Relationship Between NF-κB and Epithelial-to-mesenchymal Transition of Radiation-induced Human Esophageal Carcinoma Cells

Objective To explore the relationship between NF-κB and epithelial-to-mesenchymal transition (EMT) of human esophageal carcinoma cells induced by the radiation.

Methods We irradiated cumulatively human esophageal carcinoma cells Eca109 with 60Gy to get Eca109R60 cells. The radio-resistance was detected by means of a standard colony-formation assay. Cells morphological change was observed under microscope. Meanwhile,Real-time PCR and immunocytochemistry were used to detect the expression level of NF-κB,E-cadherin and Vimentin in esophageal epithelial cell lines Eca109 and Eca109R60,respectively.

Results Eca109R60 cells had EMT-like phenotype and stronger irradiation resistance(IR). In Eca109R60 cells,the expression level of E-cadherin mRNA was significantly down-regulated (P=0.003) . There were significant upregulation in the expression levels of Vimentin and NF-κB mRNA (P=0.004,P=0.004) . It showed a negative correlation between NF-κB and E-cadherin by the correlation analysis. There was not an evident correlation between NF-κB and Vimentin,but a trend to negative correlation. From the result of immunocytochemistry staining,a weaker expression of E-cadherin protein while stronger expression of Vimentin and NF-κB p65 protein were found.

Conclusion  The radio-resistance of human esophageal carcinoma cells Eca109R60 may be regulated through the interaction between EMT and NF-κB signaling pathway.