Activation of bypass signals such as MET and AXL has been identified as one of possible resistant mechanisms to EGFR-TKI. Since various oncoproteins are dependent on HSP90 for its maturation and stability, we investigated the effect of AUY922, a newly developed HSP90 inhibitor of non-geldanamycin class, in lung cancer cells with MET- and AXL-mediated resistance. We established resistant cell lines with HCC827 harboring the deletion mutation on exon 19 of EGFR gene by long-term exposure to increasing concentrations of gefitnib and erlotinib (designated as HCC827/GR and HCC827/ER, respectively). The resistance of HCC827/GR was mediated by MET activation, whereas AXL activation caused resistance in HCC827/ER. AUY-922 treatment effectively suppressed the proliferation and induced cell death in both resistant cell lines. Accordingly, down-regulation of MET and AXL leading to decreased activation of Akt was noted. The inhibitory effect of AUY-922 on AXL and MET was also confirmed in AXL or MET-transfected LK-2 cells. In addition, AUY-922 led to reduced capability of invasion and migration of resistant cells. AUY-922 was effective to control the tumor growth in xenograft mouse models of HCC827/GR and HCC827/ER. Our study showed AUY-922 is one of promising therapeutic options for the MET- and AXL-mediated resistance to EGFR-TKI in lung cancer.

Citation Format: Jin Kyung Rho, Yun Jung Choi, Seon Ye Kime, Gwang Sup So, Se Hoon Choi, Chang-Min Choi, Jae Cheol Lee. A HSP90 inhibitor, AUY922, is effective to overcome the MET- and AXL-mediated resistance to EGFR-TKI in lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1837. doi:10.1158/1538-7445.AM2014-1837

©2014 American Association for Cancer Research.
2014