OBJECTIVEImmortal cell line of human embryonic esophageal epithelium (SHEE) was induced by E6E7 genes of human papillomavirus (HPV) type 18 in our laboratory. To identify the fully malignant transformation at its 85th passage (SHEE85), the malignant phenotype, tumorigenesis and invasive potency were studied.

METHODThe cultured SHEE85 cells were observed under the light and the electron microscope (EM) for cell morphology, analyzed by flow cytometry for cell cycle. The tumorigenesis was assayed by plating cells in soft-agar and transplanting cells into the nude mice and SCID mice. To detect invasive potency, cells were cultured on amniotic membrane in vitro and transplanted into peritoneal cavity of mice in vivo.

RESULTSSHEE85 cells were crowded in cultivation with different sizes and shapes under light microscope, and displayed proliferative morphology under EM. Proliferative index was 47% with 12% hyperploidy cells in determination of DNA histogram. Many large colonies grew in soft-agar (4%) and the transplanted tumors were found in all 4 nude and 4 SCID mice, with strong invasive potency demonstrated in vitro and in vivo.

CONCLUSIONThe immortal esophageal epithelial cell line induced by HPV18 E6 E7 is derived from a fully malignant transformation with a strong invasive potency at the 85th passage. It is also a reliable model for studying the cellular and molecular mechanisms of carcinogenesis of the esophageal carcinoma.