Expression of sarcoma-associated antigens p102 and p200 in human sarcoma cell lines

Understanding tumor antigen expression and its correlation with the cell cycle may help in designing immunotherapy by monoclonal antibodies. Therefore, we studied the in vitro expression of sarcoma-associated antigens p102 and p200 in the G, S, and G2/M phases of sarcoma cell lines.

The expression of human cell surface sarcoma-associated antigens p102 and p200 was studied in 13 human sarcoma cell lines, using flow cytometry.

p102 was detected by monoclonal antibody 19-24-6 in all 13 sarcoma cell lines, and p200 was detected by monoclonal antibody 29-13-17 in five of 13. p102 antigen expression was 1.4- to 3.4-fold higher (p < 0.001) than p200 expression. Although sarcoma cell lines showed a wide range of p102/p200 antigen expression, over 99% of the entire in vitro and in vivo cell population was found to be p102- and/or p200-positive. In three cell lines, p102 expression was cell cycle-dependent, with relative fluorescence intensity ranging from 13.8% to 23.9% higher at the G1 phase than at the G2/M phase. In three cell lines, the expression of p200 at the GI phase was 22.4% to 40.9% percent higher than at the G2/M phase.

The heterogeneity and cell cycle dependence of p102/p200 antigen expression in sarcoma cells suggest that monoclonal antibodies 19-24-6 and 29-13-17 might be applied to the immunotherapy of sarcoma.