Effect of TW-37 on pancreatic cancer cell growth. A, dose and time responses of TW-37 on growth of pancreatic cancer cells. Cells were seeded in 96-well plates at 5,000 per well and treated with varied concentrations of TW-37 for different times. After treatment, cell densities were determined by the WST assay. Columns, mean (n = 6) of three independent experiments; bars, SD. *P < 0.05, **P < 0.01, compared with the control. B and C, cell survival of the human pancreatic cancer cell lines BxPC-3 and Colo-357. Cells treated with varied concentrations of TW-37 for 72 h were evaluated by the clonogenic assay. Photomicrographic difference in colony formation in cells untreated and treated with TW-37 (B). There was a significant reduction in the colony formation in BxPC-3 and Colo-357 cells treated with TW-37 compared with control cells (C). P values represent comparisons between cells treated by TW-37 and control using the paired t test.