RESUMO
The development of new immunomodulatory agents can impact various areas of medicine. In particular, compounds with the ability to modulate innate immunological pathways hold significant unexplored potential. Herein, we report a modular synthetic approach to the macrodiolide natural product (-)-vermiculine, an agent previously shown to possess diverse biological effects, including cytotoxic and immunosuppressive activity. The synthesis allows for a high degree of flexibility in modifying the macrocyclic framework, including the formation of all possible stereoisomers. In total, 18 analogues were prepared. Two analogues with minor structural modifications showed clearly enhanced cancer cell line selectivity and reduced toxicity. Moreover, these compounds possessed broad inhibitory activity against innate immunological pathways in human PBMCs, including the DNA-sensing cGAS-STING pathway. Initial mechanistic characterization suggests a surprising impairment of the STING-TBK1 interaction.
Assuntos
Fatores Imunológicos/farmacologia , Proteínas de Membrana/antagonistas & inibidores , Nucleotidiltransferases/antagonistas & inibidores , DNA/efeitos dos fármacos , DNA/metabolismo , Humanos , Fatores Imunológicos/síntese química , Fatores Imunológicos/química , Lactonas/síntese química , Lactonas/química , Lactonas/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Proteínas de Membrana/metabolismo , Conformação Molecular , Nucleotidiltransferases/metabolismoRESUMO
The presence of heterogeneity in responses to oncolytic virotherapy poses a barrier to clinical effectiveness, as resistance to this treatment can occur through the inhibition of viral spread within the tumor, potentially leading to treatment failures. Here we show that 4-octyl itaconate (4-OI), a chemical derivative of the Krebs cycle-derived metabolite itaconate, enhances oncolytic virotherapy with VSVΔ51 in various models including human and murine resistant cancer cell lines, three-dimensional (3D) patient-derived colon tumoroids and organotypic brain tumor slices. Furthermore, 4-OI in combination with VSVΔ51 improves therapeutic outcomes in a resistant murine colon tumor model. Mechanistically, we find that 4-OI suppresses antiviral immunity in cancer cells through the modification of cysteine residues in MAVS and IKKß independently of the NRF2/KEAP1 axis. We propose that the combination of a metabolite-derived drug with an oncolytic virus agent can greatly improve anticancer therapeutic outcomes by direct interference with the type I IFN and NF-κB-mediated antiviral responses.
Assuntos
Terapia Viral Oncolítica , Vírus Oncolíticos , Succinatos , Animais , Humanos , Terapia Viral Oncolítica/métodos , Succinatos/farmacologia , Camundongos , Linhagem Celular Tumoral , Interferon Tipo I/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Neoplasias do Colo/terapia , Neoplasias do Colo/imunologia , Neoplasias do Colo/tratamento farmacológico , Antivirais/farmacologia , NF-kappa B/metabolismo , Quinase I-kappa B/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Inflamação/tratamento farmacológico , Feminino , Vírus da Estomatite Vesicular Indiana/fisiologia , Vírus da Estomatite Vesicular Indiana/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
Covalently acting compounds experience a strong interest within chemical biology both as molecular probes in studies of fundamental biological mechanisms and/or as novel drug candidates. In this context, the identification of new classes of reactive groups is particularly important as these can expose novel reactivity modes and, consequently, expand the ligandable proteome. Here, we investigated the electrophilic reactivity of the 3-acyl-5-hydroxy-1,5-dihydro-2H-pyrrole-2-one (AHPO) scaffold, a heterocyclic motif that is e.g. present in various bioactive natural products. Our investigations were focused on the compound MT-21 - a simplified structural analogue of the natural product epolactaene - which is known to have both neurotrophic activity and ability to trigger apoptotic cell death. We found that the central N-acyl hemiaminal group of MT-21 can function as an electrophilic centre enabling divergent reactivity with both amine- and thiol-based nucleophiles, which furthermore translated to reactivity with proteins in both cell lysates and live cells. We found that in live cells MT-21 strongly engaged the lipid transport protein fatty acid-binding protein 5 (FABP5) by direct binding to a cysteine residue in the bottom of the ligand binding pocket. Through preparation of a series of MT-21 derivatives, we probed the specificity of this interaction which was found to be strongly dependent on subtle structural changes. Our study suggests that MT-21 may be employed as a tool compound in future studies of the biology of FABP5, which remains incompletely understood. Furthermore, our study has also made clear that other natural products containing the AHPO-motif may likewise possess covalent reactivity and that this property may underlie their biological activity.