DIFFERENTIAL EXPRESSION OF THE CELL-CELL ADHESION MOLECULE E-CADHERIN IN ASCITES AND SOLID HUMAN OVARIAN TUMOR-CELLS

Advanced ovarian cancers contain 2 distinct phenotypic populations: (a) free-floating tumor cells in the ascitic fluid and (b) solid tumors. Ascites cells are derived from the solid tumors and spread throughout the peritoneum. Changes in cell-cell and cell-extracellular matrix interactions are thought to be responsible for the origin of ascites cells. Since E-cadherin in these 2 phenotypic populations. Paired samples of ascites and solid tumors were obtained from patients. Both primary tumors and tumor cells isolated from an experimental model showed a marked decrease in E-cadherin expression in the ascites cells compared to the respective solid tumors. Semi-quantitative, reverse transcriptase-polymerase chain reaction (RT-PCR) was used to determine the steady-state levels of E-cadherin-specific mRNA. Results indicate that the primary tumors had significantly lower levels of E-cadherin transcript in ascites cells when compared to their solid tumor counterparts. Changes in E-cadherin expression were also reflected in the invasion capacity of tumor cells in vitro. Ascites cells were 4-fold more invasive then solid tumor cells, suggesting that ascites cells are a highly malignant phenotype. (C) 1994 Wiley-Liss, Inc.