[Combination chemotherapy with aclarubicin and cisplatinum against malignant intracranial tumor--an in vitro study]

Augmentation of cytotoxicity against cultured human tumor cell lines (5 gliomas, 2 neuroblastomas, 2 sarcomas) using a combination of Aclarubicin (ACR) and Cisplatinum (CDDP) was analysed in vitro from the viewpoints of cell growth inhibition and alteration of the DNA histogram. Synergistic effects of the combination of the two agents were observed in 7 of the 9 cell lines. In sarcoma cell lines, effects were demonstrated even by a low dose of 0.1 microgram/ml CDDP and 0.01 microgram/ml ACR. Flow cytometry studies of the DNA histogram showed increase of accumulation in the S phase following the G2-M phase and reduction of G1 phase cells in response to the combination. From the present experimental studies in vitro, it is concluded that combination chemotherapy with ACR and CDDP may be effective for sarcoma and ACNU-resistant glioma. The mechanism of the synergistic effect produced by the combination is suggested to be impairment of RNA synthesis by ACR which prevents the repair of DNA damage induced by CDDP.