MicroRNA expression patterns in the malignant progression of gliomas and a 5-microRNA signature for prognosis

// Wei Yan 1,2,* , Rui Li 2,* , Yanwei Liu 1,4,* , Pei Yang 1,4 , Zheng Wang 1,4 , Chuanbao Zhang 1,4 , Zhaoshi Bao 1,4 , Wei Zhang 1,4 , Yongping You 2 and Tao Jiang 1,3,4 1 Beijing Neurosurgical Institute, Capital Medical University, Beijing, PR China 2 Department of Neurosurgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, PR China 3 Beijing Institute for Brain Disorders Brain Tumor Center, Beijing, PR China 4 Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China * These authors contributed equally to this work Correspondence: Tao Jiang, email: // Yongping You, email: // Keywords : Anaplastic Gliomas; Secondary Glioblastomas; Proneural Glioblastomas; MicroRNAs; MiR-105-767 cluster; TCGA Received : August 24, 2014 Accepted : November 04, 2014 Published : November 04, 2014 Abstract MicroRNAs (miRNAs) are directly involved in the progression in various cancers. To date, no systematic researches have been performed on the expression pattern of miRNA during progression from low grade gliomas to anaplastic gliomas or secondary glioblastomas and those prognostic miRNAs in anaplastic gliomas and secondary glioblastomas. In the present study, high-throughput microarrays were used to measure miRNA expression levels in 116 samples in the different progression stages of glioma. We found that miRNA expression pattern totally altered when low grade gliomas progressed to anaplastic gliomas or secondary glioblastomas. However, anaplastic gliomas and secondary glioblastomas have similar expression pattern in miRNA level. Furthermore, we developed a five-miRNA signature (two protective miRNAs-miR-767-5p, miR-105; three risky miRNAs: miR-584, miR-296-5p and miR-196a) that could identify patients with a high risk of unfavorable outcome in anaplastic gliomas regardless of histology type. It should be highlighted that the five-miRNA signature can also identify patients who had a high risk of unfavorable outcome in secondary and TCGA Proneural glioblastomas, but not Neural, Classical and Mesenchymal glioblastomas. Taken together, our results demonstrate that miRNA expression patterns in the malignant progression of gliomas and a novel prognostic classifier, the five-miRNA signature, serve as a prognostic marker for patient risk stratification in anaplastic gliomas, Secondary and Proneural glioblastomas.