DNA-transformed murine teratocarcinoma cells: regulation of expression of simian virus 40 tumor antigen in stem versus differentiated cells.

摘要

Thymidine kinase-deficient (TK-; ATP:thymidine 5'-phosphotransferase, EC 2.7.1.21)F9 teratocarcinoma stem cells have been transformed with a recombinant plasmid genome consisting of the pBR322 genome linked to a herpes simplex virus type 1 thymidine kinase gene (HSV-1 tk) and a simian virus 40 (SV40) genome. A clonal line of stem cells was obtained that contains only one copy of plasmid DNA, which is integrated into murine chromosomal DNA through a site on the pBRR322 genome. The HSV-1 tk gene, which is adjacent to the SV40 genome, is expressed in stem cells, whereas SV40 gene expression is not detectable. If differentiation of these stem cells is induced, the differentiated cells express SV40 early gene products. Thus, we have constructed a stem cell which contains a set of genes (SV40), the expression of which is regulated differently in stem and differentiated cells. This cell line could be used to determine the mechanism of suppression of expression of these genes in stem cells.