Figure 4.

C/EBPδ over-expression inhibits clonogenicity in PANC-1 and MIA PaCa-2 cells. (A) Average number of colonies grown out from 100 C/EBPδ-over-expressing or control-transfected PANC-1 cells per well in three independent experiments (N = 21). Lines indicate the mean ± SEM. ** p < 0.005. Out of 2100 control-transfected cells, 356 grew into a colony. Only 205 out of 2100 C/EBPδ over-expressing cells grew out a colony. (B) Histogram and gating of CEBPD-IRES-EGFP-transduced MIA PaCa-2 cells. (C) Western blot showing over-expression of C/EBPδ and eGFP protein after transfection. The uncropped blots are provided in Figure S2. (D) CEBPD and EGFP mRNA expression of CEBPD-IRES-EGFP-transduced cells sorted by EGFP-fluorescence. Quantitative RT-PCR confirmed elevated CEBPD mRNA expression in cells expressing high EGFP mRNA (MIA PaCa-2: R² = 0.9975, * p < 0.05; PANC-1: R² = 0.9724, p = 0.0531). (E) Clonogenic assay of PANC-1 and MIA PaCa-2 cells expressing C/EBPδ at varying levels. (F) C/EBPδ expression correlates with colony formation efficiency. Plotting the number of colonies from Figure 4E against the respective CEBPD mRNA expression shows a dependency of colony formation efficiency on CEBPD levels in PANC-1 and MIA PaCa-2 cells.