RESUMEN
The combined influence of oncogenic drivers, genomic instability, and/or DNA damage repair deficiencies increases replication stress in cancer. Cells with high replication stress rely on the upregulation of checkpoints like those governed by CHK1 for survival. Previous studies of the CHK1 inhibitor prexasertib demonstrated activity across multiple cancer types. Therefore, we sought to (1) identify markers of prexasertib sensitivity and (2) define the molecular mechanism(s) of intrinsic and acquired resistance using preclinical models representing multiple tumor types. Our findings indicate that while cyclin E dysregulation is a driving mechanism of prexasertib response, biomarkers associated with this aberration lack sufficient predictive power to render them clinically actionable for patient selection. Transcriptome analysis of a pan-cancer cell line panel and in vivo models revealed an association between expression of E2F target genes and prexasertib sensitivity and identified innate immunity genes associated with prexasertib resistance. Functional RNAi studies supported a causal role of replication fork components as modulators of prexasertib response. Mechanisms that protect cells from oncogene-induced replication stress may safeguard tumors from such stress induced by a CHK1 inhibitor, resulting in acquired drug resistance. Furthermore, resistance to prexasertib may be shaped by innate immunity.
RESUMEN
Although Aurora A, B, and C kinases share high sequence similarity, especially within the kinase domain, they function distinctly in cell-cycle progression. Aurora A depletion primarily leads to mitotic spindle formation defects and consequently prometaphase arrest, whereas Aurora B/C inactivation primarily induces polyploidy from cytokinesis failure. Aurora B/C inactivation phenotypes are also epistatic to those of Aurora A, such that the concomitant inactivation of Aurora A and B, or all Aurora isoforms by nonisoform-selective Aurora inhibitors, demonstrates the Aurora B/C-dominant cytokinesis failure and polyploidy phenotypes. Several Aurora inhibitors are in clinical trials for T/B-cell lymphoma, multiple myeloma, leukemia, lung, and breast cancers. Here, we describe an Aurora A-selective inhibitor, LY3295668, which potently inhibits Aurora autophosphorylation and its kinase activity in vitro and in vivo, persistently arrests cancer cells in mitosis, and induces more profound apoptosis than Aurora B or Aurora A/B dual inhibitors without Aurora B inhibition-associated cytokinesis failure and aneuploidy. LY3295668 inhibits the growth of a broad panel of cancer cell lines, including small-cell lung and breast cancer cells. It demonstrates significant efficacy in small-cell lung cancer xenograft and patient-derived tumor preclinical models as a single agent and in combination with standard-of-care agents. LY3295668, as a highly Aurora A-selective inhibitor, may represent a preferred approach to the current pan-Aurora inhibitors as a cancer therapeutic agent.
Asunto(s)
Antineoplásicos/uso terapéutico , Aurora Quinasa A/antagonistas & inhibidores , Mitosis/efectos de los fármacos , Antineoplásicos/farmacología , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Femenino , Células HeLa , Humanos , MasculinoRESUMEN
Abemaciclib, an inhibitor of cyclin dependent kinases 4 and 6 (CDK4/6), has recently been approved for the treatment of hormone receptor-positive breast cancer. In this study, we use murine syngeneic tumor models and in vitro assays to investigate the impact of abemaciclib on T cells, the tumor immune microenvironment and the ability to combine with anti-PD-L1 blockade. Abemaciclib monotherapy resulted in tumor growth delay that was associated with an increased T cell inflammatory signature in tumors. Combination with anti-PD-L1 therapy led to complete tumor regressions and immunological memory, accompanied by enhanced antigen presentation, a T cell inflamed phenotype, and enhanced cell cycle control. In vitro, treatment with abemaciclib resulted in increased activation of human T cells and upregulated expression of antigen presentation genes in MCF-7 breast cancer cells. These data collectively support the clinical investigation of the combination of abemaciclib with agents such as anti-PD-L1 that modulate T cell anti-tumor immunity.
Asunto(s)
Aminopiridinas/uso terapéutico , Bencimidazoles/uso terapéutico , Inhibidor p15 de las Quinasas Dependientes de la Ciclina/uso terapéutico , Inhibidor p18 de las Quinasas Dependientes de la Ciclina/uso terapéutico , Receptor de Muerte Celular Programada 1/metabolismo , Aminopiridinas/farmacología , Bencimidazoles/farmacología , Inhibidor p15 de las Quinasas Dependientes de la Ciclina/farmacología , Inhibidor p18 de las Quinasas Dependientes de la Ciclina/farmacología , Humanos , Microambiente TumoralRESUMEN
Novel substituted indolocarbazoles were synthesized, and their kinase inhibitory capability was evaluated in vitro. 6-Substituted indolocarbazoles 4 were found to be potent and selective D1/CDK4 inhibitors. 4d and 4h exhibited potent and ATP-competitive D1/CDK4 activities with IC50 values of 76 and 42 nM, respectively. Both compounds had high selectivity against the other kinases. These D1/CDK4 inhibitors inhibited tumor cell growth, arrested tumor cells at the G1 phase, and inhibited pRb phosphorylation.
