Project description:<p>Metabolic reprogramming is critical for tumor initiation and progression. However, the exact impact of specific metabolic changes on cancer progression is poorly understood. Here, we integrate multimodal analyses of primary and metastatic clonally-related clear cell renal cancer cells (ccRCC) grown in physiological media to identify key stage-specific metabolic vulnerabilities. We show that a VHL loss-dependent reprogramming of branched-chain amino acid catabolism sustains the de novo biosynthesis of aspartate and arginine enabling tumor cells with the flexibility of partitioning the nitrogen of the amino acids depending on their needs. Importantly, we identify the epigenetic reactivation of argininosuccinate synthase (ASS1), a urea cycle enzyme suppressed in primary ccRCC, as a crucial event for metastatic renal cancer cells to acquire the capability to generate arginine, invade in vitro and metastasize in vivo. Overall, our study uncovers a novel mechanism of metabolic flexibility occurring during ccRCC progression, paving the way for the development of novel stage-specific therapies</p>
Project description:A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germline is associated with primordial germ cell development and during fetal gonadal sex determination. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation primordial germ cell transcriptome and epigenome (DNA methylation) was altered transgenerationally. Interestingly, the differential DNA methylation regions (DMR) and altered transcriptomes were distinct between the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DMR and transcriptional alterations were observed in the E13 PGC than E16 germ cells. Observations demonstrate an altered transgenerational epigenetic reprogramming and function of the primordial germ cells and subsequent male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided. The combined observations demonstrate ancestral exposure of a gestating female during fetal gonadal sex determination can promote transgenerational alterations in the primordial germ cell and subsequent male germline epigenetic and transcriptional programming. This altered germline programming leads to the epigenetic transgenerational inheritance of disease and phenotypic variation. Observations support the role of the primordial germ cell programming in the molecular mechanism involved and provides insights into the molecular mechanisms that control the epigenetic transgenerational inheritance phenomena. Results suggest a cascade of epigenetic and transcriptional events during germ cell development is needed to obtain the mature germline epigenome that is then transmitted transgenerationally. RNA samples from PGC of 2 F3-control lineage groups were compared to PGC of 2 F3-vinclozolin lineage groups for two embryonic age E13 and E16
Project description:In vivo reprogramming provokes a wide range of cell fate conversion. Here, we discover that in vivo induction of higher levels of OSKM in mouse somatic cells leads to increased expression of primordial germ cell (PGC)-related genes and provokes genome-wide erasure of genomic imprinting, which takes place exclusively in PGCs. Moreover, the in vivo OSKM reprogramming results in development of cancer that resembles human germ cell tumors. Like a subgroup of germ cell tumors, propagated tumor cells differentiate into trophoblasts. Moreover, these tumor cells give rise to induced pluripotent stem cells (iPSCs) with expanded differentiation potential into trophoblasts. Remarkably, the tumor-derived iPSCs are able to contribute to non-neoplastic somatic cells in adult mice. Mechanistically, DMRT1, which is expressed in PGCs, drives the reprogramming and propagation of the tumor cells in vivo. Furthermore, the DMRT1-related epigenetic landscape is associated with trophoblast competence of the reprogrammed cells and provides a therapeutic target for germ cell tumors. These results reveal an unappreciated route for somatic cell reprogramming and underscore the impact of reprogramming in development of germ cell tumors.
Project description:Cell state evolution underlies tumor development and response to therapy1, but mechanisms specifying cancer cell states and intratumor heterogeneity are incompletely understood. Schwannomas are the most common tumors of the peripheral nervous system and are treated with surgery and ionizing radiation2–5. Schwannomas can oscillate in size for many years after radiotherapy6,7, suggesting treatment may reprogram schwannoma cells or the tumor microenvironment. Here we show epigenetic reprogramming shapes the cellular landscape of schwannomas. We find schwannomas are comprised of 2 molecular groups distinguished by reactivation of neural crest development pathways or misactivation of nerve injury mechanisms that specify cancer cell states and the architecture of the tumor immune microenvironment. Schwannoma molecular groups can arise independently, but ionizing radiation is sufficient for epigenetic reprogramming of neural crest to immune-enriched schwannoma by remodeling chromatin accessibility, gene expression, and metabolism to drive schwannoma cell state evolution and immune cell infiltration. To define functional genomic mechanisms underlying epigenetic reprograming of schwannomas, we develop a technique for simultaneous interrogation of chromatin accessibility and gene expression coupled with genetic and therapeutic perturbations in single-nuclei. Our results elucidate a framework for understanding epigenetic drivers of cancer evolution and establish a paradigm of epigenetic reprograming of cancer in response to radiotherapy.