RESUMEN
PURPOSE: Uterine leiomyosarcoma (LMS) is an aggressive sarcoma and a subset of which exhibits DNA repair defects. Polo-like kinase 4 (PLK4) precisely modulates mitosis, and its inhibition causes chromosome missegregation and increased DNA damage. We hypothesize that PLK4 inhibition is an effective LMS treatment. EXPERIMENTAL DESIGN: Genomic profiling of clinical uterine LMS samples was performed, and homologous recombination (HR) deficiency scores were calculated. A PLK4 inhibitor (CFI-400945) with and without an ataxia telangiectasia mutated (ATM) inhibitor (AZD0156) was tested in vitro on gynecologic sarcoma cell lines SK-UT-1, SKN, and SK-LMS-1. Findings were validated in vivo using the SK-UT-1 xenograft model in the Balb/c nude mouse model. The effects of CFI-400945 were also evaluated in a BRCA2-knockout SK-UT-1 cell line. The mechanisms of DNA repair were analyzed using a DNA damage reporter assay. RESULTS: Uterine LMS had a high HR deficiency score, overexpressed PLK4 mRNA, and displayed mutations in genes responsible for DNA repair. CFI-400945 demonstrated effective antitumor activity in vitro and in vivo. The addition of AZD0156 resulted in drug synergism, largely due to a preference for nonhomologous end-joining DNA repair. Compared with wild-type cells, BRCA2 knockouts were more sensitive to PLK4 inhibition when both HR and nonhomologous end-joining repairs were impaired. CONCLUSIONS: Uterine LMS with DNA repair defects is sensitive to PLK4 inhibition because of the effects of chromosome missegregation and increased DNA damage. Loss-of-function BRCA2 alterations or pharmacologic inhibition of ATM enhanced the efficacy of the PLK4 inhibitor. Genomic profiling of an advanced-stage or recurrent uterine LMS may guide therapy.
Asunto(s)
Daño del ADN , Reparación del ADN , Leiomiosarcoma , Proteínas Serina-Treonina Quinasas , Neoplasias Uterinas , Ensayos Antitumor por Modelo de Xenoinjerto , Femenino , Humanos , Animales , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Leiomiosarcoma/genética , Leiomiosarcoma/tratamiento farmacológico , Leiomiosarcoma/patología , Neoplasias Uterinas/genética , Neoplasias Uterinas/tratamiento farmacológico , Neoplasias Uterinas/patología , Ratones , Línea Celular Tumoral , Reparación del ADN/efectos de los fármacos , Daño del ADN/efectos de los fármacos , Proteínas de la Ataxia Telangiectasia Mutada/antagonistas & inhibidores , Proteínas de la Ataxia Telangiectasia Mutada/genética , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Morfolinas/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Indoles/farmacología , Indoles/uso terapéutico , Piridinas , QuinolinasRESUMEN
Gastric cancer is a heterogeneous disease with diverse molecular and histological subtypes. We performed whole-genome sequencing in 100 tumor-normal pairs, along with DNA copy number, gene expression and methylation profiling, for integrative genomic analysis. We found subtype-specific genetic and epigenetic perturbations and unique mutational signatures. We identified previously known (TP53, ARID1A and CDH1) and new (MUC6, CTNNA2, GLI3, RNF43 and others) significantly mutated driver genes. Specifically, we found RHOA mutations in 14.3% of diffuse-type tumors but not in intestinal-type tumors (P < 0.001). The mutations clustered in recurrent hotspots affecting functional domains and caused defective RHOA signaling, promoting escape from anoikis in organoid cultures. The top perturbed pathways in gastric cancer included adherens junction and focal adhesion, in which RHOA and other mutated genes we identified participate as key players. These findings illustrate a multidimensional and comprehensive genomic landscape that highlights the molecular complexity of gastric cancer and provides a road map to facilitate genome-guided personalized therapy.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Mutación , Neoplasias Gástricas/genética , Uniones Adherentes , Algoritmos , Animales , Metilación de ADN , Análisis Mutacional de ADN , Epigénesis Genética , Femenino , Dosificación de Gen , Perfilación de la Expresión Génica , Variación Genética , Genoma Humano , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteína de Unión al GTP rhoA/genéticaRESUMEN
Gastric cancer is a heterogeneous disease with multiple environmental etiologies and alternative pathways of carcinogenesis. Beyond mutations in TP53, alterations in other genes or pathways account for only small subsets of the disease. We performed exome sequencing of 22 gastric cancer samples and identified previously unreported mutated genes and pathway alterations; in particular, we found genes involved in chromatin modification to be commonly mutated. A downstream validation study confirmed frequent inactivating mutations or protein deficiency of ARID1A, which encodes a member of the SWI-SNF chromatin remodeling family, in 83% of gastric cancers with microsatellite instability (MSI), 73% of those with Epstein-Barr virus (EBV) infection and 11% of those that were not infected with EBV and microsatellite stable (MSS). The mutation spectrum for ARID1A differs between molecular subtypes of gastric cancer, and mutation prevalence is negatively associated with mutations in TP53. Clinically, ARID1A alterations were associated with better prognosis in a stage-independent manner. These results reveal the genomic landscape, and highlight the importance of chromatin remodeling, in the molecular taxonomy of gastric cancer.
