We have performed experiments for molecular understanding of deregulated differentiation pathways in TSCs: The delicate balance between stem cell self-renewal and differentiation is controlled by various cell intrinsic and extrinsic factors that are critical for normal tissue homeostasis. Despite extensive phenotypic and functional similarities between TSCs and normal stem cells, the differentiation potentials of TSCs are not entirely normal. Elucidation of the differentiation pathways that are operative in both normal stem cells and TSCs will be critical for fully understanding tumorigenesis and will likely lead to novel therapeutic targets. We have also identified a set of deregulated differentiation pathways in TSCs derived from human primary glioblastoma. Elucidation of underlying molecular mechanism will provide important clues for predicting sensitivity of differentiation therapeutic approach. Characterization of TSCs in aspect of differentiation-inducing agents further revealed the limitations of traditional glioma cell lines grown in serum. For example, retinoic acid treatment and CNTF exposure potently induce differentiation in most GBM TICs but not of traditional cell lines. This prompted us to question whether many of potential tumor suppressors and/or cytostatic genes previously studied in cell lines, were not recognized. Given the ever-increasing number of potential TSGs and oncogenes in glioblastoma TSCs identified from bioinformatics approach and technical expertise of stem cell culture accumulated in the laboratories, we have set up screening systems to study the function of these genes in stem cell cultures. In addition, we have made significant progress on one of keystone projects that is to understand the genomic and molecular signaling similarities and differences between our glioma TSCs and normal neural stem cells (NSC). We have performed a very large scale study of 7 different GBM-derived TSC and normal embryonic NSC lines under both proliferative and differentiating conditions and derived high-throughput mRNA and microRNAs profiling. We are in the midst of performing the computational analyses of the signaling pathways similar and different between NSC and TSC and are about to compliment the array data by performing ChIP-seq analyses of certain transcription factors we have found to be pivotal in TSC biology. Since Dr. Gilbert came to NOB in November 2014, we have created and characterized more glioma-derived TSCs to explore the therapeutic potential of glioma stem cell biology.
| Soeda, Akio; Lathia, Justin; Williams, Brian J et al. (2017) The p38 signaling pathway mediates quiescence of glioma stem cells by regulating epidermal growth factor receptor trafficking. Oncotarget 8:33316-33328 |
| Lee, Dae-Hee; Cheul Oh, Sang; Giles, Amber J et al. (2017) Cardiac glycosides suppress the maintenance of stemness and malignancy via inhibiting HIF-1? in human glioma stem cells. Oncotarget 8:40233-40245 |
| Colwell, Nicole; Larion, Mioara; Giles, Amber J et al. (2017) Hypoxia in the glioblastoma microenvironment: shaping the phenotype of cancer stem-like cells. Neuro Oncol 19:887-896 |
