Abnormal Expression Of MicroRNAs In Plasma Of Patients With Glioma And Their Clinical Significance

Glioma is derived from the neural epithelial tissues, is the most common intracranial malignant tumors, it takes up approximately 40%～50% of all intracranial tumors.And it has the characteristics of high morbidity, high recurrence rate, case fatality rates and characteristics of low cure rates. The median survival time of glioblastoma is less than a year. Glioma has high heterogeneity, the cause of it is not yet clear, and clinical studies of it is in slow progress.Now availability of testing in glioma, efficiency of treatment and prognosis is not very good. In recent years, study on small molecule RNA (miRNAs or microRNAs) is further, and miRNAs studies of glioma are emerging.Small molecule RNA has 20～25 nucleotides, it is of small endogenous single chain RNA molecule with non-coding. It bind to target messenger RNA 3’-end combination-untranslated region in to restrain their translation or make them degradation directly, it has a function of regulation after the expression and translation of gene, thus it can regulate cell proliferation, differentiation and apoptosis. In recent years, studies have found that varieties of miRNAs’expression has a relationship with different diseases.These miRNAs are very stable and maybe very promising specific markers for disease diagnosis. The found of this kind of small RNA molecules provides new idea to diagnosis of glioma.Purpose:this study propose to detect expression of miRNAs in plasma of patients with glioma and normal people by real-time polymerase chain reaction (qRT-PCR).We screening and validate expression of miRNAs in plasma of patients with glioma and normal people to found suitable miRNAs, and make correlation analysis of miRNAs expression and glioma.To provide experimental basis for early diagnosis, monitoring and prognosis of glioma, and may provide ideas and targets for treatment.Methods:1. Using EDTA-K2 blood collection tube to collect blood 2mL of healthy subjects and patients with different levels of glioma, meningioma and pituitary tumors (10 each) and 10 cases of glioblastom (GBM) patients’blood after surgery and chemotherapy. Centrifuged by 2 times, and collect the plasma.2. Using miRNAs extraction Kit to abstract miRNAs, using real-time polymerase chain reaction to detection levels of miR-21、miR-128 and miR-342-3p in plasma of normal persons and patients with different levels of glioma and other brain tumors, and levels of miR-21、miR-128 and miR-342-3p in plasma of GBM patients before surgery, after surgery, and after chemotherapy.3. By statistical analysis software SPSS 13.0, we use Mann-Whitney u test to analysis of miRNAs data and find significant differences, P<0.05 means it has a statistically significant difference. We use receiver operating characteristic curve (ROC) to assess specificity and sensitivity of miR-21, miR-128 and miR-342-3p as markers in the diagnosis of glioma.Results:(1) compared with healthy controls, levels of miR-21 is significant higher in the plasma of patients with GBM, levels of miR-128 and miR-342-3p in plasma of patients with GBM in significantly reduced, their specificity and sensitivity can reach 90%-100% as markers in the diagnosis of GBM. (2) Levels of plasma miR-21 and not related to malignancy in glioma, levels of miR-128 can be distinguished between lower-level (II) and the higher levels of glioma (III and IV), and with the degree of malignant glioma increase, expression of plasma miR-342-3p are significantly reduced. (3) Compared with before treatment, levels of miR-21 in plasma of patients with GBM are significantly reduced after treatment, levels of miR-128 and miR-342-3p are significantly increased after treatment and there were no significant different among recovered levels of patients with GBM and the control group. (4) Levels of miR-21、miR-128 and miR-342-3p are only changed in plasma of patients with glioma, but there were no significant different in expression of these three miRNAs among patients with meningioma and pituitary tumors and healthy controls.Conclusion:miR-21、miR-128 and miR-342-3p in plasma could as a new kind of plasma markers in the diagnosis of glioma, and can be a valid marker for monitoring the effection of treatment of glioma.