Comparative transcriptomic analysis of Central Neurocytoma-derived tumor spheres as compared to its differentiated cells and fetal SVZ-derived neural stem cells.

We obtained tissues of Central neurocytomas (CNs) from surgeries of patients, and then we performed primary cultures of CN tissues. Tumor spheres of CN were isolated from the differentiated CN cells. Fetal subventricular zone tissues (this sample was derived from inevitable abortion because of fatal defects) were primary cultured as well. Going forward, we compared the RNA of the pools via microarray to identify markers of tumor stem cells of Central Neurocytomas (CNs) as compared to its differentiated cells and fetal subventricular zone (SVZ)-derived neural stem cells (NSCs) to be able to characterize its origin of CN. Interestingly, CN-tumor spheres have characteristics of Transit amplifying Type C cells and Radial glial cells (RGCs). Moreover CN-tumor spheres expressed well known cancer stem cells markers of glioblastomas. Use of human CN tumor samples (N=3) for primary cultures in this study was approved by the Institutional Review Board (IRB) of Seoul National University Hospital (IRB approval C-0710-040-223). Attributing to its benign characteristics of CN, only one sample among those three was able to make robust number of tumor spheres were made from one sample after primary culture. Other sample also made tumor spheres, but the amount of RNA was not optimal for the microarray. We compared CN-differentiated cells (N=1) and CN-derived tumor spheres (N=1) to defined specific genes, expressed on CN-tumor spheres. Gene expression of CN-tumor spheres were also compared with Fetal SVZ-derived NSCs to detect overlapped and differential expression. For a comparative study between samples, expression data was standardized using z-score transformation. For a normal control we used “GSM469410” from the public GEO database (http://www.ncbi.nlm.nih.gov/geo/).