Biology subjects

Cabrera San Millan, E.

Publications and source records attributed to Cabrera San Millan, E..

4 recordsLinked to original sources

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↗

bioRxiv2025

Deciphering the Role of Acetate in Metabolic Adaptation and Drug Resistance in Non-Small Cell Lung Cancer

Resistance to targeted therapies remains a major challenge in EGFR-mutant non-small cell lung cancer (NSCLC). Here, we describe a novel metabolic adaptation in osimertinib-resistant cells characterized by elevated acetate levels and activation of an unconventional pyruvate-acetaldehyde-acetate (PAA) shunt. Integrated transcriptomic, exometabolomic, and functional analyses reveal suppression of canonical metabolic pathways and upregulation of ALDH2 and ALDH7A1, which mediate the NADP+-dependent oxidation of acetaldehyde to acetate, generating NADPH. This shift supports reducing power essential for biosynthesis and redox balance under conditions of oxidative pentose phosphate inhibition. These metabolic changes promote endurance in resistant cells and rewire the interplay between glycolysis, the pentose phosphate pathway, and the tricarboxylic acid cycle, offering a de novo bypass for anaplerosis and bioenergetics. Systematic metabolite profiling revealed distinct transcriptomic and metabolic signatures distinguishing resistant from parental cells. Together, these findings depict a unique, resistance-driven adaptive metabolic shift, and uncover potential therapeutic vulnerabilities in osimertinib-resistant NSCLC.

biochemistry↗

bioRxiv2025

Reprogramming of Osimertinib-Resistant EGFR-mutant NSCLC: The Pyruvate-Acetaldehyde-Acetate Pathway As a Key Driver of Resistance

Osimertinib (Osi) resistance remains a significant challenge in EGFR mutant non-small-cell lung cancer (NSCLC). This study investigates the metabolic reprogramming associated with Osi resistance, identifying key metabolic vulnerabilities that may be targeted for therapeutic intervention. Employing the EGFR-mutant H1975 parental (Par) cell line and its Osi-resistant (OsiR) counterpart, we integrated transcriptomics, metabolomics, nuclear and mitochondrial genomics, functional assays and bioanalytical techniques, as well as advanced 3D imaging to comprehensively define the resistant phenotype. We found that OsiR cells exhibit mitochondrial dysfunction, including impaired oxidative phosphorylation (OXPHOS), mitochondrial DNA mutations, and altered mitochondrial gene expression. To describe this systems-level characterization, we introduce the concept of mitochondromics, a comprehensive profiling of mitochondrial genomic, transcriptomic, structural, and functional changes contributing to therapeutic resistance. Metabolomic profiling revealed a significant accumulation of glycolytic intermediates (lactate, pyruvate, acetate, and acetaldehyde) in the extracellular medium, indicating a shift toward glycolysis and activation of alternative metabolic pathways, including the Warburg effect. Notably, we identified the pyruvate-acetaldehyde-acetate (PAA) pathway as a functionally repurposed metabolic route that facilitates NADPH production, which is critical for antioxidant defense and anabolic processes in OsiR cells. Additionally, although the pentose phosphate pathway (PPP) is not the primary source of NADPH in OsiR cells, it plays a supporting role in biosynthesis, contributing to the production of amino acids, nucleotides, and vitamins. Altered expression of enzymes involved in glycolysis, the TCA cycle, and both oxidative and non-oxidative arms of the PPP further supports an adaptive metabolic network promoting cell growth and resistance to Osi. This study reveals a complex metabolic reprogramming in Osi-resistant EGFR-mutant NSCLC, where a newly identified role for the PAA pathway, alongside integrated mitochondromic alterations emerges as key driver of resistance. These insights uncover potential metabolic vulnerabilities of Osi-resistant tumors and provide a foundation for developing therapeutic strategies to counteract resistance and improve osimertinib efficacy. Targeting these metabolic pathways may offer promising avenues for overcoming resistance in clinical settings.

cancer biology↗