RESUMO
The first biologically relevant clickable probe related to the antitumor marine lipid jaspineâ B is reported. The concise synthetic route to both enantiomers relied on the supercritical fluid chromatography (SFC) enantiomeric resolution of racemic materials. The eutomeric dextrogyre derivative represents the first jaspineâ B analogue with enhanced cytotoxicity with IC50 down to 30â nm. These enantiomeric probes revealed a chiralitydependent cytoplasmic imaging of U2OS cancer cells by in situ click labeling.
Assuntos
Alcinos/química , Antineoplásicos/química , Corantes Fluorescentes/química , Sondas Moleculares/química , Esfingosina/análogos & derivados , Alcinos/síntese química , Alcinos/toxicidade , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Química Click , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Sondas Moleculares/síntese química , Sondas Moleculares/toxicidade , Esfingosina/síntese química , Esfingosina/toxicidade , EstereoisomerismoRESUMO
Hundreds of cytotoxic natural or synthetic lipidic compounds contain chiral alkynylcarbinol motifs, but the mechanism of action of those potential therapeutic agents remains unknown. Using a genetic screen in haploid human cells, we discovered that the enantiospecific cytotoxicity of numerous terminal alkynylcarbinols, including the highly cytotoxic dialkynylcarbinols, involves a bioactivation by HSD17B11, a short-chain dehydrogenase/reductase (SDR) known to oxidize the C-17 carbinol center of androstan-3-alpha,17-beta-diol to the corresponding ketone. A similar oxidation of dialkynylcarbinols generates dialkynylketones, that we characterize as highly protein-reactive electrophiles. We established that, once bioactivated in cells, the dialkynylcarbinols covalently modify several proteins involved in protein-quality control mechanisms, resulting in their lipoxidation on cysteines and lysines through Michael addition. For some proteins, this triggers their association to cellular membranes and results in endoplasmic reticulum stress, unfolded protein response activation, ubiquitin-proteasome system inhibition and cell death by apoptosis. Finally, as a proof-of-concept, we show that generic lipidic alkynylcarbinols can be devised to be bioactivated by other SDRs, including human RDH11 and HPGD/15-PGDH. Given that the SDR superfamily is one of the largest and most ubiquitous, this unique cytotoxic mechanism-of-action could be widely exploited to treat diseases, in particular cancer, through the design of tailored prodrugs.