| 摘要 |
Human esophageal epithelial cells having replicative capacity in cell culture that is enhanced compared to normal cells and are unable to produce tumors is disclosed. Normal human esophagus tissue from two autopsy specimens was explanted in serum-free medium. Epithelial outgrowths were subscultured, then transfected by strontium phosphate coprecipitation with plasmid pRSV-T consisting of the RSV-LTR promoter and the SV40 large T-antigen gene. The transfected cells formed multilayered colonies within 3-4 weeks, which were transferred and developed into cell strains (HE-451 and HE-457). Both strains grew exponentially for 8-10 weeks, then senesced. After a ''crisis'' of 6-8 months, isolated colonies developed into two lines, HET-1A from HE-457 and HET-2A from HE-451. These have now undergone 143 and 122 population doublings, respectively. Both have epithelial morphology, stain for cytokeratin and the SV40 T-antigen by immunofluorescence, and have remained nontumorigenic in athymic mice for 12 months. The immortalized esophageal lines in serum-free system are useful for investigating the action of putative esophageal carcinogens. |
