Biology subjects

Ciccaldo, M.

Publications and source records attributed to Ciccaldo, M..

3 recordsLinked to original sources

bioRxiv2025

High Tau Expression Correlates with Reduced Invasion and Prolonged Survival in Ewing Sarcoma

The microtubule-associated protein Tau (encoded by the MAPT gene) is linked to a family of neurodegenerative disorders defined as tauopathies, which are characterized by its brain accumulation in neurofibrillary tangles and neuropil threads. Newly described Tau functions comprise DNA protection, chromatin remodeling, p53 regulation and cell fate modulation, suggesting a role of Tau in oncogenesis. Bioinformatic-supported characterization of Tau in cancer reveals robust expression in bone cancer cells, in particular Ewing sarcoma (EwS) cell lines. EwS is an aggressive cancer caused by a fusion of members of the FET and ETS gene families, primarily EWSR1::FLI1. Here we found that MAPT is a EWSR1::ETS target gene and that higher Tau expression in EwS cells inhibited their migratory and invasive behavior, consistent with a more immobile and proliferative phenotype observed in EwS. Indeed, we report that high Tau expression is associated with improved overall survival of EwS patients. We also show that the sessile but proliferative phenotype of EWSR1::ETS-high cells may result from a modulatory role of Tau on focal adhesion to extracellular matrix proteins. Our data highlight the utility of determining Tau expression as a prognostic factor in EwS as well as the opportunity to target Tau expression as an innovative EwS therapy.

cancer biology↗

bioRxiv2024

A new screening assay reveals that aminoglycoside antibiotics interfere with the Tau/MDM2 interaction

MAPT gene mutations cause some neurodegenerative tauopathies and the MAPT-encoded protein Tau is deposited in neurofibrillary tangles, hallmarks of this disease family. In addition to its canonical function in regulating microtubule dynamics, Tau modulates chromatin compaction, gene expression, and the cellular response to DNA damage. During the DNA damage response, Tau positively modulates P53 by binding to MDM2 thereby preventing P53 inactivation and degradation. The aberrant presence of both MDM2 associated to neurofibrillary tangles and of P53 misfolding in brains affected by neurodegenerative diseases suggests that the sequestration of MDM2 may prevent P53 clearance in tauopathies and so contribute to progressive neuronal dysfunction and death. Following this evidence, a pharmacological inhibition of the Tau/MDM2 interaction may represent a viable strategy to reduce P53-dependent cell damage in brain disorders. With the screening FDA-approved drugs and natural compounds, we discovered that members of the aminoglycoside antibiotic family antagonize the Tau/MDM2 interaction. The use of these reagents may advance the understanding of the implication of the Tau/MDM2/P53 axis in neurodegeneration models. However, their unfavorable pharmacokinetic properties may limit their systemic use when targeting the brain.

cell biology↗

bioRxiv2024

Pharmacological GCase Activity Enhancement Inhibits Tau Accumulation

A slow decline in the autophagy-lysosomal pathway is a hallmark of the normal aging brain. Yet, an acceleration of this cellular function may propel neurodegenerative events. In fact, mutations in genes associated with the autophagy-lysosomal pathway can lead to Parkinsons disease. Also, amyloidogenic protein deposition is observed in lysosomal storage disorders, which are caused by genetic mutations representing risk factors for Parkinsons disease. For example, Gauchers disease GBA1 mutations leading to defects in lysosomal sphingolipid metabolism cause -synuclein accumulation. We observed that increased lysosomal Tau accumulation is found in human dermal fibroblasts engineered for inducible Tau expression. Inhibition of the GBA1 product GCase augmented Tau-dependent lysosomal stress and Tau accumulation. Here, we show increased Tau seed-induced Tau accumulation in Gauchers fibroblasts carrying GBA1 mutations when compared to normal fibroblasts. Pharmacological enhancement of GCase reversed this effect, notably, also in normal fibroblasts. This suggests that boosting GCase activity may represent a therapeutic strategy to slow down aging-dependent lysosomal deficits and brain protein deposition.

cell biology↗