p8 transcription is repressed by the Raf→MEK→ERK pathway. Panc-1 and BxPc-3 were cultivated in 30 mm diameter culture dishes for 24 hours and then transiently transfected with 0.5 μg of p8-CAT and 0.5 μg of pCMV/βgal plasmids. Expression plasmids pcDNA RAF BXB encoding the wild-type RAF, pcDNA RAF 301 K375W encoding a dominant negative RAF, and pcDNAIII HA ERK2 encoding wild-type ERK2 (0.5 μg) were co-transfected with p8-CAT and pCMV/βgal plasmids as indicated. Cell extracts were prepared 24 hours after transfection and CAT and β-galactosidase activities were measured. CAT activity was normalized to β-galactosidase activity. Experiments were carried out in triplicate and repeated two or three times.