Abstract 4420: Analysis of functional role of interleukin-6 secreted by tumor-associated macrophages in ovarian cancer ascites

Tumor-associated macrophages (TAMs) are known to contribute to tumor growth, invasion, and metastasis by producing various mediators. However, few studies have clarified the role of TAMs in human ovarian cancer patients. The aim of the present study was therefore to analyze the effect of TAM on ovarian cancer growth, invasion, and metastasis. Ascites were collected aseptically, and CD11b positive cells (TAMs) were purified by positive selection using magnetic-activate cell sorting (MACS) technology. Co-culture of ovarian cancer cell line, SKOV3ip1 cells, with TAMs significantly enhanced the invasive activity of cancer cells in Matrigel Boyden chamber assay. This enhancement was partially blolcked by the treatment of anti-interleukin (IL)-6 receptor antibody (Tocilizumab). Since SKOV3ip1 cells did not express IL-6 in mRNA and protein level, IL-6 secreted by TAMs were considered to play a key role in ovarian cancer invasion. In vivo ovarian cancer xenografts, i.p. treatment of Tocilizumab significantly reduced peritoneal dissemination and ascites formation. Those results suggested targeting IL-6 produced by TAMs could be a promising therapy for a subset of ovarian cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4420. doi:10.1158/1538-7445.AM2011-4420