Activation of DCX-promoter-reporter constructs in differentiating NTERA-2 cells. Upon differentiation using retinoic acid, NTERA-2DCX-EGFP clones (B and F), but not the HeLaDCX-EGFP clones, could induce the expression of the DCX-promoter-EGFP reporter (A-H). NTERA-2DCX-EGFP cells inducing the expression of EGFP upon retinoic acid treatment (I), also expressed DCX (J) and frequently Map2 (K). Parallel upregulation of the EGFP reporter and DCX mRNAs (M) and proteins (N) upon retinoic acid differentiation could also be detected in NTERA-2 clones, but not in HeLa clones. Induction of a neurogenic differentiation program following transient transfection of mouse Ngn2 also resulted in a significant induction of DCX-promoter-luciferase reporter in NTERA-2 clones, but not in HeLa clones (O).