Transfection of fetal rat intestinal epithelial cells by viral oncogenes: establishment and characterization of the E1A-immortalized SLC-11 cell line.

Intestinal epithelial cells from 19-day-old rat fetuses underwent electropermeabilization and were successfully transfected by three recombinant plasmids containing the cloned oncogenes from the human adenovirus type 2 early region E1A (SLC-11 cells) and polyoma virus and simian virus 40 large T tumor antigens (SLC-21 and SLC-41 cells). SLC-11 cells were propagated for 21 months in culture (current passage, 76; doubling time, 17 hr) and were immortalized by E1A, as shown by RNA transfer blot (Northern blot) analysis and indirect immunofluorescence of the nuclear oncoproteins. These cells were not tumorigenic in either athymic nude mice or syngeneic Wistar rats and showed a nearly normal karyotype with minimal chromosomal changes. The immortalized epithelial cell line SLC-11 retained several of the phenotypes observed in the parent cells of the intestinal mucosa, including cytoplasmic villin, cytokeratins, enkephalinase, and cell surface receptors sensitive to vasoactive intestinal peptide. It is concluded that immortal SLC-11 cells are a suitable model for studying the proliferation and differentiation of epithelial intestinal cells and analyzing cancer progression in the gastrointestinal tract.