Immortalization of EpCAM-positive fetal pancreatic cells by hTERT. (a) shows RT-PCR for hTERT expression after early and late passages of hTERT-FPC. Note the absence of hTERT expression in mature human islets and fetal pancreas, whereas hTERT-FH-B fetal human liver cells expressed hTERT (positive control). (b) shows kinetics of proliferation in primary EpCAM-positive fetal pancreatic cells and hTERT-FPC during culture over up to four weeks, which was 4-6-fold greater in the latter. Asterisks indicate P < 0.05. (c) shows RT-PCR for insulin, which was expressed in mature islets (lane 1), fetal pancreas (lane 2) and primary EpCAM-positive cells during early and late culture (lanes 3 and 4), as well as an early passage (P3) of hTERT-FPC (lane 5) but not in hTERT-FPC after further cell culture (lane 6).