Circ_CLIP2 promotes glioma progression through targeting the miR-195-5p/HMGB3 axis.

BACKGROUND: Circular RNA (circRNA) has been demonstrated to play key roles in regulating glioma progression. Understanding the regulatory mechanism of circRNA in glioma is vital to reveal the pathogenesis of glioma and develop novel therapeutic strategies. Therefore, our study focuses on the role and underlying mechanism of Circ_CLIP2 in glioma. METHODS: The expression of Circ_CLIP2, miR-195-5p and HMGB3 in glioma cells and tissues were analyzed using qRT-PCR. Cell proliferation was determined with colony formation and MTT assays. Cell cycle and apoptosis were examined by flow cytometry. Western blot was conducted for analyzing HMGB3, PCNA, Bax, Bcl-2, cleaved-caspase 3, Wnt-1 and ß-catenin. Dual-luciferase reporter assay was measured to investigate the interaction among Circ_CLIP2, miR-195-5p and HMGB3. RESULTS: The expression of Circ_CLIP2 and HMGB3 were increased while miR-195-5p was down-regulated in glioma cells and patients. Silencing of Circ_CLIP2 inhibited cell proliferation, enhanced cell apoptosis and inhibited the Wnt/ß-catenin signaling pathway. Circ_CLIP2 suppressed miR-195-5p expression by directly sponging miR-195-5p. MiR-195-5p inhibited HMGB3 expression via directly targeting HMGB3. Knockdown of miR-195-5p facilitated cell proliferation, inhibited cell apoptosis and activated Wnt/ß-catenin signaling, which were reversed by silencing of HMGB3. CONCLUSION: Knockdown of Circ_CLIP2 suppresses glioma progression by targeting miR-195-5p/HMGB3 thus inhibiting Wnt/ß-catenin signaling. This study may provide potential therapeutic targets against glioma.

[Corrigendum] MicroRNA-375 inhibits glioma cell proliferation and migration by downregulating RWDD3 in vitro.

The authors of the above article drew to our attention that they had identified three instances of data overlapping between data panels, suggesting that data purportedly showing results obtained under different experimental conditions had been derived from the same original source. Comparing between the two figures, two pairs of panels in Fig. 4B (the Mimics control and blank experiments for the U87 and U251 cell lines) were shown to be overlapping, and a further pair of panels showed overlapping data in Fig. 6B (the data panels for the miR­375 mi + .pCDNA/RWDD3 and miR­375 mi + .pCDNA experiments for the U87 cell line). The authors were able to re­examine the original data files and retrieve the correct data panels. The errors in these figures arose through inadvertently assembling Figs. 4 and 6 incorrectly. The revised versions of Figs. 4 and 6, featuring the corrected data panels for the Mimics control and blank experiments for the U87 and U251 cell lines in Fig. 4B, and the correct data for the U87 cell line in Fig. 6B, are shown opposite and on the next page, respectively. Note that the corrections to the data shown in these Figures do not affect the overall conclusions reported in the paper. The authors are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published in Oncology Reports 39: 1825-1834, 2018; DOI: 10.3892/or.2018.6261].

[Retracted] MicroRNA-375 inhibits glioma cell proliferation and migration by downregulating RWDD3 in vitro.

The authors of the above article drew to our attention that, in the above paper, they had identified three instances of data overlapping between data panels, suggesting that data purportedly showing results obtained under different experimental conditions had been derived from the same original source. Comparing among the data panels, two pairs of panels in Fig. 4B were shown to be overlapping, and a further pair of panels showed overlapping data in Fig. 6B. The authors were presented with an opportunity to correct their figures in a Corrigendum, although it has subsequently come to light that the replacement figures themselves featured problems with overlapping data. Given the errors that have been identified in the compilation of the figures in this article, the Editor of Oncology Reports has decided that this article should be retracted from the publication owing to a lack of overall confidence in the presented data. The authors all agree to the retraction of this article, and the Editor and the authors apologize for any inconvenience that might result from this retraction. [the original article was published in Oncology Reports 39: 1825-1834, 2018; DOI: 10.3892/or.2018.6261].

Knockdown of HOXC6 inhibits glioma cell proliferation and induces cell cycle arrest by targeting WIF-1 in vitro and vivo.

