One of the major functions of programmed cell death (apoptosis) is the removal of cells that suffered oncogenic mutations, thereby preventing cancerous transformation. By making use of a Double-Headed-EP (DEP) transposon, a P element derivative made in our laboratory, we made an insertional mutagenesis screen in Drosophila melanogaster to identify genes that, when overexpressed, suppress the p53-activated apoptosis. The DEP element has Gal4-activatable, outward-directed UAS promoters at both ends, which can be deleted separately in vivo. In the DEP insertion mutants, we used the GMR-Gal4 driver to induce transcription from both UAS promoters and tested the suppression effect on the apoptotic rough eye phenotype generated by an activated UAS-p53 transgene. By DEP insertions, 7 genes were identified, which suppressed the p53-induced apoptosis. In 4 mutants, the suppression effect resulted from single genes activated by 1 UAS promoter (Pka-R2, Rga, crol, and Spt5). In the other 3 (Orct2, Polr2M, and stg), deleting either UAS promoter eliminated the suppression effect. In qPCR experiments, we found that the genes in the vicinity of the DEP insertion also showed an elevated expression level. This suggested an additive effect of the nearby genes on suppressing apoptosis. In the eukaryotic genomes, there are coexpressed gene clusters. Three of the DEP insertion mutants are included, and 2 are in close vicinity of separate coexpressed gene clusters. This raises the possibility that the activity of some of the genes in these clusters may help the suppression of the apoptotic cell death.

• Klíčová slova
• Drosophila, activating insertional mutagenesis, apoptosis, p53, suppression,
• MeSH
• apoptóza * MeSH
• dominantní geny MeSH
• Drosophila melanogaster * genetika   MeSH
• fenotyp MeSH
• inzerční mutageneze * metody   MeSH
• nádorový supresorový protein p53 * genetika   metabolismus   MeSH
• promotorové oblasti (genetika) MeSH
• proteiny Drosophily * genetika   metabolismus   MeSH
• supresorové geny MeSH
• transpozibilní elementy DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• nádorový supresorový protein p53 * MeSH
• p53 protein, Drosophila MeSH Prohlížeč
• proteiny Drosophily * MeSH
• transpozibilní elementy DNA MeSH

The development of targeted anti-cancer therapies through the study of cancer genomes is intended to increase survival rates and decrease treatment-related toxicity. We treated a transposon-driven, functional genomic mouse model of medulloblastoma with 'humanized' in vivo therapy (microneurosurgical tumour resection followed by multi-fractionated, image-guided radiotherapy). Genetic events in recurrent murine medulloblastoma exhibit a very poor overlap with those in matched murine diagnostic samples (<5%). Whole-genome sequencing of 33 pairs of human diagnostic and post-therapy medulloblastomas demonstrated substantial genetic divergence of the dominant clone after therapy (<12% diagnostic events were retained at recurrence). In both mice and humans, the dominant clone at recurrence arose through clonal selection of a pre-existing minor clone present at diagnosis. Targeted therapy is unlikely to be effective in the absence of the target, therefore our results offer a simple, proximal, and remediable explanation for the failure of prior clinical trials of targeted therapy.

• MeSH
• buněčné klony účinky léků   metabolismus   patologie   MeSH
• cílená molekulární terapie metody   MeSH
• Drosophila melanogaster cytologie   genetika   MeSH
• genom lidský genetika   MeSH
• kraniospinální iradiace MeSH
• lidé MeSH
• lokální recidiva nádoru genetika   patologie   terapie   MeSH
• meduloblastom genetika   patologie   radioterapie   chirurgie   terapie   MeSH
• modely nemocí na zvířatech MeSH
• mutační analýza DNA MeSH
• myši MeSH
• nádory mozečku genetika   patologie   radioterapie   chirurgie   terapie   MeSH
• radioterapie řízená obrazem MeSH
• selekce (genetika) účinky léků   MeSH
• signální transdukce MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH