressed cancer cell growth, migration and invasion in vitro, as well as impeded tumor growth in vivo. In a mechanical study, circ_0015756 directly bound to miR-145–5p, and inhibition of miR-145–5p reversed the effects of circ_0015756 knockdown on OC cells. Moreover, miR-145–5p directly targeted PSAT1, and miR-145–5p weakened OC cell growth, migration and invasion via targeting PSAT1. Importantly, further studies confirmed that circ_0015756 could indirectly regulate PSAT1 expression via sponging miR-145–5p. In all, circ_0015756 accelerated OC tumorigenesis through regulating miR-145–5p/PSAT1 axis, providing a new therapeutic target for OC.     

Circ_0058106 promotes proliferation,metastasis and EMT process by regulating Wnt2b/β-catenin/c-Myc pathway through miR-185-3p in hypopharyngeal squamous cell carcinoma

Hypopharyngeal squamous cell carcinoma (HSCC) accounts 95% of hypopharyngeal cancer, which is characterized by high early metastasis rate and poor prognosis. It is reported that circular RNA is involved in the occurrence and development of cancer; however, the role of circRNA in hypopharyngeal cancer has little been investigated. We performed hypopharyngeal carcinoma circRNA microarray and qRT-PCR verification. The results showed circ_0058106 expression level was significantly upregulated in tumor tissues than in corresponding normal tissues. We found that circ_0058106 upregulation promoted proliferation, migration and invasion of HSCC cells, while knockdown of circ_0058106 inhibited proliferation, migration and invasion of HSCC cells both in vitro and in vivo. Bioinformatics predicted circ_0058106 may interact with miR-185-3p. We verified circ_0058106 directly bound miR-185-3p and downregulated miR-185-3p expression by using dual-luciferase reporter assay and qRT-PCR. Moreover, we proved circ_0058106 promoted HSCC cells tumorigenesis and EMT process by regulating Wnt2b/β-catenin/c-Myc pathway via miR-185-3p. In conclusion, our findings firstly confirmed the carcinogenic effect of circ_0058106 in promoting HSCC cells tumorigenesis, metastasis, invasion and EMT process by regulating Wnt2b/β-catenin/c-Myc pathway through sponging miR-185-3p, indicating that circ_0058106 may be a new therapeutic target and prognostic marker for HSCC.Subject terms: Head and neck cancer, Head and neck cancer     

Circ_0061012 contributes to IL-22-induced proliferation,migration and invasion in keratinocytes through miR-194-5p/GAB1 axis in psoriasis

Psoriasis is a chronic inflammation-associated skin disorder featured by excessive proliferation and abnormal differentiation of keratinocytes. Here, we intended to investigate the role of circular RNA 0061012 (circ_0061012) in psoriasis progression. The expression of circ_0061012, SLMO2-ATP5E readthrough (SLMO2-ATP5E) messenger RNA (mRNA), microRNA-194-5p (miR-194-5p) and GRB2 associated binding protein 1 (GAB1) mRNA was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and metastasis were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell assays. Western blot assay was used to measure the protein levels of Ki67, matrix metallopeptidase 9 (MMP9) and GAB1. Dual-luciferase reporter assay and RNA immune co-precipitation (RIP) assay were used to verify the interaction between miR-194-5p and circ_0061012 or GAB1. Circ_0061012 abundance was significantly enhanced in lesional skin samples from psoriasis patients than that in normal skin specimens from healthy volunteers. Interleukin-22 (IL-22) treatment increased the expression of circ_0061012 in a dose-dependent manner. Circ_0061012 silencing alleviated IL-22-induced promoting effects in the proliferation, migration and invasion of HaCaT cells. Circ_0061012 interacted with miR-194-5p, and miR-194-5p knockdown counteracted circ_0061012 silencing-mediated influences in IL-22-induced HaCaT cells. GAB1 was a target of miR-194-5p in HaCaT cells, and miR-194-5p hampered proliferation and metastasis which were induced by IL-22 partly through targeting GAB1. Circ_0061012 elevated the expression of GAB1 through sponging miR-194-5p in HaCaT cells. Circ_0061012 accelerated IL-22-induced proliferation and metastasis in HaCaT cells through enhancing GAB1 expression via sponging miR-194-5p in psoriasis.     

Changes in cytoarchitecture and mobility in B16F1 melanoma cells induced by 5-Br-2'-dU coincide with Rock2, miRNAs 138-5p and 455-3p reciprocal expressions

