AIM:To investigate the correlation between ezrin expressionand invasive phenotype formation in malignantly transformedesophageal epithelial cells.METHODS:The experimental cell line employed in thepresent study was originated form the progressive inductionof a human embryonic esophageal epithelial cell line (SHEE)by the E6E7 genes of human papillomavirus (HPV) type 18.The cells at the 35~(th) passage after induction called SHEEIMMwere in a state of immortalized phase and used as the control,while that of the 85~(th) passage denominated as SHEEMTrepresented the status of cells that were malignantlytransformed.The expression changes of ezrin and its mRNAin both cell passages were respectively analyzed by RT-PCRand Western blot.Invasive phenotype was assessed in vivoby inoculating these cells into the severe combinedimmunodeficient (SCID) mice via subcutaneous andintraperitoneal injection,and in vitro by inoculating them onthe surface of the amnion membranes,which then wasdetermined by light microscopy and scanning electronmicroscopy.RESULTS:Upregulated expression of ezrin protein and itsmRNA was observed in SHEEMT compared with that inSHEEIMM cells.The SHEEMT cells inoculated in SCID micewere observed forming tumor masses in both visceral organsand soft tissues in a period of 40 days with a specialpropensity to invading mesentery and pancreas,but did notexhibit hepatic metastases.Pathologically,these tumor cellsharboring larger nucleus,nucleolus and less cytoplasm couldinfiltrate and destroy adjacent tissues.In the in vitro study,the inoculated SHEEMT cells could grow in cluster on theamniotic epithelial surface and intrude into the amnioticstroma.In contrast,unrestricted growth and invasivenesswere not found in SHEEIMM cells in both in vivo and in vitroexperiment.CONCLUSION:The upregulated ezrin expression is one ofthe important factors that are possibly associated with the invasive phenotype formation in malignantly transformedesophageal epithelial cells. AIM: To investigate the correlation between ezrin expression and invasive phenotype formation in malignantly transforme desophageal epithelial cells. METHODS: The experimental cell line employed in thepresent study was originated form the progressive inductionof a human embryonic esophageal epithelial cell line (SHEE) by theE6E7 genes of human papillomavirus (HPV) type 18. The cells at the 35th (th) passage after induction called SHEEIMMwere in a state of immortalized phase and used as the control, while that of the 85th (th) passage denominated as SHEEMTrepresented the status of cells that were malignantly transformed, the expression changes of ezrin and its mRNA both both cells were respectively analyzed by RT-PCR and Western blot .vasive phenotype was assessed in vivoby inoculating these cells into the severe combined immunodeficient (SCID) mice by subcutaneous and traititoneal injection, and in vitro by inoculating them on the surface of the amnion membranes, which then wasdetermined by lig ht microscopy and scanning electron microscopy .RESULTS: Upregulated expression of ezrin protein and its mRNA was observed in SHEEMT compared with that in SHEEIMM cells. The SHEEMT cells inoculated in SCID micewere observed formation of tumor masses in both visceral organs and soft tissues in a period of 40 days with a special propensity to invading mesentery and pancreas, but did notexhibit hepatic metastases. Pathologically, these tumor cells are larger nucleus, nucleolus and less cytoplasm could infiltrate and destroy adjacent tissues. In the in vitro study, the inoculated SHEEMT cells could grow in cluster on the amniotic epithelial surface and intrude into the amnioticstroma. in contrast, unrestricted growth and invasiveness not found in SHEEIMM cells in both in vivo and in vitro experiment. CONCLUSION: The upregulated ezrin expression is one of the important factors that are associated with the invasive phenotype formation in malignantly transformedesophageal epithelial cells .