[Biological characteristics of human fetal esophageal epithelial cell line immortalized by the E6 and E7 gene of HPV type 18].

OBJECTIVE

Biological features including proliferation, differentiation and cell death of SHEE cell line, an immortalized epithelium of the fetal esophageal epithelium induced by HPV 18 E6E7 AAV, were studied.

METHODS

SHEE cell line being cultured for more than 50 passages, were cultured in 199 growth medium and were examined by light, electron and fluorescence microscopy for growth rate, morphological features and chromosome analysis, by flow cytometry for cell proliferative dynamics, by immunohistochemistry for Ki67 and cytokeratin, and by terminal DNA transferase label (TUNEL) for apoptosis.

RESULTS

At the 20th passage, the SHEE cell remained monolayer, anchorage-dependent and attachment-inhibited growth. The growth curve showed proliferative phase 3-8th days, top-plate phase 9-10th days and attenuative phase after 10th days. Proliferative index(PIx) 34.0%, mitotic index (MI) 2.74% (1.20%-4.80%), apoptotic index (AI) 1.30%-6.90%, chromosome analysis mainly 46 (44-54/nucleus) and DNA distribution in diploidy were calculated and described. The tonofilament expression in cell cytoplasm by electron-microscopy and positive reaction of cytokeratin by immunochemistry showed differentiative character of squamous epithelium. The cell apoptosis occured in the proliferative phase and especially increased in attenuative phase.

CONCLUSION

Of biological behaviors, the SHEE cells are close to the basal cells of their original fetal esophageal mucosa keeping proliferative and differentiative potency. This study suggests that the cell death (including cell apoptosis) may be an important factor in studying of cell growth regulation and it may be an research area for cellular biological behaviors.