RESUMEN
Reverse transcriptase (RT) is responsible for replicating the HIV-1 genome and is a validated therapeutic target for the treatment of HIV infections. During each cycle of the RT-catalyzed DNA polymerization process, inorganic pyrophosphate is released as the by-product of nucleotide incorporation. Small molecules were identified that act as bioisosteres of pyrophosphate and can selectively freeze the catalytic cycle of HIV-1 RT at the pre-translocated stage of the DNA- or RNA-template-primer-enzyme complex.
Asunto(s)
Difosfatos/farmacología , Transcriptasa Inversa del VIH/antagonistas & inhibidores , Inhibidores de la Transcriptasa Inversa/farmacología , Bibliotecas de Moléculas Pequeñas/farmacología , Biocatálisis , ADN Viral/efectos de los fármacos , ADN Viral/genética , Difosfatos/síntesis química , Difosfatos/química , Relación Dosis-Respuesta a Droga , Transcriptasa Inversa del VIH/genética , Transcriptasa Inversa del VIH/metabolismo , Estructura Molecular , Polimerizacion/efectos de los fármacos , Inhibidores de la Transcriptasa Inversa/síntesis química , Inhibidores de la Transcriptasa Inversa/química , Bibliotecas de Moléculas Pequeñas/síntesis química , Bibliotecas de Moléculas Pequeñas/química , Relación Estructura-ActividadRESUMEN
In order to explore the interactions of bisphosphonate ligands with the active site and an allosteric pocket of the human farnesyl pyrophosphate synthase (hFPPS), substituted indole and azabenzimidazole bisphosphonates were designed as chameleon ligands. NMR and crystallographic studies revealed that these compounds can occupy both sub-pockets of the active site cavity, as well as the allosteric pocket of hFPPS in the presence of the enzyme's Mg(2+) ion cofactor. These results are consistent with the previously proposed hypothesis that the allosteric pocket of hFPPS, located near the active site, plays a feed-back regulatory role for this enzyme.
Asunto(s)
Difosfonatos/metabolismo , Geraniltranstransferasa/química , Geraniltranstransferasa/metabolismo , Sitio Alostérico , Dominio Catalítico , Difosfonatos/química , Humanos , Ligandos , Magnesio/metabolismo , Simulación del Acoplamiento Molecular , Unión ProteicaRESUMEN
ATR is a key kinase in the DNA-damage response (DDR) that is synthetic lethal with several other DDR proteins, making it an attractive target for the treatment of genetically selected solid tumors. Herein we describe the discovery of a novel ATR inhibitor guided by a pharmacophore model to position a key hydrogen bond. Optimization was driven by potency and selectivity over the related kinase mTOR, resulting in the identification of camonsertib (RP-3500) with high potency and excellent ADME properties. Preclinical evaluation focused on the impact of camonsertib on myelosuppression, and an exploration of intermittent dosing schedules to allow recovery of the erythroid compartment and mitigate anemia. Camonsertib is currently undergoing clinical evaluation both as a single agent and in combination with talazoparib, olaparib, niraparib, lunresertib, or gemcitabine (NCT04497116, NCT04972110, NCT04855656). A preliminary recommended phase 2 dose for monotherapy was identified as 160 mg QD given 3 days/week.
Asunto(s)
Neoplasias , Humanos , Proteínas de la Ataxia Telangiectasia Mutada , Neoplasias/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , GemcitabinaRESUMEN
Novel analogues of C-2-substituted thienopyrimidine-based bisphosphonates (C2-ThP-BPs) are described that are potent inhibitors of the human geranylgeranyl pyrophosphate synthase (hGGPPS). Members of this class of compounds induce target-selective apoptosis of multiple myeloma (MM) cells and exhibit antimyeloma activity in vivo. A key structural element of these inhibitors is a linker moiety that connects their (((2-phenylthieno[2,3-d]pyrimidin-4-yl)amino)methylene)bisphosphonic acid core to various side chains. The structural diversity of this linker moiety, as well as the side chains attached to it, was investigated and found to significantly impact the toxicity of these compounds in MM cells. The most potent inhibitor identified was evaluated in mouse and rat for liver toxicity and systemic exposure, respectively, providing further optimism for the potential value of such compounds as human therapeutics.
