Involvement of H type 1 carbohydrate antigen in cell adhesion to vascular endothelial cells of human endometrial cancer.

A number of previously published studies have suggested that blood-group-related carbohydrate antigens, expressed on cancer cell membranes, may be related to the cytobiological characteristics (invasiveness, metastasizing potential, etc.) of cancer. In our previous study, we divided SNG-II, a human endometrial cancer cell line, into SNG-S and SNG-W and compared their properties. In that study, we found that H type 1 carbohydrate antigen, which is scarcely expressed on SNG-S but strongly expressed on SNG-W, may play a significant role in the adhesion of SNG-W to vascular endothelial cells. In the present study, we clarified in some detail, the relationship between H type 1 carbohydrate antigen and endothelial cell adhesion, and also compared the propensity for hematogenous metastasis of these two cell lines in vivo. The following results were obtained: 1. The adhesion of SNG-W to human umbilical vein endothelial cells (1), was inhibited in a concentration-dependent manner by the addition of one H type 1 monoclonal antibody. 2. In the flow cytometric analysis using single carbohydrate-conjugated fluorescent beads, it was shown that H type 1 carbohydrate-attached beads adhered to HUVECs. On the other hand, beads conjugated with Lewis, Lewis, or H type 2 carbohydrate antigen did not adhere to HUVECs. 3. In an in vivo study using a nude mouse model of lung metastasis, SNG-W was found to show a significantly greater propensity for blood-borne metastasis than SNG-S. These results suggest that the H1 carbohydrate antigen expressed on the cancer cell membrane serves as an adhesion factor for vascular endothelial cells, and that endometrial cancer expressing high levels of this antigen has a high propensity for blood-borne metastasis, suggesting that the expression of this antigen on the cancer cells may serve as an indicator of poor prognosis.