Biology subjects

Visconte, V.

Publications and source records attributed to Visconte, V..

3 recordsLinked to original sources

bioRxiv2026

Persistent Malignant Stem Cells Drive Relapse After Transplantation in the Myelodysplastic Neoplasms

The myelodysplastic neoplasms (MDS) are initiated in hematopoietic stem cells (HSCs). Allogeneic transplantation is the only curative treatment, but relapse remains common. To detect rare MDS HSCs, we developed an ultra-low-input DNA sequencing assay and applied it to a multicenter post-transplant cohort. HSC mutation detection preceded relapse by a mean of 98 days and strongly predicted relapse (95.7% vs. 30.3%; hazard ratio, 8.8; P=1.5e-7). Mutations detected only in unfractionated marrow did not predict relapse. We developed methods to measure donor-host HSC chimerism, improving relapse prediction sensitivity. Single-cell protein, DNA, and RNA analyses with mitochondrial lineage tracing confirmed MDS cell enrichment within immunophenotypically- and transcriptionally-defined HSCs, identifying shared ribosomal gene downregulation and candidate mechanisms of venetoclax sensitivity. Venetoclax/azacytidine depleted detectable MDS HSCs in longitudinally evaluated patients. These findings establish that HSC mutation detection predicts post-transplant relapse, provide a rationale for preemptive intervention, and define shared biological features of transplant-resistant MDS HSCs.

cancer biology↗

bioRxiv2026

Multi-hit STAG2 mutations define a high-risk subset of MDS and reveal convergent evolutionary targeting of cohesin

STAG2 is the most frequently mutated cohesin gene in myeloid neoplasms, yet the significance of multiple mutations within this X-linked tumor suppressor remains unknown. We analyzed a cohort of 1,967 adult patients with myeloid neoplasms and identified 233 cases (12%) harboring STAG2 mutations, including 38 cases (16%) with multiple STAG2 hits. Patients with multi-hit STAG2 mutations exhibited increased multilineage dysplasia compared with single-hit cases and experienced inferior overall survival, an effect driven primarily by patients with myelodysplastic syndromes (MDS). To investigate the molecular basis of recurrent STAG2 acquisition, we performed long-read sequencing in representative cases with phaseable STAG2 mutations. In the informative case examined, distinct truncating STAG2 mutations did not co-occur on the same DNA molecule, supporting independent acquisition rather than stepwise allelic inactivation. Cohort-level variant allele frequency patterns were consistent with recurrent evolutionary targeting of STAG2 across related clonal populations. Together, these findings support a model in which multi-hit STAG2 mutations arise through convergent evolution and define a biologically distinct, adverse-risk subset of MDS.

cancer biology↗

bioRxiv2025

Enhanced FLI1 accessibility mediates STAG2-mutant leukemogenesis

Chromatin architecture governs transcriptional output and cell identity; however, how its disruption promotes leukemic transformation remains incompletely understood. Here, we show that loss of the cohesin subunit STAG2 creates a hyper-accessible chromatin landscape that amplifies FLI1 activity and extends its binding to ectopic loci. Using multi-omic analyses in human AML samples, cell lines, and mouse models, we identify chromatin-dependent co-occupancy of FLI1 and Menin, accompanied by amplification of Menin occupancy at non-canonical loci beyond its HOXA/MEIS1 targets. Therapeutically, the aberrant expansion of Menin binding drives an altered response towards Revumenib and activates interferon response pathways, creating a therapeutic vulnerability to Menin inhibition. Functionally, STAG2/NPM1c co-mutation drives a stem cell-like immunophenotype and a fully penetrant leukemia in vivo. Collectively, these findings define a model in which cohesin loss rewires transcription factor occupancy to amplify oncogenic chromatin programs and expose context-specific therapeutic dependencies.

cancer biology↗