Oncogenic CD44 is essential for pancreatic cancer tumorigenesis: A novel targeted therapeutic strategy

Figure 4 CD44 knockout increases DNA damage and enhances cisplatin-induced DNA cleavage in pancreatic cancer cells. A: DNA damage in pancreatic cells was assessed by the measurement of the protein level of γ-H2AX, a widely used DNA breakage marker, with western blotting. CD44-KO and CD44-expressing Panc-1 cells (Ctrl) were incubated with the anti-cancer drug cisplatin at concentrations of 0-5 μM; B-E: CD44-KO induced an increase in the γ-H2AX level, even in the absence of cisplatin, and further enhanced DNA damage in the presence of cisplatin; F and G: CD44-KO and CD44-expressing Panc-1 cells were first treated with either 0 μM or 5 μM cisplatin for 48 hours, then stained with γ-H2AX-specific antibody and FITC-secondary antibody, and imaged with a confocal microscope (800 ×); red: γ-H2AX, blue: DAPI, Merge: γ-H2AX and DAPI. Data in Figure 4A-E are shown as the mean ± SD of three independent replicates. ^bP < 0.01 vs CD44-NT in an unpaired t test.