Author of

• 20182

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  P3.03 - Chemotherapy/Targeted Therapy (ID 719)

  • Event: WCLC 2017
  • Type: Poster Session with Presenters Present
  • Track: Chemotherapy/Targeted Therapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)

  • 24047

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    P3.03-002 - Histone Deacetylase Inhibition Enhances the Antitumor Activity of a MEK Inhibitor in Lung Cancer Cells Harboring RAS Mutations (ID 7917)

    09:30 - 09:30  |  Author(s): A. Tanimoto
    • Abstract

    Background:
    Non-small-cell lung cancer (NSCLC) can be identified by precise molecular subsets based on genomic alterations that drive tumorigenesis and include mutations in EGFR, KRAS, and various ALK fusions. However, despite effective treatment for EGFR and ALK, promising therapeutics have not been developed for patients with KRAS mutations. Therefore, novel therapeutic strategies for KRAS mutated cancer based on molecular mechanisms are needed to improve their prognosis. It has been reported that one way the RAS-ERK pathway contributes to tumorigenesis is by affecting stability and localization of FOXO3a protein, an important regulator of cell death and the cell cycle.
    
    Method:
    We used NSCLC cells with RAS mutation to evaluate the effect of a MEK inhibitor in combination with a HDAC inhibitor through the expression and localization of FOXO proteins in vitro and in vivo. Protein expression was examined by Western blotting.
    
    Result:
    Combined treatment with a MEK inhibitor and a HDAC inhibitor showed synergistic effects on cell viability of RAS mutated lung cancer cells through activation of FOXOs, with a subsequent increase in BIM and cell cycle inhibitors. Moreover, in a mouse xenograft model, the combination of belinostat and trametinib significantly decreases tumor formation through FOXOs by increasing BIM and increase in cell cycle inhibitors p21 and p27.
    
    Conclusion:
    These findings demonstrate that FOXOs might be one of the critical pathways in RAS driven lung cancer cells, suggesting that the dual molecular targeted therapy for MEK and HDACs may be promising as novel therapeutic strategy in NSCLC with specific populations of RAS mutations.