The mixture of κ-neocarrabiose-sulfate, κ-neocarrahexaose-sulfate and κ-neocarraoctaose-sulfate were prepared from κ-carrageenan with enzyme. The anti-tumor and anti-angiogenic activity of obtained κ-carrageenan oligosaccharides (KOS), were explored. The results showed that KOS could inhibit the proliferation, migration and tube formation of ECV304 cells, and could inhibit the growth of new vessels in CAM model. KOS displayed strong anti-tumor activity in both S180 and MCF-7 xenograft models. Only human CD105 was detected in MCF-7 xenograft tumor, moreover KOS could decrease the growing of new blood vessels derived from tumor cell. Real-time PCR results showed that KOS could suppress the mRNA expression of human VEGF, bFGF, bFGFR and CD105 in MCF-7 xenograft tumor. All these results indicated that KOS has anti-tumor and anti-angiogenic activity in vivo and in vitro. Especially K has the potency to inhibit the differentiation of tumor cell to blood vessel endothelial cell.
