RESUMO
A novel class of Hsp90 inhibitors, structurally distinct from previously reported scaffolds, was developed from rational design and optimization of a compound library screen hit. These aminoquinazoline derivatives, represented by compound 15 (SNX-6833) or 1-(2-amino-4-methylquinazolin-7-yl)-3,6,6-trimethyl-6,7-dihydro-1H-indol-4(5H)-one, selectively bind to Hsp90 and inhibit its cellular activities at concentrations as low as single digit nanomolar.
Assuntos
Antineoplásicos/síntese química , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Indóis/síntese química , Quinazolinas/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Choque Térmico HSP90/química , Humanos , Indóis/farmacologia , Modelos Moleculares , Ligação Proteica , Quinazolinas/farmacologia , Bibliotecas de Moléculas Pequenas , Relação Estrutura-AtividadeRESUMO
In the course of our Heat Shock 90 program, certain carbazole compounds were identified which had an off-target antiproliferative activity. To understand the off-target activity, we studied one analog with strong activity. We discovered that it had an effect on tubulin polymerization kinetics and was competitive with colchicine. Additional analogs were made, and a number of potent compounds were identified.
Assuntos
Antimitóticos/química , Carbazóis/química , Indóis/química , Antimitóticos/síntese química , Antimitóticos/farmacologia , Carbazóis/síntese química , Carbazóis/farmacologia , Linhagem Celular Tumoral , Colchicina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Indóis/síntese química , Indóis/farmacologia , Tubulina (Proteína)/metabolismoRESUMO
Hsp90 maintains the conformational stability of multiple proteins implicated in oncogenesis and has emerged as a target for chemotherapy. We report here the discovery of a novel small molecule scaffold that inhibits Hsp90. X-ray data show that the scaffold binds competitively at the ATP site on Hsp90. Cellular proliferation and client assays demonstrate that members of the series are able to inhibit Hsp90 at nanomolar concentrations.
Assuntos
Antineoplásicos/farmacologia , Carbazóis/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Trifosfato de Adenosina/química , Antineoplásicos/síntese química , Antineoplásicos/química , Ligação Competitiva , Carbazóis/síntese química , Carbazóis/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Choque Térmico HSP90/química , Humanos , Modelos Moleculares , Estrutura Molecular , Peso Molecular , Bibliotecas de Moléculas Pequenas , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
A chemoproteomics-based drug discovery strategy is presented that utilizes a highly parallel screening platform, encompassing more than 1000 targets, with a focused chemical library prior to target selection. This chemoproteomics-based process enables a data-driven selection of both the biological target and chemical hit after the screen is complete. The methodology has been exemplified for the purine binding proteome (proteins utilizing ATP, NAD, FAD). Screening of an 8000 member library yielded over 1500 unique protein-ligand interactions, which included novel hits for the oncology target Hsp90. The approach, which also provides broad target selectivity information, was used to drive the identification of a potent and orally active Hsp90 inhibitor, SNX-5422, which is currently in phase 1 clinical studies.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Proteínas de Choque Térmico HSP90/metabolismo , Proteômica/métodos , Trifosfato de Adenosina/metabolismo , Administração Oral , Animais , Ligação Competitiva , Ensaios Clínicos Fase I como Assunto , Feminino , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/química , Humanos , Camundongos , Modelos Moleculares , Conformação Molecular , Bibliotecas de Moléculas Pequenas/administração & dosagem , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Especificidade por SubstratoRESUMO
A novel class of heat shock protein 90 (Hsp90) inhibitors was developed from an unbiased screen to identify protein targets for a diverse compound library. These indol-4-one and indazol-4-one derived 2-aminobenzamides showed strong binding affinity to Hsp90, and optimized analogues exhibited nanomolar antiproliferative activity across multiple cancer cell lines. Heat shock protein 70 (Hsp70) induction and specific client protein degradation in cells on treatment with the inhibitors supported Hsp90 inhibition as the mechanism of action. Computational chemistry and X-ray crystallographic analysis of selected member compounds clearly defined the protein-inhibitor interaction and assisted the design of analogues. 4-[6,6-Dimethyl-4-oxo-3-(trifluoromethyl)-4,5,6,7-tetrahydro-1H-indazol-1-yl]-2-[(trans-4-hydroxycyclohexyl)amino]benzamide (SNX-2112, 9) was identified as highly selective and potent (IC(50) Her2 = 11 nM, HT-29 = 3 nM); its prodrug amino-acetic acid 4-[2-carbamoyl-5-(6,6-dimethyl-4-oxo-3-trifluoromethyl-4,5,6,7-tetrahydro-indazol-1-yl)-phenylamino]-cyclohexyl ester methanesulfonate (SNX-5422, 10) was orally bioavailable and efficacious in a broad range of xenograft tumor models (e.g. 67% growth delay in a HT-29 model) and is now in multiple phase I clinical trials.
Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Descoberta de Drogas , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , ortoaminobenzoatos/administração & dosagem , ortoaminobenzoatos/farmacologia , Administração Oral , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios Clínicos como Assunto , Feminino , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacocinética , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Concentração Inibidora 50 , Camundongos , Modelos Moleculares , Conformação Molecular , Pró-Fármacos/farmacocinética , Especificidade por Substrato , ortoaminobenzoatos/química , ortoaminobenzoatos/farmacocinéticaRESUMO
OBJECTIVE: To evaluate the ability of SNX-7081, a novel small molecule inhibitor of Hsp90, to block components of inflammation, including cytokine production, protein kinase activity, and angiogenic signaling. A close analog was evaluated in preclinical in vivo models of rheumatoid arthritis (RA). METHODS: SNX-7081 binding to Hsp90 was characterized in Jurkat cells and RA synovial fibroblasts (RASFs). Inhibition of NF-kappaB nuclear translocation was evaluated in cellular systems, using lipopolysaccharide (LPS), tumor necrosis factor alpha, or interleukin-1beta stimulation. Suppression of cytokine production in THP-1 cells, human umbilical vein endothelial cells, and RASFs was studied. Disruption of MAPK signaling cascades by SNX-7081 following growth factor stimulation was assessed. SNX-7081 was tested in 2 relevant angiogenesis assays: platelet-derived growth factor activation of fibroblasts and LPS-induced nitric oxide (NO) release in J774 macrophages. A close analog, SNX-4414, was evaluated in rat collagen-induced arthritis and adjuvant-induced arthritis, following oral treatment. RESULTS: SNX-7081 showed strong binding affinity to Hsp90 and expected induction of Hsp70. NF-kappaB nuclear translocation was blocked by SNX-7081 at nanomolar concentrations, and cytokine production was potently inhibited. Growth factor activation of ERK and JNK signaling was significantly reduced by SNX-7081. NO production was also sharply inhibited. In animal models, SNX-4414 fully inhibited paw swelling and improved body weight. Scores for inflammation, pannus formation, cartilage damage, and bone resorption returned to normal. CONCLUSION: The present results demonstrate that a small molecule Hsp90 inhibitor can impact inflammatory disease processes. The strong in vivo efficacy observed with SNX-4414 provides preclinical validation for consideration of Hsp90 inhibitors in the treatment of RA.