Figure 5.

pTpT effects on cell proliferation. Normal human keratinocytes (A) and fibroblasts (B) and SCC12F cells (C) were maintained as described. Preconfluent cultures were given fresh medium supplemented with either 100 μM pTpT or diluent. Cells were collected by trypsinization daily and counted by Coulter counter. Values represent averages ± SD of duplicate cultures. Dose response experiments with fibroblasts and SCC12F cells found similar degrees of growth inhibition with pTpT concentrations between 50 μM and 150 μM and lesser inhibition at 25 μM. (D) Cultures of the p53-null H1299 lung carcinoma cell line (17) were given fresh medium supplemented with either 100 μM pTpT or diluent, and cells were collected on consecutive days by trypsinization and counted by Coulter counter. Values represent averages ± SD of duplicate cultures.