[Application of anti-p-105 monoclonal antibody to analysis of mode of action of antitumor agents].

For the elucidation of the mode of action of anti-tumor agents, the cell cycle analysis of etoposide and podophyllotoxin was examined by means of the multiparameter flow cytometry using an anti-p-105 monoclonal antibody. The p-105 is one of the proliferation associated nuclear antigens and its expression increases with a cell cycle progression, especially in mitotic phase. Thus, we have applied its anti-monoclonal antibody to the discrimination between M and G2 phases of the gastric cancer cells. The results revealed that etoposide caused a G2 block and retarded an S phase transition, and podophyllotoxin caused both G2 and M phase blocks in the gastric cancer cells. This cell cycle analysis using an anti-p-105 monoclonal antibody would be a useful analysis of the antitumor agents, especially for M phase analysis of human cancer cells because of its rapidity and convenience.