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Amatruda, J.

Publications and source records attributed to Amatruda, J..

5 recordsLinked to original sources

Robust statistical assessment of Oncogenotype to Organotropism translation in xenografted zebrafish

Organotropism results from the functional versatility of metastatic cancer cells to survive and proliferate in diverse microenvironments. This adaptivity can originate in clonal variation of the spreading tumor and is often empowered by epigenetic and molecular reprogramming of cell regulatory circuits. Related to organotropic colonization of metastatic sites are environmentally-sensitive, differential responses of cancer cells to therapeutic attack. Accordingly, understanding the organotropic profile of a cancer and probing the underlying driver mechanisms are of high clinical importance. However, determining systematically the organotropism of one cancer versus the organotropism of another cancer, potentially with the granularity of comparing the same cancer type between patients or tracking the evolution of a cancer in a single patient for the purpose of personalized treatment, has remained very challenging. It requires a host organism that allows observation of the spreading pattern over relatively short experimental times. Moreover, organotropic patterns often tend to be statistically weak and superimposed by experimental variation. Thus, an assay for organotropism must give access to statistical powers that can separate meaningful heterogeneity, i.e., heterogeneity that determines organotropism, from meaningless heterogeneity, i.e., heterogeneity that causes experimental noise. Here we describe an experimental workflow that leverages the physiological properties of zebrafish larvae for an imaging-based assessment of organotropic patterns over a time-frame of 3 days. The workflow incorporates computer vision pipelines to automatically integrate the stochastic spreading behavior of a particular cancer xenograft in tens to hundreds of larvae allowing subtle trends in the colonization of particular organs to emerge above random cell depositions throughout the host organism. We validate our approach with positive control experiments comparing the spreading patterns of a metastatic sarcoma against non-transformed fibroblasts and the spreading patterns of two melanoma cell lines with previously established differences in metastatic propensity. We then show that integration of the spreading pattern of xenografts in 40 - 50 larvae is necessary and sufficient to generate a Fish Metastatic Atlas page that is representative of the organotropism of a particular oncogenotype and experimental condition. Finally, we apply the power of this assay to determine the function of the EWSR1::FLI1 fusion oncogene and its transcriptional target SOX6 as plasticity factors that enhance the adaptive capacity of metastatic Ewing sarcoma.

cancer biology↗

Tumor-associated stroma shapes the spatial tumor immune microenvironment of primary Ewing sarcomas

To date, few studies have detailed the tumor microenvironment (TME) of Ewing sarcoma (EwS). The TME has a vital role in cancer survival and progression with implications in drug resistance and immune escape. By performing spatially resolved transcriptomic analysis of primary treatment-naive EwS samples, we discovered greater stromal enrichment in localized EwS tumors compared to metastatic EwS tumors. Through spatial ligand-receptor analysis, we show that the stromal enriched regions harbor unique extracellular matrix related cytokines, immune recruitment and proinflammatory microenvironmental signals, implying EwS stroma may play an anti-tumorigenic role by acting as an immune recruitment center. All EwS tumors expressed pro-tumorigenic MIF-CD74 immune signaling, suggesting a potential immune-evasive mechanism and immunotherapy target. Our findings provide insight into tumor cell/stromal cell interactions in EwS and serve as a valuable resource for further investigations in the tumor immune microenvironment of EwS.

cancer biology↗

Caveolin-1 regulates context-dependent signaling and survival in Ewing Sarcoma.

Plasticity is a hallmark function of cancer cells, yet the mechanisms that enable dynamic switching between survival states remain incompletely understood. Here, we identify Caveolin-1, a membrane-domain scaffolding protein, as a context-dependent regulator of survival signaling in Ewing sarcoma (EwS). Single-cell analyses reveal a distinct subpopulation of EwS cells marked by high CD99 and elevated Caveolin-1 expression. These CD99High cells exhibit unique morphology, transcriptional programs, and markedly enhanced survival both under chemotherapeutic challenge and in vivo. Importantly, CD99High and CD99Low states are reversible, providing EwS cells with a flexible route to survival-oriented plasticity. Mechanistically, we show that Caveolin-1 in CD99High cells orchestrates PI3K/AKT survival signaling by modulating the spatial organization of PI3K activity on the plasma membrane. We propose that the CD99High state establishes a Caveolin-1-driven signaling architecture that supports survival through mechanisms distinct from those used by CD99Low cells. These findings uncover a dynamic state transition in EwS cells and position Caveolin-1 as a key driver of context-specific survival signaling.

cancer biology↗

VGLL2-NCOA2 leverages developmental programs for pediatric sarcomagenesis

Clinical sequencing efforts are uncovering numerous fusion genes in childhood solid tumors, yet few methods exist to delineate fusion-oncogenes from structural changes of unknown significance. One such novel fusion gene is VGLL2-NCOA2, which was described by us and others in patients with congenital sarcomas but has lacked functional validation. To determine if this fusion is an oncogene, and how it is driving disease, we developed a vertebrate zebrafish model and mouse allograft model of human VGLL2-NCOA2 driven sarcomagenesis. We found that VGLL2-NCOA2 is indeed an oncogene and is sufficient to generate mesenchymal tumors that recapitulate the human disease at the histological and transcriptional level. Zebrafish VGLL2-NCOA2 tumors display features of arrested skeletal muscle development, and a subset transcriptionally cluster with somitogenesis in developing embryos. By comparing tumor and embryonic gene expression signatures, we identified developmentally regulated targets that VGLL2-NCOA2 potentially leverages for tumorigenesis. These targets highlight the core biology of the disease and could represent therapeutic opportunities. Specifically, a RAS family GTPase, arf6/ARF6, involved in actin remodeling and rapid cycling of endocytic vesicles at the plasma membrane, is highly expressed during zebrafish somitogenesis and in VGLL2-NCOA2 tumors. In zebrafish tumors, arf6 protein is highly expressed and is absent from mature skeletal muscle. In VGLL2-NCOA2 mouse allograft models and patient tumors, ARF6 mRNA is overexpressed as compared to skeletal muscle or normal controls. More broadly, ARF6 is overexpressed in adult and pediatric sarcoma subtypes as compared to mature skeletal muscle. Overall, our cross-species comparative oncology approach provides evidence that VGLL2-NCOA2 is an oncogene which leverages developmental programs for tumorigenesis, and that one of these programs, the reactivation or persistence of arf6/ARF6, could represent a therapeutic opportunity.

cancer biology↗

Profiling site-specific cell states of Ewing Sarcoma xenografts in zebrafish

Tissue microenvironments affect the functional states of cancer cells, but determining these influences in vivo has remained a significant challenge. We present a quantitative high-resolution imaging assay of cancer cell morphology in zebrafish xenografts to probe functional adaptation to variable cell extrinsic cues and molecular interventions. We focus on Ewing Sarcoma, a pediatric cancer driven by a single oncogenic fusion protein EWSR1-FLI1, and with little to no additional somatic mutations, making it a prototypical form of cancer whose adaptation to microenvironments is likely driven by acute, non-genomic mechanisms. Using computer vision analysis of 3D cell shapes, we find systematic shifts in the distribution of cell morphotypes between distinct sites in the fish embryo. We also find site-specific morphological responses to differential expression of EWSR1-FLI1. Combining these data we propose a model where Ewing Sarcoma cancer cell plasticity is sensitive both to expression fluctuation of EWSR1-FLI1 and signals from the surrounding tissue microenvironment, with either or both factors possibly contributing to the oncogenic potential of these cells.

cancer biology↗