Gene expression profiling of mouse embryonic stem cell progeny differentiated by Lumelsky's protocol

Successful conversion of embryonic stem (ES) cells into insulin-producing cells has been reported by Lumelsky et al. (Science 2001;292:1389-1394); however, it remains controversial. In this study, we investigated the properties of ES cell progeny-induced differentiation according to Lumelsky's protocol by immunocytochemistry, oligonucleotide microarray and real-time RT-PCR. Insulin-positive cells were observed at stages 3, 4 and 5. Microarray analysis demonstrated upregulation and appearance of some genes involved in pancreatic development but not beta-cell-specific functional genes in cells at stage 5. Similarly, real-time RT-PCR revealed that expression of beta-cell-specific functional genes such as islet amyloid polypeptide, insulin I and II was not increased in cells at stage 5. These results suggest that terminal differentiation of ES cell progeny toward functional pancreatic beta-cell is insufficient. This study also demonstrates the usefulness of multiple time-course expression profiles for validating differentiation fates of ES cell progeny.