Analysis of the potential prognostic of ELAVL2, FOCAD and MLLT3 in glioblastoma

Background: There is a crucial demand to identify molecular markers for cancer to improve the personalized treatment, diagnosis and prognosis. Our research group described a frequently deleted region (chr9p22.1-p21.3) in gliomas, with genes potentially important in the development of this tumor type, including ELAVL2, FOCAD and MLLT3. Objectives: Therefore, the aim of this study was to analyze the expression of those genes as potential biomarkers for glioblastoma (GBM) prognosis. Design and setting: The study was retrospective with samples collected at Barretos Cancer Hospital. Methods: Immunohistochemistry reactions were performed for ELAVL2, FOCAD and MLLT3 proteins in 83 GBM samples. The reactions were evaluated using scores of intensity and extension, ranging from 0 to 6 in total. Patients with expression scores between 0 and 2 were considered negative for the expression of the specific gene, and those with scores between 3 and 6 were considered positive. Clinicopathological and molecular data from patients (age, gender, tumor location, KPS, and overall survival) were correlated with the expression of each gene. Results: ELAVL2-expressing tumors showed a trend to develop in the temporal lobe (P=0.052), whereas they were not found in the frontal lobe. Patients with FOCAD expression were older (>45y.o., p<0.001). Overall survival was not influenced by ELAVL2 or FOCAD expression. Patients with MLLT3 expression presented a marginal improved overall survival (p=0.077) when compared with patients without expression. Conclusion: Although there was a correlation of ELAVL2 and FOCAD with tumor location and age, respectively, these genes did not show prognostic potential in glioblastomas. MLLT3 showed potential prognostic, albeit more studies are warranted with larger cohorts.