A Hierarchy of Self-Renewing Tumor-Initiating Cell Types in Glioblastoma

ABSTRACT: The neural stem cell marker CD133 is reported to identify cells within glioblastoma (GBM) that can initiate neurosphere growth and tumor formation, however, instances of CD133- cells exhibiting similar properties have also been reported. Here, we show that some PTEN-deficient GBM tumors produce a series of CD133+ and CD133- self-renewing tumor-initiating cell types and provide evidence that these cell types constitute a lineage hierarchy. Our results show that the capacities for self-renewal and tumor initiation in GBM need not be restricted to a uniform population of stem-like cells, but can be shared by a lineage of self-renewing cell types expressing a range of markers of forebrain lineage. Keywords: Expression and copy number analysis of glioblastomas and neurosphere forming derivative cell lines of same. DNA analysis and Expression profiling: DNA from patient tumor mincates was profiled for copy number changes on Affymetrix 500k chips and sequenced for mutations in exons 4-8 of p53 and exons 5&6 of PTEN. For determination of amplification, samples with mean relative copy number estimates of >3 for SNPs residing within the locus were scored as amplified. Copy number losses were determined using data from 30 SNPs within or immediately flanking the locus of interest. Relative copy number losses that were statistically significant at the p<.001 level were scored as losses regardless of the magnitude of the alteration. DNA from neurosphere lines was analyzed for copy number alterations by profiling on Agilent 244K arrays. Relative copy number estimates were determined using the GLAD segmentation algorithm. For expression profiling, RNA was extracted as previously described (Phillips et al., 2006) and profiled on Agilent WHG (for patient samples) or WHG 4x44 chips (for neurosphere lines and grafts) according to the manufacturer's (Agilent technologies, Palo Alto CA) protocol.

ORGANISM(S): Homo sapiens

SUBMITTER: Chen R 

PROVIDER: S-ECPF-GEOD-19612 | biostudies-other | 2010 Apr

REPOSITORIES: biostudies-other