Aphidicolin inhibits cell growth by accumulation of G2 cells

In order to clarify in vivo target(s) of aphidicolin, the cell cycle phase at which normal human diploid cells were accumulated with this drug was examined by flow cytofluorometry. More than 80% of the cells moved through S phase and were accumulated at G2 phase at the drug dose under which growth of the cells was completely inhibited but there was no apparent cell death. On the other hand, at the higher dose, cell detachment occurred through the first entry of the cells to early S phase. Apparently, in vivo effects of aphidicolin are much more complicated than simple inhibition of DNA synthesis.