A system for transformation of rat liver cells in vitro by acute treatment with aflatoxin.

Aflatoxin B1 (AFB1) induced rat liver cancer is a well studied system of hepatocarcinogenesis. AFB1 has also been used to transform cultured rat liver derived cells in vitro. Cells in culture often have a reduced capacity to metabolise the AFB1 to its active metabolite, and often prolonged periods of exposure to the toxin have to be employed, with a long latency in the appearance of transformed cells in culture. We report here the transformation of a rat liver derived cell line by acute treatment with AFB1. An extrinsic metabolising system of quail microsomes, which convert AFB1 to its epoxide form with high efficiency, was used to activate the AFB1. A dose dependent cytotoxicity was obtained and neoplastic transformation was seen in the higher doses used. The enzyme GGT which has strong association with liver cell transformation both in vivo and in vitro was also elevated in the treated cells.