Cerebrospinal Fluid MicroRNA Signatures as Diagnostic Biomarkers in Brain Tumors
Central European Institute of Technology (CEITEC), Masaryk University, Brno 625 00, Czech Republic
Department of Comprehensive Cancer Care, Masaryk Memorial Cancer Institute, Brno 656 53, Czech Republic
Department of Neurosurgery, University Hospital Brno, Brno 625 00, Czech Republic
Faculty of Medicine, Masaryk University, Brno 625 00, Czech Republic
Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Faculty of Medicine, Masaryk University, Brno 656 53, Czech Republic
Authors to whom correspondence should be addressed.
Cancers 2019, 11(10), 1546; https://doi.org/10.3390/cancers11101546
Received: 3 August 2019 / Revised: 28 September 2019 / Accepted: 9 October 2019 / Published: 12 October 2019
(This article belongs to the Special Issue Tumors of the Central Nervous System: An Update)
Central nervous system (CNS) malignancies include primary tumors that originate within the CNS as well as secondary tumors that develop as a result of metastatic spread. Circulating microRNAs (miRNAs) were found in almost all human body fluids including cerebrospinal fluid (CSF), and they seem to be highly stable and resistant to even extreme conditions. The overall aim of our study was to identify specific CSF miRNA patterns that could differentiate among brain tumors. These new biomarkers could potentially aid borderline or uncertain imaging results onto diagnosis of CNS malignancies, avoiding most invasive procedures such as stereotactic biopsy or biopsy. In total, 175 brain tumor patients (glioblastomas, low-grade gliomas, meningiomas and brain metastases), and 40 non-tumor patients with hydrocephalus as controls were included in this prospective monocentric study. Firstly, we performed high-throughput miRNA profiling (Illumina small RNA sequencing) on a discovery cohort of 70 patients and 19 controls and identified specific miRNA signatures of all brain tumor types tested. Secondly, validation of 9 candidate miRNAs was carried out on an independent cohort of 105 brain tumor patients and 21 controls using qRT-PCR. Based on the successful results of validation and various combination patterns of only 5 miRNA levels (miR-30e, miR-140, let-7b, mR-10a and miR-21-3p) we proposed CSF-diagnostic scores for each tumor type which enabled to distinguish them from healthy donors and other tumor types tested. In addition to this primary diagnostic tool, we described the prognostic potential of the combination of miR-10b and miR-196b levels in CSF of glioblastoma patients. In conclusion, we performed the largest study so far focused on CSF miRNA profiling in patients with brain tumors, and we believe that this new class of biomarkers have a strong potential as a diagnostic and prognostic tool in these patients.