Project description:The remarkable evolutionary capacity of cancer poses major challenges to current therapeutic efforts, and results from the vast clonal heterogeneity and ability of individual cancer cells to adapt to diverse selective pressures. More complete mechanistic understanding of the basis of therapeutic resistance has been limited by difficulties in coupling information regarding genetic and epigenetic alterations present within individual cells to their respective transcriptomic and functional outputs. To this end, we developed a novel high-complexity expressed barcode system, ClonMapper, that integrates DNA barcoding with single-cell RNA-sequencing and clonal isolation to characterize thousands of clones within a mixed cancer cell population. In applying this system to the chronic lymphocytic leukemia cell line HG3 in the setting of resistance to fludarabine-based chemotherapy, we discover pretreatment sub-populations with distinct expression profiles (i.e. upregulated Wnt, Notch and CXCR4 signaling) that not only confer distinct treatment survivorship trajectories, but also provide the basis for long-term clonal equilibrium between co-existing clones in the absence of treatment. Characterization of individual clones comprising these sub-populations revealed remarkable genetic heterogeneity and the persistence of unique transcriptomic signatures throughout treatment exposure. These data reveal the diverse clonal characteristics and therapeutic responses of a heterogeneous cancer cell population and highlight the unprecedented resolution that can be achieved using ClonMapper.
Project description:The remarkable evolutionary capacity of cancer poses major challenges to current therapeutic efforts, and results from the vast clonal heterogeneity and ability of individual cancer cells to adapt to diverse selective pressures. More complete mechanistic understanding of the basis of therapeutic resistance has been limited by difficulties in coupling information regarding genetic and epigenetic alterations present within individual cells to their respective transcriptomic and functional outputs. To this end, we developed a novel high-complexity expressed barcode system, ClonMapper, that integrates DNA barcoding with single-cell RNA-sequencing and clonal isolation to characterize thousands of clones within a mixed cancer cell population. In applying this system to the chronic lymphocytic leukemia cell line HG3 in the setting of resistance to fludarabine-based chemotherapy, we discover pretreatment sub-populations with distinct expression profiles (i.e. upregulated Wnt, Notch and CXCR4 signaling) that not only confer distinct treatment survivorship trajectories, but also provide the basis for long-term clonal equilibrium between co-existing clones in the absence of treatment. Characterization of individual clones comprising these sub-populations revealed remarkable genetic heterogeneity and the persistence of unique transcriptomic signatures throughout treatment exposure. These data reveal the diverse clonal characteristics and therapeutic responses of a heterogeneous cancer cell population and highlight the unprecedented resolution that can be achieved using ClonMapper.
Project description:The remarkable evolutionary capacity of cancer poses major challenges to current therapeutic efforts, and results from the vast clonal heterogeneity and ability of individual cancer cells to adapt to diverse selective pressures. More complete mechanistic understanding of the basis of therapeutic resistance has been limited by difficulties in coupling information regarding genetic and epigenetic alterations present within individual cells to their respective transcriptomic and functional outputs. To this end, we developed a novel high-complexity expressed barcode system, ClonMapper, that integrates DNA barcoding with single-cell RNA-sequencing and clonal isolation to characterize thousands of clones within a mixed cancer cell population. In applying this system to the chronic lymphocytic leukemia cell line HG3 in the setting of resistance to fludarabine-based chemotherapy, we discover pretreatment sub-populations with distinct expression profiles (i.e. upregulated Wnt, Notch and CXCR4 signaling) that not only confer distinct treatment survivorship trajectories, but also provide the basis for long-term clonal equilibrium between co-existing clones in the absence of treatment. Characterization of individual clones comprising these sub-populations revealed remarkable genetic heterogeneity and the persistence of unique transcriptomic signatures throughout treatment exposure. These data reveal the diverse clonal characteristics and therapeutic responses of a heterogeneous cancer cell population and highlight the unprecedented resolution that can be achieved using ClonMapper.
Project description:The remarkable evolutionary capacity of cancer poses major challenges to current therapeutic efforts, and results from the vast clonal heterogeneity and ability of individual cancer cells to adapt to diverse selective pressures. More complete mechanistic understanding of the basis of therapeutic resistance has been limited by difficulties in coupling information regarding genetic and epigenetic alterations present within individual cells to their respective transcriptomic and functional outputs. To this end, we developed a novel high-complexity expressed barcode system, ClonMapper, that integrates DNA barcoding with single-cell RNA-sequencing and clonal isolation to characterize thousands of clones within a mixed cancer cell population. In applying this system to the chronic lymphocytic leukemia cell line HG3 in the setting of resistance to fludarabine-based chemotherapy, we discover pretreatment sub-populations with distinct expression profiles (i.e. upregulated Wnt, Notch and CXCR4 signaling) that not only confer distinct treatment survivorship trajectories, but also provide the basis for long-term clonal equilibrium between co-existing clones in the absence of treatment. Characterization of individual clones comprising these sub-populations revealed remarkable genetic heterogeneity and the persistence of unique transcriptomic signatures throughout treatment exposure. These data reveal the diverse clonal characteristics and therapeutic responses of a heterogeneous cancer cell population and highlight the unprecedented resolution that can be achieved using ClonMapper.
Project description:It is elusive whether clonal selection of tumor cells in response to ionizing radiation (IR) is a deterministic or stochastic process. With high resolution clonal barcoding and tracking of over 400.000 HNSCC patient-derived tumor cells the clonal dynamics of tumor cells in response to IR was analysed. Fractionated IR induced a strong selective pressure for clonal reduction. This significantly exceeded uniform clonal survival probabilities indicative for a strong clone-to clone difference within tumor cells. Survival to IR is driven by a deterministic clonal selection of a smaller population which commonly survives radiation, while increased clonogenic capacity is a result of clonal competition of cells which have been selected stochastically. The ratio of these parameters is amenable to radiation sensitivity which correlates to prognostic biomarkers of HNSCC. Evidence for the existence of a rare subpopulation with an intrinsically radiation resistant phenotype was found at a frequency of 0.6-3.3%. With cellular barcoding we introduce a novel functional heterogeneity associated qualitative readout for evaluating the contribution of stochastic and deterministic clonal selection processes in response to IR.
Project description:It is elusive whether clonal selection of tumor cells in response to ionizing radiation (IR) is a deterministic or stochastic process. With high resolution clonal barcoding and tracking of over 400.000 HNSCC patient-derived tumor cells the clonal dynamics of tumor cells in response to IR was analysed. Fractionated IR induced a strong selective pressure for clonal reduction. This significantly exceeded uniform clonal survival probabilities indicative for a strong clone-to clone difference. within tumor cells. Survival to IR is driven by a deterministic clonal selection of a smaller population which commonly survives radiation, while increased clonogenic capacity is a result of clonal competition of cells which have been selected stochastically. The ratio of these parameters is amenable to radiation sensitivity which correlates to prognostic biomarkers of HNSCC. Evidence for the existence of a rare subpopulation with an intrinsically radiation resistant phenotype was found at a frequency of 0.6-3.3%. With cellular barcoding we introduce a novel functional heterogeneity associated qualitative readout for evaluating the contribution of stochastic and deterministic clonal selection processes in response to IR. To analyze transcriptomic changes of HNSCC cell lines after fractionated Photon IR (5x4Gy), RNAseq analysis was performed on irradiated cells in comparison to untreated control cells (EBI submission E-MTAB-9693)