MicroRNA-194 overexpression protects against hypoxia/reperfusion-induced HK-2 cell injury through direct targeting Rheb

Renal ischemia-reperfusion injury, a major cause of renal failure, always leads to acute kidney injury and kidney fibrosis. MicroRNAs (miRs) have been reported to be associated with renal ischemia-reperfusion injury. miR-194 was downregulated following renal ischemia-reperfusion injury; however, the function and mechanism of miR-194 in renal ischemia-reperfusion injury have not yet been fully understood. In the present study, we constructed renal ischemia-reperfusion injury model in vitro through treatment of human kidney proximal tubular epithelial cells HK-2 by hypoxia/reperfusion (H/R). We observed that miR-194 was decreased in H/R-induced HK-2 cells. miR-194 mimic increased H/R-induced HK-2 cell survival, whereas miR-194 inhibitor further strengthened H/R- inhibited HK-2 cell survival. Also, we observed that miR-194 overexpression suppressed oxidative stress markers, including malondialdehyde, glutathione, and secretion of pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α; however, miR-194 inhibitor showed the reverse effects. Results from dual-luciferase analysis confirmed that Ras homology enriched in brain (Rheb) was a direct target of miR-194. Finally, we corroborated that miR-194 affected cell growth, oxidative stress, and inflammation through targeting Rheb in H/R-induced HK-2 cells. In conclusion, our results suggested that miR-194 protect against H/R-induced injury in HK-2 cells through direct targeting Rheb.     

Circ_0005075 promotes hepatocellular carcinoma progression by suppression of microRNA-335

Accumulating evidence suggests that noncoding RNAs play a vital role in cancer biology. Circular RNAs (circRNAs), a newly defined class of endogenously widespread noncoding RNAs, have been intensively reported to influence cell function and development, and even cancer prognosis by sponging microRNAs in various types of cancer. Nevertheless, the circRNAs research in hepatocellular carcinoma (HCC) still remains far insufficient. Herein, we investigated the role of a newly defined circRNAs, circ_0005075, in HCC development. We found circ_0005075 was upregulated in HCC tissues. HCC progression was suppressed by downregulation of circ_0005075 in vitro and in vivo, and the suppression was partially reversed by inhibition of microRNA-335 (miR-335) expression. Further, we found the expression of mitogen-activated protein kinase 1 (MAPK1) was substantially regulated by circ_0005075 and miR-335. Mechanically, it was demonstrated that circ_0005075 could directly bind to miR-335 and miR-335 could bind to MAPK1. Our data provide evidence that circ_0005705 promotes the HCC progression by sponging miR-335 and further regulating MAPK1 expression.     

Exosomes from human-bone-marrow-derived mesenchymal stem cells protect against renal ischemia/reperfusion injury via transferring miR-199a-3p

Renal ischemia/reperfusion (I/R) injury is the main reason for acute kidney injury (AKI) and is closely related to high morbidity and mortality. In this study, we found that exosomes from human-bone-marrow-derived mesenchymal stem cells (hBMSC-Exos) play a protective role in hypoxia/reoxygenation (H/R) injury. hBMSC-Exos were enriched in miR-199a-3p, and hBMSC-Exo treatment increased the expression level of miR-199a-3p in renal cells. We further explored the function of miR-199a-3p on H/R injury. miR-199a-3p was knocked down in hBMSCs with a miR-199a-3p inhibitor. HK-2 cells cocultured with miR-199a-3p-knockdown hBMSCs were more susceptible to H/R injury and showed more apoptosis than those cocultured with hBMSCs or miR-199a-3p-overexpressing hBMSCs. Meanwhile, we found that HK-2 cells exposed to H/R treatment incubated with hBMSC-Exos decreased semaphorin 3A (Sema3A) and activated the protein kinase B (AKT) and extracellular-signal-regulated kinase (ERK) pathways. However, HK-2 cells cocultured with miR-199a-3p-knockdown hBMSCs restored Sema3A expression and blocked the activation of the AKT and ERK pathways. Moreover, knocking down Sema3A could reactivate the AKT and ERK pathways suppressed by a miR-199a-3p inhibitor. In vivo, we injected hBMSC-Exos into mice suffering from I/R injury; this treatment induced functional recovery and histologic protection and reduced cleaved caspase-3 and Sema3A expression levels, as shown by immunohistochemistry. On the whole, this study demonstrated an antiapoptotic effect of hBMSC-Exos, which protected against I/R injury, via delivering miR-199a-3p to renal cells, downregulating Sema3A expression and thereby activating the AKT and ERK pathways. These findings reveal a novel mechanism of AKI treated with hBMSC-Exos and provide a therapeutic method for kidney diseases.     

