“…Recently, it has been highlighted that cell proliferation, apoptosis, adhesion, invasion and metastasis represent potential biological targets for treating osteosarcoma [35], and that one of the most potent natural drugs for this application may be fucoidan. Fucoidanhas been shown to inhibit cancer cells by inducing apoptosis via several mechanisms [21,22,24,29,33,[36][37][38][39][40][41], such as inhibition of cell proliferation and invasion by targeting cell cycle proteins and the PI3K-Akt-mTOR pathway [42], inhibition of Vascular Endothelial Growth Factor and Matrix Metalloproteinases [30], enhancing ubiquitin-dependent TGFβ receptor degradation [23,43] and regulating the miR-29c/ADAM12 and miR-17-5p/PTEN axes [44].This study simultaneously compares the anti-cancer activities of crude fucoidans from two brown seaweed species F. vesiculosus and S. filipendula, and the effects of low-, medium-and high-MW (LMW, MMW and HMW) fractions of fucoidan derived from S. filipendula against MG63 osteosarcoma cells. Using size-fractionated fucoidan, we also demonstrate that as the molecular weight of fucoidan increases, the anti-cancer activity of fucoidan also increases.…”