OBJECTIVETo evaluate the inhibitory effect of 5-fluorouracil (5-Fu) on HT-1080 human fibrosarcoma cells in vitro.

METHODSHT-1080 human fibrosarcoma cells were cultured for 3 days in the proliferation period. Then adriamycin or 5-Fu at different concentrations were used to treat these cells for 24 h, 72 h and 144 h. MTT assay was used to evaluate the cytotoxic effects through measuring optical density and calculating the inhibition rate of cell growth. Morphologic changes of the cells were observed under a phase contrast microscope. Flow cytometry (FCM) was performed to detect the changes in cell cycle and DNA ploidy in the fibrosarcoma cells treated with 5-Fu.

RESULTS10 µg/ml 5-Fu showed an inhibition rate of 45.9% (24 h), 64.7% (72 h) and 90.6% (144 h) of the HT-1080 cell growth. 100 µg/ml 5-Fu showed an inhibition rate of 53.1% (24 h), 86.4% (72 h), 93.0% (144 h) of the HT-1080 cell growth, results similar to those in the adriamycin group. Untreated fibrosarcoma cells accounted for 67.5% in G(1) phase, 21.2% in S phase and 11.3% in G(2) phase. With the increasing drug concentrations, cells in G(1) + S phase increased rapidly and no cells in G(2) phase were observed later. The cells treated with 5-Fu showed a G(1) + S cell cycle arrest.

CONCLUSIONS5-Fu has an antitumor activity in human fibrosarcoma HT-1080 cells in vitro, in a time-dependent and dose-dependent manner. The cytotoxity of 5-Fu at high concentrations and continuous use can induce tumor cell cycle arrested at G(1) + S phase, a similar result induced with adriamycin.