Abstract

The effect of low molecular weight fucans (LMW fucans) has been examined on the proliferation of tumour cells. These LMW fucans are not active on all tumour cell lines. They are not cytotoxic and inhibit CCL39 fibroblast cells and human colon adenocarcinoma Colo320DM proliferation (85% and 50% of inhibition respectively). The active concentration of sulphated polysaccharide is about 10 micrograms/mL for CCL39 cells and 100 micrograms/mL for COLO 320 DM. This inhibitory effect is fetal calf serum concentration and cell density dependent. Furthermore, fucans are internalized into CCL39 cells within the first hours of incubation. They are distributed into the cytoplasmic compartment but not in the nucleus, and are not excreted after one week of contact. In the case of COLO 320 DM cells, the same fluorescent fucan is not internalized after one week of contact, but remains strongly fixed on the cytoplasmic membrane. This inhibitory effect is not accompanied by any modifications of the cell distribution in the various phases of the cell cycle. There are no significant differences in the antitumor effect either between the various LMW fucan or with the crude extract.