ROCK2 is a protein involved in the restructuring of the cytoskeleton in cell adhesion and contractibility processes. miR-138-5p and miR-455-3p regulate Rock2 expression, cell proliferation, migration, and invasion in different experimental cell models. However, their participation in the cytoarchitecture and mobility of B16F1 melanoma cells exposed to 5-Br-2'-dU is partially known. This work aimed to analyze ROCK2 and miRs 138-5p and 455-3p expression associated with morphological and mobility changes of B16F1 mouse melanoma cells exposed to the thymidine analog 5-Bromo-2'-deoxyuridine (5-Br-2'-dU). We observed an increase (2.2X n = 3, p < 0.05) in the cell area, coinciding with an increase in cell diameter (1.27X n = 3, p < 0.05), as well as greater cell granularity, capacity for circularization, adhesion, which was associated with more significant polymerization of F-actin, collapsed in the intermediate filaments of vimentin (VIM), and coinciding with a decrease in migration (87%). Changes coincided with a decrease in Rock2 mRNA expression (2.88X n = 3, p < 0.05), increased vimentin and a reciprocal decrease in miR-138-5p (1.8X), and an increase in miR-455-3p (2.39X). The Rock2 kinase inhibitor Y27632 partially rescued these changes. These results suggest ROCK2 and VIM regulate the morphological and mobility changes of B16 melanoma cells after exposure to 5-Br-2'-dU, and its expression may be reciprocally regulated, at least in part, by miR-138-5p and miR-455-3p.     

Circ_0021573 acts as a competing endogenous RNA to promote the malignant phenotypes of human ovarian cancer cells

Circular RNAs (circRNAs) have been reported to be implicated in the tumorigenesis and progression of ovarian cancer. Here, the study was designed to explore the activity of human circ_0021573 in ovarian cancer pathogenesis and its regulation through the competing endogenous RNA (ceRNA) crosstalk. Circ_0021573, microRNA (miR)? 936, and cullin 4B (CUL4B) were quantified by qRT-PCR and western blot. Cell proliferation ability was detected by XTT, 5-Ethynyl-2′-Deoxyuridine (EdU), and colony formation assays. Cell apoptosis, migration, and invasion were assessed by flow cytometry, wound-healing, and transwell assays, respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to evaluate the direct relationship between miR-936 and circ_0021573 or CUL4B 3′UTR. Xenograft studies were applied to assess the role of circ_0021573 in tumor growth. Our data showed that circ_0021573 expression is enhanced in human ovarian cancer. Inhibition of circ_0021573 impedes cell proliferation, migration, and invasion and promotes apoptosis in vitro, as well as diminishes tumor growth in vivo. Mechanistically, circ_0021573 contains a miR-936 binding site, and miR-936 is a relevant mediator of circ_0021573 regulation. MiR-936 direct targets and inhibits CUL4B. MiR-936-mediated suppression of CUL4B hinders cell proliferation, migration, and invasion and accelerates apoptosis in vitro.. These data suggested that circ_0021573 might promote the malignant phenotypes of ovarian cancer cells by functioning as a ceRNA for miR-936 to induce CUL4B, which provided a promising target for the prevention and inhibition of ovarian cancer.     

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.     

lncRNA NEAT1 facilitates melanoma cell proliferation,migration, and invasion via regulating miR-495-3p and E2F3

Melanoma contributes a lot to skin cancer-related deaths. lncRNAs are implicated in various diseases, including melanoma. lncRNA NEAT1 is frequently dysregulated and can play important roles in multiple cancers. Nevertheless, little has been studied about the function of NEAT1 in melanoma progression. In our present research, we displayed NEAT1 was overexpressed in melanoma cells. A series of functional assays showed that overexpression of NEAT1 promoted the proliferation, migration, and invasion of melanoma cells. By contrast, NEAT1 knockdown obviously restrained melanoma cell progression. Mechanistically, it was revealed that NEAT1 could directly bind with miR-495-3p, which led to a negative effect on miR-495-3p levels. In addition, miR-495-3p was significantly decreased in melanoma cells. Furthermore, E2F3 was postulated as the target of miR-495-3p and overexpression of this miR could suppress the levels of E2F3. Meanwhile, it was exhibited that melanoma cell proliferation, migration, and invasion induced by E2F3 silence was abrogated by miR-495-3p. Moreover, an in vivo xenograft nude mice model was established using A375 cells and it was indicated that NEAT1 promoted melanoma progression in vivo via regulating the miR-495-3p/E2F3 axis. In conclusion, we suggest that NEAT1 exerts an oncogenic effect on melanoma development via inhibition of miR-495-3p and induction of E2F3. NEAT1 might serve as a crucial prognostic biomarker of melanoma.     

Circ_0002984 induces proliferation,migration and inflammation response of VSMCs induced by ox-LDL through miR‑326-3p/VAMP3 axis in atherosclerosis

