CD4 + CD25high Regulatory T Cell Numbers and FOXP3 mRNA Expression in Patients with Advanced Esophageal Cancer Before and After Chemotherapy

We evaluated the changes in CD4 + CD25high regulatory T (Treg) cells and FOXP3 mRNA expression in patients with advanced esophageal cancer as well as its clinical significance. For this purpose, the frequencies of peripheral blood Treg cells in 68 patients with advanced esophageal cancer and 40 healthy controls were determined by flow cytometry, and FOXP3 mRNA expression in Treg cells of 40 patients was determined by RT–PCR. The data show that Treg cell numbers were significantly higher (P < 0.01) in esophageal cancer patients (1.82 ± 0.54% of CD4 + T cells) as compared with healthy controls (1.52 ± 0.70% of CD4+ T cells). Treg cell numbers in the patients were significantly higher (P < 0.05) before chemotherapy (1.82 ± 0.54% of CD4 + T cells) than after chemotherapy (1.66 ± 0.58% of CD4 + T cells). Expression of the FOXP3 mRNA in the patients was significantly lower (P < 0.05) after chemotherapy (0.266 ± 0.028% of CD4 + T cells) than before chemotherapy (0.318 ± 0.027% of CD4 + T cells). It was, therefore, concluded that Treg cell numbers as well as FOXP3 mRNA expression in advanced esophageal cancer patients were significantly decreased after chemotherapy. Notably, FOXP3 gene may thus be involved in regulating the numbers and function of Treg cells in advanced esophageal cancer patients receiving chemotherapy.