Selective Suppression of Cell Growth and Programmed Cell Death-Ligand 1 Expression in HT1080 Fibrosarcoma Cells by Low Molecular Weight Fucoidan Extract

Mar Drugs. 2019 Jul 19;17(7):421. doi: 10.3390/md17070421.


Low molecular weight fucoidan extract (LMF), prepared by an abalone glycosidase digestion of a crude fucoidan extracted from Cladosiphon novae-caledoniae Kylin, exhibits various biological activities, including anticancer effect. Various cancers express programmed cell death-ligand 1 (PD-L1), which is known to play a significant role in evasion of the host immune surveillance system. PD-L1 is also expressed in many types of normal cells for self-protection. Previous research has revealed that selective inhibition of PD-L1 expressed in cancer cells is critical for successful cancer eradication. In the present study, we analyzed whether LMF could regulate PD-L1 expression in HT1080 fibrosarcoma cells. Our results demonstrated that LMF suppressed PD-L1/PD-L2 expression and the growth of HT1080 cancer cells and had no effect on the growth of normal TIG-1 cells. Thus, LMF differentially regulates PD-L1 expression in normal and cancer cells and could serve as an alternative complementary agent for treatment of cancers with high PD-L1 expression.

Keywords: Cancer; N-Ras; fucoidan; human normal diploid fibroblast (TIG-1 cells); human sarcoma cell line (HT1080 cells); low molecular weight fucoidan extract; neuroblastoma-rat sarcoma; programmed cell death-ligand 1; programmed cell death-ligand 2.

MeSH terms

  • Apoptosis / drug effects
  • B7-H1 Antigen / antagonists & inhibitors*
  • B7-H1 Antigen / metabolism
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Drug Screening Assays, Antitumor
  • Fibrosarcoma / drug therapy*
  • Fibrosarcoma / pathology
  • Humans
  • Molecular Weight
  • Phaeophyta / chemistry*
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Plant Extracts / therapeutic use
  • Polysaccharides / chemistry
  • Polysaccharides / pharmacology*
  • Polysaccharides / therapeutic use


  • B7-H1 Antigen
  • CD274 protein, human
  • Plant Extracts
  • Polysaccharides
  • fucoidan