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Biology subjects

Royston, D.

Publications and source records attributed to Royston, D..

6 recordsLinked to original sources

A platform for deep topographic multiomic mapping of the bone marrow environment in multiple myeloma

Multiple myeloma is a genetically complex plasma cell malignancy in which profound intratumoral heterogeneity shapes disease progression and therapeutic resistance. Genomic subclones dynamically emerge and evolve under treatment pressure, yet their spatial organization within intact bone marrow remains poorly defined. We hypothesized that genetically distinct myeloma subclones occupy spatially discrete ecological niches associated with unique molecular and microenvironmental states. To test this, we here demonstrate a proof-of-concept spatial tri-omics workflow combining laser capture microdissection-based genomics and deep LC-MS/MS proteomics with single-cell spatial transcriptomics, integrated by digital co-registration of adjacent tissue sections. Applied to a myeloma bone marrow trephine, this approach enabled coordinated profiling of matched anatomical regions demonstrating that genomic, transcriptomic and proteomic profiles converged to define clone-specific microenvironmental programmes. We show that genetically distinct myeloma subclones occupy mutually exclusive regions of the same bone marrow biopsy. Remarkably, an aggressive del(17p) clone and a gain(12q) clone occupied defined anatomical territories within the same trephine-biopsied section, each clone exhibiting distinct genomic, transcriptomic, proteomic and cellular ecosystems. The del(17p) clone localized to a fibrotic, osteolytic and angiogenic niche enriched for activated stromal cells, osteoblasts, osteoclasts and immunoregulatory myeloid populations, whereas the gain(12q) clone occupied a comparatively quiescent marrow niche with limited stromal remodelling. Together, these findings demonstrate that genetically distinct myeloma subclones establish spatially and biologically discrete ecological niches through coordinated remodelling of stromal, immune and bone compartments, providing a framework for understanding clonal evolution within the bone marrow microenvironment.

cancer biology↗

Redefining the topology of the human bone marrow using augmented spatial transcriptomic analysis

The bone marrow (BM) is the main site of haematopoiesis in adult life. Our understanding of the pathogenesis of BM-derived blood cancers is limited by lack of spatial contextualisation. While emerging spatial transcriptomic (ST) platforms offer unprecedented opportunities for spatially-resolved cellular phenotyping, we recognise and incorporate the power of AI-based tissue feature detection to enhance ST workflows. We perform ST analysis to define the topology of the normal bone marrow (BM) and BM in myeloproliferative neoplasms (MPNs), profiling 5,104,452 cells across 30 human BM samples. Following rigorous histology-based QC, we identify spatially-restricted trajectories of haematopoiesis and extend our understanding of the haematopoietic stem cell (HSC) niche. We find that BM fibrosis in MPN is associated with expansion of distinct immune and stromal co-enriched cell neighbourhoods. We then present a machine learning (ML)-based model trained on ST data that quantifies BM microenvironmental deviation, identifying heretofore unrecognised inter- and intra-individual sample heterogeneity in MPN. Our study demonstrates the potential for AI-based augmented ST analysis, and redefines our understanding of human BM topology.

cancer biology↗

Wnt-dependent spatiotemporal reprogramming ofbone marrow niches drives fibrosis

Bone marrow fibrosis is the most extensive matrix remodeling of the microenvironment and can include de novo formation of bone (osteosclerosis). Spatiotemporal information on the contribution of distinct bone marrow niche populations to this process is incomplete. We demonstrate that fibrosis-inducing hematopoietic cells cause profibrotic reprogramming of perivascular CXCL12 abundant reticular (CAR) progenitor cells resulting in loss of their hematopoiesis-support and upregulation of osteogenic and pro-apoptotic programs. In turn, peritrabecular osteolineage cells (OLCs) are activated in an injury-specific, Wnt-dependent manner, comparable to skeletal repair. OLCs fuel bone marrow fibrosis through their expansion and skewed differentiation, resulting in osteosclerosis and expansion of Ly6a+ fibroblasts. NCAM1 expression marks peritrabecular OLCs and their expansion into the central marrow is specific for fibrosis in mice and patients. Peritrabecular stromal b-catenin expression is linked to fibrosis in patients and inhibition of Wnt signaling reduces bone marrow fibrosis and osteosclerosis, possibly being a clinically relevant therapeutic target.

molecular biology↗

A pro-inflammatory stem cell niche drives myelofibrosis through a targetable galectin 1 axis

