Correlation between adenosine triphosphate (ATP)-binding cassette transporter G2 (ABCG2) and drug resistance of esophageal cancer and reversal of drug resistance by artesunate

The present study investigated the correlation between the abnormal expression of adenosine triphosphate (ATP)-binding cassette transporter G2 (ABCG2) in esophageal cancer and the drug resistance of esophageal cancer, the reversal effect in drug resistance of artesunate (Art), and the mechanism underlying esophageal cancer using nude mice with subcutaneous xenograft as an animal model. The gene and protein expression of ABCG2 was detected in 80 cases of esophageal cancer, atypical dysplasia, and normal mucosa. A subcutaneous xenograft tumor mouse model was established by subcutaneous inoculation of esophageal cancer cell line Eca109/ABCG2 into BALB/c nu/nu nude mice. The reversal of drug resistance by Art in esophageal cancer was studied in vivo. The mice model was injected intraperitoneally with Art and/or doxorubicin (ADM). The animals were divided into six groups: high dose Art (50 mg/kg), low dose Art (25 mg/kg), ADM (1 mg/kg), ADM and high-dose Art, ADM and low-dose Art, and physiological saline as a control. ABCG2 protein expression and cellular ADM concentration were detected by flow cytometry. The mRNA and protein expressions of ABCG2 in esophageal cancer were significantly higher than that in the normal esophagus (P < 0.01). The volume and mass of the subcutaneously implanted tumors in the ADM+Art high- and low-dose groups were significantly decreased than that in the control group (P < 0.05), while the apoptosis rate of tumor cells and the cellular concentration of ADM were increased significantly (P < 0.05), and the ABCG2 protein expression in the tumor cells decreased significantly (P < 0.05). Abnormally high expression of ABCG2 in esophageal cancer tissues is involved in the multidrug resistance of esophageal cancer. In vivo studies showed that Art could reverse the esophageal cancer drug resistance by regulating the ABCG2 expression in tumor cells.