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Anthonydhason, V.

Publications and source records attributed to Anthonydhason, V..

4 recordsLinked to original sources

β3-Integrin controls pericyte metabolic states and shapes tumour-stromal metabolic crosstalk in breast cancer

Pericytes are emerging as dynamic regulators of the tumour microenvironment. Yet, their role in tumour metabolism remains elusive. Here, we investigate whether {beta}3-integrin regulates pericyte metabolic state and shapes stromal-tumour metabolic interactions in breast cancer. By integrating spatial and single-cell transcriptomics from human breast tumours with multi-omics profiling of tumour-derived pericytes in vitro, we identify two {beta}3-integrin-dependent metabolic states. {beta}3-integrin-high pericytes display a metabolically active phenotype characterised by increased glycolysis and enhanced de novo serine/glycine synthesis, supporting collagen production. In contrast, {beta}3-integrin loss induces a lipid-associated state, marked by neutral lipid accumulation and lipid droplets. Mechanistically, {beta}3-integrin regulates this metabolic switch via mTOR signalling. Importantly, these states extend beyond pericytes, with adjacent cancer cells shifting towards fatty acid oxidation and lipid use near {beta}3-integrin-low pericytes. Together, our findings establish {beta}3-integrin as a key metabolic switch in pericytes and highlight their role in driving tumour metabolic plasticity.

cancer biology↗

Mural β3-integrin signposts Stroma6, a gene signature predicting early relapse in low-risk and chemoresistant breast cancer

The Oncotype DX (ODX) assay guides adjuvant chemotherapy in ER+/HER2- breast cancer but overlooks drivers from the tumour stroma, leaving some low-risk and chemotherapy-spared patients vulnerable to rapid relapse. Here, we show that perivascular mural {beta}3-integrin protein expression predicts early (3-year) relapse in ODX low-risk patients (HR = 15.80, P = 0.010), from which we derived a translatable 6-gene stromal signature, termed Stroma6. High Stroma6 expression predicted early recurrence in the ODX low-risk discovery cohort, with zero early relapses in the low-expression group. External validation in the METABRIC dataset confirmed that Stroma6 independently predicts rapid recurrence in ODX low-risk patients (HR = 11.68, P = 0.002). Furthermore, Stroma6 utility extends to clinical chemoresistance, independently predicting early events in a pan-subtype cohort with residual disease following neoadjuvant chemotherapy (HR = 2.29, P = 0.003). Ultimately, Stroma6 is a robust prognostic signature identifying patients at high risk of early recurrence across diverse clinical contexts.

cancer biology↗

Patient-associated mutations in Drosophila Alk perturb neuronal differentiation and promote survival

Activating Anaplastic Lymphoma Kinase (ALK) receptor tyrosine kinase (RTK) mutations occur in pediatric neuroblastoma and are associated with poor prognosis. To study ALK-activating mutations in a genetically controllable system we employed CRIPSR/Cas9, incorporating orthologues of the human oncogenic mutations ALKF1174L and ALKY1278S in the Drosophila Alk locus. AlkF1251L and AlkY1355S mutant Drosophila exhibit enhanced Alk signaling phenotypes, but unexpectedly depend on the Jelly belly (Jeb) ligand for activation. Both AlkF1251L and AlkY1355S mutant larval brains display hyperplasia, represented by increased numbers of Alk-positive neurons. Despite this hyperplasic phenotype, no brain tumors were observed in mutant animals. We show that hyperplasia in Alk mutants was not caused by significantly increased rates of proliferation, but rather by decreased levels of apoptosis in the larval brain. Using single-cell RNA sequencing (scRNA-seq), we identify perturbations during temporal fate specification in AlkY1355S mutant mushroom body lineages. These findings shed light on the role of Alk in neurodevelopmental processes and highlight the potential of activating Alk mutations to perturb specification and promote survival in neuronal lineages.

cancer biology↗

DamID transcriptional profiling identifies the Snail/Scratch transcription factor Kahuli as Alk target in the Drosophila visceral mesoderm.

Development of the midgut visceral muscle of Drosophila crucially depends on Anaplastic Lymphoma Kinase (Alk) receptor tyrosine kinase (RTK) signalling, which is needed to specify founder cells (FCs) in the circular visceral mesoderm (VM). While activation of the Alk receptor by its ligand Jelly Belly (Jeb) is well characterized, only a small number of target molecules have been identified. Here, we assayed RNA polymerase II (Pol II) occupancy in VM cells by using the targeted DamID (TaDa) approach. To identify Alk targets we employed comparative analysis of embryos overexpressing Jeb versus embryos with abrogated Alk activity, revealing differential expression of a number of genes, including the Snail/Scratch family transcription factor Kahuli (Kah). Upon further in vivo validation, we confirmed that Alk signalling regulates Kah mRNA expression in the VM. We show that Kah mutants display defects in the formation of midgut constrictions, similar to that of pointed (pnt) mutants. Analysis of publicly available ChIP data defined a Kah target-binding site similar to that of Snail. In addition, we compared genes that were differentially expressed in Kah mutants with publicly available Kah- and Pnt-ChIP datasets identifying a set of common target genes putatively regulated by Kah and Pnt in midgut constriction. Taken together, we (i) report a rich dataset of Alk responsive loci in the embryonic VM, (ii) provide the first functional characterization of the Kah transcription factor, identifying a role in embryonic midgut constriction, and (iii) suggest a model in which Kah and Pnt cooperate in embryonic midgut morphogenesis.

developmental biology↗