Culture and characterization of human brain tumor stem cells
Date
2011
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Abstract
Diffusely infiltrating gliomas, of which glioblastoma (GBM) is most common, are highly aggressive brain tumors with dismal outcomes. Application of the Cancer Stem Cell (CSC) hypothesis to glioma led to the discovery of Brain Tumor Stem Cells (BTSCs) and a direct link to Neural Stem Cells (NSCs). In this thesis I begin by trying to identify characteristics that distinguish BTSCs from NSCs. I cultured cells isolated from GBMs, using the neurosphere culture system, in order to understand their growth requirements. GBM BTSCs proliferated in the absence of exogenous mitogenic stimulation and gave rise to multipotent GBM spheres that were capable of self-renewal. Epidermal growth factor and fibroblast growth factor-2 enhanced GBM BTSC survival and proliferation. Implantation of exogenous mitogen independent GBM BTSCs led to the formation of highly invasive intracranial tumors in immunocompromised mice. Thus, exogenous mitogen independence is one characteristic that distinguishes GBM BTSCs from NSCs. I then ask whether BTSCs can be isolated from other gliomas, specifically oligodendroglioma. Investigating the biology of oligodendroglioma, and its characteristic combined deletion of chromosomal arms 1 p and 19q, has been hampered by the lack of cell lines that harbor these traits. Cells from anaplastic oligodendrogliomas cultured in serum-free conditions, followed by serial propagation and expansion, led to the establishment of permanent cell lines that maintained the genetic signature of the parent tumors. Furthermore, these oligodendroglioma cells displayed features of BTSCs in vitro. These lines may be important tools for understanding the biology of oligodendroglioma and the function of their defining genetic traits. Finally, I employed the neurosphere culture system in order to generate 70 cell lines that collectively comprise a cellular model system of GBM. This robust model system harbors characteristic genetic abnormalities of GBM that permit sub-grouping of the cell lines. Importantly, this system recapitulates the heterogeneity of GBM and facilitates both in vitro and in vivo studies of phenotypic and molecular sub-groups. By coupling cell line generation with molecular characteristics and patient outcome, the model system has direct clinical relevance. In sum, the results demonstrate that glioma heterogeneity is evident in BTSCs isolated from individual tumors. This unique experimental system will permit elucidation of mechanisms that underlie glioma BTSC biology together with preclinical studies that evaluate novel therapeutic strategies.
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Bibliography: p. 168-182.
Some pages are in colour.
Includes copy of Certification of Animal Protocol Approval form. Original with original copy of Partial Copyright Licence.
Includes a copy of Copyright Permissions. Originals with original copy of Partial Copyright Licence.
Some pages are in colour.
Includes copy of Certification of Animal Protocol Approval form. Original with original copy of Partial Copyright Licence.
Includes a copy of Copyright Permissions. Originals with original copy of Partial Copyright Licence.
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Citation
Kelly, J. J. (2011). Culture and characterization of human brain tumor stem cells (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/4486