Bouricha, O. | bioRxiv Science

bioRxiv2025

Microenvironmental TGF-β is an early driver of NF1-associated tumour formation

Neurofibromatosis Type 1 (NF1) is a common tumour predisposition syndrome characterised by neurofibromas - Nf1-/- Schwann cell (SC)-derived tumours of peripheral nerves. We and others have shown that Nf1 loss in SCs is insufficient for neurofibroma formation but cooperates with an injury microenvironment to form tumours, but the mechanisms remained unknown. Here, we identify macrophage-secreted TGF-{beta} as the microenvironmental injury signal that is essential for tumourigenesis. Analysis of the earliest stages of neurofibroma formation showed that tumours arise from a population of Nf1-/- SCs that escape the regenerating nerve shortly after injury. Here, they reside in a distinct microenvironment conducive for tumourigenesis, where TGF-{beta} disrupts SC/axonal interactions and SC re-differentiation. Pharmacological inhibition of TGF-{beta} for a short therapeutic window during this early stage inhibited tumour formation, highlighting the potential to normalise Nf1-/- SCs and identifying TGF-{beta} as a potential therapeutic target to both treat and prevent neurofibroma formation.

cell biology↗

bioRxiv2025

Chromosome-Specific Aneuploidy Engineering via dCas9-Induced Centromeric Chromatin Relaxation

Aneuploidy, the gain or loss of chromosomes, is prevalent in both normal and disease conditions, however, experimental approaches to engineer and study aneuploidy remain limited, leaving its functional significance under-characterized. Here, we present CRISPR-Taiji (CRISPRt), an efficient method for inducing chromosome-specific mis-segregation and aneuploidy generation across all 24 human chromosomes via dead Cas9 (dCas9)-induced centromeric chromatin relaxation. Using CRISPRt with scRNA-seq, we generated the first comprehensive transcriptomic alteration landscape of nearly all autosomal aneuploidies at chromosome-arm resolution. This genotype-phenotype map provides causal evidence linking recurrent aneuploidies in clear cell renal cell carcinoma (ccRCC) to molecular and clinical phenotypes observed in patient tumors. Notably, chromosome 3(p) loss, the ccRCC initiating event, specifically drives strong interferon signaling activation, offering novel insights into ccRCC tumorigenesis and immune modulation. Overall, we establish CRISPRt as a simple, efficient and scalable approach for chromosome-specific aneuploidy engineering and characterization in preclinical models to advance aneuploidy research across diverse biological contexts.

genomics↗