Synergistic Effect of Geranylgeranyltransferase Inhibitor, GGTI, and Docetaxel on the Growth of Prostate Cancer Cells
Figure 4
Combined effect of GGT and docetaxel. (a) Cells were exposed to GGTI (1 μM) in combination with docetaxel (10-10 M). Following 72 h incubation, the cell growth was determined. Lane 1: control, lane 2: GGTI, lane 3: docetaxel, and lane 4: GGTI and docetaxel. (b) Cells were incubated in the serial concentrations of GGTI, docetaxel, or combination of those agents for 72 h. Cell growth was determined, and combination effect was analyzed by isobologram. The individual doses of GGTI and docetaxel to achieve 90% (dotted line) growth inhibition (Fa = 0.90), 75% (hyphenated line) growth inhibition (Fa = 0.75), and 50% (straight line) growth inhibition (Fa = 0.50) were plotted on the - and -axes. Combination index values are represented by points above (indicate antagonism between drugs) or below the lines (indicate synergy). (X symbol) ED50, (plus sign) ED75, and (closed circle) ED90.