BACKGROUND: Homeobox C6 (HOXC6) is one of several HOXC genes and is frequently overexpressed in multiple cancers. However, the function and mechanism of HOXC6 in glioma remain unclear. METHODS: The expression level of HOXC6 and its relationship with prognosis in glioma were determined through the TCGA database. The expressions of HOXC6 mRNA in glioblastoma tissues and normal brain tissues were detected by qRT-PCR and Western blot. To explore the role of HOXC6 in glioma, a lentiviral vector that expressed HOXC6-shRNA was constructed and transfected into glioma U87 cells. The expression levels of HOXC6 and WNT inhibitory factor 1 (WIF-1) in the glioma U87 cells after transfection with HOXC6-shRNA were measured by real-time PCR and Western blot． CCK-8, colony formation and EdU assays were used to measure the effects of HOXC6 on U87 cell proliferation, and flow cytometry was used to monitor the changes in the cell cycle and cell apoptosis after transfection with HOXC6-shRNA. Xenograft tumors were examined in vivo for the carcinogenic effects and prognostic value of HOXC6 in glioma tissues. RESULTS: In this study, HOXC6 was highly expressed in human glioma tissues, and a high expression of HOXC6 was associated with poor prognosis in GBM patients. We demonstrated that HOXC6 was highly expressed in human GBM tissues and three glioma cell lines. The knockdown of HOXC6 expression significantly inhibited the proliferation and colony formation ability of U87 cells by blocking cell cycle progression in the G0/G1 phase and induced apoptosis. In addition, we found that the mRNA and protein levels of WIF-1 were substantially increased after transfection with HOXC6-shRNA compared with Ctrl-shRNA in vitro. Consistent with the results of the in vitro assays, the xenograft assay and immunohistochemistry also demonstrated that in response to HOXC6 inhibition, the tumor growth and Ki-67 expression level were inhibited and the WIF-1 expression was increased in vivo. CONCLUSIONS: In conclusion, the results of the current study indicate that HOXC6 promotes glioma U87 cell growth through the WIF-1/Wnt signaling pathway and HOXC6 might be a novel target in clinical treatment for gliomas.

MicroRNA-375 inhibits glioma cell proliferation and migration by downregulating RWDD3 in vitro.

Derived from brain glial cells, gliomas are currently the most common primary tumours in the central nervous system and are characterised by a high recurrence rate and poor prognosis. RWDD3 (RWD domain-containing sumoylation enhancer, also termed RSUME), which can be induced by cellular stress, such as CoCl2, heat shock and hypoxia, may play a crucial role in tumour angiogenesis, growth and metastasis. MicroRNAs (miRNAs) have been demonstrated to act as negative regulators of post-transcriptional gene expression and are involved in tumour growth and metastasis. In the present study, we explored the role of RWDD3 in glioma cell proliferation and invasion by the knockdown of RWDD3 with lentiviral shRNA and demonstrated that miRNA hsa-miR-375, regulates RWDD3 and has an important role in glioma progression. We found that expression of RWDD3 in high-grade gliomas was significantly higher than that noted in normal brain tissues and lower-grade gliomas in vivo. Knockdown of RWDD3 effectively led to cell cycle arrest, decreased proliferation and invasion, and increased apoptosis in human glioma cell lines. Furthermore, miR-375 was downregulated in human gliomas and overexpression of miR-375 caused downregulation of RWDD3 in glioma cells as well as inhibited their motility. Thus, these findings suggest that RWDD3 and miR-375 may function as therapeutic biomarkers for glioma patients.

Lentivirus­mediated knockdown of chondroitin polymerizing factor inhibits glioma cell growth in vitro.

Glioma is the most common primary tumor in the central nervous system, characterized by rapid progression, aggressive behavior, frequent recurrence and poor prognosis. In the present study we demonstrated that chondroitin polymerizing factor (CHPF) is highly expressed in human glioma tissues and 4 glioma cell lines. To explore the role of CHPF in glioma, a lentiviral vector expressing CHPF shRNA was constructed and transfected into the glioma U251 cells, which stably downregulated the expression levels of the CHPF gene in U251 cells in vitro. U251 cell proliferation inhibition rates were determined by MTT assay. The effect of survivin shRNA on U251 cell cycle distribution and cell apoptosis was determined by flow cytometry. Compared to the shRNA­Ctrl group of cells, the shRNA-CHPF group of cells exhibited decreased proliferation and a significant increase in the proportion of cells in the G0/G1 phase. In addition, we found that knockdown of the expression of CHPF increased apoptosis in glioma U251 cells. Therefore, our results confirmed that CHPF promotes growth and inhibits apoptosis in glioma U251 cells. Thus, by in vivo and in vitro data, the present study suggests that CHPF could be a new potential therapeutic target for glioma.

BRAF-activated lncRNA predicts gastrointestinal cancer patient prognosis: a meta-analysis.

