Reduced expression of interleukin-13 receptor alpha2 promotes growth of hepatocellular carcinoma

Abstract

Introduction: Interleukin-13 receptor alpha2 (IL13Rα2) has been reported to be associated with invasion and metastasis of digestive cancers including colorectal cancer and pancreatic cancer. However, little is known about its role on hepatocellular carcinoma (HCC). This study aims to investigate the effect of IL13Rα2 on the progression of HCC. Methods: Expression of IL13Rα2 was measured on 81 Human liver tissue samples, which were collected from patients received hepatectomy, by immunohistochemistry and on 14 HCC cell lines by western blot. Independents factors, overall survival (OS) and recurrence-free survival (RFS) of patients were compared between high-IL13Rα2 expression group and low-IL13Rα2 group.HepG2 and SMMC7721 HCC cell lines were selected to knock down IL13Rα2 expression by PLKO-Tet-On lentivirus. Cell Counting Kit-8 (CCK-8) assays and colony formation assays were performed on selected cell lines. HepG2-vector and HepG2-sh IL13Rα2 cells were used to perform in vivo tumorigenicity assay. Results: IL13Rα2 showed higher expression in adjacent-tumor tissues than tumor tissues (P< 0.001). Differentiation of HCC was the only independent factor associated with IL13Rα2 expression in tumor tissues (HR: 0.19, 95%CI: 0.067-0.538, P =0.002). No significant difference of OS and RFS were found between high-IL13Rα2 expression group and low-IL13Rα2 group. Knockdown of IL13Rα2 promoted growth of HepG2 and SMMC7721 cells. Subcutaneous tumors from HepG2-sh IL13Rα2 cells showed larger in volume and heavier in weight (P< 0.05), in comparison to their empty control. Conclusion: Our research clarified that reduced expression of IL13Rα2 promoted growth of hepatocellular carcinoma.