Sporidesmin and gliotoxin induce cell detachment and perturb microfilament structure in cultured liver cells.

Changes in cell morphology and cell adhesion occurred when cultured cells from the rat liver cell strain C3 were exposed to the fungal toxins, sporidesmin or gliotoxin. Both toxins caused loss of attachment of the cells to the plastic of tissue culture plates and this effect was preceded by loss of actin cables. Other changes included cytoplasmic vacuolation and blocked entry into S-phase of the cell cycle. Under these conditions [3H]thymidine incorporation into the cells was also diminished but changes were not detected in the amount of cellular actin, or in the accessibility of cell surface proteins to iodination carried out by the Bolton and Hunter method. The observations suggest that disruption of microfilaments is one of the earliest effects of these toxins on eukaryotic cells.