Large scale integration and interactive exploration of cancer data – with applications to glioblastoma
Abstract: Glioblastoma is the most common malignant brain tumor, with a median survival of approximately 15 months. The standard of care treatment consists of surgical resection followed by radiotherapy and chemotherapy, where chemotherapy only prolongs survival by approximately 3 months. There is therefore an urgent need for new approaches to better understand the molecular vulnerabilities of glioblastoma. To this end, we have conducted four interdisciplinary studies.In study 1 we develop a method for efficiently constructing and exploring large integrative network models that include multiple cohorts and multiple types of molecular data. We apply this method to 8 cancers from The Cancer Genome Atlas (TCGA) and make the integrative network available for exploration and visualization through a custom web interface.In study 2 we establish a biobank of 48 patient derived glioblastoma cell cultures called the Human Glioma Cell Culture (HGCC) resource. We show that the HGCC cell cultures represent all transcriptional subtypes, carry genomic aberrations typical of glioblastoma, and initiate tumors in vivo. The HGCC is an open resource for translational glioblastoma research, made available through hgcc.se.In study 3 we extend the analysis of HGCC cell cultures both in terms of number (to over 100) and in terms of data types (adding mutation, methylation and drug response data). Large-scale drug profiling starting from over 1500 compounds identified two distinct groups of cell cultures defined by vulnerability to proteasome inhibition, p53/p21 activity, stemness and protein turnover. By applying machine learning methods to the combined drug profiling and matched genomics data we construct a first network of predictive biomarkers.In study 4 we use the methods developed in study 1 applied to the data generated in studies 2 and 3 to construct an integrative network model of HGCC and glioblastoma data from TCGA. We present an interactive method for exploring this network based on searching for network patterns representing specific hypotheses defined by the user.In conclusion, this thesis combines the development of integrative models with applications to novel data relevant for translational glioblastoma research. This work highlights several potentially therapeutically relevant aspects, and paves a path towards more comprehensive and informative models of glioblastoma.
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