Fig. 6. Pancreatic differentiation of HPPL. The expression of Pdx1, insulin, glucagon, and lipase was examined by RT-PCR. HPPL before pancreatic differentiation (lane 1) and HPPL depleted of dexamethasone (Dex) and added with retinoic acid (RA) (lane 2) were compared. Adult pancreas (lane 3) and liver (lane 4) were also examined for the expression of these genes as positive and negative controls, respectively. After HPPL became confluent, dexamethasone and insulin/transferrin/selenium (ITS) were eliminated from the culture medium. Then, HPPL were incubated for an additional 5 days with 2 µM RA. Gene expression was examined by RT-PCR. The thermal cycle was repeated 30 times for lipase and GAPDH, 35 times for Pdx1 and insulin, and 40 times for glucagon.