Fluorescence microscopy of DES-induced morphologic transformation in unfixed, cultured cells

Cultured baby Syrian hamster kidney cells (BHK 21), synchronized with hydroxyurea (HU), were treated with varying amounts of the carcinogen diethylstilbestrol (DES) during the first mitosis. DES-induced morphologic transformation was assessed by fluorescence microscopy of acridine orange, supravitally stained cells. Traditional karyotyping techniques were used to monitor DES-induced aneuploidy in parallel cell cultures. A total of 618 photomicrographs were obtained by systematic manual scanning of three replicate experiments each using three different DES treatment levels and a no DES control. These photomicrographs were randomized and graded blind by three independent observers. Each photomicrograph was graded for cellular morphologic transformation and a judgement as to whether DES treatment had been used. A definite dose-response relationship for both morphologic transformation, as well as for aneuploidy was observed. These findings portend a significance for use of fluorescence microscopy of morphologic transformation of unfixed supravitally stained mammalian cells, for the rapid assessment (24 h or less) of compounds that promote aneuploidization and carcinogenesis.