Glycyrol Alone or in Combination with Gefitinib Is Effective against Gefitinib-Resistant HCC827GR Lung Cancer Cells

Gefitinib has been clinically demonstrated to be effective in the first-line setting for patients with advanced EGFR-mutated non-small cell lung cancer (NSCLC). However, acquired therapeutic resistance to gefitinib almost unavoidably develops, posing a major hurdle for its clinical utilization. Our previous study showed that glycyrol (GC), a representative of coumarin compounds isolated from the medicinal plant licorice, was effective against A549 lung cancer cells in both cell culture and a murine xenograft model. In this follow-up study, we evaluated the effect of glycyrol against gefitinib-resistant NSCLC and its ability to overcome the resistance using gefitinib-resistant HCC827GR cells. Results showed that glycyrol was effective against HCC827GR cells in both in vitro and in vivo. Moreover, glycyrol was able to significantly increase the sensitivity of HCC827GR cells to gefitinib, mechanistically associated with inactivating MET, which is a known important contributor to the resistance of HCC827GR cells to gefitinib. The findings of the present study suggest that glycyrol holds potential to be developed as a novel agent against gefitinib-resistant NSCLC.