IN-VITRO CHARACTERIZATION OF SOFT-TISSUE TUMOR CHEMOSENSITIVITY

Background: The benefit of performing chemotherapy on soft tissue sarc omas remains controversial. The present study deals with the in vitro characterisation of the influence of 3 antitumoral agents on the growt h of 8 sarcoma cell lines. Materials and Methods: Cell growth was moni tored by means of the MTT colorimetric assay, which was fur-ther valid ated by a direct cell counting method. The three drugs tested included doxorubicin (ADR), cisplatin (DDP) and dacarbazine (DTIC). ADR was te sted at 10(-5) M, 10(-6) M and 10(-7) M; DDP at 10(-5) M, 10(-6) M and 10(-7) M and DTIC at 10(-3) M, 10(-4) M and 10(-5) M. A combination o f the three drugs was also tested in order to ascertain whether a syne rgistic effect on cell growth inhibition could be obtained A potential antineoplastic agent-induced influence on cell growth was determined 3 days after the addition of the diverse drug(s) to the culture media. The cell concentration was specifically adapted to each cell line. Th e 8 cell lines included 3 leiomyosarcomas, 1 malignant mixed Mullerian tumour, 3 rhabdomyosarcomas and 1 fibrosarcoma. Results: The results show that of the three drugs tested, ADR was the most efficient in ter ms of the level of cell growth inhibition obtained and the number of c ell lines whose growth was significantly inhibited. Of the three drugs , the least active was DDP. A significant synergistic effect was obser ved when the three drugs were added together to the culture medium. Th is synergistic effect was evident at the lowest doses tested for each drug. Whatever the histopathological type, the 8 cell lines exhibited a wide range of response to chemotherapy. Conclusions: The present stu dy shows that the inhibition induced by 10(-7) M ADR, 10(-7) M DDP and 10(-5) M DTIC on sarcoma cell line growth is significantly more effic ient than if each agent is tested individually. The in vitro methodolo gy used here fits in with clinical reality because it enables sarcoma cell heterogeneity to be taken into account.