Author of

• 11515

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  P2.05 - Poster Session 2 - Preclinical Models of Therapeutics/Imaging (ID 158)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Biology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11542

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    P2.05-027 - Generation and Biological Character Analysis of EGFR-TKI Resistant Cell Line (ID 2030)

    09:30 - 09:30  |  Author(s): Y. Shen
    • Abstract

    Background
    Patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor (EGFR) mutations derive remarkable benefit from treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKIs). But drug-resistant problem appears sequentially and novel therapeutic strategies should be explored to overcome EGFR-TKI resistance. As the first EGFR-TKI in China and the third in world, icotinib shows good efficacy and tolerability in patients with advanced NSCLC. This study aims to establish icotinib resistant cell line-HCC827/IR and analyze it’s biological character for further study of EGFR-TKIs resistance.

    Methods
    HCC827 is a cell line with a deletion in the exon 19 of EGFR gene. HCC827 cells were exposed to increasing concentrations of icotinib (10nM to 20uM). Cells with the ability to grow in 20uM of icotinib were obtained 8 months after the initial drug exposure. The cell proliferation, viability, distribution of cell cycle, EGFR gene sequence (exon 18, 19, 20 and 21), EGFR-TKIs cross-resistance and the response to a histone deacetylases inhibitor (Chidamide, CS055) were evaluated after allowing the cells to grow in drug-free conditions for 2 months.

    Results
    Population doubling time (PDT) of HCC827/IR was not different from HCC827 (32.3±6.0h vs. 36.3±2.4h, P=0.198). In the cell cycle distributions of HCC827/IR, the cell number in G0/G1 phase were decreased (P=0.035), but the cell number in S and G2/M phase had no significant change compared with parent cells (P=0.388 and P=0.205, respectively). The resistance index (RI=HCC827IR~IC50~/ HCC827~IC50~) of HCC827/IR to icotinib was (1.98±0.15)×10[3]. And HCC827/IR cells also showed high resistance to the other two EGFR-TKIs (gefitinib and erlotinib), the RI of gefitinib and erlotinib was (2.36±0.082)×10[3 ]and (1.069±0.004)×10[3], respectively. But, the sequence of EGFR gene did not changed before and after resistance to EGFR-TKIs. In addition, HCC827/IR was sensitive to CS055 (IC~50~=254±32nM).

    Conclusion
    This study successfully established icotinib resistant NSCLC cell line-HCC827/IR. HCC827/IR cells had some different biological characters compared with parent cells and showed high cross-resistance to other EGFR-TKIs, but it was sensitive to CS055. The results could provide experimental reference for clinical application of TKIs and provide cell line model for further study of TKI-resistance.