Project description:In a radiation mass casualty event, exposed populations will suffer dose-dependent toxicity to multiple-organ systems. Although several therapies are FDA-approved for treatment of the hematopoietic acute radiation syndrome (H-ARS), there are no FDA-approved medical countermeasures (MCM) for either acute gastrointestinal injury (GI) or late multi-organ toxicities known as the delayed effects of acute radiation exposure (DEARE). Prior data suggest activation of the alternative renin angiotensin (RAS) enzyme angiotensin-converting enzyme 2 (ACE2) has therapeutic potential for mitigating multi-organ radiation injury, including GI acute radiation syndrome (GI-ARS). Here, we evaluated whether pharmacologic activation of ACE2 mitigates GI-ARS in rodent models and protects against DEARE in GI-ARS survivors.
Project description:Post-radiation sarcomas are rare secondary cancers arising from radiation therapies. To date, few genetic specificities have been described for such malignancies and the oncogenesis of sarcomas with complex genetics (both sporadic and post-radiation) remains largely misunderstood. We performed genomic analyses on both sporadic and post-radiation sarcomas to study their copy-number alterations. This analysis is described in Lesluyes et al. 2019 (PMID: 31243333).
Project description:Here, we performed single-cell RNA sequencing (scRNA-seq) of a human fetal jejunum tissue sample from 1 individual biological specimen age 40 weeks post conception. The data set is composed of cells from diverse intestinal lineages.
Project description:- We revealed that inhibition of glutamine metabolism via genetic deletion or pharmacological inhibition of glutaminase (Gls1) radiosensitizes primary sarcomas in vivo. To delineate the potential mechanism(s) of radiosensitization post radiation therapy (RT), we performed proteomic analysis of Gls1+/+ and Gls1fl/flsarcomas 48 hours post 10 Gy RT. We found that 490 and 217 proteins were differentially expressed in Gls1fl/flsarcomas post 0 Gy and 10 Gy compared to Gls1+/+ sarcomas, respectively. Hallmark pathway analysis revealed that Gls1 deletion with or without RT decreased the expression of protein related to proliferation and translation (E2F targets and G2M checkpoint). Interestingly, Gls1 deletion post-RT increased innate immune response marked by elevated interferon-alpha, interferon-gamma, and natural killer (NK) cell responses. Flow cytometry analysis further validated these findings and showed significantly elevated NK cells, but not dendritic and myeloid cells in primary Gls1-deficient sarcomas compared to Gls1-proficient sarcomas post-RT. Collectively, proteomic and flow cytometry datasets suggested that innate immune response is partly accountable for radiosensitizing Gls1-deficient sarcomas.
Project description:Radiation is the frontline treatment for malignant gliomas. Intra-tumoral heterogeneity has been proposed to grant cancer cells a superior trajectory and survival advantage to avoid therapeutic interventions including radiation. However, direct evidence to support the hypothesis via the transcriptome dynamics of glioma during radiation therapy is limited. The current study aim to measure the functional subpopulation dynamics before and after radiation treatment that assist the radiation resistance at single cell resolution. We investigate the single cell transcriptome and biological pathways of primary glioma mouse model and post-radiation early/late time point. Specifically, we used the RCAS mouse model for gliomas, which overexpress PDGFRA as the model. Using single cell transcriptome, for the first time, we confirmed the proneural classification of PDGFRA RCAS glioma mouse model and its heterogeneity. We found that recurrent dominant subpopulations are featured with elevated proliferation rate and hypoxia. In addition, we identified a subpopulation of radiation resistant cells in at early time points with elevated stemness. Lastly, the subpopulations composition undergoes large changes at late time point when the tumor recurred. Single cell transcriptome profiling of radiation treated mouse glioma mouse model identified tumor cell subpopulations dynamics. It provides novel insights into the molecular phenotype and biological functions of radiation resistant tumor cell population.