RESUMEN
We describe the asymmetric synthesis of a highly substituted ω-octynoic acid derivative and demonstrate its utility for generating complex macrocycles from unprotected peptides. The molecule harbors an isolated quaternary center that displays four uniquely functionalized arms, each of which can be reacted orthogonally in sequence as the molecule is integrated into peptide structure. These processing sequences entail (1) scaffold ligation, (2) macrocyclization via internal aromatic alkylations or catalyzed etherifications, (3) acyliminium ion mediated embedding of condensed heterocycles, and (4) terminal alkyne derivatization or dimerization reactions. Numerous polycycles are prepared and fully characterized in this study. Factors that influence reaction efficiencies and selectivity are also probed. We construct a novel mimic of the second mitochondria derived activator of caspase using these techniques, wherein subtle variations in macrocycle connectivity have a marked impact on performance. In general, the chemistry is an important step toward facile, systematic access to complex peptidomimetics synthesized by directly altering the structure and properties of machine-made oligomers.
Asunto(s)
Compuestos Macrocíclicos/química , Péptidos/química , CiclizaciónRESUMEN
Castration-resistant prostate cancers (CRPCs) lose sensitivity to androgen-deprivation therapies but frequently remain dependent on oncogenic transcription driven by the androgen receptor (AR) and its splice variants. To discover modulators of AR-variant activity, we used a lysate-based small-molecule microarray assay and identified KI-ARv-03 as an AR-variant complex binder that reduces AR-driven transcription and proliferation in prostate cancer cells. We deduced KI-ARv-03 to be a potent, selective inhibitor of CDK9, an important cofactor for AR, MYC, and other oncogenic transcription factors. Further optimization resulted in KB-0742, an orally bioavailable, selective CDK9 inhibitor with potent anti-tumor activity in CRPC models. In 22Rv1 cells, KB-0742 rapidly downregulates nascent transcription, preferentially depleting short half-life transcripts and AR-driven oncogenic programs. In vivo, oral administration of KB-0742 significantly reduced tumor growth in CRPC, supporting CDK9 inhibition as a promising therapeutic strategy to target AR dependence in CRPC.
Asunto(s)
Antagonistas de Receptores Androgénicos/farmacología , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Receptores Androgénicos/genética , Transcripción Genética/efectos de los fármacos , Antagonistas de Receptores Androgénicos/uso terapéutico , Animales , Línea Celular Tumoral , Quinasa 9 Dependiente de la Ciclina/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Modelos Moleculares , Neoplasias de la Próstata Resistentes a la Castración/genética , Inhibidores de Proteínas Quinasas/uso terapéuticoRESUMEN
The transcription factor Max is a basic-helix-loop-helix leucine zipper (bHLHLZ) protein that forms homodimers or interacts with other bHLHLZ proteins, including Myc and Mxd proteins. Among this dynamic network of interactions, the Myc/Max heterodimer has crucial roles in regulating normal cellular processes, but its transcriptional activity is deregulated in a majority of human cancers. Despite this significance, the arsenal of high-quality chemical probes to interrogate these proteins remains limited. We used small molecule microarrays to identify compounds that bind Max in a mechanistically unbiased manner. We discovered the asymmetric polycyclic lactam, KI-MS2-008, which stabilizes the Max homodimer while reducing Myc protein and Myc-regulated transcript levels. KI-MS2-008 also decreases viable cancer cell growth in a Myc-dependent manner and suppresses tumor growth in vivo. This approach demonstrates the feasibility of modulating Max with small molecules and supports altering Max dimerization as an alternative approach to targeting Myc.
Asunto(s)
Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Lactamas/farmacología , Compuestos Policíclicos/farmacología , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Represoras/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Transcripción Genética/efectos de los fármacos , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/química , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Línea Celular , Dimerización , Modelos Animales de Enfermedad , Humanos , Lactamas/síntesis química , Lactamas/uso terapéutico , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Neoplasias/tratamiento farmacológico , Compuestos Policíclicos/síntesis química , Compuestos Policíclicos/uso terapéutico , Regiones Promotoras Genéticas , Unión Proteica , Proteínas Proto-Oncogénicas c-myc/metabolismo , Ratas , Proteínas Represoras/química , Proteínas Represoras/genética , Bibliotecas de Moléculas Pequeñas/uso terapéutico , Rayos UltravioletaRESUMEN
A Friedel-Crafts alkylation is described that efficiently transforms tryptophan-containing peptides into macrocycles of varying ring connectivity. Factors are surveyed that influence the distribution of regioisomers, with a focus on indole C3-alkylations leading to bridged endo-pyrroloindolines. We probe the stability and stereochemistry of these pyrroloindolines, study their rearrangement to C2-linked indolic macrocycles, and demonstrate a scalable, stereoselective synthesis of this compound class. Placing the macrocyclization in sequence with further template-initiated annulation leads to extraordinary polycyclic products and further demonstrates the potential for this chemistry to drive novel peptidomimetic lead discovery programs.