Table 1

Cell-killing activity of cytotoxic compounds on human tumor cell lines and normal human primary cells

Cells were seeded into 96-well plates at 10,000 cells/well (0.1 ml/well). Various dilutions of the indicated drugs in 0.1 ml were added to the cells. The cultures were then incubated at 37°C for 72 h, at which time, 20 μl of alamar blue solution were added to each well. After an additional 7-h incubation, the plates were read at 570 and 600 nm. EC50s for the cell killing are expressed as the percentage of reduction in cell numbers relative to the media controls. All studies were performed in triplicate. We analyzed other prostate tumor lines (PC3 and DuPRO), but these cells were not sensitive to vinblastine. We also analyzed a number of primary normal human prostate epithelial (NHPE) cells from CAMBREX. These NHPE cells were not sensitive to vinblastine. LNCaP, PSA-producing prostate carcinoma tumor cell line; Colo320, human colorectal adenocarcinoma cell line; T-47D, human breast ductal carcinoma cell line. ND, not determined.

CompoundLNCaPEC50m) for cell killing
NHBENHME
Colo320T47D
Desacetyl-vinblastine0.10.20.15612.5
4-O-Prolyl-desacetyl-vinblastine131.6NDND
Vinblastine-conjugate1.614>50>100>100