A conditionally immortalized human pancreatic beta cell line

Access to an unlimited number of human pancreatic beta cells represents a major challenge in the field of diabetes to better dissect human beta cell functions and to make significant progress in drug discovery and cell replacement therapies. We previously reported the generation of the EndoC-bH1 human beta cell line that was generated by targeted oncogenesis in human fetal pancreases followed by in vivo cell differentiation in mice. Such cell line displayed many functional properties of adult beta cells. Here we devised a novel strategy to generate conditionally immortalized human beta cell lines based on CRE-mediated excision of immortalizing transgenes. The resulting EndoC-bH2 cell line can be massively amplified in vitro. Transgenes are next efficiently excised upon CRE expression leading to cell proliferation arrest and strong enhancement of beta cell specific features such as insulin expression, content and secretion. Excised EndoC-bH2 cells are close to authentic human beta cells and represent a unique tool to further study beta cell function and to understand why adult human beta cells are refractory to proliferation and how to achieve drug-dependent mobilization towards beta cell expansion. Expression profile of human beta cell lineEndoC-bH2 before and after excision of an immortalization cassette (SV40 LT and hTERT) is compared to human exocrine pancreas cell line SKPC and adult human islets from cadaveric donors. Three replicates were used for each sample group. The three adult human islets samples were taken from GEO series GSE40709 (GSM999550, GSM999551 and GSM999552) and normalized with H357 and SKPC cell line samples using RMA.