Identification of a predictive gene expression marker for recurrence in childhood ependymoma using microarray analysis

1531 Background: Ependymomas (EPN) account for 6–12% of all intracranial tumors in children. Even after complete resection and radiation, almost half the patients are likely to relapse. The role of chemotherapy in this tumor is uncertain. If children, who are at high risk of relapsing, could be identified at diagnosis then innovative therapy could be offered to them. Methods: RNA was extracted from 9 EPN specimens obtained at diagnostic surgery with appropriate consent and IRB approval. Retrospective clinical outcomes were obtained from the neuro-oncology data base with IRB permission. Extracted RNA was applied to Affymetrix HG-U133 plus2 microarray chips. To evaluate the results of microarray analysis, the data mining program GeneSpring was utilized. Results gathered from data mining were validated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry. Results: Interleukin-13 Receptor alpha 2 (IL13RA2) mRNA expression was identified as a potential marker of re...