Atherosclerosis can result in multiple cardiovascular diseases. Circular RNAs (CircRNAs) have been reported as significant non-coding RNAs in atherosclerosis progression. Dysfunction of vascular smooth muscle cells (VSMCs) is involved in atherosclerosis. However, up to now, the effect of circ_0002984 in atherosclerosis is still unknown. Currently, we aimed to investigate the function of circ_0002984 in VSMCs incubated by oxidized low-density lipoprotein (ox-LDL). Firstly, our findings indicated that the expression levels of circ_0002984 were significantly up-regulated in the serum of atherosclerosis patients and ox-LDL-incubated VSMCs. Loss of circ_0002984 suppressed VSMC viability, cell cycle distribution and migration capacity. Then, we carried out ELISA assay to determine TNF-α and IL-6 levels. The data implied that lack of circ_0002984 obviously repressed ox-LDL–stimulated VSMC inflammation. Meanwhile, miR-326-3p, which was predicted as a target of circ_0002984, was obviously down-regulated in VSMCs treated by ox-LDL. Additionally, after overexpression circ_0002984 in VSMCs, a decrease in miR-326-3p was observed. Subsequently, miR-326-3p was demonstrated to target vesicle-associated membrane protein 3 (VAMP3). Therefore, we hypothesized that circ_0002984 could modulate expression of VAMP3 through sponging miR-326-3p. Furthermore, we confirmed that up-regulation of miR-326-3p rescued the circ_0002984 overexpressing-mediated effects on VMSC viability, migration and inflammation. Additionally, miR-326-3p inhibitor-mediated functions on VSMCs were reversed by knockdown of VAMP3. In conclusion, circ_0002984 mediated cell proliferation, migration and inflammation through modulating miR-326-3p and VAMP3 in VSMCs, which suggested that circ_0002984 might hold great promise as a therapeutic strategy for atherosclerosis.     

MicroRNA-1296-5p suppresses the proliferation,migration, and invasion of human osteosarcoma cells by targeting NOTCH2

Osteosarcoma (OS) is a highly aggressive bone tumor with a poor prognosis. MicroRNAs are revealed to exerts essential roles in the carcinogenesis and tumor invasion of OS. But, the function of miR-1296-5p and its related mechanism in OS progression have not yet been studied. This study discovered the levels of miR-1296-5p in OS and corresponding noncancerous tissues, and we demonstrated that miR-1296-5p level was markedly downregulated in tumor specimens as compared with nontumor tissues. In addition, we discovered that miR-1296-5p was also underexpressed in OS cells compared with the hFOB1.19 osteoblast cells. Interestingly, the reduced expression of miR-1296-5p was confirmed to associated with large tumor size, advanced tumor stages, and distance metastasis, respectively. Patients with OS low-expressing miR-1296-5p showed a prominent shorter survival. In addition, gain-of-function assays verified that miR-1296-5p overexpression remarkably repressed OS cell proliferation, migration, and invasion. Conversely, depletion of miR-1296-5p facilitated the growth and mobility of OS cells. Notably, miR-1296-5p inversely modulated notch receptor 2 (NOTCH2) in OS cells. The level of NOTCH2 messenger RNA was negatively correlated with miR-1296-5p level in OS samples. NOTCH2 knockdown markedly suppressed the abilities of MG-63 cell proliferation and mobility. More importantly, the restoration of NOTCH2 prominently rescued miR-1296-5p-induced tumor-suppressive effects on MG-63 cells. In conclusion, our study identified the reduced expression of miR-1296-5p, which contributed to OS progression. miR-1296-5p might be a promising prognostic marker and therapeutic target in OS.     

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.

     

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.

     

miR-338-3p suppresses neuroblastoma proliferation,invasion and migration through targeting PREX2a

MicroRNAs (miRNA) can regulate cancer cell proliferation and metastasis. Here, we show that miR-338-3p is down-regulated in metastatic tumor tissues compared to primary tumors, and that that miR-338-3p can inhibit cell proliferation by inducing cell cycle arrest, as well as restrain cell migration and invasion. PREX2a is confirmed as a direct target of miR-338-3p. Knockdown of PREX2a inhibits cell proliferation, migration and invasion through the PTEN/Akt pathway. miR-338-3p-dependent inhibition of proliferation and invasion can be rescued by PREXa. Overall, this study demonstrates that miR-338-3p affects the PTEN/Akt pathway by down-regulating PREX2a. This newly identified function of miR-338-3p provides novel insights into neuroblastoma and may foster therapeutic applications.     

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.     

CircRNA has_circ_0006427 suppresses the progression of lung adenocarcinoma by regulating miR-6783–3p/DKK1 axis and inactivating Wnt/β-catenin signaling pathway

Recently, circular RNAs (circRNAs) are identified as a novel class of noncoding RNAs playing important roles in human malignant tumors. However, the regulatory function of circRNA in lung adenocarcinoma (LUAD) is still largely unknown. Present study aimed to explore the role of circ_0006427 in LUAD progression. Firstly, the downregulation of circ_0006427 in LUAD tissues and cell lines was revealed by microarray analysis and qRT-PCR analysis. And we also confirmed the circ_0006427 as a prognostic target in LUAD patients. Functionally, overexpression of circ_0006427 effectively suppressed cell proliferation, migration and invasion. Mechanistically, circ_0006427 was found to be predominantly located in the cytoplasm of LUCA cell, and was further revealed to positively regulate DKK1 in LUAD by sponging miR-6783–3p. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis and western blot analysis revealed that circ_0006427 inactivated Wnt/β-catenin signaling pathway by upregulating DKK1. At last, rescue assays proved the function of circ_0006427/miR-6783–3p/DKK1 axis in LUAD progression. In conclusion, our study revealed that circ_0006427 suppressed lung adenocarcinoma progression through regulating miR-6783–3p/DKK1 axis.