Investigation of the diagnostic and prognostic values of some specific microRNAs in meningiom tumors

Primary brain tumors are classified as glial or non-glial and benign or malignant. Menenjiomas are common benign intracranial tumors. Although the name meningioma refers to a tumor of the lining of the brain called the 'Meninx', it has actually been shown to originate from the spider web-shaped 'arachnoid' membrane (arachnoid cover cells). The vast majority of meningiomas are benign, well circumscribed, slow growing and surgically treatable tumors. The degree of resection and histological degree are the most influential factors in the prognosis of meningioma patients. According to the World Health Organization (WHO) classification, the vast majority of menenjiomas are grade 1 (typical / benign), less than 10% grade II (atypical / moderate) and III (anaplastic / malignant) tumors. Menenjioma tumors are pathologically evaluated by taking tissue biopsy. There is no biomarker that can be used for diagnostic and prognostic purposes in blood samples obtained non-invasively. Biomarkers that can be evaluated in non-invasive samples such as serum are needed because biopsy, which is an interventional diagnostic method, can be risky and evaluation is subjective. MicroRNAs are 18-22 nucleotide-long, endogenous, non-protein-coding RNA molecules that negatively regulate gene expression at the post-transcriptional level. In our study, miRNAs that we think are associated with meningioma were studied. In our study; Meningioma tumor of miR-145, miR-34a-3p, miR-200a, miR-335, miR-106a-5p, miR-219-5p, miR-375, miR-409-3p miR-197 and miR-224 we aimed to investigate whether it can be used as a biomarker for diagnosis and/or prognosis. Total RNA isolation was performed in meningioma group and healthy control group. cDNA was obtained from these samples. The pre-amplification process was performed from the obtained cDNAs. Afterwards, samples and primers were loaded onto the chip and the miRNA expression level was checked with the help of the biomark device. In our study, miR-197 was found to be the most expressed miRNA in meningiomas compared to other miRNAs. miR-197, miR-34a, miR-375, miR-219 a and miR-224 stand out as potential biomarkers in meningiomas in human serum samples. In addition, according to the WHO classification, we think that a potential biomarker can be used in miR-197, miR-34a, miR-375 grade I and miR-375 grade II.