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Glioma is the most common and fatal primary malignant brain tumor. Glioma stem cells (GSCs) may be an important factor in glioma cell proliferation, invasion, chemoradiotherapy tolerance, and recurrence. Therefore, discovering novel GSCs related circular RNAs (circRNAs) may finds out a prospective target for the treatment of glioma. A novel circRNA-CHAF1A (circCHAF1A) was first found in our study. CircCHAF1A was overexpressed in glioma and related to the low survival rate. Functionally, it was found that no matter in vitro or in vivo, circCHAF1A can facilitate the proliferation and tumorigenesis of TP53wt GSCs. Mechanistically, circCHAF1A upregulated transcription factor HOXC8 expression in GSCs through miR-211-5p sponging. Then, HOXC8 can transcriptionally upregulate MDM2 expression and inhibited the antitumor effect of p53. Furtherly, the RNA binding protein FMR1 can bind to and promoted the expression of circCHAF1A via maintaining its stability, while HOXC8 also transcribed the FMR1 expression to form a feedback loop, which may be involved in the malignant transformation of glioma. The novel feedback loop among FMR1, circCHAF1A, miR-211-5p, and HOXC8 in GSCs can facilitate the proliferation and tumorigenesis of glioma and GSCs. It also provided a helpful biomarker for diagnosis and prognostic evaluation of glioma and may be applied to molecular targeted therapy.

Background Glioma is the most common and lethal primary brain tumor in adults, and angiogenesis is one of the key factors contributing to its proliferation, aggressiveness, and malignant transformation. However, the discovery of novel oncogenes and the study of its molecular regulating mechanism based on circular RNAs (circRNAs) may provide a promising treatment target in glioma. Methods Bioinformatics analysis, qPCR, western blotting, and immunohistochemistry were used to detect the expression levels of ISL2, miR-342–3p, circRNA ARF1 (cARF1), U2AF2, and VEGFA. Patient-derived glioma stem cells (GSCs) were established for the molecular experiments. Lentiviral-based infection was used to regulate the expression of these molecules in GSCs. The MTS, EDU, Transwell, and tube formation assays were used to detect the proliferation, invasion, and angiogenesis of human brain microvessel endothelial cells (hBMECs). RNA-binding protein immunoprecipitation, RNA pull-down, dual-luciferase reporter, and chromatin immunoprecipitation assays were used to detect the direct regulation mechanisms among these molecules. Results We first identified a novel transcription factor related to neural development. ISL2 was overexpressed in glioma and correlated with poor patient survival. ISL2 transcriptionally regulated VEGFA expression in GSCs and promoted the proliferation, invasion, and angiogenesis of hBMECs via VEGFA-mediated ERK signaling. Regarding its mechanism of action, cARF1 upregulated ISL2 expression in GSCs via miR-342–3p sponging. Furthermore, U2AF2 bound to and promoted the stability and expression of cARF1, while ISL2 induced the expression of U2AF2, which formed a feedback loop in GSCs. We also showed that both U2AF2 and cARF1 had an oncogenic effect, were overexpressed in glioma, and correlated with poor patient survival. Conclusions Our study identified a novel feedback loop among U2AF2, cARF1, miR-342–3p, and ISL2 in GSCs. This feedback loop promoted glioma angiogenesis, and could provide an effective biomarker for glioma diagnosis and prognostic evaluation, as well as possibly being used for targeted therapy.

The iron-chelating agent di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) has been found to inhibit cell growth and to induce apoptosis in several human cancers. However, its effects and mechanism of action in glioma are unknown. Human glioma cell line LN229 and patient-derived glioma stem cells GSC-42 were applied for both in vitro and in vivo xenograft nude mouse experiments. The anti-tumor effects of Dp44mT were assessed using MTS, EdU, TUNEL, Western blotting, qRT-PCR, luciferase reporter, chromatin immunoprecipitation and immunohistochemical assays. We found that Dp44mT can upregulate the expression of the anti-oncogene N-myc downstream-regulated gene (NDRG)2 by directly binding to and activating the RAR-related orphan receptor (ROR)A. In addition, we found that NDRG2 overexpression suppressed inflammation via activation of interleukin (IL)-6/Janus kinase (JAK)2/signal transducer and activator of transcription (STAT)3 signaling. Our data indicate that Dp44mT may serve as an effective drug for the treatment of glioma by targeting RORA and enhancing NDRG2-mediated IL-6/JAK2/STAT3 signaling.

