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Vetrie, D.

Publications and source records attributed to Vetrie, D..

4 recordsLinked to original sources

CD180 identifies chemoresistant stem-like blasts and reveals a KMT2A-driven vulnerability in acute myeloid leukaemia

Relapse and chemoresistance remain major challenges in paediatric acute myeloid leukaemia (PAML), particularly in KMT2A-rearranged (KMT2A-r) subtypes where conventional markers such as CD34 are often absent, complicating measurable residual disease (MRD) detection. Leukaemia stem/regenerating cells (LSC/LRC) drive disease initiation, progression, and relapse, sharing stemness and chemoresistance properties that make them critical therapeutic targets. Using high-dimensional spectral flow cytometry, we identified CD180, a Toll-like receptor-like surface protein, as highly expressed on blasts and stem-like populations in KMT2A-r AML, while near absent on normal haematopoietic stem cells (HSCs). PAML KMT2A-r exhibits an unconventional immunophenotype dominated by CD34-CD180 populations. Integrated single-cell transcriptomics and functional profiling revealed CD180high clusters enriched for quiescence, oxidative phosphorylation, and KMT2A/LSC stemness signatures. CD180 cells demonstrated robust leukaemia-initiating capacity in xenograft models and persisted through therapy, re-emerging at relapse with phenotypic plasticity. Epigenomic analysis showed CD180 is a direct transcriptional target of the KMT2A::MLLT3 fusion complex, regulated by intragenic enhancers and downregulated by menin and BET inhibitors. Longitudinal single-cell analysis confirmed persistence and clonal evolution of CD180 populations during treatment and relapse, underscoring their mechanistic role in chemoresistance and disease progression. In summary, CD180 marks dynamic, relapse-driving populations in KMT2A-r PAML, persists through therapy, and importantly is near absent on normal HSCs, offering a selective therapeutic window. These findings position CD180 as a clinically actionable biomarker for MRD detection and a compelling therapeutic target for eradicating chemoresistant, stem-like cells in paediatric AML. Main PointsO_LICD180 marks chemoresistant, relapse-driving stem-like blasts in KMT2A-r paediatric AML, overcoming CD34-based MRD limitations. C_LIO_LIAbsent on normal HSCs, CD180 is a KMT2A::MLLT3 target and actionable for MRD, relapse prediction, and CD180-directed therapies. C_LI NoveltyThis study introduces CD180 as a novel biomarker and therapeutic target in AML, particularly KMT2A-rearranged subtypes where conventional markers are often absent. Unlike MRD strategies focused on bulk blasts, CD180 marks chemoresistant, stem-like populations driving relapse, critical reservoirs poorly defined in paediatric AML. This work fills a major gap in prognostic assessment and therapy by enabling precise detection of relapse-driving cells and offering a selective therapeutic window.

cancer biology↗

The long non-coding RNA FAM30A regulates the Musashi2-RUNX1 axis and is required for LSC function in AML cells

High expression of the long non-coding RNA (lncRNA) FAM30A has been previously associated with leukemic stem cell (LSC) activity and poor prognosis in both adult and paediatric acute myeloid leukaemia (AML) patients, yet it has not been functionally studied. This study provides the first cellular characterization of FAM30A focussing on an internal tandemly organised region, referred to as FAM30A repeats. FAM30A levels correlated with canonical AML LSC signatures and FAM30A depletion decreased cell viability as well as increased sensitivity to chemotherapeutics. It also inhibited colony formation, promoted granulocytic differentiation and abrogated leukemic engraftment in murine bone marrow in vivo. Overexpression of FAM30A repeats in this setting enhanced stemness, proliferation, chemoresistance, and engraftment thus highlighting the biological relevance of this region for LSC biology. On the molecular level, FAM30A repeats interact with the pro-LSC regulator Musashi-2 (MSI2), positively influencing expression of its targets including RUNX1 isoforms. We herein uncover that this FAM30A-MSI2-RUNX1 regulatory loop is of potential relevance for LSC maintenance in AML. These findings provide valuable insights into FAM30As cellular role and highlight its targeting potential for eliminating LSCs and improving treatment outcomes in AML patients.

