Production of IL1-beta by ovarian cancer cells induces mesothelial cell beta1-integrin expression facilitating peritoneal dissemination

Abstract

Abstract Background A crucial step in the metastatic spread of ovarian cancer (OC) is the adhesion and implantation of tumor cells to the peritoneal mesothelium. In order to study this step in the cascade, we derived a pro-metastatic human ovarian carcinoma cell line (MFOC3) from the non-metastatic FOC3 line. Methods Molecular profiling of the isogeneic lines identified differentially expressed genes, and investigation for a role in dissemination for specific factors was achieved by development of a co-culture adhesion assay utilizing monolayers of human mesothelial cells. Results After murine intraperitoneal inoculation, the FOC3 cell line formed no metastases, but the MFOC3 subline formed metastases in > 80% of SCID mice. MFOC3 cells also adhered 2-3 times more avidly to mesothelial monolayers. This adhesion was inhibited by neutralizing antibodies to IL-1β and enhanced by recombinant IL-1β (p in vitro and significantly reduced metastases in vivo. Immunohistochemical analysis of a cohort of 96 ovarian cancer cases showed that negative IL-1β expression was significantly associated with an improved overall survival rate. Conclusions These results suggest that a IL-1β/β1-integrin axis plays a role in ovarian tumor cell adhesion to mesothelia, a crucial step in ovarian cancer dissemination.

Keywords

• ovarian cancer
• peritoneal dissemination
• IL-1β
• β1 integrin
• mesothelial cell