RET inhibition in novel patient-derived models of RET fusion-positive lung adenocarcinoma reveals a role for MYC upregulation Journal Article


Authors: Hayashi, T.; Odintsov, I.; Smith, R. S.; Ishizawa, K.; Liu, A. J. W.; Delasos, L.; Kurzatkowski, C.; Tai, H.; Gladstone, E.; Vojnic, M.; Kohsaka, S.; Suzawa, K.; Liu, Z.; Kunte, S.; Mattar, M. S.; Khodos, I.; Davare, M. A.; Drilon, A.; Cheng, E.; de Stanchina, E.; Ladanyi, M.; Somwar, R.
Article Title: RET inhibition in novel patient-derived models of RET fusion-positive lung adenocarcinoma reveals a role for MYC upregulation
Abstract: Multi-kinase RET inhibitors, such as cabozantinib and RXDX-105, are active in lung cancer patients with RET fusions; however, the overall response rates to these two drugs are unsatisfactory compared to other targeted therapy paradigms. Moreover, these inhibitors may have different efficacies against RET rearrangements depending on the upstream fusion partner. A comprehensive preclinical analysis of the efficacy of RET inhibitors is lacking due to a paucity of disease models harboring RET rearrangements. Here, we generated two new patient-derived xenograft (PDX) models, one new patient-derived cell line, one PDX-derived cell line, and several isogenic cell lines with RET fusions. Using these models, we re-examined the efficacy and mechanism of action of cabozantinib and found that this RET inhibitor was effective at blocking growth of cell lines, activating caspase 3/7 and inhibiting activation of ERK and AKT. Cabozantinib treatment of mice bearing RET fusion-positive cell line xenografts and two PDXs significantly reduced tumor proliferation without adverse toxicity. Moreover, cabozantinib was effective at reducing growth of a lung cancer PDX that was not responsive to RXDX-105. Transcriptomic analysis of lung tumors and cell lines with RET alterations showed activation of a MYC signature and this was suppressed by treatment of cell lines with cabozantinib. MYC protein levels were rapidly depleted following cabozantinib treatment. Taken together, our results demonstrate that cabozantinib is an effective agent in preclinical models harboring RET rearrangements with three different 5′ fusion partners (CCDC6, KIF5B and TRIM33). Notably, we identify MYC as a protein that is upregulated by RET expression and downregulated by treatment with cabozantinib, opening up potentially new therapeutic avenues for the combinatorial targetin of RET fusion-driven lung cancers. The novel RET fusion-dependent preclinical models described here represent valuable tools for further refinement of current therapies and the evaluation of novel therapeutic strategies. © 2021. Published by The Company of Biologists Ltd
Keywords: myc; nsclc; ret fusion pdx; ret inhibitor; transcriptome profiling
Journal Title: Disease Models & Mechanisms
Volume: 14
Issue: 2
ISSN: 1754-8403
Publisher: Company of Biologists  
Date Published: 2021-02-01
Start Page: dmm047779
Language: English
DOI: 10.1242/dmm.047779
PUBMED: 33318047
PROVIDER: scopus
PMCID: PMC7888717
DOI/URL:
Notes: Article -- Export Date: 1 April 2021 -- Source: Scopus
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MSK Authors
  1. Marc Ladanyi
    1328 Ladanyi
  2. Romel Somwar
    111 Somwar
  3. Emily H Cheng
    78 Cheng
  4. Alexander Edward Drilon
    633 Drilon
  5. Lukas   Delasos
    14 Delasos
  6. Roger Stephen Smith
    20 Smith
  7. Marissa   Mattar
    57 Mattar
  8. Ken Suzawa
    11 Suzawa
  9. Morana Vojnic
    17 Vojnic
  10. Hui-Chun Tai
    4 Tai
  11. Siddharth Kunte
    8 Kunte
  12. Zebing Liu
    5 Liu