RESUMO
Glioblastoma (GBM) is a devastating malignancy with few therapeutic options. We identify PRMT5 in an in vivo GBM shRNA screen and show that PRMT5 knockdown or inhibition potently suppresses in vivo GBM tumors, including patient-derived xenografts. Pathway analysis implicates splicing in cellular PRMT5 dependency, and we identify a biomarker that predicts sensitivity to PRMT5 inhibition. We find that PRMT5 deficiency primarily disrupts the removal of detained introns (DIs). This impaired DI splicing affects proliferation genes, whose downregulation coincides with cell cycle defects, senescence and/or apoptosis. We further show that DI programs are evolutionarily conserved and operate during neurogenesis, suggesting that they represent a physiological regulatory mechanism. Collectively, these findings reveal a PRMT5-regulated DI-splicing program as an exploitable cancer vulnerability.
Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , Íntrons , Proteína-Arginina N-Metiltransferases/fisiologia , Animais , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Glioma/tratamento farmacológico , Glioma/genética , Ensaios de Triagem em Larga Escala , Humanos , Isoquinolinas/farmacologia , Camundongos , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Pirimidinas/farmacologia , Splicing de RNARESUMO
In vivo interrogation of the function of genes implicated in tumorigenesis is limited by the need to generate and cross germline mutant mice. Here we describe approaches to model colorectal cancer (CRC) and metastasis, which rely on in situ gene editing and orthotopic organoid transplantation in mice without cancer-predisposing mutations. Autochthonous tumor formation is induced by CRISPR-Cas9-based editing of the Apc and Trp53 tumor suppressor genes in colon epithelial cells and by orthotopic transplantation of Apc-edited colon organoids. ApcΔ/Δ;KrasG12D/+;Trp53Δ/Δ (AKP) mouse colon organoids and human CRC organoids engraft in the distal colon and metastasize to the liver. Finally, we apply the orthotopic transplantation model to characterize the clonal dynamics of Lgr5+ stem cells and demonstrate sequential activation of an oncogene in established colon adenomas. These experimental systems enable rapid in vivo characterization of cancer-associated genes and reproduce the entire spectrum of tumor progression and metastasis.
Assuntos
Neoplasias Colorretais/genética , Modelos Animais de Doenças , Edição de Genes/métodos , Genes Neoplásicos/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/secundário , Transplante de Órgãos/métodos , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Metástase NeoplásicaRESUMO
This corrects the article DOI: 10.1038/nbt.3836.