Biology subjects

Casanova, E.

Publications and source records attributed to Casanova, E..

6 recordsLinked to original sources

bioRxiv2026

A cell death screen identifies macrophage-depleting agents with therapeutic potential

Macrophages are critical regulators of inflammation and tissue homeostasis, yet aberrant macrophage activation contributes to a wide spectrum of inflammatory and malignant diseases. Therapeutic strategies that directly reduce macrophage numbers have shown promise, but macrophage survival pathways remain incompletely defined, limiting the development of targeted therapeutic strategies. Here, we establish a high-throughput screening platform to identify small molecule inhibitors that impair macrophage survival. Screening a library of more than 2,000 targeted compounds in a cell survival assay, combined with in silico and in vitro analysis of macrophage specificity, revealed the identification of three potent inhibitors: BIX-01294, GSK-J4, and Masitinib. All three compounds downregulated leukemia inhibitory factor receptor (LIFR), whose inhibition markedly reduced macrophage viability. In vivo, these inhibitors effectively depleted large peritoneal macrophages, ameliorated key symptoms of macrophage activation syndrome (MAS), and suppressed tumor growth in a syngeneic transplanted melanoma model as well as in an autochthonous lung cancer model. Together, these findings identify small molecule-mediated macrophage depletion as a promising therapeutic strategy and establish an experimental approach to uncover regulators of macrophage survival.

immunology↗

bioRxiv2026

Ex vivo stem-like cell families model evolution of glioblastoma therapeutic resistance

Glioblastoma (GBM) arises from stem-like cells (GSCs) that exhibit intrinsic therapeutic resistance and can be positively selected by treatment, rendering recurrent GBM intractable. Mechanistic dissection of therapeutic resistance evolution has been limited by scarce matched primary/recurrent tractable models. To address this gap, we developed "resistant GSC families", a within-patient matched platform that models therapy-driven selection by ex vivo deriving, from the same primary whole GBM, temozolomide (TMZ)- and ionizing radiation (IR)-selected GSCs, alongside a treatment-naive control (CTRL-GSC). This design enables pressure-specific dissection of resistance evolution, separating chemotherapy- and radiotherapy-associated genetic alterations and adaptations that are often confounded in primary-versus-recurrent comparisons. Using this framework, we link TMZ-driven relapse-like states to either mismatch repair (MMR)-dependent stable resistance or O6-methylguanine-DNA methyltransferase (MGMT)-independent drug tolerance, and identify adaptive DNA damage response and cell-cycle changes as a route to increased radioresistance. Across pressures, treatment-emergent GSCs accumulate chromosomal alterations and exhibit adaptive phenotypic remodeling, including increased receptor tyrosine kinase activity. Resistant GSC families represent a model enabling mechanistic studies and hypothesis-driven testing of strategies aimed at preventing or treating GBM recurrence.

cancer biology↗

bioRxiv2024

Multiplex genome editing eliminates the Warburg Effect without impacting growth rate in mammalian cells

The Warburg effect is ubiquitous in proliferative mammalian cells, including cancer cells, but poses challenges for biopharmaceutical production, as lactate accumulation inhibits cell growth and protein production. Previous efforts to eliminate lactate production via knockout have failed in mammalian bioprocessing since lactate dehydrogenase has proven essential. However, here we eliminated the Warburg effect in Chinese hamster ovary (CHO) and HEK293 cells by simultaneously knocking out lactate dehydrogenase and regulators involved in a negative feedback loop that typically inhibits pyruvate conversion to acetyl-CoA. In contrast to long-standing assumptions about the role of aerobic glycolysis, Warburg-null cells maintain wildtype growth rate while producing negligible lactate. Further characterization of Warburg-null CHO cells showed a compensatory increase in oxygen consumption, a near total reliance on oxidative metabolism, and higher cell densities in fed-batch cell culture. These cells remained amenable for production of diverse biotherapeutic proteins, reaching industrially relevant titers and maintaining product glycosylation. Thus, the ability to eliminate the Warburg effect is an important development for biotherapeutic production and provides a tool for investigating a near-universal metabolic phenomenon.

bioengineering↗

bioRxiv2023

High-throughput ligand profile characterization in novel biosensor cell lines expressing seven heterologous olfactory receptors for the detection of volatile plant biomarkers

Agriculturally important crop plants emit a multitude of volatile organic compounds (VOCs), which are excellent indicators of their health status and/or their interaction with pathogens and pests. Here, we present the generation of a novel cellular biosensor panel for the recognition of fungal pathogen-related VOCs we had identified in the field as well as during controlled inoculations of several crop plants. The panel consists of seven stable HEK293 cell lines each expressing a functional Drosophila olfactory receptor as a biosensing element and a genetically encoded fluorescent calcium indicator protein. For high-throughput measurement of odorant binding by the cells, fluorescence response was detected in an automated 384-well microplate reader upon the injection of tester VOCs. Biosensor cell lines were characterized for their reference ligand binding in more detail, then a set of 66 VOCs was profiled on all cell lines over a concentration range of three orders of magnitude (1 M to 100 M). Forty-six VOCs (70%) evoked a response in at least one biosensor cell line and certain VOCs could activate the cell lines already from the nanomolar (ppb) concentration. Interaction profiles mapped in this study will support biosensor development for agricultural applications, but the olfactory receptor proteins may also be purified from these cell lines at sufficient yields for further processing including structure determination or coupling with artificial sensor devices.

molecular biology↗

bioRxiv2018

MTHFD1 is a genetic interactor of BRD4 and links folate metabolism to transcriptional regulation

The histone acetyl-reader BRD4 is an important regulator of chromatin structure and transcription, yet factors modulating its activity have remained elusive. Here we describe two complementary screens for genetic and physical interactors of BRD4, which converge on the folate pathway enzyme MTHFD1. We show that a fraction of MTHFD1 resides in the nucleus, where it is recruited to distinct genomic loci by direct interaction with BRD4. Inhibition of either BRD4 or MTHFD1 results in similar changes in nuclear metabolite composition and gene expression, and pharmacologic inhibitors of the two pathways synergize to impair cancer cell viability in vitro and in vivo. Our finding that MTHFD1 and other metabolic enzymes are chromatin-associated suggests a direct role for nuclear metabolism in the control of gene expression.

cancer biology↗

bioRxiv2017

Non-blocking modulation contributes to sodium channel inhibition by a covalently attached photoreactive riluzole analog

Sodium channel inhibitor drugs decrease pathological hyperactivity in various diseases including pain syndromes, myotonia, arrhythmias, nerve injuries and epilepsies. Inhibiting pathological but not physiological activity, however, is a major challenge in drug development. Sodium channel inhibitors exert their effects by a dual action: they obstruct ion flow (\"block\"), and they alter the energetics of channel opening and closing (\"modulation\"). Ideal drugs would be modulators without blocking effect, because modulation is inherently activity-dependent, therefore selective for pathological hyperactivity. Can block and modulation be separated? It has been difficult to tell, because the effect of modulation is obscured by confromation-dependent association/dissociation of the drug. To eliminate dynamic association/dissociation, we used a photoreactive riluzole analog which could be covalently bound to the channel; and found, unexpectedly, that drug-bound channels could still conduct ions, although with modulated gating. The finding that non-blocking modulation is possible, may open a novel avenue for drug development because non-blocking modulators could be more specific in treating hyperactivity-linked diseases.

pharmacology and toxicology↗