Circ-EZH2 knockdown reverses DDAH1 and CBX3-mediated cell growth and invasion in glioma through miR-1265 sponge activity.

Accumulating evidence has indicated the important roles of circular RNAs (circRNAs) in different tumors. However, their detailed regulatory mechanisms in glioma are not fully understood. In this study, the functional role of a novel circRNA, circ-EZH2, was investigated by cell counting kit-8 (CCK-8), colony formation, flow cytometry, and transwell experiments. The regulatory mechanism of circ-EZH2 was explored by bioinformatics analysis, quantitative real-time PCR (qRT-PCR), Western blot and dual-luciferase reporter assay. We identified that circ-EZH2 was overexpressed in glioma tissues and cell lines. Further studies revealed that ectopic expression of circ-EZH2 significantly promoted cell growth, migration and invasion but inhibited cell apoptosis. By contrast, silencing of circ-EZH2 induced the opposite effects. Additionally, we found circ-EZH2 served as a miRNA sponge for miR-1265 to release its suppression on DDAH1 and CBX3. Rescue assays further revealed that the oncogenic function of circ-EZH2 was partly dependent on its modulation of DDAH1 and CBX3. Our study unraveled a novel molecular pathway in glioma and may provide a new perspective for the treatment of glioma.

Gao F ，Du Y ，Zhang Y ，Ren D ，Xu J ，Chen D ... -  《-》

Hsa_circ_0071589 promotes carcinogenesis via the miR-600/EZH2 axis in colorectal cancer.

Previous studies have revealed that miRNAs and lncRNAs participate in the pathogenesis of colorectal cancer (CRC); however, whether circular RNAs (circRNAs) are also involved remains unclear. In the present study, qRT-PCR was used to examine the expression of hsa_circ_0071589, miR-600, and enhancer of zeste homolog 2 (EZH2) in CRC. MTT assay, colony formation assay, transwell assay, and wound-healing assay were performed to assess the effects of hsa_circ_0071589, miR-600, and EZH2 on CRC cell viability, proliferation, invasion, and migration. Bioinformatics analysis, luciferase reporter assay, and RIP assay were used to explore the correlations among hsa_circ_0071589, miR-600, and EZH2 expression in CRC cells. The results showed that hsa_circ_0071589 expression was significantly higher in CRC tissues than in normal tissues. Blockage of hsa_circ_0071589 in CRC cells inhibited tumor growth, invasion and migration. Hsa_circ_0071589 was able to promote the expression of EZH2 by acting as a sponge of miR-600. In addition, miR-600 expression was negatively correlated to hsa_circ_0071589 expression in CRC tissues. These results demonstrated that the hsa_circ_0071589/miR-600/EZH2 axis may play critical regulatory roles in the pathogenesis of CRC and may serve as a novel therapy target in CRC.

Yong W ，Zhuoqi X ，Baocheng W ，Dongsheng Z ，Chuan Z ，Yueming S ... -  《-》

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.

Qu Y ，Zhu J ，Liu J ，Qi L ... -  《-》

Circular RNA hsa-circ-0012129 Promotes Cell Proliferation and Invasion in 30 Cases of Human Glioma and Human Glioma Cell Lines U373, A172, and SHG44, by Targeting MicroRNA-661 (miR-661).

Xie G 《MEDICAL SCIENCE MONITOR》

Circular RNA TTBK2 promotes the development of human glioma cells via miR-520b/EZH2 axis.

Yuan DH ，Zhao J ，Shao GF 《-》