Asunto(s)
Antineoplásicos/síntesis química , Carbazoles/síntesis química , Ciclina D1/metabolismo , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Indoles/síntesis química , Proteínas Proto-Oncogénicas , Antineoplásicos/química , Antineoplásicos/farmacología , Carbazoles/química , Carbazoles/farmacología , División Celular/efectos de los fármacos , Quinasa 4 Dependiente de la Ciclina , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Fase G1/efectos de los fármacos , Humanos , Indoles/química , Indoles/farmacología , Fosforilación , Proteína de Retinoblastoma/metabolismo , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
A novel series of pyrrolo[3,4-c] carbazoles fused with a quinolinyl/isoquinolinyl moiety were synthesized and their D1/CDK4 inhibitory and antiproliferative activity were evaluated. Compound 8H, 14H-isoquinolinyl[6,5-a]-pyrrolo[3,4-c]carbazole-7,9-dione (1d) was found to be a highly potent D1/CDK4 inhibitor with an IC(50) of 69 nM. Compound 1d also inhibited tumor cell growth, arrested tumor cells in G1 phase and inhibited pRb phosphorylation.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Carbazoles/síntesis química , Carbazoles/farmacología , Ciclina D1/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Proteínas Proto-Oncogénicas , Ciclo Celular , Cristalografía por Rayos X , Quinasa 4 Dependiente de la Ciclina , Ciclización , Dimetilsulfóxido , Humanos , Cinética , Fosforilación , Células Tumorales CultivadasRESUMEN
The synthesis of a novel series of 1,7-annulated indolocarbazoles 2 and 16 is described. These compounds were found to be potent cyclin dependent kinase inhibitors with good antiproliferative activity against two human carcinoma cell lines. These inhibitors also arrested tumor cells at the G1 phase and inhibited pRb phosphorylation.
Asunto(s)
Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Indoles/síntesis química , Inhibidores de Proteínas Quinasas/síntesis química , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Línea Celular Tumoral , Quinasas Ciclina-Dependientes/metabolismo , Inhibidores de Crecimiento/síntesis química , Inhibidores de Crecimiento/farmacología , Humanos , Indoles/farmacología , Inhibidores de Proteínas Quinasas/farmacologíaRESUMEN
A series of indolo[2,3-a]pyrrolo[3,4-c]carbazoles and their bis-indolylmaleimides precursors have been prepared in order to compare their activity as D1-CDK4 inhibitors. Both enzymatic and antiproliferative assays have shown that the structurally more constrained indolo[2,3-a]pyrrolo[3,4-c]carbazoles are consistently more active (8-42-fold) in head-to-head comparison with their bis-indolylmaleimides counterparts. Cell-cycle analysis using flow cytometry have also shown that the indolocarbazoles are selective G1 blockers while the bis-indolylmaleimides arrest cells in the G2/M phase.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Carbazoles/síntesis química , Carbazoles/farmacología , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Pirroles/síntesis química , Pirroles/farmacología , División Celular/efectos de los fármacos , Línea Celular Tumoral , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Citometría de Flujo , Humanos , Conformación Molecular , Relación Estructura-ActividadRESUMEN
The synthesis and CDK inhibitory properties of a series of indolo[6,7-a]pyrrolo[3,4-c]carbazoles is reported. In addition to their potent CDK activity, the compounds display antiproliferative activity against two human cancer cell lines. These inhibitors also effect strong G1 arrest in these cell lines and inhibit Rb phosphorylation at Ser780 consistent with inhibition of cyclin D1/CDK4.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Carbazoles/síntesis química , Carbazoles/farmacología , Ciclina D1/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Proteínas Proto-Oncogénicas , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular Tumoral , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Quinasa 4 Dependiente de la Ciclina , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Humanos , Fosforilación , Rubidio/metabolismo , Relación Estructura-ActividadRESUMEN
The synthesis of new analogues of Arcyriaflavin A in which one indole ring is replaced by an aryl or heteroaryl ring is described. These new series of aryl[a]pyrrolo[3,4-c]carbazoles were evaluated as inhibitors of Cyclin D1-CDK4. A potent and selective D1-CDK4 inhibitor, 7a (D1-CDK4 IC(50)=45 nM), has been identified. The potency, selectivity profile against other kinases, and structure-activity relationship (SAR) trends of this class of compounds are discussed.