MITOGEN INDEPENDENCE IDENTIFIES A HIGHLY MALIGNANT POPULATION OF TUMOR STEM CELLS

摘要

The present invention is directed to a method for isolating and establishing Growth Factor-Independent (GF-I) Tumor Stem Cells (TSCs) from tumor biopsies or tumor cell lines consisting in culturing cells in serum-free mitogen-free culture medium. The method discloses cell growth in a culture medium, which does neither comprise serum, nor EGF (Epidermal Growth factor) and FGF-2 (Fibroblast Growth Factor), nor both, nor EGF or FGF-2 derivatives with the same mitogenic characteristics of the parent molecules. According to a preferred embodiment, the method is directed to the isolation of Tumor stem cells (TSCs) from glioblastoma multiforme (GBM) or from other brain tumors or brain tumor cell lines. GF-lndependent TSCs can be identified and expanded in vitro providing a homogeneous population of multipotent, self-renewing and highly tumorigenic Growth Factor-Independent TSCs, distinguishable from tumor stem cells derived with other methods, grown in parallel, for the above characteristics. The invention also encompasses therapeutic methods based on Tumor Stem Cells isolated as described.