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Chris Bobba

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    P3.03 - Biology (Not CME Accredited Session) (ID 969)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall
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      P3.03-12 - Cyclic Mechanical Strain and Myoferlin Modulates Lung Adenocarcinoma Cell Proliferation and Erlotinib Resistance (ID 14342)

      12:00 - 13:30  |  Author(s): Chris Bobba

      • Abstract
      • Slides


      Lung cancer patients with mutations in the epithelial growth factor receptor (EGFR) are treated with tyrosine kinase inhibitors (TKI) such as Erlotinib. Although resistance to EGFR-TKI is common, it is not known how biomechanical factors in the lung tumor microenvironment alters resistance. Alveolar epithelial cells experience 15% cyclic strain while increased tumor stiffness result in 40-fold decrease in cyclic strain. However, it is not known if cyclic mechanical strain alters the sensitivity of lung adenocarcinoma cells to EGFR-TKI. Mechanical stretch and silencing a membrane repair protein, myoferlin (MYOF), results in fluidization of the actin cytoskeleton. In this study we investigated how cyclic strain and silencing MYOF modulates EGFR expression and Erlotinib sensitivity in lung adenocarcinoma cells.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      A Flexcell system was used expose human lung adenocarcinoma cells (A549 and H1299) to 0.2Hz cyclic strain (0-15%) for 72h. To knockdown MYOF expression, cells were treated with 30uM siRNA for 24h. Cells were expose to a range of Eroltinib concentrations and a MTT cell proliferation assay was used to determine the concentration require to reduce proliferation by 50% (i.e. IC50). Western blots and immunohistochemistry were used to quantify EGFR expression and localization.

      4c3880bb027f159e801041b1021e88e8 Result

      Increasing the magnitude of cyclic strain caused a dramatic decrease in IC50 for A549 and H1299 cells. Similarly, silencing MYOF lead to a dramatic decrease in IC50 in A549 and H1299 cells. Cyclic strain and MYOF knockdown resulted in both increased EGFR expression and internalization.wclc figure.png

      8eea62084ca7e541d918e823422bd82e Conclusion

      Low levels of cyclic strain in the lung tumor microenvironment lead to increased Erlotinib resistance and exposure to physiologic levels of cyclic strain initiates EGFR signaling and increases Erlotinib sensitivity. This highlights the need for modeling and characterizing the mechanics of the lung tumor microenvironment to investigate how cyclic strain and MYOF expression influence chemosensitivity to other cancer therapeutics.


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