Lung cancer is the leading cause of cancer-associated mortality. Mutations in the EGFR gene are among the most important inducers of lung tumor development, but success of personalized therapies is still limited because of toxicity or developing resistances. We expressed constitutively active EGFR (EGFR CA) exclusively in the airway system of Drosophila melanogaster and performed comprehensive phenotyping. Ectopic expression of EGFR CA induced massive hyper-and metaplasia, leading to early death. We used the lethal phenotype as a readout and screened a library of FDA-approved compounds and found that among the 1,000 compounds, only the tyrosine kinase inhibitors (TKI) afatinib, gefitinib, and ibrutinib rescued lethality in a whole-animal screening approach. Furthermore, we screened the library in the presence of a subtherapeutic afatinib dose and identified bazedoxifene as a synergistically acting compound that rescues EGFRinduced lethality. Our findings highlight the potential of Drosophila-based whole-animal screening approaches not only to identify specific EGFR inhibitors but also to discover compounds that act synergistically with known TKIs. Moreover, we showed that targeting the EGFR together with STAT-signaling is a promising strategy for lung tumor treatment.

Based on this finding, drugs that specifically target the corresponding gene products or associated signaling pathways are currently used as first-and/or second-line therapies. Although these drugs are tailored to the underlying driver mutations, their effectiveness is currently limited due to development of resistance, inefficient delivery or toxicity (Kandoth et al., 2013;Rosell et al., 2012). Therefore, novel compounds or combinations of compounds that specifically target these driver mutations or downstream signaling systems are urgently needed as effective therapeutic options.Animal models of these different lung cancer subtypes, especially tailored transgenic mouse models, are currently an integral part of corresponding research pipelines. Currently, these mouse models are produced in different ways. Here, both the transfer of oncogenes with, e.g., adenoviruses, but also the use of inducible expression systems that limit oncogene expression to the target

<div>Abstract<p>Lung cancer is the leading cause of cancer-associated mortality. Mutations in the <i>EGFR</i> gene are among the most important inducers of lung tumor development, but success of personalized therapies is still limited because of toxicity or developing resistances. We expressed constitutively active EGFR (EGFR^CA) exclusively in the airway system of <i>Drosophila melanogaster</i> and performed comprehensive phenotyping. Ectopic expression of EGFR^CA induced massive hyper- and metaplasia, leading to early death. We used the lethal phenotype as a readout and screened a library of FDA-approved compounds and found that among the 1,000 compounds, only the tyrosine kinase inhibitors (TKI) afatinib, gefitinib, and ibrutinib rescued lethality in a whole-animal screening approach. Furthermore, we screened the library in the presence of a subtherapeutic afatinib dose and identified bazedoxifene as a synergistically acting compound that rescues EGFR-induced lethality. Our findings highlight the potential of <i>Drosophila</i>-based whole-animal screening approaches not only to identify specific EGFR inhibitors but also to discover compounds that act synergistically with known TKIs. Moreover, we showed that targeting the EGFR together with STAT-signaling is a promising strategy for lung tumor treatment.</p></div>

<p>KEGG pathway analysis of differentially transcribed genes between EGFR OE and control airways</p>

<p>Whole animal screening of Drosophila larvae with FDA approved compound</p>