Upregulation of interleukin-8 and polarized epithelial expression of interleukin-8 receptor A in ovarian carcinomas

Abstract

Background. The chemokine interleukin-8 is present in a variety of tumor types with suggested effects on proliferation, migration, and angiogenesis. Elevated levels of interleukin-8 are present in cyst fluids from malignant ovarian tumors. The origin and potential targets for this chemokine in ovarian tumors were investigated in this study. Methods. Interleukin-8 and its receptors were analyzed in 26 ovarian samples, including both normal and neoplastic tissue, with immunohistochemistry, Western blotting, and in situ hybridization. Results. The mRNA for IL-8 was detected in higher amounts in the epithelial compartments compared to stromal areas, while the IL-8 protein was present in both epithelial and stromal areas, and in cystic formations of the tumors. The tissue levels of IL-8 protein increased with lower differentiation of the tumors. Both types of IL-8 receptors were detected in most specimens. A typical expression pattern for IL-8 receptor A was detected, with expression only on the luminal side of the epithelial tumor cells, while IL-8 receptor B was more evenly distributed in the tissue. Conclusions. An increased synthesis of IL-8 during dedifferentiation of the tumor, and a typical expression pattern of the IL-8 receptor A were detected, indicating a function for IL-8 in biology of epithelial ovarian cancer.