Abstract 3318: A distinct subpopulation within CD133 positive brain tumor cells shares characteristics with endothelial progenitor cells

The cell surface marker CD133 was proposed as a brain tumor stem cell marker. However there have been substantial controversies regarding the necessity and role of CD133 in tumorigenesis. This study aimed to characterize CD133 positive cells in brain tumors. Fresh human brain tumor specimens and whole blood were collected from the same patients [medulloblastoma (N=6), glioblastoma (N=4), ependymoma (N=1), and atypical teratoid/rhabdoid tumor (ATRT, N=2)]. Dual FACS staining for CD133/CD34, functional assay of CD133 positive cells from different origin for tumorigenesis and angiogenesis were done. We also investigated the in vivo tumorigenic potential and histological characteristics of four distinct groups on the basis of expression of CD133/CD34 markers (CD133+, CD133+/CD34+, CD133+/CD34-, and CD133-). CD133 positive brain tumor cells coexpressed significantly higher positivity for CD34 (67.97 ± 5.34 % in CD133 (+) cells vs. 11.96 ± 1.48 % in CD133 (−) cells, P Our data suggest the presence of a distinct subpopulation of CD133 positive cells isolated from human brain tumors, with characteristics of EPCs. Therefore, interpreting the results of experiments carried out with “CD133-positive BTSCs” should be extrapolated with caution. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3318. doi:10.1158/1538-7445.AM2011-3318