Inhibitory Effect of (−)-Epigallocatechin and (−)-Epigallocatechin Gallate against Heregulin β1-Induced Migration/Invasion of the MCF-7 Breast Carcinoma Cell Line

Abstract

Migration/invasion is involved in the multiple steps of metastasis, resulting in a poor prognosis of breast cancer. (−)-Epigallocatechin-3-gallate (EGCG) in green tea inhibits the metastasis of some cancer cell lines. Cell migration/invasion assays using Boyden chambers demonstrated that (−)-epigallocatechin (EGC), another green tea catechin, inhibited heregulin-β1 (HRG)-induced migration/invasion of MCF-7 human breast carcinoma cells to approximately the same extent as EGCG. Assays of cytoskeletal reorganization, Western blotting and immunoprecipitation suggested that EGCG inhibited this migration/invasion by suppressing the HRG-stimulated activation of epidermal growth factor receptor-related protein B2 (ErbB2)/ErbB3/protein kinase B (Akt), whereas EGC did so through pathways including the disruption of the HRG-stimulated activation of ErbB2/ErbB3 but not Akt. EGC, as well as EGCG, could play an important role against the promotion of metastasis of breast cancer cells.