Hsa_circ_0088212-mediated miR-520 h/APOA1 axis inhibits osteosarcoma progression

BackgroundIt has been known for decades that circRNAs are deregulated in cancer. Here, we characterized the role and underlying mechanism of circ_0088212 in osteosarcoma.MethodsThe expression levels of circ_0088212, miR-520 h, and APOA1 were determined by RT-qPCR. RNase R digestion was performed to verify the circular structure of circ_0088212. CCK8 and transwell invasion assays were conducted to examine the in vitro malignancy of osteosarcoma. Caspase-3 activity was also measured.An in vivo model of osteosarcoma was constructed to examine the in vivo effect of circ_0088212 on osteosarcoma. Luciferase reporter, RNA RIP, and RNA pull-down assays were performed to verify the interaction between miR-520 h and APOA1 or circ_0088212.ResultsCirc_0088212 and APOA1 were expressed at low levels in osteosarcoma tissues and cells, while miR-520 h was highly expressed. Overexpression of circ_0088212 was found to inhibit the in vitro and in vivo growth of osteosarcoma. Mechanistically, miR-520 h was the target of circ_0088212 and APOA1 was the target of miR-520 h. Circ_0088212 downregulated miR-520 h expression, while miR-520 h overexpression abolished the inhibitory effect of circ_0088212 on osteosarcoma cell proliferation and migration. Furthermore, miR-520 h overexpression led to reduced APOA1 expression, while APOA1 overexpression counteracted the oncogenic effect of miR-520 h in osteosarcoma cells.ConclusionOur findings demonstrated that circ_0088212 might exert a tumor-suppressive activity in osteosarcoma by sponging and sequestering miR-520 h away from APOA1. This suggests that the circ_0088212/miR-520 h/APOA1 axis may be a promising therapeutic target for osteosarcoma intervention.     

Hsa_circ_0088212-mediated miR-520 h/APOA1 axis inhibits osteosarcoma progression

BackgroundIt has been known for decades that circRNAs are deregulated in cancer. Here, we characterized the role and underlying mechanism of circ_0088212 in osteosarcoma.MethodsThe expression levels of circ_0088212, miR-520 h, and APOA1 were determined by RT-qPCR. RNase R digestion was performed to verify the circular structure of circ_0088212. CCK8 and transwell invasion assays were conducted to examine the in vitro malignancy of osteosarcoma. Caspase-3 activity was also measured.An in vivo model of osteosarcoma was constructed to examine the in vivo effect of circ_0088212 on osteosarcoma. Luciferase reporter, RNA RIP, and RNA pull-down assays were performed to verify the interaction between miR-520 h and APOA1 or circ_0088212.ResultsCirc_0088212 and APOA1 were expressed at low levels in osteosarcoma tissues and cells, while miR-520 h was highly expressed. Overexpression of circ_0088212 was found to inhibit the in vitro and in vivo growth of osteosarcoma. Mechanistically, miR-520 h was the target of circ_0088212 and APOA1 was the target of miR-520 h. Circ_0088212 downregulated miR-520 h expression, while miR-520 h overexpression abolished the inhibitory effect of circ_0088212 on osteosarcoma cell proliferation and migration. Furthermore, miR-520 h overexpression led to reduced APOA1 expression, while APOA1 overexpression counteracted the oncogenic effect of miR-520 h in osteosarcoma cells.ConclusionOur findings demonstrated that circ_0088212 might exert a tumor-suppressive activity in osteosarcoma by sponging and sequestering miR-520 h away from APOA1. This suggests that the circ_0088212/miR-520 h/APOA1 axis may be a promising therapeutic target for osteosarcoma intervention.     

