[Mechanism of cisplatin and peplomycin therapy on head and neck carcinoma].

Results of chemotherapy for head and neck cancer are now improving owing to the development of concomitant use of chemotherapeutic agents such as cisplatin or peplomycin. Concomitant use of the two agents has been favored clinically. However, fundamental study on the combination therapy has not been carried out sufficiently. In the present study we studied the cell kinetics of tumor cells by the combination of cisplatin and peplomycin using flowcytometric analysis and electron microscopy. Survival of tumor cells was lowest, when peplomycin was administrated 3 days after cisplatin. Cell kinetics showed an accumulation at the S and G2M stage in this situation, By the electron microscopic study, microvilli of tumor cells disappeared and the blebbing of tumor cells was observed, when cisplatin alone was administrated. However, when the combination of cisplatin and peplomycin was administrated to the tumor cells, tumor cells enlarged. The results suggest that the mechanism of combination therapy differed from the mechanism of cisplatin alone.