Human peritoneal mesothelial cells are more potent than ovarian cancer cells in producing tumor marker CA-125.

The aim of the present study was to investigate the extent to which human peritoneal mesothelial cells (HPMCs) are able to participate in the release of tumor marker CA-125 in ovarian cancer and other conditions associated with an involvement of the peritoneum. For this purpose CA-125 shedding was measured in the supernatant culture medium of HPMCs obtained from various donors and seven well-established ovarian cancer cell lines (OVCAR-3, 2780, 2774, SKOV-6, SKOV-8, HOC-7, HTB-77). Furthermore, the influence of inflammatory cytokines [interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma)] on CA-125 release in normal and malignant cells was also studied. Constitutive CA-125 shedding was found to be about five times higher in HPMCs as compared with the investigated ovarian cancer cell lines. IL-1 beta and TNF-alpha treatment of HPMCs resulted in a significant reduction in CA-125 release; however, no consistent pattern in CA-125 secretion was found during incubation with either IL-1 beta or TNF-alpha in the various malignant cell lines. IFN-gamma, on the other hand, induced a highly significant increase in CA-125 secretion in ovarian cancer cells, but did not influence the shedding of CA-125 in HPMCs.