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.     

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.     

MiR-150-5p protects against septic acute kidney injury via repressing the MEKK3/JNK pathway

BackgroundSeptic acute kidney injury (AKI) is associated with increased morbidity and mortality in critically ill patients. MicroRNA is reportedly involved in sepsis-induced organ dysfunction, while the role of miR-150 in septic AKI remains ambiguous.MethodsQuantitative real-time PCR (qRT-PCR) was carried out to examine miR-150-5p expression in both septic AKI patients and volunteers without septic AKI. Lipopolysaccharide (LPS) was used to treat renal tubular epithelial cell line HK-2 and C57/BL6 mice to establish in vitro and in vivo sepsis-induced AKI models. Cell apoptosis was determined using TdT-mediated dUTP nick end labeling (TUNEL) staining and flow cytometry. Cell viability was tested using a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Renal pathological changes were examined via Hematoxylin-Eosin (H&E) staining, and renal function was measured via blood urea nitrogen (BUN) and creatinine (Cre) measurements. The MEKK3/JNK profile and oxidative stress markers (including COX2 and iNOS) were examined by immunoblot analysis, and the expression levels of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and oxidative stress markers (MDA, SOD, and CAT) were evaluated by ELISA.ResultsMiR-150-5p was down-regulated in the serum of patients with septic AKI (compared to healthy volunteers). Moreover, miR-150-5p levels were lower in LPS-treated HK-2 cell lines and in the septic AKI mouse model. Additionally, Stat-3 activation mediated the decrease of miR-150-5p. Functionally, miR-150-5p agomir attenuated LPS-induced apoptosis in HK-2 cells, in addition to renal inflammatory responses and oxidative stress. In contrast, inhibition of miR-150-5p aggravated LPS-induced apoptosis, inflammatory reactions and oxidative stress. Furthermore, miR-150-5p agomir decreased BUN and Scr levels in the septic AKI mice model repressed TNF-α, IL-6 and IL-1β, and up-regulated SOD and CAT down-regulated MDA in the kidney tissues. Moreover, miR-150-5p was identified as a target gene for Stat3, and the overexpression of Stat3 partially promoted the effect of down-regulating miR-150-5p on LPS-induced HK2 cell injury. Mechanistically, the MEKK3/JNK pathway was identified as a functional target of miR-150-5p, and the knockdown of MEKK3 showed protective effects against LPS mediated HK-2 cell apoptosis.ConclusionStat3-mediated miR-150-5p exerted protective effects in sepsis-induced acute kidney injury by regulating the MEKK3/JNK pathway.     

Downregulation of XIST ameliorates acute kidney injury by sponging miR-142-5p and targeting PDCD4

Acute kidney injury (AKI) is a common kidney disease that markedly affects public health. To date, the roles of long noncoding RNA XIST in AKI are poorly understood. Here, we investigated the biological functions of XIST in AKI. We observed that XIST expression increased in patients with AKI and HK-2 cells stimulated by CoCl₂. In addition, a rat AKI model induced by ischemia–reperfusion was established. Tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2 messenger RNA expression were induced in vivo; moreover, XIST expression was upregulated. Knockdown of XIST significantly repressed CoCl₂-triggered injury in HK-2 cells. However, microRNA (miR)-142-5p, a downstream target of XIST, was downregulated in AKI. miR-142-5p was repressed by XIST and miR-142-5p could inhibit CoCl₂-induced injury in HK-2 cells. Moreover, PDCD4 expression was significantly increased in AKI. PDCD4 was predicted to be the target of miR-142-5p. Subsequently, loss of PDCD4 was able to retard injury in HK-2 cells exposed to CoCl_2. Thus, we suggest that XIST regulates miR-142-5p and PDCD4, and it has the potential to function as a biomarker in therapeutic strategies for AKI.     