BRAF activated non-coding RNA (BANCR) is often dysregulated in cancer. We performed a meta-analysis to clarify its functions as a prognostic indicator in malignant tumors. We searched the PubMed, Medline, OVID, Cochrane Library, and Web of Science databases to identify BANCR-related studies. Nine original studies and 898 total patients were included in the meta-analysis. Hazard ratios (HR) and 95% confidence intervals (CI) were extracted from the included studies to determine the relationship between BANCR expression and patient overall survival (OS). Odds ratios (OR) were calculated using RevMan 5.3 software to assess associations between BANCR expression and pathological parameters. High BANCR expression correlated with lymph node metastasis (LNM) (OR = 3.41, 95% CI: 1.82-6.37, P = 0.0001), distant metastasis (DM) (OR = 2.98, 95% CI: 1.76-5.07, P < 0.0001), tumor stage (OR = 3.11, 95% CI: 1.89-5.12, Z = 3.25, P < 0.0001), and poor OS (pooled HR = 1.98, 95% CI: 1.20-3.27, P = 0.008) in gastrointestinal (GI) cancer patients, but not in non-GI cancer patients. Our results support the notion that BANCR as a promising prognostic biomarker in Chinese patients with GI cancer.

Long non-coding RNA HULC as a potential prognostic biomarker in human cancers: a meta-analysis.

Since the long non-coding RNA HULC (Highly Upregulated in Liver Cancer) is dysregulated in many cancers, we performed a meta-analysis to determine its prognostic potential in malignant tumors. We searched electronic databases, including PubMed, Medline, OVID, Cochrane Library and Web of Science from inception until August 14, 2016 and identified seven studies with 730 cancer patients for the meta-analysis. We analyzed the hazard ratios (HRs) and 95% confidence intervals (CIs) to determine the relationship between HULC expression and overall survival (OS). We also using RevMan5.3 software to calculate odds ratio (ORs) to assess the association between HULC expression and pathological parameters, including lymph node metastasis (LNM), distant metastasis (DM) and the tumor stage. Our analysis showed that higher HULC expression was associated with OS (HR= 0.50, 95% CI: 0.35-0.70, P <0.00001), LNM (OR=0.20, 95 % CI 0.06-0.64), DM (OR=0.27, 95% CI: 0.13-0.54) and the tumor stage (OR=0.39, 95 % CI 0.25-0.64). These meta-analysis data demonstrate that higher HULC expression can be a useful prognostic biomarker in human cancers.

SNORD47, a box C/D snoRNA, suppresses tumorigenesis in glioblastoma.

SNORD47 is a member of the C/D box small nucleolar RNAs, which have been implicated in cancer development. We intended to investigate the therapeutic potential of SNORD47 in glioma. We found that the expression of SNORD47 was downregulated in glioma tissues samples and inversely associated with advanced tumor stage (WHO grade IV). Kaplan-Meier survival analysis revealed that glioma patients with high SNORD47 expression had longer overall survival than those with low SNORD47 expression. SNORD47 suppressed the proliferation of glioma cells and induced G2 phase arrest. In addition, upregulation of SNORD47 suppressed invasion and epithelial-mesenchymal transition in glioma cells, and combination treatment with lenti-SNORD47 could augment the anti-tumor effect of temozolomide. These results showed that SNORD47 acted as a tumor suppressor in glioma, and provided the potential anti-tumor function in glioma treatment.

Over-expression of LRIG1 suppresses biological function of pituitary adenoma via attenuation of PI3K/AKT and Ras/Raf/ERK pathways in vivo and in vitro.

Pituitary adenomas (PAs) are well known as a common intracranial benign tumor, and a portion of PAs are refractory to current therapeutic methods. ErbB receptors family signaling pathway regulates the expression of PAs activation associated gene. Inhibition of epidermal growth factor receptor (EGFR) can inhibit proliferation of PAs. Leucine-rich repeats and immunoglobulin-like domains protein 1 ( LRIG1), a negative mediated gene of ErbB receptors family, plays a role in many tumors. However, there are seldom researches about the functional role of LRIG1 in PAs. The aim of this study is to explore the potential effect of LRIG1 and its regulating mechanism in PAs. First, we investigated the role of LRIG1 in cell migration, invasion of PAs with transfected LRIG1 or control. Then, we explored its impact on cell proliferation and apoptosis of PAs in vivo. To study the regulating mechanism of LRIG1, we examined the expression of molecular factor of PI3K/AKT and Ras/Raf/ERK pathway using Western blotting in vitro and RT-PCR in vitro and in vivo. It was found that LRIG1 over-expression inhibited cell migration, invasion and proliferation, and promoted apoptosis of PAs in vivo and in vitro. Furthermore, LRIG1 suppressed the expression of signaling of PI3K/AKT and Ras/Raf/ERK pathways in PAs. LRIG1, as a negative mediated gene of tumor, can inhibit biological function of PAs via inhibiting PI3K/AKT and Ras/Raf/ERK pathways, and it might be a new target for gene therapy of PAs.