Myeloproliferative neoplasms are stem cell-driven cancers associated with a large burden of morbidity and mortality. The majority of patients present with early-stage disease, but a substantial proportion progress to myelofibrosis and/or secondary leukemia, advanced cancers with a poor prognosis and high symptom burden. Currently, it remains difficult to predict progression, and we lack therapies that reliably prevent or reverse fibrosis development. A major bottleneck to the discovery of disease-modifying therapies has been an incomplete understanding of the interplay between perturbed cellular and molecular states. Several cell types have individually been implicated, but a comprehensive analysis of myelofibrotic bone marrow is lacking. We therefore mapped the crosstalk between bone marrow cell types in myelofibrotic bone marrow. We found that inflammation and fibrosis are orchestrated by a quartet of immune and stromal cell lineages - with basophils and mast cells creating a TNF signaling hub, communicating with megakaryocytes, mesenchymal stromal cells and pro-inflammatory fibroblasts. We identified the y-galactoside binding protein galectin 1 as a striking biomarker of progression to myelofibrosis and poor survival in multiple patient cohorts, and as a promising therapeutic target, with reduced myeloproliferation and fibrosis in vitro and in vivo and improved survival following galectin 1 inhibition. In human bone marrow organoids, TNF increased galectin 1 expression, suggesting a feedback loop wherein the pro-inflammatory MPN clone creates a self-reinforcing niche, fueling progression to advanced disease. This study provides a valuable resource for studying hematopoietic cell-niche interactions, with broad relevance for cancer-associated inflammation and disorders of tissue fibrosis.

cancer biology↗

Improving the diagnosis and classification of Ph-negative myeloproliferative neoplasms through deep phenotyping

Myeloproliferative neoplasms (MPNs) are clonal disorders characterized by excessive proliferation of myeloid lineages. Accurate classification and appropriate management of MPNs requires integration of clinical, morphological and genetic findings. Despite major advances in understanding the molecular and genetic basis, morphological assessment of the bone marrow trephine (BMT) remains paramount in differentiating between MPN subtypes and reactive conditions. However, morphological assessment is heavily constrained by a reliance on subjective, qualitative and poorly reproducible criteria. To address this, we have developed a machine-learning strategy for the automated identification and quantitative analysis of megakaryocyte morphology using clinical BMT samples. Using a sample cohort of recently diagnosed or established ET (n = 48) and reactive control cases (n = 42) we demonstrated a high predictive accuracy (AUC = 0.95) of automated tissue ET diagnosis based upon these specific megakaryocyte phenotypes. These separate morphological phenotypes showed evidence of specific genotype associations, which offers promise that an automated cell phenotyping approach may be of clinical diagnostic utility as an adjunct to standard genetic and molecular tests. This has great potential to assist in the routine assessment of newly diagnosed or suspected MPN patients and those undergoing treatment / clinical follow-up. The extraction of quantitative morphological data from BMT sections will also have value in the assessment of new therapeutic strategies directed towards the bone marrow microenvironment and can provide clinicians and researchers with objective, quantitative data without significant demands upon current routine specimen workflows.

pathology↗

Single-cell analyses reveal aberrant pathways for megakaryocyte-biased hematopoiesis in myelofibrosis and identify mutant clone-specific targets

Myelofibrosis is a severe myeloproliferative neoplasm characterised by increased numbers of abnormal bone marrow megakaryocytes that induce progressive fibrosis, destroying the hematopoietic microenvironment. To determine the cellular and molecular basis for aberrant megakaryopoiesis in myelofibrosis, we performed high-throughput single-cell transcriptome profiling of 50,538 hematopoietic stem/progenitor cells (HSPCs), single-cell proteomics, genomics and functional assays. We identified an aberrant pathway for direct megakaryocyte differentiation from the earliest stages of hematopoiesis in myelofibrosis and associated aberrant molecular signatures, including surface antigens selectively expressed by JAK2-mutant HSPCs. Myelofibrosis megakaryocyte progenitors were heterogeneous, with distinct expression of fibrosis and proliferation-associated genes and putative therapy targets. We validated the immunoglobulin receptor G6B as a promising JAK2-mutant clone-specific antigen warranting further development as an immunotherapy target. Our study paves the way for selective targeting of the myelofibrosis clone and more broadly illustrates the power of single-cell multi-omics to discover tumor-specific therapeutic targets and mediators of tissue fibrosis.

cancer biology↗