Asunto(s)
Antineoplásicos/uso terapéutico , Inhibidores Enzimáticos/uso terapéutico , Geranilgeranil-Difosfato Geranilgeraniltransferasa/antagonistas & inhibidores , Mieloma Múltiple/tratamiento farmacológico , Pirimidinas/uso terapéutico , Tiofenos/uso terapéutico , Animales , Antineoplásicos/síntesis química , Antineoplásicos/metabolismo , Antineoplásicos/toxicidad , Células de la Médula Ósea/efectos de los fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/toxicidad , Femenino , Proteínas Fúngicas/antagonistas & inhibidores , Proteínas Fúngicas/metabolismo , Geranilgeranil-Difosfato Geranilgeraniltransferasa/metabolismo , Humanos , Hígado/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Estructura Molecular , Unión Proteica , Pirimidinas/síntesis química , Pirimidinas/metabolismo , Pirimidinas/toxicidad , Ratas , Saccharomyces cerevisiae/enzimología , Relación Estructura-Actividad , Tiofenos/síntesis química , Tiofenos/metabolismo , Tiofenos/toxicidadRESUMEN
Post-translational prenylation of the small GTP-binding proteins (GTPases) is vital to a plethora of biological processes, including cellular proliferation. We have identified a new class of thienopyrimidine-based bisphosphonate (ThP-BP) inhibitors of the human geranylgeranyl pyrophosphate synthase (hGGPPS) that block protein prenylation in multiple myeloma (MM) cells leading to cellular apoptosis. These inhibitors are also effective in blocking the proliferation of other types of cancer cells. We confirmed intracellular target engagement, demonstrated the mechanism of action leading to apoptosis, and determined a direct correlation between apoptosis and intracellular inhibition of hGGPPS. Administration of a ThP-BP inhibitor to a MM mouse model confirmed in vivo downregulation of Rap1A geranylgeranylation and reduction of monoclonal immunoglobulins (M-protein, a biomarker of disease burden) in the serum. These results provide the first proof-of-principle that hGGPPS is a valuable therapeutic target in oncology and more specifically for the treatment of multiple myeloma.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Geranilgeranil-Difosfato Geranilgeraniltransferasa/antagonistas & inhibidores , Mieloma Múltiple/patología , Prenilación de Proteína/efectos de los fármacos , Apoptosis/efectos de los fármacos , Dominio Catalítico , Proliferación Celular/efectos de los fármacos , Inhibidores Enzimáticos/química , Geranilgeranil-Difosfato Geranilgeraniltransferasa/química , Geranilgeranil-Difosfato Geranilgeraniltransferasa/metabolismo , Humanos , Concentración 50 Inhibidora , Modelos Moleculares , Pirimidinas/química , Pirimidinas/farmacología , Proteínas de Unión al GTP rap1/metabolismoRESUMEN
The human farnesyl pyrophosphate synthase (hFPPS), a key regulatory enzyme in the mevalonate pathway, catalyzes the biosynthesis of the C-15 isoprenoid farnesyl pyrophosphate (FPP). FPP plays a crucial role in the post-translational prenylation of small GTPases that perform a plethora of cellular functions. Although hFPPS is a well-established therapeutic target for lytic bone diseases, the currently available bisphosphonate drugs exhibit poor cellular uptake and distribution into nonskeletal tissues. Recent drug discovery efforts have focused primarily on allosteric inhibition of hFPPS and the discovery of non-bisphosphonate drugs for potentially treating nonskeletal diseases. Hit-to-lead optimization of a new series of thienopyrimidine-based monosphosphonates (ThP-MPs) led to the identification of analogs with nanomolar potency in inhibiting hFPPS. Their interactions with the allosteric pocket of the enzyme were characterized by crystallography, and the results provide further insight into the pharmacophore requirements for allosteric inhibition.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Geraniltranstransferasa/antagonistas & inhibidores , Pirimidinas/farmacología , Descubrimiento de Drogas , HumanosRESUMEN
Bisphosphonates can mimic the pyrophosphate leaving group of the nucleotidyl transfer reaction and effectively inhibit RNA/DNA polymerases. In a search of HIV-1 reverse transcriptase (RT) inhibitors, a new chemotype of nonhydrolyzable purine diphosphate mimic was synthesized. A modular synthetic protocol was developed, utilizing 2-amino-6-(methylthio)-4-(trimethylsilyl)nicotinonitrile as the key synthon in the preparation of highly substituted 2-aminonicotinonitriles. These building blocks were subsequently elaborated to the pyrido[2,3-d]pyrimidine bisphosphonates (PYPY-BPs). Biochemical screening identified analogs of PYPY-BPs that inhibit HIV-1 RT-catalyzed DNA synthesis.