Action of FR901228, a novel antitumor bicyclic depsipeptide produced by Chromobacterium violaceum no. 968, on Ha-ras transformed NIH3T3 cells.

FR901228, a novel antitumor antibiotic, reversed the transformed morphology of the Ha-ras transformants, Ras-1 cells, and inhibited their growth. The reduction of c-myc expression was observed in FR901228-treated Ras-1 cells by RNA dot-blot hybridization. This reduction of c-myc expression and morphological reversion of the transformed cells to normal were correlated with growth inhibition (G0/G1 arrest in cell cycle).