Kyse520

The ESCC cell lines, including CaEs-17, TE-1, Eca109, KYSE520, KYSE30, EC9706, and TE-10 were obtained from ATCC. The normal esophageal epithelial cell lines, including HEEC and Het-1A were obtained from Suran biotechnology Co., Ltd (Shanghai, China). All cells were maintained in Dulbecco's Modi ed Eagle Medium supplemented with 10 % fetal bovine serum and 10 % penicillin-streptomycin at 37 °C in a humidi ed incubator containing 5% CO 2 .
Establishment of ADM-resistant cells ADM-resistant cells Eca109/ADM and EC9706/ADM were incubated from parental Eca109 and EC9706 cells under continuous exposure to ADM with gradually increasing concentrations of docetaxel from 5 nM to 200 nM in the culture medium. Brie y, Eca109 and EC9706 cells were incubated rst with 5 nM ADM for 2 days followed by incubation in the absence of ADM until the ADM-sensitive clones died. Then, survivable cells were cultured in the presence of 10 nM Dox. The same procedure was repeated until cells that were viable at 200 nM ADM were obtained. The surviving cells repopulated and after 10 months, the cells dividing freely in 10 nM and 200 nM ADM-containing media were considered as resistant cell lines and labeled as "Eca109/ADM" and "EC9706/ADM," respectively.