Modulation of tumour marker CA-125 expression in cultured ovarian carcinoma cells

The aim of this study was to elucidate whether proliferation of ovarian carcinoma cells may affect the biosynthesis and release of CA-125. In a cell culture model the tumour marker CA-125 expression in cytosol, surface membrane, and release into culture medium was studied in six human carcinoma cell lines. Cell cycle analysis of propidium iodide stained nuclei was performed using a fluorescent activated cell sorter. The turnover of CA-125 is very rapid, within 24 h the equivalent amount found in each cell was also released in the supernatant culture medium. A good relation between cytosolic, membrane, and released CA-125 was observed. CA-125 expression was associated predominantly with the G0G1 phase of the cell cycle and was dependent on cell density. The results presented here demonstrate that factors associated with tumour cell proliferation could influence the CA-125 serum level in ovarian cancer patients.