Epigenetic inactivation of secreted frizzled-related protein 2 in esophageal squamous cell carcinoma

Figure 6 Colony formation assays. A: The representative dishes of transfection with pcDNA3.1V5HisA/secreted frizzled-related protein 2 (SFRP2) or empty vector (pcDNA3.1 V5HisA). Left: colonies formed by control cells. Right: colonies formed by cell strains with stably transfected SFRP2; B: Quantitative analyses of colony formation efficiency. Values are the mean ± SD of at least 3 independent experiments. The relative colony formation efficiency of SFRP2-transfected esophageal squamous cell carcinoma cells were lower than those of mock-transfected cells (^aP < 0.05).