The Three-Layer Concentric Model of Glioblastoma: Cancer Stem Cells, Microenvironmental Regulation, and Therapeutic Implications

Figure 2

Phenotypic and molecular characteristics of the three concentric layers model of GBM. Inner portions of tumor mass display more immature cancer cells (Nestin⁺) and account for the highest percentages of cancer stem cells identified by CD133 staining. This identified stem cell population is resistant to alkylating agents-based chemotherapy in vitro. Peripheral GBM cells show a more differentiated phenotype (GFAP+, β-III-tubulin⁺) with low levels or absence of CD133⁺ cells. These peripheral tumor cells are highly sensitive to Temozolomide.