CircIQGAP1 regulates RCAN1 and RCAN2 through the mechanism of ceRNA and promotes the growth of malignant glioma.

Circular RNA (circRNA) is one of non-coding RNA with specific circular structure, which has been found to be involved in regulating a series of malignant biological behaviors in many malignant tumors. In this study, based on the IDH1 molecular typing of gliomas, we identified a significant downregulation of circRNA (circIQGAP1) expression in IDH1 mutant gliomas by high-throughput sequencing. In 79 tissue samples, we confirmed that circIQGAP1 expression was significantly downregulated in IDH1 mutant gliomas, and that low circIQGAP1 expression was positively associated with better prognosis. Knockdown of circIQGAP1 in glioma cell lines inhibited glioma cell malignancy and conversely overexpression of circIQGAP1 promoted glioma malignancy. circIQGAP1 regulated glioma cell migration, proliferation, invasion and apoptosis through miR-1256/RCAN1/Bax/Bcl-2/Caspase3 and miR-622/RCAN2/Bax/Bcl-2/Caspase3 axes. These results suggest that circIQGAP1 plays an important role in glioma development, promotes tumor growth, and is a potential therapeutic target for glioma.

Pathological Grade-Associated Transcriptome Profiling of lncRNAs and mRNAs in Gliomas.

The aim of the present study was to explore the expression profiles of lncRNAs and mRNAs in glioma patients and to elucidate any potential relationship between lncRNAs and mRNAs in glioma. High-throughput transcriptome sequencing of mRNAs and lncRNAs from six normal tissues and 16 glioma tissues (grade II, six cases; grade III, four cases; and grade IV, six cases) was performed. Series test of cluster (STC) analysis was used to screen significant trending models associated with glioma. Gene co-expression networks were constructed for the differentially expressed lncRNAs and mRNAs, and gene-ontology (GO) and pathway-enrichment analyses were further performed. Quantitative real-time PCR was performed to validate the five most differentially expressed lncRNAs and mRNAs. After filtering the raw sequencing data, we found 578 lncRNAs and 3,216 mRNAs that were significantly dysregulated in glioma (fold change ≥ 2, p < 0.05). Twenty model profiles of lncRNA and 10 model profiles of mRNA were summarized, and three patterns of lncRNAs and two patterns of mRNAs were of clinical significance. Three gene co-expression networks between mRNAs and lncRNAs were built to clarify the relationship between lncRNAs and mRNAs in glioma. GO and pathway analyses indicated that the differentially expressed lncRNAs and mRNAs were enriched in several biological processes and signaling pathways associated with tumorigenesis. Both lncRNAs and mRNAs exhibited dynamic differential expression profiles that indicated their potential roles in different degrees of glioma malignancy. A series of bioinformatics analyses indicated that most of these lncRNAs and mRNAs are involved in important biological processes and pathways associated with the pathogenesis of glioma. These results provide potential directions and valuable resources for future investigations via the comprehensive integration of these lncRNAs and mRNAs.

Examination of Plasma Cell-Free DNA of Glioma Patients by Whole Exome Sequencing.

OBJECTIVES: To analyze the plasma cell-free DNA (Cf-DNA) in glioma patients with high throughout sequencing for a novel non-invasive method for the early diagnosis and management of glioma. METHODS: Six patients with glioma were recruited from the Affiliated Hospital of Nantong University from June 2015 to September 2016. Their plasma samples were tested for Cf-DNA by whole exon sequencing and mutations were analyzed by bioinformatics. RESULTS: After filtering the raw sequencing data of Cf-DNA, 33,173 mutations were obtained from 12,462 genes of which 442 genes and 655 mutation sites were identical to that in the Catalogue of Somatic Mutations in Cancer database. However, when we compared the Cf-DNA data with the glioma mutated loci in the Cancer Genome Alta database, only 4 mutations matched with the glioma sequences in the Cancer Genome Alta and did not correspond to that of the paired-tumor tissues. CONCLUSIONS: There were some cancer-related somatic mutations in the Cf-DNA of glioma patients, but no identical mutations were found in the paired solid tumors. Therefore, plasma Cf-DNA mutations may not be a suitable marker for the detection of glioma.