Biology subjects

Belnoue-Davis, H. L.

Publications and source records attributed to Belnoue-Davis, H. L..

4 recordsLinked to original sources

bioRxiv2024

Integrating diverse statistical methods to analyse stage-discriminatory cell interactions in colorectal neoplasia

Spatial biology has the potential to unlock information about the disrupted cellular ecosystems that define human disease. Quantitative analysis of spatially-resolved cell interactions allows mapping of tissue self-organisation and assessment of why cells interact differently in physiological and pathological contexts. However, the complexity of mammalian tissues, that occur across a spectrum of length scales, presents significant challenges for spatial analysis, increasing the gap between our capacity to generate and biologically interpret these datasets. Here, we have adapted a range of mathematical tools to develop a suite of spatial descriptors, and deployed them to determine how cell interactions change as colorectal cancer progresses from benign precursors. We demonstrate that combining mathematical analyses permits insightful examination of tissue organisational structures and identifies variable cell-interaction pathways that underpin disease progression. Mathematical tool triangulation can cross-corroborate spatial biology findings, facilitating development of analysis pipelines that are robust to individual method limitations.

cancer biology↗

bioRxiv2024

GREMLIN1 disrupts intestinal epithelial-mesenchymal crosstalk to induce a wnt-dependent ectopic stem cell niche via stromal remodelling

In homeostasis, counterbalanced morphogen signalling gradients along the vertical axis of the intestinal mucosa regulate the fate and function of epithelial and stromal cell compartments. Here, we used a disease-positioned mouse, and human tissue, to explore the consequences of pathological Bone Morphogenetic Protein (BMP) signalling dysregulation on epithelial- mesenchymal interaction. Aberrant pan-epithelial expression of the secreted BMP antagonist GREM1, resulted in ectopic crypt formation with lineage tracing demonstrating the presence of Lgr5(-) stem/progenitor cells. Isolated epithelial cell Grem1 expression had no effect on individual cell fate, indicating an intercompartmental impact of mucosal-wide BMP antagonism. Treatment with a novel anti-Grem1 antibody abrogated the polyposis phenotype, and triangulation of specific pathway inhibitors defined a pathological sequence of events, with wnt-ligand dependent ectopic stem cell niches formed through stromal remodelling following BMP disruption. These data support an emerging co-evolutionary model of intestinal cell compartmentalisation based on bidirectional regulation of epithelial-mesenchymal cell fate and function. One Sentence SummaryPathological epithelial GREM1 expression induces therapeutically reversible ectopic stem cell niches through stromal remodelling

cancer biology↗

bioRxiv2022

β-catenin obstructs γδ T cell immunosurveillance in colon cancer through loss of BTNL expression

WNT/{beta}-catenin signaling endows cancer cells with proliferative capacity and immune-evasive functions that impair anti-cancer immunosurveillance by conventional, cytoxtoic T cells. However, the impact of dysregulated WNT signalling on unconventional, tissue-resident T cells, specifically in colon cancer is unknown. Here, we show that cancer cells in Apc-mutant mouse models escape immunosurveillance from gut-resident intraepithelial lymphocytes (IELs) expressing {gamma}{delta} T cell receptors ({gamma}{delta}TCRs). Analysis of late-stage tumors from mice and humans revealed that {gamma}{delta}IELs are largely absent from the tumor microenvironment, and that butyrophilin-like (BTNL) molecules, which can critically regulate {gamma}{delta}IEL through direct {gamma}{delta}TCR-interactions, are also downregulated. We could attribute this to {beta}-catenin stabilization, which rapidly decreased expression of the transcription factors, HNF4A and HNF4G, that we found to bind promoter regions of Btnl genes, thereby driving their expression in normal gut epithelial cells. Indeed, inhibition of {beta}-catenin signaling restored Btnl1 gene expression and {gamma}{delta} T cell infiltration into tumors. These observations highlight an immune-evasion mechanism specific to WNT-driven colon cancer cells that disrupts {gamma}{delta}IEL immunosurveillance and furthers cancer progression.

cancer biology↗

bioRxiv2022

Molecular phenotyping of colorectal neoplasia shows dynamic and adaptive cancer stem cell population admixture

Intestinal homeostasis is underpinned by LGR5+ve crypt-base columnar stem cells (CBCs), but following injury, dedifferentiation results in the emergence of LGR5-ve regenerative stem cell populations (RSCs), characterised by fetal transcriptional profiles. Neoplasia hijacks regenerative signalling, so we assessed the distribution of CBCs and RSCs in mouse and human intestinal tumors. Using combined molecular-morphological analysis we demonstrate variable expression of stem cell markers across a range of lesions. The degree of CBC-RSC admixture was associated with both epithelial mutation and microenvironmental signalling disruption, and could be mapped across disease molecular subtypes. The CBC-RSC equilibrium was adaptive, with a dynamic response to acute selective pressure, and adaptability was associated with chemoresistance. We propose a fitness landscape model where individual tumors have equilibrated stem cell population distributions along a CBC-RSC phenotypic axis. Cellular plasticity is represented by position shift along this axis, and is influenced by cell-intrinsic, extrinsic and therapeutic selective pressures.

cancer biology↗