Abstract: [Abstract] Objective To establish the nude mice model of esophageal cancer drug resistant xenograft and explore the mechanism of esophageal cancer drug resistance. Methods 36 nude mice (BALB/c nu/nu, 4 weeks old) were divided into six groups randomly, 6 each group. Nude mice were respectively inoculated with Eca109 or Eca109/ABCG2 cells subcutaneously in the left subscapularis. xenograft nude mice model was established. The experimental groups received ADM (1, 4mg/kg/3d, respectively), for 7 times. The negative control group received saline. ABCG2 mRNA expression level of xenograft was detected by RT-PCR. ABCG2 protein expression level, cell apoptosis and ADM content in cells of xenograft were detected by flow cytometry. Results The model of esophageal cancer xenograft in nude mice was successfully established, the tumorigenic rate was 100%. After the end of experiment, In the same ADM concentration group, volume, weight and ABCG2 expression of transplanted tumor inoculated with Eca109/ABCG2 cells was significantly higher than transplanted tumor inoculated with Eca109 cells (P<0.05), but the cell apoptosis and ADM content was significantly lower(P<0.05). Conclusion The nude mice xenograft inoculated with Eca109/ABCG2 cells model was an ideal animal model of esophageal cancer drug resistance with ABCG2 resistance phenotype, which provided the ideal animal model for researching the relationship between the ABCG2 and drug resistance of esophageal cancer.

Key words: Esophageal squamous cell carcinoma, Flow cytometry, multidrug resistance, ABCG2