RESUMEN
Aberrant activation of MAPK signaling leads to the activation of oncogenic transcriptomes. How MAPK signaling is coupled with the transcriptional response in cancer is not fully understood. In 2 MAPK-activated tumor types, gastrointestinal stromal tumor and melanoma, we found that ETV1 and other Pea3-ETS transcription factors are critical nuclear effectors of MAPK signaling that are regulated through protein stability. Expression of stabilized Pea3-ETS factors can partially rescue the MAPK transcriptome and cell viability after MAPK inhibition. To identify the players involved in this process, we performed a pooled genome-wide RNAi screen using a fluorescence-based ETV1 protein stability sensor and identified COP1, DET1, DDB1, UBE3C, PSMD4, and COP9 signalosome members. COP1 or DET1 loss led to decoupling between MAPK signaling and the downstream transcriptional response, where MAPK inhibition failed to destabilize Pea3 factors and fully inhibit the MAPK transcriptome, thus resulting in decreased sensitivity to MAPK pathway inhibitors. We identified multiple COP1 and DET1 mutations in human tumors that were defective in the degradation of Pea3-ETS factors. Two melanoma patients had de novo DET1 mutations arising after vemurafenib treatment. These observations indicate that MAPK signaling-dependent regulation of Pea3-ETS protein stability is a key signaling node in oncogenesis and therapeutic resistance to MAPK pathway inhibition.
Asunto(s)
Proteínas Portadoras/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Melanoma/metabolismo , Mutación , Proteínas Proto-Oncogénicas c-ets/metabolismo , Transcriptoma/efectos de los fármacos , Ubiquitina-Proteína Ligasas/metabolismo , Vemurafenib/farmacología , Proteínas E1A de Adenovirus/genética , Proteínas E1A de Adenovirus/metabolismo , Animales , Proteínas Portadoras/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Sistema de Señalización de MAP Quinasas/genética , Melanoma/tratamiento farmacológico , Melanoma/genética , Melanoma/patología , Ratones , Ratones SCID , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-ets/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcriptoma/genética , Ubiquitina-Proteína Ligasas/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A substantial fraction of the genome is transcribed in a cell-type-specific manner, producing long non-coding RNAs (lncRNAs), rather than protein-coding transcripts. Here, we systematically characterize transcriptional dynamics during hematopoiesis and in hematological malignancies. Our analysis of annotated and de novo assembled lncRNAs showed many are regulated during differentiation and mis-regulated in disease. We assessed lncRNA function via an in vivo RNAi screen in a model of acute myeloid leukemia. This identified several lncRNAs essential for leukemia maintenance, and found that a number act by promoting leukemia stem cell signatures. Leukemia blasts show a myeloid differentiation phenotype when these lncRNAs were depleted, and our data indicates that this effect is mediated via effects on the MYC oncogene. Bone marrow reconstitutions showed that a lncRNA expressed across all progenitors was required for the myeloid lineage, whereas the other leukemia-induced lncRNAs were dispensable in the normal setting.
Asunto(s)
Diferenciación Celular , Regulación de la Expresión Génica , Hematopoyesis , Leucemia Mieloide Aguda/patología , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Animales , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , RatonesRESUMEN
BACKGROUND: Drosophila melanogaster females show changes in behavior and physiology after mating that are thought to maximize the number of progeny resulting from the most recent copulation. Sperm and seminal fluid proteins induce post-mating changes in females, however, very little is known about the resulting gene expression changes in female head and central nervous system tissues that contribute to the post-mating response. RESULTS: We determined the temporal gene expression changes in female head tissues 0-2, 24, 48 and 72 hours after mating. Females from each time point had a unique post-mating gene expression response, with 72 hours post-mating having the largest number of genes with significant changes in expression. At most time points, genes expressed in the head fat body that encode products involved in metabolism showed a marked change in expression. Additional analysis of gene expression changes in dissected brain tissues 24 hours post-mating revealed changes in transcript abundance of many genes, notably, the reduced transcript abundance of genes that encode ion channels. CONCLUSIONS: Substantial changes occur in the regulation of many genes in female head tissues after mating, which might underlie aspects of the female post-mating response. These results provide new insights into the physiological and metabolic changes that accompany changes in female behaviors.