Figure 2.

PMPMEase is overexpressed and is hyperactive in lung cancer cells. A. Cultured human lung fibroblasts (WI-38) cells, alveolar adenocarcinoma (A549) cells and non-small cell carcinoma (H460) cells were lysed and assayed for PMPMEase activity using RD-PNB as substrate. The specific activities are expressed as the amount of product formed/h/mg of total protein ± SEM of triplicate determinations. B. Western blot analysis of whole cell lysates showing relative expressions of PMPMEase and GAPDH in normal and lung cancer cells under normal cell culture conditions. C. Cells were treated with varying concentrations of L-28 for 24 h as described in the methods. The viability of the treated cells was determined by fluorescence using the resazurin reduction assay. The results are expressed as the means (± SEM, N = 4) relative to the controls. D. Aliquots of cell lysates were assayed for PMPMEase activity after 3 h incubation at 37°C using RD-PNB as the substrate in the presence of L-28.