Project Funding Details

Our project builds on data suggesting that paragangliomas/pheochromocytomas (PGLs) develop through a deregulated neural crest developmental program driven by infection of PGL stem-like cells with a CMV-like virus, which causes metabolic rewiring and epigenetic modifications promoting proliferation/differentiation along mesenchymal (vascular) and neural (glial-neuronal) lineages. The project relies on new methods to isolate tumor-derived CMV from tumor tissue and urine of patients; on metabolic data from CMV-infected cells provided by our collaborator Cecilia Soderberg Nauclèr; on data on normal paragangliar development and on neuroblastoma stem-like cells, provided by our collaborators Igor Adameyko and Ninib Baryawno. We hypothesize that genetically predisposed subjects develop PGL because pre-existing defects in metabolism and hypoxia responses facilitate tumorigenic infection of PGL stem-like cells expressing CMV receptors linked to mesenchymal (vascular/perivascular) and neural (glial/neuronal) differentiation, which results in the build-up of an organoid tumor mass. We aim at the genomic and functional characterization of the PGL CMV-like virus and at the definition of the role of this virus and of other triggering factors on the metabolic and epigenetic control of neural crest differentiation. Our new concept of PGL origin will be substantiated by identifying host, viral and niche factors precipitating and driving neural crest differentiation, CMV replication and enhanced proliferation of PGL cells. We also aim at validating in preclinical models PGL treatments targeting CMV and neural crest development. CMV particles are isolated from PGL/PDX tissues, urine of patients and PDX mice using Rous's protocol coupled with PEG precipitation and characterized by FACS and EM. Isolated particles are used to: define CMV heterogeneity using Nanopore Sequencing; infect/superinfect normal or PGL cultures in comparison with lab CMV strains. Infected cells are used to assess cytopathic, transcriptional (single-cell sequencing) and transforming effects. 2D transcriptomics integrated with single-cell sequencing is used to identify the PGL cell of origin and whether infection hijacks neural crest developmental programs utilizing receptors on PGL stem-like cells. Interactions between CMV and neural crest differentiation are assessed by comparing PGL/PDX-derived data to data from physiologic paragangliar development. Drugs targeting the CMV-infected PGL cells directly or through microenvironmental interactions are identified using patient-derived in vitro and in vivo PGL models. We cannot understand and cure PGL unless we shed light on the genome diversity of the PGL-associated CMV virus in comparison to known CMV strains. We must also understand the cellular landscape of PGL in relation to the virus that likely gains control over the paragangliar stem cell compartment and reprograms to its own advantage cell growth and differentiation. We predict that carriers of PGL-related mutations have a lower threshold for chronic CMV infection of the stem-like PGL cell compartment and have epigenetic marks that promote CMV-driven neoplastic growth in the context of epigenetic deregulation. Our studies will also highlight new therapeutic targets in preclinical models. We propose PGL as a new model of human carcinogenesis at the interface between genetic variation, development and viral infection. This model could apply to other cancers where CMV-like viruses were controversially reported.