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Andrew Godwin

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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
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    • Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall
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      P3.03-13 - Downregulation of miRNA-506 Mediates EGFR-TKI Resistance Through Inducing Sonic Hedgehog Signaling in Non-Small-Cell Lung Cancer Cell Lines (ID 14149)

      12:00 - 13:30  |  Author(s): Andrew Godwin

      • Abstract
      • Slides


      Lung cancer is the leading cause of cancer related mortality among both women and men in the United States and worldwide. Epidermal Growth Factor Receptor (EGFR) mutation predicts response to a tyrosine kinase inhibitor (TKI) of EGFR in approximately 25% of patients. All ANSCLC patients with EGFR mutation eventually develop resistance to EGFR-TKI. The mechanism of resistance is not fully elucidated but majority of the cases is related to emergence of clones with T790M mutation in EGFR, and amplification of MET. Recently, increasing numbers of miRNAs, non-coding RNAs are correlated with the drug resistance indicating that miRNAs may serve as novel targets and/or promising predictive biomarkers for anti-EGFR therapy. In this study, we investigated the role of miRNA-506 in the regulation of Sonic Hedgehog (SHh) in TKI-resistant lung cancer cell lines.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      To generate cell lines resistant to EGFR TKI, HCC4006 cells were exposed to increasing concentrations of erlotinib over 6 months with increasing concentration upto 20 μM. The resultant clones (designated HCC4006 ER1 to HCC4006 ER4), following expansion from single cell. Cell viability was measured by crystal violet staining assay. The expression of miRNA in parental and resistant clones was checked by real-time qRT-PCR. The mRNA and protein expression level of SHh was determined by real-time qRT-PCR and Western blot. Invasive/migratory ability of parental and resistant clones was measured by Boyden chamber assays. EMT and stemness markers were evaluated by Western blot. Single-cell suspensions from pre-treated cells were re-suspended at a density of 500 cells/ml mammocult media in ultralow attachment dishes. Number as well as the size of the tumorosphere/spheroids in specified experimental set-up was monitored and recorded alternate day for 8-10 days.

      4c3880bb027f159e801041b1021e88e8 Result

      The studies demonstrated that miR-506 was downregulated in resistant clone as compared to parental cell lines which promotes significantly the invasive/migratory ability and EMT phenotypes of lung cancer cells through induction of SHh. Interestingly, ectopic expression of miRNA-506 in these resistant cells inhibits SHh signaling and thus reprograms EMT, EGFR-TKI resistance and stemness.

      8eea62084ca7e541d918e823422bd82e Conclusion

      Our data suggest that miR-506 downregulation and induction of SHh are associated with resistance to EGFR-TKI. miR-506 interference and inhibition of SHh pathway are potential therapeutic strategy to reverse resistance to EGFR-TKI in NSCLC with EGFR mutation.


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