miR-21-5p in extracellular vesicles obtained from adipose tissue-derived stromal cells facilitates tubular epithelial cell repair in acute kidney injury

Background aimsAcute kidney injury (AKI) is often associated with poor patient outcomes. Extracellular vesicles (EVs) have a marked therapeutic effect on renal recovery. This study sought to explore the functional mechanism of EVs from adipose tissue-derived stromal cells (ADSCs) in tubular epithelial cell (TEC) repair in AKI.MethodsADSCs were cultured and EVs were isolated and identified. In vivo and in vitro AKI models were established using lipopolysaccharide (LPS).ResultsEVs increased human kidney 2 (HK-2) cell viability; decreased terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells and levels of kidney injury molecule 1, cleaved caspase-1, apoptosis-associated speck-like protein containing a CARD, gasdermin D-N, IL-18 and IL-1β; and elevated pro-caspase-1. EVs carried miR-21-5p into LPS-induced HK-2 cells. Silencing miR-21-5p partly eliminated the ability of EVs to suppress HK-2 cell pyroptosis and inflammation. miR-21-5p targeted toll-like receptor 4 (TLR4) and inhibited TEC pyroptosis and inflammation after AKI by inhibiting TLR4. TLR4 overexpression blocked the inhibitory effects of EVs on TEC pyroptosis and inflammation. EVs suppressed the nuclear factor-κB/NOD-like receptor family pyrin domain-containing 3 (NF-κB/NLRP3) pathway via miR-21-5p/TLR4. Finally, AKI mouse models were established and in vivo assays verified that ADSC-EVs reduced TEC pyroptosis and inflammatory response and potentiated cell repair by mediating miR-21-5p in AKI mice.ConclusionsADSC-EVs inhibited inflammation and TEC pyroptosis and promoted TEC repair in AKI by mediating miR-21-5p to target TLR4 and inhibiting the NF-κB/NLRP3 pathway.     

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.     

Has_circ_0055625 from circRNA profile increases colon cancer cell growth by sponging miR-106b-5p

Circular RNAs (circRNA) are endogenous noncoding RNAs and play important roles in cancer; however, the roles of circRNAs in colon cancer are far from clear. The circRNA expression profile in colon cancer tissues was analyzed by microarray. The data from microarray showed that there were 198 upregulated and 136 downregulated circRNAs in colon cancer tissues. Among the top 10 upregulated circRNAs, hsa_circ_0055625 (circ_0055625) was confirmed to be significantly upregulated in colon cancer tissues. Further analysis demonstrated that circ_0055625 might get involved in the pathogenesis of colon cancer by functioning as miRNA sponges and performed bioinformatics analysis of the predicted circ_0055625/miR-106b-5p (miR-106b)/ITGB8 network. Moreover, we found that circ_0055625 expression was associated with pathological TNM stage and metastasis. These data indicated that circ_0055625/miR-106b/ITGB8 played a role in promoting tumor growth and metastasis, which suggested that circ_0055625 was a potential biomarker of colon cancer.     

p53 induces miR-199a-3p to suppress mechanistic target of rapamycin activation in cisplatin-induced acute kidney injury

How p53 participates in acute kidney injury (AKI) progress and what are the underlying mechanisms remain illusive. For this issue, it is important to probe into the role of p53 in cisplatin-induced AKI. We find that p53 was upregulated in cisplatin-induced AKI, yet, pifithrin-α inhibites the p53 expression to attenuated renal injury and cell apoptosis both in vivo cisplatin-induced AKI mice and in vitro HK-2 human renal tubular epithelial cells. To knock down p53 by siRNA significantly decreased the miRNA, miR-199a-3p, expression in HK-2 cells. Blockade of miR-199a-3p significantly reduced cisplatin-induced cell apoptosis and inhibited caspase-3 activity. Mechanistically, we identified that miR-199a-3p directly bound to mechanistic target of rapamycin (mTOR) 3′-untranslated region and overexpressed miR-199a-3p reduce the expression and phosphorylation of mTOR. Furthermore, we demonstrated that p53 inhibited mTOR activation through activating miR-199a-3p. In conclusion, our findings reveal that p53, upregulating the expression of miR-199a-3p affects the progress of cisplatin-induced AKI, which might provide a promising therapeutic target of AKI.     

