Identification of Pigment Epithelium-Derived Factor Protein Forms with Distinct Activities on Tumor Cell Lines
Retina R28 Cell Survival Assays: (a) real-time cell impedance monitoring of PEDF cell survival activity in serum-starved R28 cells in the presence of increasing concentrations of PEDF. The cell index was normalized relative to the cell numbers at the time of PEDF addition. (b) Plot of relative cell numbers quantified based on intracellular ATP content performed at end point (see (a)). (c) Bright field images of R28 cells were taken at end point (48 h) of cells treated with PEDF proteins at concentrations indicated on the top. (d) Plot of relative cell numbers quantified based on intracellular ATP content performed at 48 h. Each point is the average of duplicate wells. Error bars indicate average ± SD.