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Mazzanti, L.

Publications and source records attributed to Mazzanti, L..

3 recordsLinked to original sources

Combined inhibition of AIF/CHCHD4 interaction and GLS1 to exploit metabolic vulnerabilities in pediatric osteosarcoma

Osteosarcoma is a malignant bone tumor with a high risk of metastatic relapse and poor outcomes due to primary and acquired chemoresistance. This highlights the medical need to develop effective targeted approaches to overcome chemoresistance. Recent studies have revealed the roles of metabolic reprogramming and mitochondria-nucleus crosstalk in osteosarcoma progression, indicating the potential of these cellular processes as therapeutic targets. The complex formed by mitochondrial apoptosis-inducing factor (AIF) and coiled-coil-helix-coiled-coil-helix domain-containing protein 4 (CHCHD4) orchestrates the import and oxidative folding of cysteine-rich, nuclear-encoded proteins, thereby regulating key mitochondrial functions and metabolism. Here, we identified mitoxantrone as an inhibitor of the AIF/CHCHD4 mitochondrial import machinery and revealed a new mitoxantrone-induced metabolic vulnerability in some osteosarcoma cell line models, characterized by intracellular glutamine accumulation and an increase in nucleotide synthesis. As a result, synergy was found between mitoxantrone and the glutaminase inhibitor telaglenastat in both in vitro and in vivo osteosarcoma models. Collectively, our findings position the AIF/CHCHD4 complex as a druggable therapeutic target and provide a combination strategy for mitoxantrone/telaglenastat treatment to overcome metabolic adaptations and chemoresistance in osteosarcoma. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/716303v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@1229e58org.highwire.dtl.DTLVardef@1c9af45org.highwire.dtl.DTLVardef@120d2borg.highwire.dtl.DTLVardef@11e8216_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Engineered flavonoid disrupts mitochondrial AIF/CHCHD4 complex for targeted cancer therapy

Oncogenic metabolism depends on multifaceted mechanisms, including bidirectional inter-organelle communication between mitochondria and the nucleus, facilitating cellular adaptation at the transcriptomic, proteomic, and metabolomic levels. The mitochondrial protein complex composed of apoptosis-inducing factor (AIF) and coiled-coil-helix-coiled-coil-helix domain-containing protein 4 (CHCHD4) is essential for this mitochondrio-nuclear communication. The AIF/CHCHD4 complex mediates the mitochondrial import of cysteine-enriched nuclear gene-encoded proteins, thereby adapting the mitochondrial proteome to cellular energy demands. We report the discovery of M30-E05, an engineered flavonoid that binds to the NADH pocket of AIF, preventing its dimerization and disrupting the AIF/CHCHD4 complex. Molecular docking and gel electrophoresis analysis of mitochondrial AIF/CHCHD4 substrates expression confirm this mechanism. In cancer cells, M30-E05 reduces the expression of nuclear gene-encoded mitochondrial proteins such as AIF, CHCHD4, COX17, and MICU1. In addition, M30-E05 fragments the mitochondrial network and impairs mitochondrial respiration, causing profound alterations, particularly in lipid and aminoacid metabolism, as revealed by kinetic measurements of oxygen consumption and mass spectrometric metabolomics. Importantly, M30-E05 significantly reduces the viability of a human adult and pediatric osteosarcoma cancer cell panel, including those from patient-derived xenografts (PDX) of osteosarcomas, and induces apoptosis. When orally administered for two weeks to immunodeficient NSG mice, M30-E05 inhibited tumor growth in a subcutaneous PDX xenograft model without apparent toxicity. We anticipate that M30-E05, as a first-in-class metabolic inhibitor, could serve as the lead compound for a new class of targeted antineoplastic agents. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/642976v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1b1add9org.highwire.dtl.DTLVardef@cac7corg.highwire.dtl.DTLVardef@101c9corg.highwire.dtl.DTLVardef@1c6845f_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

Biasing RNA coarse-grained folding simulations with Small--Angle X--ray Scattering (SAXS) data

RNA molecules can easily adopt alternative structures in response to different environmental conditions. As a result, a molecules energy landscape is rough and can exhibits a multitude of deep basins. In the absence of a high-resolution structure, Small Angle X-ray Scattering data (SAXS) can narrow down the conformational space available to the molecule and be used in conjunction with physical modeling to obtain high-resolution putative structures to be further tested by experiments. Because of the low-resolution of this data, it is natural to implement the integration of SAXS data into simulations using a coarse-grained representation of the molecule, allowing for much wider searches and faster evaluation of SAXS theoretical intensity curves than with atomistic models. We present here the theoretical framework and the implementation of a simulation approach based on our coarse-grained model HiRE-RNA combined with SAXS evaluations "on-the-fly" leading the simulation toward conformations agreeing with the scattering data, starting from partially folded structures as the ones that can easily be obtained from secondary structures predictions based tools. We show on three benchmark systems how our approach can successfully achieve high-resolution structures with remarkable similarity with the native structure recovering not only the overall shape, as imposed by SAXS data, but also the details of initially missing base pairs.

biophysics↗