Effects of (−)-epigallocatechin-3-gallate on EGFR- or Fusion Gene-driven Lung Cancer Cells

(−)-Epigallocatechin-3-gallate (EGCG) has been shown to bind to several receptors including epidermal growth factor receptor (EGFR). EGFR tyrosine kinase inhibitors and anaplastic lymphoma kinase (ALK) inhibitors are effective for non-small cell lung cancers harboring activating EGFR mutations and ALK or c-ros oncogene 1 (ROS1) fusion genes, respectively. We investigated the effects of EGCG on EGFR- or fusion gene-driven lung cancer cells such as PC-9, RPC-9, H1975, H2228 and HCC78. The five cell lines had similar sensitivity to EGCG. Phosphorylated (p)EGFR, pAkt and pErk in PC-9, RPC-9 and H1975 cells were suppressed by EGCG (50 or 100 μM). EGCG also inhibited pALK in H2228, pROS1 in HCC78, and pErk and pAkt in both cell lines. All the xenograft tumors established using the 5 cell lines in EGCG-treated groups were significantly smaller than the tumors in the vehicle-treated groups. The numbers of tumor blood vessels of xenograft tissues in EGCG-treated mice were significantly lower than those in vehicle-treated mice. In conclusion, EGCG may be effective for EGFR-driven lung tumors irrespective of the presence of T790M, and for ALK or ROS1 fusion gene-driven lung tumors.