Background: Cellular self-renewal capacity in glioblastomas is heterogeneous, with only stem-like cells having this property. These cells generate a specific tumor phenotype, but no link with tumor location or molecular characteristics has ever been made.
Methods: Two cells lines, established from cell-dissociated glioblastomas and A2B5+ magnetic cell sorting, were used to decipher the mechanisms of cell migration in glioblastomas. GBM6 was derived from a glioblastoma close to the subventricular zone, whereas GBM9 was derived from a cortical glioblastoma and contained a high number of CD133(+) cells.
Results: Orthotopic injections in both the subventricular zone and the cortex of nude mice showed that GBM6 and GBM9 cells had a differential pattern of migration that mirrored that of adult and fetal normal neural stem cells, respectively. GBM6 demonstrated higher tumorigenicity than GBM9, and whichever cell line was injected, subventricular zone-implanted tumors were larger than cortical ones. In vitro, GBM6 and GBM9 displayed high autorenewal and proliferation rates, and their expression profiles and genomic status showed that they had distinctive molecular signatures: GBM6 was classified as a mesenchymal glioblastoma and GBM9 as a proneural glioblastoma.
Conclusions: Altogether, our findings suggest that tumor location in addition to molecular signature influence tumor growth and migration pattern.