Expression of interleukin-13 receptor α2 in cancer cells of colorectal cancer patients with liver metastasis and its relationship with myeloid-derived suppressor cells

Objective To investigate the expression of interleukin-13 receptor α2(IL-13Rα2)in cells of colorectal cancer patients with liver metastasis and its relationship with myeloid-derived suppressor cells(MDSCs). Methods Paraffin sections of 68 patients with colorectal cancer surgery in Huashan Hospital Affiliated to Fudan University from 2000 to 2013 were retrospectively analyzed. The expression of IL-13Rα2 was observed after routine immunostaining. Anti-CD11B antibody and anti-CD33 antibody were used for double staining. Fluorescent antibody, goat anti-rabbit immunoglobulin(H+L)antibody and goat anti-mouse immunoglobulin(H+L)antibody were used to display CD33. Three pathologists independently evaluated IL-13Rα2 stained slides in a double-blind manner. Results The positive rate of IL-13Rα2 in colorectal cancer patients with liver metastasis was the highest(90.8%), followed by brain metastasis(65.0%), primary lesions(60.0%), and other metastases(53.0%), and there were significant differences(P<0.05). There was a linear correlation between the expression of IL-13Rα2 and the number of MDSCs in cases with liver metastasis(r=0.740, P<0.05). The average survival time of 48 patients with distant metastasis was(12.6±5.2)months. Conclusion The increased level of IL-13Rα2 suggests that the prognosis of colorectal cancer patients with distant metastasis is poor, and it is speculated that IL-13Rα2 can induce proliferation of MDSCs and promote liver metastasis by regulating colorectal cancer cells.