Project description:Gliomas can originate upon transformation of adult Neural Progenitor Cells (NPCs) to Tumor Initiating Cells (TICs). Studies on human Glioma TICs (GTICs) have focused on the use of primary tumors from which GTICs could be isolated. Therefore investigations on the driver events underlying NPC transformation and human glioma initiation remain limited to the use of human embryonic material. Here we report on the development of strategies for the modeling of human gliomagenesis based on the use of human induced Pluripotent Stem Cells (hiPSCs). Transformation of hiPSC-derived NPCs (iNPCs) by defined genetic alterations led to the establishment of tractable human GTIC models suitable for studying the early steps of gliomagenesis as well as for screening studies. Dysregulation of PI3K, MAPK and p53 signaling in iNPCs led to the acquisition of functional GTIC properties. In vivo transplantation led to the formation of highly aggressive, infiltrative and heterogeneous tumors upon limited dilutions and secondary transplantation, faithfully recapitulating gliomagenesis. Metabolic modulation by chemical approaches compromised GTIC viability. Pilot screening of 101 anti-cancer compounds identified 3 molecules specifically targeting transformed iNPCs and primary GTICs. Together, our results demonstrate the potential of hiPSCs for the functional testing of putative driver mutations underlying human tumorigenesis and pave new avenues for the development of personalized cancer therapeutics.
Project description:Gliomas can originate upon transformation of adult Neural Progenitor Cells (NPCs) to Tumor Initiating Cells (TICs). Studies on human Glioma TICs (GTICs) have focused on the use of primary tumors from which GTICs could be isolated. Therefore investigations on the driver events underlying NPC transformation and human glioma initiation remain limited to the use of human embryonic material. Here we report on the development of strategies for the modeling of human gliomagenesis based on the use of human induced Pluripotent Stem Cells (hiPSCs). Transformation of hiPSC-derived NPCs (iNPCs) by defined genetic alterations led to the establishment of tractable human GTIC models suitable for studying the early steps of gliomagenesis as well as for screening studies. Dysregulation of PI3K, MAPK and p53 signaling in iNPCs led to the acquisition of functional GTIC properties. In vivo transplantation led to the formation of highly aggressive, infiltrative and heterogeneous tumors upon limited dilutions and secondary transplantation, faithfully recapitulating gliomagenesis. Metabolic modulation by chemical approaches compromised GTIC viability. Pilot screening of 101 anti-cancer compounds identified 3 molecules specifically targeting transformed iNPCs and primary GTICs. Together, our results demonstrate the potential of hiPSCs for the functional testing of putative driver mutations underlying human tumorigenesis and pave new avenues for the development of personalized cancer therapeutics.
Project description:Gliomas can originate upon transformation of adult Neural Progenitor Cells (NPCs) to Tumor Initiating Cells (TICs). Studies on human Glioma TICs (GTICs) have focused on the use of primary tumors from which GTICs could be isolated. Therefore investigations on the driver events underlying NPC transformation and human glioma initiation remain limited to the use of human embryonic material. Here we report on the development of strategies for the modeling of human gliomagenesis based on the use of human induced Pluripotent Stem Cells (hiPSCs). Transformation of hiPSC-derived NPCs (iNPCs) by defined genetic alterations led to the establishment of tractable human GTIC models suitable for studying the early steps of gliomagenesis as well as for screening studies. Dysregulation of PI3K, MAPK and p53 signaling in iNPCs led to the acquisition of functional GTIC properties. In vivo transplantation led to the formation of highly aggressive, infiltrative and heterogeneous tumors upon limited dilutions and secondary transplantation, faithfully recapitulating gliomagenesis. Metabolic modulation by chemical approaches compromised GTIC viability. Pilot screening of 101 anti-cancer compounds identified 3 molecules specifically targeting transformed iNPCs and primary GTICs. Together, our results demonstrate the potential of hiPSCs for the functional testing of putative driver mutations underlying human tumorigenesis and pave new avenues for the development of personalized cancer therapeutics.
Project description:Background In vivo stable isotope tracing is useful for natively surveying glioma metabolism but can be difficult to implement. Stable isotope tracing is tractable using in vitro glioma models, but most models lack nutrient conditions and cell populations relevant to human gliomas. This limits our ability to study glioma metabolism in the presence of an intact tumor microenvironment (TME) and immune-metabolic crosstalk. Methods We optimized an in vitro stable isotope tracing approach for human glioma explants and glioma stem-like cell (GSC) lines that integrates human plasma-like medium (HPLM). We performed 15N2-glutamine tracing in GSC monocultures and human IDH-wildtype glioblastoma explants and developed an analytical framework to evaluate microenvironment-dependent metabolic features that distinguish them. We also conducted spatial transcriptomics to assess transcriptional correlates to metabolic activities. Results Human plasma-like medium culture preserved glioma explant viability and stemness while unmasking metabolic and immune programs suppressed by conventional culture conditions. Stable isotope tracing in HPLM revealed TME-dependent and TME-independent features of tumor metabolism. Tissue explants recapitulated tumor cell-intrinsic metabolic activities, such as synthesis of immunomodulatory purines. Unlike GSC monocultures, tissue explants captured tumor cell-extrinsic activities associated with stromal cell metabolism, as exemplified by astrocytic guanosine diphosphate mannose production in heterocellular explants. Finally, glioma explants displayed tumor subtype-specific metabolic reprogramming, including robust pyrimidine degradation in mesenchymal cells. Conclusions We present a tractable approach to assess glioma metabolism in vitro under physiologic nutrient levels and in the presence of an intact TME. This platform opens new avenues to interrogate glioma metabolism and its interplay with the immune microenvironment.
Project description:Spatiotemporal analyses using brain slice culture and brain clearing demonstrated that human induced pluripotent stem cell-derived neural stem cells (iPSC-NSCs) possess higher tumor-trophic migratory capacity than fetal NSCs, adipose tissue and bone marrow derived mesenchymal stem cells (MSCs). NSCs expressing prodrug converting enzyme fusion gene exhibited strong anti-tumor effect for glioma stem cell in vivo models. The present research concepts may become a platform of cell-based gene therapy for glioma.
Project description:Genetic variants in lipid metabolism influence the risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD), cirrhosis, and end-stage liver disease (ESLD). The mechanisms by which these variants drive disease are poorly understood. Because of the PNPLA3-I148M variant's strong correlation with all stages of the MASLD spectrum and the lack of tractable therapeutic targets, we sought to understand its impact on cellular function and liver metabolism. Primary human hepatocytes (HAH) and iPSC-derived hepatocytes (iHeps) from healthy individuals possessing the PNPLA3-I148M mutation were characterized for changes in lipid metabolism, cellular stress, and survival. Using lipidomics, metabolomics, stable isotope tracing, and flux propensity analysis, we created a comprehensive metabolic profile of the changes associated with the PNPLA3-I148M variant. Functional analysis showed that the presence of the PNPLA3-I148M variant increased endoplasmic reticulum stress, mitochondrial dysfunction, and peroxisomal β-oxidation, ultimately leading to cell death via ferroptosis. Nutritional interventions, ferroptosis-specific inhibitors, and genetic approaches modulating GPX4 activity in PNPLA3-I148M HAH and iHeps decreased programmed cell death. Our findings indicate that therapies targeting ferroptosis in patients carrying the PNPLA3-I148M variant could affect the development of MASLD and ESLD and highlight the utility of iPSC-based models for the study of genetic contributions to hepatic disorders.