Overexpression of PRAF3 induces apoptosis of ESCC cells. Eca109 and TE-1 cells were infected with Ad.PRAF3 (or Ad.Null) at a MOI of 100. The expression of PRAF3 and its effect on cell apoptosis were detected at 72 hr post-infection. (A, B) The expression level of PRAF3 mRNA and protein was detected by qRT-PCR and western blot and normalized to that of GAPDH and β-actin, respectively. Histogram showed the expression level of PRAF3 mRNA (A) and protein (B) in Ad.PRAF3 -infected and Ad.Null -infected ESCC cells. (C) Cells were stained with annexin V-FITC and propidium iodide (PI). Flow cytometric contour plots showed the percentage of stained cells. Histogram showed the percentage of Annexin V+/PI- and Annexin V+/PI+ cells of Ad.PRAF3-infected and Ad.Null-infected ESCC cells. Data represent mean ± SEM from 4 independent experiments; **, P < 0.01 by t test.