Inhibition of in vitro Tumor Cell Invasion by Transmethylation Inhibitors

Abstract

Three inhibitors of S‐adenosylmethionine‐mediated transmethylation, 5′‐methylthioadenosine (MTA), 2′‐deoxyadenosine and sinefungin, inhibited in vitro invasion by a highly invasive clone (Cl‐30) of rat ascites hepatoma cells, AH 130 (AH cells). Difluoromethylthioadenosine (DFMTA), a non‐metabolizable derivative of MTA, also caused strong inhibition of invasion at concentrations that did not suppress the growth of the tumor cells. Cl‐30 cells precultured in methionine‐depleted medium showed decreased invasiveness. DFMTA was also effective on the invasion by fibrosarcoma, B16 melanoma and human lung carcinoma cell lines.