RESUMO
Lung cancer is the leading cause of cancer death worldwide, with lung adenocarcinoma being the most common subtype. Many oncogenes and tumor suppressor genes are altered in this cancer type, and the discovery of oncogene mutations has led to the development of targeted therapies that have improved clinical outcomes. However, a large fraction of lung adenocarcinomas lacks mutations in known oncogenes, and the genesis and treatment of these oncogene-negative tumors remain enigmatic. Here, we perform iterative in vivo functional screens using quantitative autochthonous mouse model systems to uncover the genetic and biochemical changes that enable efficient lung tumor initiation in the absence of oncogene alterations. Generation of hundreds of diverse combinations of tumor suppressor alterations demonstrates that inactivation of suppressors of the RAS and PI3K pathways drives the development of oncogene-negative lung adenocarcinoma. Human genomic data and histology identified RAS/MAPK and PI3K pathway activation as a common feature of an event in oncogene-negative human lung adenocarcinomas. These Onc-negativeRAS/PI3K tumors and related cell lines are vulnerable to pharmacologic inhibition of these signaling axes. These results transform our understanding of this prevalent yet understudied subtype of lung adenocarcinoma. SIGNIFICANCE: To address the large fraction of lung adenocarcinomas lacking mutations in proto-oncogenes for which targeted therapies are unavailable, this work uncovers driver pathways of oncogene-negative lung adenocarcinomas and demonstrates their therapeutic vulnerabilities.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/genética , Animais , Genes Supressores de Tumor , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Mutação , Oncogenes , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas p21(ras)/genéticaRESUMO
Cre-loxP recombination is widely used for genetic manipulation of the mouse genome. Here, we report generation and characterization of a new Cre line, Stella-Cre, where Cre expression cassette was targeted to the 3' UTR of the Stella locus. Stella is specifically expressed in preimplantation embryos and in the germline. Cre-loxP recombination efficiency in Stella-Cre mice was investigated at several genomic loci including Rosa26, Jak2, and Npm1. At all the loci examined, we observed 100% Cre-loxP recombination efficiency in the embryos and in the germline. Thus, Stella-Cre mice serve as a very efficient deleter line.
Assuntos
Expressão Gênica , Integrases/genética , Recombinação Genética , Proteínas Repressoras/genética , Regiões 3' não Traduzidas/genética , Animais , Sítios de Ligação Microbiológicos/genética , Bacteriófago P1/genética , Blastocisto , Proteínas Cromossômicas não Histona , Embrião de Mamíferos/metabolismo , Feminino , Citometria de Fluxo , Células Germinativas/metabolismo , Integrases/metabolismo , Janus Quinase 2/genética , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Transgênicos , Proteínas Nucleares/genética , Nucleofosmina , Proteínas/genética , RNA não Traduzido , Proteínas Repressoras/metabolismo , beta-Galactosidase/genética , beta-Galactosidase/metabolismoRESUMO
In mammals, members of the tumor necrosis factor (TNF) family play an important role in the regulation of cellular proliferation, differentiation and programmed cell death. We describe isolation and characterization of an orthologous ligand/receptor axis in Drosophila. The ligand, designated Eiger, is a type II membrane glycosylated protein, which can be cleaved at residue 145 and released from the cell surface as a soluble factor, thereby representing the first potential cytokine to be described in Drosophila. Eiger exists in two alternatively spliced isoforms, Eiger long (Eiger-L) and Eiger short (Eiger-s), both of which are expressed throughout development and in the adult. We also describe the isolation and characterization of a novel Drosophila member of the TNF receptor family, designated Wengen, which is a type I membrane protein that can physically interact with the recently described TRAF2 homolog dTRAF2. Both Eiger and Wengen are expressed in distinctive patterns during embryogenesis and Eiger is responsive to genotoxic stress. Forced expression of Eiger-L, Eiger-s or Wengen, caused apoptotic cell death which could be rescued by caspase inhibitors or the JNK phosphatase Puckered. In addition, Eiger-induced cell killing was attenuated by RNAi-mediated suppression of Wengen. Our results illustrate that Eiger and Wengen represent proximal components of an evolutionarily conserved TNF-like signaling pathway in Drosophila.