Biology subjects

Parrinello, S.

Publications and source records attributed to Parrinello, S..

5 recordsLinked to original sources

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↗

bioRxiv2024

Dynamics of microglia-glioblastoma crosstalk at the far infiltration zone

The interaction of glioblastoma (GB) and microglia is critical due to its implications for tumor progression, immune response modulation, and potential therapeutic strategies. However, the role of microglia in GB pathogenesis remains unclear, especially regarding the in vivo dynamics of their interplay. Performing three-photon imaging in an autochthonous, immunocompetent mouse GB model, we examined tumor/microglia dynamics within previously inaccessible regions at the GB far infiltration zone in the corpus callosum. Initially, microglia increased tissue surveillance upon encountering GB-cells in sparsely infiltrated areas. In contrast, when GB-cell density increased, microglia reduced surveillance, suggesting a biphasic response to tumor invasion. Additionally, microglia were not uniformly attracted to infiltrating GB-cells; only a subset moved directionally toward them within a defined spatial range. This study provides insight into the heterogeneity of the immune response to tumor invasion and the dynamics of microglia-GB interactions in vivo. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=124 SRC="FIGDIR/small/614016v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@24b1d8org.highwire.dtl.DTLVardef@1180609org.highwire.dtl.DTLVardef@346dbforg.highwire.dtl.DTLVardef@1144dd_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2022

Diet suppresses tumour initiation by maintaining quiescence of mutation-bearing neural stem cells

Glioblastoma is thought to originate from neural stem cells (NSCs) of the subventricular zone that acquire genetic alterations. In the adult brain, NSCs are largely quiescent, suggesting that deregulation of quiescence maintenance may be a pre-requisite for tumour initiation. Although inactivation of the tumour suppressor p53 is a frequent event in gliomagenesis, whether, or how, it affects quiescent NSCs (qNSCs) remains unclear. Here we show that p53 maintains quiescence by inducing fatty acid oxidation (FAO) and that acute p53 deletion in qNSCs results in their premature activation to a proliferative state. Mechanistically, this occurs through direct transcriptional induction of PPARGC1a, which in turn activates PPAR to upregulate FAO genes. Strikingly, dietary supplementation with fish oil containing omega-3 fatty acids, natural PPAR ligands, fully restores quiescence of p53-deficient NSCs and delays tumour initiation in a glioblastoma mouse model. Thus, diet can silence glioblastoma driver mutations, with important implications for cancer prevention.

cancer biology↗

bioRxiv2021

Glioblastoma cell fate is differentially regulated by the microenvironments of the tumour bulk and infiltrative margin

Glioblastoma recurrence originates from invasive cells at the tumour margin that escape surgical debulking, but their biology remains poorly understood. Here we generated three somatic mouse models recapitulating the main glioblastoma driver mutations to characterise margin cells. We find that, regardless of genetics, tumours converge on a common set of neural- like cellular states. However, bulk and margin display distinct neurogenic patterns and immune microenvironments. The margin is immune-cold and preferentially follows developmental-like trajectories to produce astrocyte-like cells. In contrast, injury-like programmes dominate in the bulk, are associated with immune infiltration and generate lowly-proliferative injured neural progenitor-like (iNPCs) cells. In vivo label-retention approaches further demonstrate that iNPCs account for a significant proportion of dormant glioblastoma cells and are induced by interferon signalling within T-cell niches. These findings indicate that tumour region is a major determinant of glioblastoma cell fate and therapeutic vulnerabilities identified in bulk may not extend to the margin residuum.

cancer biology↗

bioRxiv2020

The white matter is a pro-differentiative microenvironment for glioblastoma

Glioblastomas are hierarchically organised tumours driven by glioma stem cells that retain partial differentiation potential. Glioma stem cells are maintained in specialised microenvironments, but how they undergo lineage progression outside of these niches remains unclear. Here we identify the white matter as a differentiative niche for glioblastomas with oligodendrocyte lineage competency. Tumour cells in contact with white matter acquire pre-oligodendrocyte-like fate, resulting in decreased proliferation and invasion. Differentiation is a response to white matter injury, which is caused by tumour infiltration itself in a tumoursuppressive feedback loop. Mechanistically, tumour cell differentiation is driven by selective white matter upregulation of SOX10, a master regulator of normal oligodendrogenesis. SOX10 overexpression or treatment with myelination-promoting agents that upregulate endogenous SOX10, mimic this response, leading to white matter-independent pre-oligodendrocyte-like differentiation and tumour suppression in vivo. Thus, glioblastoma recapitulates an injury response and exploiting this latent programme may offer treatment opportunities for a subset of patients.

cancer biology↗