FTI-277 is an inhibitor of farnesyl transferase (FTase); a highly potent Ras CAAX peptidomimetic which antagonizes both H- and K-Ras oncogenic signaling. IC50 value: Target: FTase inhibitor in vitro: Treatment with FTI-277 (20 microM) for 48 h prior to irradiation led to a significant decrease in survival of radioresistant cells expressing the 24-kDa isoform (HeLa 3A) but had no effect on the survival of control cells (HeLa PINA). The radiosensitizing effect of FTI-277 is accompanied by a stimulation of postmitotic cell death in HeLa 3A cells and by a reduction in G(2)/M-phase arrest in both cell types [1]. Treatment of PC-3 cells with GGTI-298 and FTI-277 inhibited migration and invasion in a time- and dose-dependent manner [3]. in vivo: FTI-277 treatment prevented increased PTP-1B and PTEN protein expression in burned mice as compared with vehicle alone. In contrast, FTI-277 did not significantly alter protein expression of PTP-1B and PTEN in sham-burned mice [2].