The present Study was conducted to identify effective factors that could induce differentiation of pancreatic ductal epithelial cells (PDECs) into insulin-producing cells. We examined the effect of hepatocyte growth factor (HGF) and betacellulin-delta 4 (BTC-54) on PDECs. We isolated PDECs from adult rats and stimulated them with HGF and BTC-delta 4 for 28 days. We observed several characteristics of PDECs after induction, including functional changes in PDECs, differentiation rate, and expression levels of critical transcription factors. We observed that insulin content and glucose-induced insulin secretion were significantly higher in induced PDECs compared to control PDECs. The expression of markers specific to mature beta-cells, i.e., insulin and glucose transporter-2 (GLUT2) was also observed. An analysis of the expression of different transcription factors (PDX-1, Ngn3, NeuroD, and Pax4) revealed that cell-specific gene expression patterns varied from 7 to 28 days after treatment. Hence, we conclude that treatment with a combination of HGF and BTC-delta 4 is effective in inducing the differentiation of PDECs into insulin-secreting cells. (C) 2009 Elsevier Inc. All rights reserved.