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.     

Upregulated circular RNA circ_0007534 indicates an unfavorable prognosis in pancreatic ductal adenocarcinoma and regulates cell proliferation,apoptosis, and invasion by sponging miR-625 and miR-892b

Circular RNAs (circRNAs) have been regarded as critical regulators of human diseases and biological markers in some types of malignancies, including pancreatic ductal adenocarcinoma (PDAC). Recently, circ_0007534 has been identified as a novel cancer-related circRNA. Nevertheless, its clinical relevance, functional roles, and mechanism have not been studied in PDAC. In the current study, real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of circ_0007534 in 60-paired PDAC tissue samples and different cell lines. Loss-of-function and gain-of-function assays were performed to detect cell proliferation, apoptosis, and metastatic properties affected by circ_0007534. An animal study was also carried out. The luciferase reporter assay was performed to uncover the underlying mechanism of circ_0007534. As a result, circ_0007534 was overexpressed not only in PDAC tissues but also in a panel of PDAC cell lines, and this overexpression is closely associated with advanced tumor stage and positive lymph node invasion. In addition, circ_0007534 may be regarded as an independent prognostic factor for patients with PDAC. For the part of functional assays, circ_0007534 significantly increased cell proliferation, migratory, and invasive potential of PDAC cells. Circ_0007534 could inhibit cell apoptosis partly via a Bcl-2/caspase-3 pathway. The xenograft study further confirmed the cell growth promoting the role of circ_0007534. Mechanistically, miR-625 and miR-892b were sponged by circ_0007534. The oncogenic functions of circ_0007534 is partly dependent on its regulation of miR-625 and miR-892b. In conclusion, our study illuminates a novel circRNA that confers an oncogenic function in PDAC.     

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     

Hsa_circ_0088212-mediated miR-520 h/APOA1 axis inhibits osteosarcoma progression

BackgroundIt has been known for decades that circRNAs are deregulated in cancer. Here, we characterized the role and underlying mechanism of circ_0088212 in osteosarcoma.MethodsThe expression levels of circ_0088212, miR-520 h, and APOA1 were determined by RT-qPCR. RNase R digestion was performed to verify the circular structure of circ_0088212. CCK8 and transwell invasion assays were conducted to examine the in vitro malignancy of osteosarcoma. Caspase-3 activity was also measured.An in vivo model of osteosarcoma was constructed to examine the in vivo effect of circ_0088212 on osteosarcoma. Luciferase reporter, RNA RIP, and RNA pull-down assays were performed to verify the interaction between miR-520 h and APOA1 or circ_0088212.ResultsCirc_0088212 and APOA1 were expressed at low levels in osteosarcoma tissues and cells, while miR-520 h was highly expressed. Overexpression of circ_0088212 was found to inhibit the in vitro and in vivo growth of osteosarcoma. Mechanistically, miR-520 h was the target of circ_0088212 and APOA1 was the target of miR-520 h. Circ_0088212 downregulated miR-520 h expression, while miR-520 h overexpression abolished the inhibitory effect of circ_0088212 on osteosarcoma cell proliferation and migration. Furthermore, miR-520 h overexpression led to reduced APOA1 expression, while APOA1 overexpression counteracted the oncogenic effect of miR-520 h in osteosarcoma cells.ConclusionOur findings demonstrated that circ_0088212 might exert a tumor-suppressive activity in osteosarcoma by sponging and sequestering miR-520 h away from APOA1. This suggests that the circ_0088212/miR-520 h/APOA1 axis may be a promising therapeutic target for osteosarcoma intervention.