ABSTRACT
BACKGROUND: Insulin like growth factor 2 (IGF2) is an important embryonic mitosis growth promoting factor, whichplays a critical role in the process of maintaining normal cell growth. The gene expression of IGF2 is under epigeneticregulation in the way of genomic imprinting. Imprinting loss of IGF2 is likely to be associated with the abnormaldevelopment of the individual and tumorigenesis.OBJECTIVE: To investigate the effect of imprinting loss of IGF2 gene on the differentiation of mouse embryonic stemcells into islet-like cells.METHODS: Two kinds of mouse embryonic stem cells (SF1-G and SF1-1) were induced to differentiate into islet-likecells in vitro. The expression of Insulin gene was detected by real-time PCR and cell immunofluorescence. Theexpression of IGF2 was detected by the polymerase chain reaction-restriction fragment length polymorphism in the cellsbefore and after induced differentiation. The level of insulin released at terminal differentiation stage was tested by insulinrelease assay in vitro.RESULTS AND CONCLUSION: (1) There was no change in the imprinting state of the two kinds of mouse embryonicstem cells with normal and imprinted IGF-2 gene before and after differentiation. (2) In the induced cells, the expressionlevel of insulin in the SF1-1 group was higher than that in the SF1-G group, although there was no significant differencein the insulin release between the two kinds of cells. (3)The imprinting loss of IGF-2 gene may be related to theup-regulation of insulin mRNA expression in terminal cells during induced differentiation.