Biology subjects

Menichetti, L.

Publications and source records attributed to Menichetti, L..

3 recordsLinked to original sources

bioRxiv2026

GABAergic Circuit Activation Induces a Therapeutically Responsive State for anti-PD-L1 Immunotherapy in Glioblastoma

Glioblastoma (GBM) disrupts cortical excitatory-inhibitory balance and establishes an immunosuppressive microenvironment that limits therapeutic efficacy. Whether restoring inhibitory signaling can restrain glioma progression and improve responsiveness to immune checkpoint blockade remains unknown. Peritumoral parvalbumin-positive (PV+) interneurons were bidirectionally manipulated by chemogenetics in orthotopic GL261 gliomas to assess tumor growth and neurological function. GABAB signaling was pharmacologically activated with baclofen in GL261 and CT-2A models and combined with anti-PD-L1 blockade in GL261. Therapeutic response, survival, tumor rechallenge, and early myeloid remodeling were evaluated. Human GBM single-cell transcriptomic data were analyzed to examine the relationship between GABAergic and PD-L1 intercellular signaling. PV activation transiently restrained glioma growth, reduced tumor proliferation and preserved cortical function, whereas PV+ silencing increased seizure susceptibility and neurological impairment without accelerating tumor growth. Baclofen monotherapy did not affect survival, whereas its combination with anti-PD-L1 immunotherapy induced complete tumor eradication in 66% of GL261-bearing mice, prolonged survival, and conferred durable protection against tumor rechallenge. Combination therapy also altered the proportions of Arg1+ and CD11c+ cells within the intratumoral F4/80+ compartment. Human single-cell analysis revealed a shared myeloid-centered communication axis linking GABAB and PD-L1 signaling. These findings identify GABAergic signaling as a modulator of GBM progression and demonstrate that combining baclofen with anti-PD-L1 induces durable tumor regression, and prolongs survival in the GL261 model, supporting a neuro-immune framework for combining GABAergic modulation with immunotherapy.

cancer biology↗

bioRxiv2026

Longitudinal per-lesion in vivo imaging reveals allele-dependent resistance evolution in EGFR-mutant lung cancer

Acquired resistance to targeted therapies remains an inevitable outcome in EGFR-mutant non-small cell lung cancer, yet the spatiotemporal dynamics through which resistant clones emerge and evolve in vivo remain incompletely understood. In particular, how distinct oncogenic EGFR alleles shape evolutionary trajectories under therapeutic pressure within native tumor microenvironments remains unclear. Here, we establish a longitudinal in vivo imaging framework to resolve tumor evolution at single-lesion resolution in genetically engineered mouse models (GEMMs) harboring three clinically relevant EGFR mutations: exon 19 deletion (EGFRD19), L858R (EGFRLR), and L858R/T790M (EGFRLT). Using high-resolution micro-computed tomography, three-dimensional reconstruction, and per-lesion volumetric tracking, we quantitatively map tumor growth dynamics, therapeutic response, and resistance emergence over time in individual lesions within the same animal. We find that EGFR alleles impose distinct evolutionary trajectories. EGFRLT -driven tumors exhibit shorter latency and early emergence of lesions with intrinsic resistance to osimertinib. In contrast, EGFRD19 and EGFRLR tumors show slower growth kinetics, more homogeneous initial responses, and delayed acquisition of resistance during prolonged treatment. Importantly, longitudinal per-lesion imaging reveals marked spatial heterogeneity across all genotypes. Within the same lung microenvironment, individual lesions undergo complete regression, sustained response, or progressive growth, reflecting parallel and spatially distinct evolutionary trajectories. These divergent behaviors emerge despite shared systemic therapy and identical host environment, underscoring lesion-intrinsic and genotype-dependent constraints on evolution. Together, these findings identify oncogenic EGFR genotype as a key determinant of the temporal and spatial architecture of resistance evolution under targeted therapy. More broadly, we provide a quantitative framework to resolve tumor evolution in vivo at lesion-level resolution, applicable to dissecting spatiotemporal dynamics of tumor growth and therapeutic response across oncogene-driven cancers.

cancer biology↗

bioRxiv2025

The two sides of resistance: aggressiveness and mitotic instability as the Achilles heel of Osimertinib-resistant NSCLC

Non-small cell lung cancer (NSCLC) represents majority of lung cancer cases and remains a leading cause of cancer mortality worldwide. Tumors carrying activating mutations in the epidermal growth factor receptor (EGFR) are highly sensitive to EGFR tyrosine kinase inhibitors (TKIs), with third-generation inhibitors such as Osimertinib now established as standard of care. However, acquired resistance to Osimertinib inevitably develops, involving both genetic and non-genetic mechanisms, the latter playing a major role in sustaining cellular plasticity and promoting tumor aggressiveness. Among regulators of adaptive programs, the Polycomb protein BMI1 has emerged as a key factor driving stemness, epithelial-to-mesenchymal transition (EMT), and therapy resistance in multiple cancers, yet its role in Osimertinib resistance remains poorly defined. Here, we show that Osimertinib-resistant H1975 cells, which display greater aggressiveness than their parental counterparts, are enriched in BMI1 target genes and mitotic cell-cycle pathways, establishing a dependency on microtubule dynamics and mitotic control. Functionally, BMI1 drives migration, invasiveness, and tumor progression in resistant cells. This mitotic dependency creates a therapeutic vulnerability that can be exploited with Unesbulin (PTC596), a BMI1 inhibitor that destabilizes microtubules and induces mitotic catastrophe, thereby effectively suppressing tumor growth in vitro and in vivo. Our findings establish BMI1 as a central mediator of Osimertinib resistance and provide a mechanistic and therapeutic rationale for targeting BMI1 and mitotic weaknesses in refractory EGFR-mutant NSCLC.

cancer biology↗