cancer biology↗

Tyrosine kinase inhibitor independent gene expression signature in CML offers new targets for LSPC eradication therapy

2Tyrosine kinase inhibitors (TKI) have revolutionised the treatment of CML. However, TKI do not eliminate the leukaemia stem cells (LSC), which can reinitiate the disease. Thus, finding new therapeutic targets in CML LSC is key to finding a curative treatment. Using microarray datasets, we defined a list of 227 genes which were differentially expressed in CML LSC compared to healthy controls but were not affected by TKI in vitro. Two of them, CD33 and PPIF, are targeted by gemtuzumab-ozogamicin and cyclosporin A, respectively. We treated CML and control CD34+ cells with either drug with or without imatinib to investigate the therapeutic potential of the TKI-independent gene expression programme. Cyclosporine A in combination with imatinib reduced the number of CML CFC compared with non-CML controls, but only at supra-therapeutic concentrations. Gemtuzumab-ozogamicin showed a EC50 of 146ng/mL, below the plasma peak concentration of 630ng/mL observed in AML patients and below the EC50 of 3247ng/mL observed in non-CML cells. Interestingly, gemtuzumab-ozogamicin seems to promote cell cycle progression in CML CD34+ cells and demonstrated activation of the RUNX1 pathway in a RNAseq experiment. This suggests that targeting the TKI-independent genes in CML LSC could be exploited for the development of new therapies in CML. 1 Simple summaryChronic myeloid leukaemia (CML) is initiated by a group of cancer cells called leukaemia stem cells (LSC). These LSC can survive current tyrosine kinase inhibitor (TKI) treatments and upon treatment withdrawal, are able to re-initiate the disease. Thus, eradicating the LSC would likely cure CML. In this study, we have identified a number of genes which expression is different between LSC and their healthy counterparts (haematopoietic stem cells) but are not affected by TKI treatment. We hypothesised that these genes may be potential therapeutic targets against LSC and used two different drugs, gemtuzumab-ozogamicin and cyclosporine A, to treat CML in vitro. We found that both drugs have a stronger effect on CML cells than in healthy cells. Therefore, we propose that the list of genes we identified could represent a novel source of therapeutic targets against CML.

cancer biology↗

A KDM4A-PAF1-mediated epigenomic network is essential for acute myeloid leukemia cell self-renewal and survival

Epigenomic dysregulation is a common pathological feature in human hematological malignancies. H3K9me3 emerges as an important epigenomic marker in acute myeloid leukemia (AML). Its associated methyltransferases, such as SETDB1, suppress AML leukemogenesis, whilst H3K9me3 demethylases KDM4C is required for mixed lineage leukemia rearranged AML. However, the specific role and molecular mechanism of action of another member of KDM4 family, KDM4A has not previously been clearly defined. In this study, we delineated and functionally validated the epigenomic network regulated by KDM4A. We show that selective loss of KDM4A is sufficient to induce apoptosis in a broad spectrum of human AML cells. This detrimental phenotype results from a global accumulation of H3K9me3 and H3K27me3 at KDM4A targeted genomic loci thereby causing down-regulation of a KDM4A-PAF1 controlled transcriptional program essential for leukemogenesis, distinct from that of KDM4C. From this regulatory network, we further extracted a KDM4A-9 gene signature enriched with leukemia stem cell activity; the KDM4A-9 score alone or in combination with the known LSC17 score, effectively stratifies high-risk AML patients. Together, these results establish the essential and unique role of KDM4A for AML self-renewal and survival, supporting further investigation of KDM4A and its targets as a potential therapeutic vulnerability in AML.

cancer biology↗