Biology subjects

Parrinello, S.

Publications and source records attributed to Parrinello, S..

3 recordsLinked to original sources

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↗