Expression data from GBM and normal neural CD133+ and CD133- cells

We use gene expression data to provide a three-faceted analysis on the links between molecular subclasses of glioblastima, epithelial-to mesenchymal transition (EMT) and CD133 cell surface protein. The contribution of this paper is three-folded: First, we used a newly identified signature for epithelial-to-mesenchymal transition in human mammary epithelial cells, and demonstrated that genes in this signature have significant overlap with genes differentially expressed in all known GBM subtypes. However, the overlap between the genes up-regulated in the mesenchymal subtype of GBM and in the EMT signature was more significant than other GBM subtypes. Second, we provided evidence that there is a negative correlation between the genetic signature of EMT and that of CD133 cell surface protein, a putative marker for neural stem cells. Third, we studied the correlation between GBM molecular subtypes and the genetic signature of CD133 cell surface protein. We demonstrated that the mesenchymal and neural subtypes of GBM have the strongest correlations with the CD133 genetic signature. While the mesenchymal subtype of GBM demonstrates similarity with the signatures of both EMT and CD133, it also demonstrates some differences with each of these signatures that is partly due to the fact that the signatures of EMT and CD133 are inversely related to each other. Taken together this data sheds light on role of the mesenchymal transition and neural stem cells, and their mutual interaction, in molecular subtypes of glioblastoma multiforme. Two GBM samples (BT1 and BT2) and two normal samples (N1 and N2) were sorted for CD133 expression (overall eight samples, four positive and four negative).