Aim Epidermal growth factor‐containing fibulin‐like extracellular matrix protein 1(EFEMP1) has been found to be involved in the occurrence and development of many cancers. The relationship between EFEMP1 and the development of hepatocellular carcinoma (HCC) and the molecular mechanism are not fully understood. Methods Real‐time polymerase chain reaction (PCR) and tissue microarray were used to detect the expression of EFEMP1 in HCC cell lines and tissue. Methylation‐specific PCR assay was used to measure the methylation level of EFEMP1 in HCC cell lines and tissue. To study the function of EFEMP1 on cell function, Huh7 and HepG2 were infected with lentiviral particles expressing EFEMP1. MTT assay and colony formation assay were used to examine the effect of EFEMP1 on cell proliferation. Annexin‐VAPC/7‐AAD double were used to detect the effect of EFEMP1 on cell apoptosis. To further detect the effect of EFEMP1 on the development of HCC in vivo, we performed the tumor formation experiment in nude mice. Gene chip was used to detect the expression profile of Huh7 and HepG2 overexpressing EFEMP1. To further screen out the differences, GO analysis and pathway analysis were performed. To study the effects of SEMA3B, specific siRNA was used to inhibit the expression of SEMA3B. Chi‐squared test and rank sum test were used to analyze the relationship between EFEMP1 expression and HCC clinical characteristic. Results The study found that the expression of EFEMP1 was significantly decreased in HCC cell lines and HCC tissues. The expression level of EFEMP1 was related to the TNM (the extent of the tumor, the extent of spread to the lymph nodes, the presence of metastasis) stage and the prognosis of patients with HCC. The decrease of protein expression suggested that the patient prognosis was worse, and the protein level of EFEMP1 may be an independent factor in the prognosis of HCC patients. Promoter methylation may be one of the reasons for EFEMP1 inhibition. EFEMP1 could inhibit the proliferation of HCC cells and promoted the apoptosis of HCC cells to regulate the development of HCC. And EFEMP1 promoted the apoptosis of HCC cells mainly through the mitochondrial apoptosis pathway. EFEMP1 may inhibit the proliferation of HCC cells through the SEMA3B gene in the Axon guidance pathway. Conclusion In summary, our research revealed the regulation of EFEMP1 on cell proliferation and apoptosis in HCC. EFEMP1 may suppress the growth of HCC cells by promoting SEMA3B.

Increasing evidences show that microRNAs (miRNAs) are involved in the regulation of tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). miR-369 works as a tumor suppressor in both lung cancer and thyroid cancer. However, the potential biological function of miR-369 in HCC is unknown. Herein, we for first found that miR-369 expression was downregulated in HCC tissues and predicted the poor prognosis of HCC patients. Forced miR-369 expression inhibited the proliferation and metastasis of HCC cells in vitro and in vivo. Mechanically, bioinformatics and luciferase reporter analysis identified Zinc finger E-box binding homeobox 1 (ZEB1) as a direct target of miR-369 in HCC cells. miR-369 overexpressing downregulated the ZEB1 mRNA and protein expression in HCC cells. miR-369 expression was negatively associated with ZEB1 expression in human HCC tissues. More importantly, the ZEB1 siRNA diminished the discrepancy of growth and metastasis capacity between miR-369 overexpression HCC cells and control cells.

Background: Glioma has a poor prognosis, and is the most common primary and lethal primary malignant tumor in the central nervous system. Retinoic acid receptor-related orphan receptor A (RORA) is a member of the ROR subfamily of orphan receptors and plays an anti-tumor role in several cancers. Methods: A cell viability assay, the Edu assay, neurosphere formation assay, and xenograft experiments were used to detect the proliferative abilities of glioma cell line, glioma stem cells (GSCs). Western blotting, ELISAs, and luciferase reporter assays were used to detect the presence of possible microRNAs. Findings: Our study found for the first time that RORA was expressed at low levels in gliomas, and was associated with a good prognosis. RORA overexpression inhibited the proliferation and tumorigenesis of glioma cell lines and GSCs via inhibiting the TNF-α mediated NF-κB signaling pathway. In addition, microRNA-18a had a promoting effect on gliomas, and was the possible reason for low RORA expression in gliomas. Interpretation: RORA may be a promising therapeutic target in the treatment of gliomas. Keywords: Glioma, Glioma stem cells, RORA, Tumorigenesis, microRNA-18a

