Brain Astrocytoma Patients With Specific Serum Microrna Expression Profiling Screening And Clinical Value Evaluation

Astrocytomas are the the most common refractoy and primary nervous system tumours, accout for about 75% of neuroepithelial tumors. It is divided into WHOâ… -â…£grade. Grade I is benign and grade II-IV is malignant cases, grade II has an inherent tendency to high grades.High grade astrocytoma is shown infiltrative growth, surgical eradicate impossible, high recurrence and low median survival rate. Recently, for the high grade astrocytoma clinical therapeutic strategies maily is surgical resection and adjuvant radiotherapy and chemotherapy, but the prognos is poor and the recurrence rate is 100%. Histopathologic diagnosis of astrocytoma is the gold standard, but the organization is invasive detection. It is difficult to achieve early diagnosis of tumors and treatment of timely monitoring. CT, MRI and enhanced scan diagnosis is commonly used in clinical diagnosis, but astrocytoma imaging manifestations of the complexity, diversity and non-typicality, imaging diagnosis level is still unsatisfactory. Collection of blood samples is non-invasive, and easily obtained. However, there are no astrocytoma-specific targets such serum markers, so astrocytoma remains a disease for which non-invasive, clinically applicable serum biomarkers for early detection and targeted prevention are highly desirable.MicroRNAs (miRNAs) are a class of approximately 22 nu-cleotide noncoding RNAs that mediate post-transcriptional gene regulation by binding to and repressing specific messenger RNA targets. MiRNA closely related to more physiological activities especially tumors; it plays a tumor-suppressor genes or oncogene role in tumorigenesis and development. Recent studies have found that there is abundant and stable miRNA in human serum, and some cancer patients showed specific changes in miRNA expression profiles, suggesting that serum miRNA as a new non-invasive potential of tumor markers for diagnosis and prognosis assessment. But there has not been relevant in patients with astrocytoma reported.Objectives:In this study, we determined the serum miRNA expression profile in astrocytoma patients in order to develop a novel diagnostic astrocytoma-biomarker and evaluate its prediction, diagnosis, classification and prognostic value.Methods:First, An initial screen of miRNA expression was performed in serum samples from untreated 44 cases of high-grade malignant astrocytoma patients (â…¢-â…£grade) and 43 age-and gender-matched normal by solexa sequencing. Then using RT-qPCR assay in serum samples (33 cases III-IV and 33 normal controls) for tainingset, selected a group of significant changes miRNA;validted in 55 cases of grade III and IV to get a group of stable changes miRNA; Furthermore, detected in grade 1(15 cases),â…¡(55 cases) and astrocytic hyperplasia (14 cases). All of the samples were preoperative serum and 80 normal serum as control. In addition, detected in another 14 cases serum of postoperative malignant astrocytoma patient. Finally, cluster analysis and ROC curves were used to evaluate the clinical value of miRNA.Results:Solexa sequencing showed that, the serum miRNA proportion of all small RNA molecules were 51.55% and 21.77% of the high grade malignant astrocytoma patients and normal controls, respectively. Serum miRNA expression profile in astrocytoma patients were significant different from controls and 50 serum miRNA were markedly change regulated in astrocytoma patients compared to controls(35 down,15 up). RT-qPCR identified a profile of seven serum miRNAs:miR-15b*,miR-23a,miR-133a,miR-150*,miR-197,miR-497and miR-548b-5p to be biomarkers (p<0.001) for astrocytoma in training set include 33 astrocytoma and 33 controls.This results were further confirmed in another 45 astrocytoma and 47 controls (p<0.001) for miR-15b*,miR-23a,miR-133a, miR-150*, miR-197, miR-497 and miR-548b-5p. Several of seven miRNAs have a significant difference in different grade of astrocytomas patients. The dendrogram generated by the cluster analysis showed a clear separation of the astrocytoma samples from the control samples based on the seven-serum miRNA profile. Result show that 100% of grade I cases and 82.5% of control samples were classified correctly.97.4% gradeâ…¢-â…£and 91.3% of control samples were classified correctly. In addition, it can be gradeâ… and gradeâ…¡completely classified. In addition, it can be grade I and gradeâ…¡completely classified. ROC curve analysis showed that, the AUC of gradeâ… and normal samples ranged from 0.892 to 1.000 for 7 miRNA,0.795 to 0.979 of gradeâ…¡and normal samples,0.651 to0.937 of gradeâ… and II;7 miRNA in the serum of patients after surgery were significantly increased (P<0.001).Conclusions:Serum miRNA expression profile of in astrocytoma patients were significant different from controls; We determined a profile of seven serum miRNAs were down-regulated in astrocytoma patients, especially in malignant patients; some of the miRNA can be hyperplasia, benign and malignant astrocytoma distinguished clearly;And 7 miRNA that increased significantly in postoperative patients;The 7 miRNA group can be used as a novel blood-based biomarker for the diagnosis of astrocytoma,for diagnosis, classification and prognostic value.