Expression analyses of TP53 3′UTR variation affecting miR-125b binding in p53-null cells. (A) Schematic representation of the p53 cDNA construct and 3′UTR variants. (B) Western blot of p53 expression in p53-null H1299 cells transfected with p53 constructs. (C) Western blot of p53 expression in p53-null H1299 cells transfected with p53 constructs with or without miR-125b. β-actin was used as a control.