RESUMO
OBJECTIVE: The objective of the study was to investigate interleukin-6 receptor (IL6R) isoforms and sheddases in the ovarian tumor microenvironment. STUDY DESIGN: Expression of IL6R and sheddases was measured in tissue samples of papillary serous ovarian carcinomas and benign ovaries by real-time polymerase chain reaction and immunohistochemistry. Murine xenograft samples were tested by enzyme-linked immunosorbent assay to discriminate and evaluate tumor and host contributions of IL6R. RESULTS: IL6R expression was increased in malignant ovarian tumors and localized to epithelial cells. Expression of a soluble splice variant of IL6R was increased in malignant tumors, as were the sheddases for the full-length isoform. An in vivo xenograft model showed that host IL6R expression is also increased and regulated by tumor-associated inflammation. CONCLUSION: IL6R is overexpressed in epithelial ovarian malignancies because of increases in a soluble IL6R variant, in the sheddases for full-length IL6R and host IL6R expression. Soluble IL6R may be an efficacious target for reducing IL6-mediated ovarian tumor progression.
