Induction of polyploidy in Adenovirus E1-transformed cells by the mitotic inhibitor colcemid

Adenovirus-transformed cells were tested for their ability to synthesize DNA in the presence of cell cycle inhibitory drugs. We show that transformed cells are completely resistant to the mitotic inhibitor colcemid, partly resistant to lovastatin, mimosine, aphidicolin and genistein but not to hydroxyurea or thymidine. When treated with colcemid, AdE1-transformed cells continue to synthesize DNA but do not divide and, therefore, become highly polyploid. This effect is dependent on the presence of both E1A and E1B.