The platelet-derived growth factor (PDGF) signaling pathway plays important roles in development and progression of human cancers. In our study, we aimed to identify genetic variants of the PDGF pathway genes associated with pancreatic cancer (PC) risk in European populations using three published genome-wide association study datasets, which consisted of 9,381 cases and 7,719 controls. The expression quantitative trait loci (eQTL) analysis was also performed using data from the 1000 Genomes, TCGA and GTEx projects. As a result, we identified two potential susceptibility loci (rs5757573 and rs6001516) of PDGFB associated with PC risk [odds ratio (OR) = 1.10, 95% confidence interval (CI) = 1.05-1.16, and p = 4.70 × 10-5 for the rs5757573 C allele and 1.21, 1.11-1.32, and 2.01 × 10-5 for the rs6001516 T allele]. Haplotype analysis revealed that the C-T haplotype carriers had a significantly increased risk of PC than those carrying the T-C haplotype (OR = 1.23, 95% CI = 1.12-1.34, p =5.00 × 10-6 ). The multivariate regression model incorporating the number of unfavorable genotypes (NUGs) with age and sex showed that carriers with 1-2 NUGs, particularly among 60-70 age group or males, had an increased risk of PC, compared to those without NUG. Furthermore, the eQTL analysis revealed that both loci were correlated with a decreased mRNA expression level of PDGFB in lymphoblastoid cell lines and pancreatic tumor tissues (p = 0.015 and 0.071, respectively). Our results suggest that genetic variants in PDGFB may play a role in susceptibility to PC. Further population and functional validations of our findings are warranted.

Epithelial-mesenchymal transition (EMT) is an early and key process in the metastatic cascade during the progression of colorectal cancer (CRC). The aim of the present study was to identify deregulated EMT-related microRNAs (miRNAs/miRs) of CRC and assess the effect of differentially expressed miRNAs on the prognosis of patients with CRC. Genome-wide expression profiling of miRNAs was assessed in 3 EMT-negative and 3 EMT-positive CRC tissues. Differentially expressed miRNA was further validated in 90 pairs of CRC and corresponding paracarcinoma tissues using the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A total of 6 miRNAs (miR-10a-5p miR-204-3p, miR-1224-3p, miR-193a-3p, miR-365a-3p and miR-3678-3p) were identified to be differentially expressed between different EMT statuses of CRC tissues. Following validation using RT-qPCR, 3 miRNAs (miR-10a-5p, miR-365a-3p and miR-193a-3p) were selected for subsequent studies. The expression levels of miR-10a-5p, miR-193a-3p and miR-365a-3p were markedly increased compared with levels in corresponding paracarcinoma tissues. Survival analyses revealed that down-regulation of miR-193a-3p was associated with worse prognosis of patients with CRC, particularly in female and older patients. The results of the present study indicate that miR-193a-3p may be an EMT-related biomarker and serve as a novel prognostic factor for CRC.

Background: Glioma is the most common primary malignant tumor in the central nervous system with frequent hypoxia and angiogenesis. Limb-bud and heart (LBH) is a highly conserved transcription cofactor that participates in embryonic development and tumorigenesis. Methods: The conditioned media from LBH regulated human glioma cell lines and patient-derived glioma stem cells (GSCs) were used to treat the human brain microvessel endothelial cells (hBMECs). The function of LBH on angiogenesis were examined through methods of MTS assay, Edu assay, TUNEL assay, western blotting analysis, qPCR analysis, luciferase reporter assay and xenograft experiment. Findings: Our study found for the first time that LBH was overexpressed in gliomas and was associated with a poor prognosis. LBH overexpression participated in the angiogenesis of gliomas via the vascular endothelial growth factor A (VEGFA)-mediated extracellular signal-regulated kinase (ERK) signaling pathway in human brain microvessel endothelial cells (hBMECs). Rapid proliferation of gliomas can lead to tissue hypoxia and hypoxia inducible factor-1 (HIF-1) activation, while HIF-1 can directly transcriptionally regulate the expression of LBH and result in a self-reinforcing cycle. Interpretation: LBH may be a possible treatment target to break the vicious cycle in glioma treatment. Funding Statement: This work was funded by National Natural Science Foundation of China (No. 81101917, 81270036, 30901736), the Plan to Focus on Research and Development from Science and Technology project of Liaoning Province (No. 2017225029), Natural Science Foundation of Liaoning Province (No. 20170541022), Science and Technology Plan Project of Shenyang City (No. 18-014-4-11), and Fund for Scientific Research of The First Hospital of China Medical University (No. FHCMU- FSR), and Shanghai Sailing Program (No. 19YF1439000). Declaration of Interests: The authors have declared that no conflict of interest exists. Ethics Approval Statement: This study was approved by the ethics committee of the First Affiliated Hospital of China Medical University and written informed consent was obtained from all patients.

