RESUMEN
Actin barbed end-binding macrolides have been shown to inhibit cancer cell motility and invasion of extracellular matrix (ECM), evoking their potential utility as therapies for metastatic cancers. Unfortunately, the direct use of these compounds in clinical settings is impeded by their limited natural abundance, challenging total synthesis, and detrimental effects on normal tissues. To develop potent analogues of these compounds that are simpler to synthesize and compatible with cell-specific targeting systems, such as antibodies, we designed over 20 analogues of the acyclic side chain (tail) of the macrolide Mycalolide B. These analogues probed the contributions of four distinct regions of the tail towards the inhibition of actin polymerization and ECM invasion by human lung cancer A549 cells. We observed that two of these regions tolerate considerable substituent variability, and we identified a specific combination of substituents that leads to the optimal inhibition of the ECM invasion activity of A549 cells.
Asunto(s)
Actinas , Neoplasias Pulmonares , Humanos , Macrólidos/farmacología , Movimiento Celular , Invasividad Neoplásica/prevención & controlRESUMEN
Cancer metastasis is a complex process involving highly motile tumor cells that breach tissue barriers, enter the bloodstream and lymphatic system, and disseminate throughout the body as circulating tumor cells. The primary cellular mechanism contributing to these critical events is the reorganization of the actin cytoskeleton. Mycalolide B (MycB) is an actin-targeting marine macrolide that can suppress proliferation, migration, and invasion of breast and ovarian cancer cells at low nanomolar doses. Through structure-activity relationship studies focused on the actin-binding tail region (C24-C35) of MycB, we identified a potent truncated derivative that inhibits polymerization of G-actin and severs F-actin by binding to actin's barbed end cleft. Biological analyses of this miniature MycB derivative demonstrate that it causes a rapid collapse of the actin cytoskeleton in ovarian cancer cells and impairs cancer cell motility and invasion of the extracellular matrix (ECM) by inhibiting invadopodia-mediated ECM degradation. These studies provide essential proof-of-principle for developing actin-targeting therapeutic agents to block cancer metastasis and establish a synthetically tractable barbed end-binding pharmacophore that can be further improved by adding targeting groups for precision drug design.
Asunto(s)
Actinas/antagonistas & inhibidores , Antineoplásicos/farmacología , Matriz Extracelular/efectos de los fármacos , Toxinas Marinas/farmacología , Oxazoles/farmacología , Actinas/metabolismo , Antineoplásicos/síntesis química , Antineoplásicos/química , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Matriz Extracelular/metabolismo , Femenino , Humanos , Toxinas Marinas/síntesis química , Toxinas Marinas/química , Modelos Moleculares , Estructura Molecular , Oxazoles/síntesis química , Oxazoles/química , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
Stem cells display a fundamentally different mechanism of proliferation control when compared to somatic cells. Uncovering these mechanisms would maximize the impact in drug discovery with a higher translational applicability. The unbiased approach used in phenotype-based drug discovery (PDD) programs can offer a unique opportunity to identify such novel biological phenomenon. Here, we describe an integrated phenotypic screening approach, employing a combination of in vitro and in vivo PDD models to identify a small molecule increasing stem cell proliferation. We demonstrate that a combination of both in vitro and in vivo screening models improves hit identification and reproducibility of effects across various PDD models. Using cell viability and colony size phenotype measurement we characterize the structure activity relationship of the lead molecule, and identify that the small molecule inhibits phosphorylation of ERK2 and promotes stem cell proliferation. This study demonstrates a PDD approach that employs combinatorial models to identify compounds promoting stem cell proliferation.
RESUMEN
A divergent approach to obtain a latrunculin family based hybrid macrocyclic toolbox is developed. A practical, stereoselective synthesis of a common substructure present in latrunculin A and latrunculol A was achieved. This was further utilized in the macrocyclic diversity synthesis. The amino acid moiety embedded in the 15-membered macrocyclic ring allows for the exploration of various chiral side chains as one of the diversity sites.
Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Macrólidos/síntesis química , Tiazolidinas/síntesis química , Aminoácidos/química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Diseño de Fármacos , Macrólidos/química , Modelos Moleculares , Estructura Molecular , Tiazolidinas/químicaAsunto(s)
Proteínas/química , Bibliotecas de Moléculas Pequeñas , Proteínas 14-3-3/química , Animales , Proteínas Reguladoras de la Apoptosis/antagonistas & inhibidores , Proteínas HSP90 de Choque Térmico/química , Humanos , Unión Proteica , Proteínas Proto-Oncogénicas c-bcl-2/química , Tubulina (Proteína)/químicaRESUMEN
A highly practical and modular synthesis to obtain a diverse 14-membered ring-based macrocyclic toolbox is achieved. These compounds were further tested in zebrafish assays related to early embryonic development, angiogenesis, and neurogenesis, respectively. 1.4c was identified as an antiangiogenesis agent.
Asunto(s)
Inhibidores de la Angiogénesis/síntesis química , Inhibidores de la Angiogénesis/farmacología , Compuestos Macrocíclicos/síntesis química , Compuestos Macrocíclicos/farmacología , Inhibidores de la Angiogénesis/química , Animales , Diseño de Fármacos , Desarrollo Embrionario/efectos de los fármacos , Femenino , Compuestos Macrocíclicos/química , Estructura Molecular , Morfogénesis/efectos de los fármacos , Neovascularización Patológica , Embarazo , Relación Estructura-Actividad , Pez Cebra/embriologíaRESUMEN
Molecular iodine facilitated the reaction of 5,5-dimethyl-1,3-cyclohexanedione with aromatic aldehydes in iso-propanol affording a variety of 1,8-dioxo-octahydroxanthenes in high yields. Most of the compounds synthesized showed good anti-proliferative properties in vitro against three cancer cell lines and 9-(2-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione possessing a 2-hydroxy phenyl group at C-9 position was found to be promising. Further structure elaboration of the same compound and the crystal structure analysis and hydrogen bonding patterns of another compound that is, 9-(4-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione prepared by using this methodology is presented.