25^th World Cancer Conference

Ovarian cancer is a remarkably metastatic disease that is often characterized by widespread peritoneal dissemination. Recently, several studies have suggested that tumor microenvironment plays a significant role in ovarian cancer metastasis. However, the interaction between macrophages and mesothelial cells for ovarian cancer metastasis is unclear. We first investigated the effect of macrophages on gene expression pattern in mesothelial cells. Following treatment of mesothelial cells with conditioned medium (CM) of macrophages, we conducted a comparative analysis of global expression changes in mesothelial cells using mRNA sequencing. When compared to that in unstimulated-macrophages, 945 genes were upregulated and 777 genes were down-regulated more than 2-fold in macrophage-stimulated mesothelial cells (MSM). Among the total 1722 genes, 94 genes including WNT7B were known to be associated with the regulation of cell adhesion. Interestingly, knockdown of WNT7B using siRNA attenuated the adhesion of ovarian cancer cells to mesothelial cells. These results indicate that the enhanced levels of WNT7B in MSM may play a role in the peritoneal dissemination of ovarian cancer.