Background Activated hepatic stellate cell (HSC) is the main fibrogenic cell type in the injured liver. miRNA plays an important role in activation and proliferation of HSC. Methods Our previous study examined the expression profiles of microRNAs in quiescent and activated HSC. Real-time PCR and western blot were used to detect the expression of Collagen type I (Col 1) and Alpha-Smooth Muscle Actin (α-SMA). CCK-8 and Edu assay was used to measure the proliferation rate of HSC. Luciferase reporter gene assay was used to tested the binding between miR-338-3p and Cyclin-dependent kinase 4 (CDK4). Results We found overexpression of miR-338-3p could inhibit Col 1 and α-SMA, two major HSC activation markers, whereas miR-338-3p inhibitor could promote them. Besides, miR-338-3p overexpression could suppress the growth rate of HSC. Further, we found that CDK4, a pleiotropic signaling protein, was a direct target gene of miR-338-3p. Moreover, we found that overexpression of CDK4 could block the effects of miR-338-3p. Conclusions We found miR-338-3p is an anti-fibrotic miRNA which inhibits cell activation and proliferation. Our findings suggest that miR-338-3p/CDK4 signaling pathway participates in the regulation of HSC activation and growth and may act as a novel target for further anti-fibrotic therapy.

Reprogrammed metabolism is one of the hallmarks of cancer. The dysregulation of glycolysis in cancer has been heavily studied. However, it remains largely unclear how other metabolic processes are regulated in cancer cells. Here we show that microRNA-182 (miR-182) suppresses pyruvate dehydrogenase (PDH) kinase 4 (PDK4) and promotes lung tumorigenesis. miR-182 is dysregulated and inversely correlated with PDK4 in human lung adenocarcinomas. The miR-182-PDK4 axis regulates lung cancer cell growth by modulating the activity of PDH, the gatekeeping enzyme of pyruvate flux into acetyl-CoA, and subsequently de novo lipogenesis of cancer cells. Suppression of lipogenesis by silencing ATP citrate lyase (ACLY) and fatty acid synthase (FASN) or by chemical inhibitors diminishes the effects of miR-182-PDK4 in tumor growth. Alteration of de novo lipogenesis also affects reactive oxygen species (ROS) production and the downstream JNK signaling pathway. Hence, our work suggests that the miR-182-PDK4 axis is a crucial regulator of cancer cell metabolism and a potential target for antitumor therapy.

Numerous studies indicate that long noncoding RNAs (lncRNAs) are dysregulated in hepatocellular carcinoma (HCC) and might serve as potential diagnostic biomarkers and therapeutic targets of HCC. Therefore, it is interesting to globally identify the lncRNAs altered in HCC. In our study, we used microarray to profile the levels of lncRNAs and mRNAs in three pairs of HCC and their adjacent noncancerous samples. We found lncRNA-SVUGP2, which is a splice variant of the UGP2 gene, was down-regulated in HCC samples and correlates with a better prognosis in patients with HCC. Overexpression of lncRNA-SVUGP2 in HepG2 and Hep3B liver cancer cells suppresses cell proliferation in vitro and tumor growth in vivo. Moreover, lncRNA-SVUGP2 suppresses the invasion ability of liver cancer cell lines and downregulates the mRNA and protein levels of MMP2 and 9. Additionally, lncRNA-SVUGP2 positively or negatively correlates with many mRNAs in liver cancer tissues, indicating it is multifunctional in regulating carcinogenesis.