|Budget Amount *help
¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1998 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1997 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Among several human ovarian tumors, which include mucinous cystadenocarcinoma, serous cystadenocarcinoma, and clear cell adenocarcinoma, the mucinous cystadenocarcinoma showed a unique glycosphingolipid composition. More than 90% of the acidic glycosphingolipids in the mucinous cystadenocarcinoma is comprised of sulfolipids, which are hardly detected in normal ovary and are contained in concentrations of less than 40% in the type of ovarian tumors.
Cells of the human tumor cell line RMG- 1, derived from a clear cell adenocarcinoma of the ovary were injected intraperitoneally into nude mice, and the cells obtained from the tumor nodules in the mesenterium were found to form a larger number of, and larger-sized, tumor nodules than the original RMG- 1 cells. The RMG- 1-h cells, transferred into culture from the tumor nodules after a 4th in vivo passage, showed a dissemination potential as high as that of cells disseminating directly from the tissues, and exceedingly higher than that of RMG
- 1 cells. To assess the molecular bases of the different biological properties of RMG- 1 and RMG- 1 -h cells, we compared the content and expression of various carbohydrate antigens in both cells. In contrast to the broad histogram for the Le^x-bearing cells among RMG- 1 cells in flow cytometry, the weakly and moderately positive cells toward anti-Le^x antibody were found to be eliminated from the histogram for the RMG- 1 -h cells, resulting in the enrichment of cells strongly expressing Le^x, which may account for the high dissemination potential. In addition, the adhesion of RMG- 1 cells to mesothelial cells was found to be significantly inhibited by pretreatment of the cells with anti-Le^x antibody, indicating Le^x mediated cell-to-cell interaction between ovarian cancer cells and mesothelial cells. Thus, the high dissemination potential of ovarian cancer cells was shown to be mediated by the Le^x-determinant and the Le^x-bearing cells are enriched by repeated in vivo passage of the cells into nude mice. Less