Low Molecular Weight Fucoidan Prevents Radiation-Induced Fibrosis and Secondary Tumors in a Zebrafish Model

Abstract

Radiotherapy often causes unwanted side effects such as radiation-induced fibrosis and second malignancies. Fucoidan, a sulfated polysaccharide extracted from brown seaweed, has many biological effects including anti-inflammation and anti-tumor. In the present study, we investigated the radioprotective effect of Oligo-Fucoidan (OF) using a zebrafish animal model. Adult zebrafish of wild-type and transgenic fish with hepatocellular carcinoma were orally fed with Oligo-Fucoidan before irradiation. Quantitative PCR, Sirius red stain, hematoxylin, and eosin stain were used for molecular and pathological analysis. Whole genomic microarrays were used to discover the global program of gene expression after Oligo-Fucoidan treatment and identified distinct classes of up- and downregulated genes/pathways during this process. Using Oligo-Fucoidan oral gavage in adult wild-type zebrafish, we found Oligo-Fucoidan pretreatment decreased irradiation-induced fibrosis in hepatocyte. Using hepatitis B virus X antigen (HBx), Src and HBx, Src, p53−/+ transgenic zebrafish liver cancer model, we found that Oligo-Fucoidan pretreatment before irradiation could lower the expression of lipogenic factors and enzymes, fibrosis, and cell cycle/proliferation markers, which eventually reduced formation of liver cancer compared to irradiation alone. Gene ontology analysis revealed that Oligo-Fucoidan pretreatment increased the expression of genes involved in oxidoreductase activity in zebrafish irradiation. Oligo-Fucoidan also decreased the expression of genes involved in transferase activity in wild-type fish without irradiation (WT), nuclear outer membrane-endoplasmic reticulum membrane network, and non-homologous end-joining (NHEJ) in hepatocellular carcinoma (HCC) transgenic fish. Rescue of those genes can prevent liver cancer formation. Conclusions: Our results provide evidence for the ability of Oligo-Fucoidan to prevent radiation-induced fibrosis and second malignancies in zebrafish.

Low molecular weight fucoidan inhibits hepatocarcinogenesis and nonalcoholic fatty liver disease in zebrafish via ASGR/STAT3/HNF4A signaling

“…30 We also proved OF prevents radiation induced fibrosis and secondary tumor formation. 31 Previously, OF inhibits radiation induced lung fibrosis in mouse model through reducing inflammatory cytokine, 53 and fucoidan inhibits cell proliferation, migration, and cell arrest in HepG2 hepatoma cell. 60 In this study, we further demonstrated that OF effectively reducing HCC incidence in different transgenic zebrafish HCC models including diet-induced obesity of [HBx,src] and [HBx,src,p53 −/+ ] models, as well as CD36 transgenic zebrafish under high-fat diet induced HCC.…”

“…The [ HBx,src ] and [ HBx,src,p53 −/+ ] transgenic zebrafish were allocated to two different diets: normal diet (NOR) with 6.9 mg cysts/fish/day of Artemia and diet‐induced obesity (DIO) with 83 mg cysts/fish/day of Artemia for 2 months starting at 3 months of age as described previously 14 . OF (0.051 mg in 5 μL) was administrated by oral gavage thrice a week for 1 month starting at 4 months of age, by injected slowly into the intestinal tract of anesthetized (with 150 mg/L MS‐222) adult fish using flexible tubing as described previously 31 . After 1 month of OF oral feeding, we sacrificed the fish, extracted the RNA, and paraffin embedding for H&E stain was performed as described previously 30,31 .…”

“…31 After 1 month of OF oral feeding, we sacrificed the fish, extracted the RNA, and paraffin embedding for H&E stain was performed as described previously. 30,31 The quantitative real-time PCR (qPCR) primers are listed in Table 1.…”

“…33 The same material has been used in different experiments including in vitro and in vivo models, and demonstrated that OF exhibits hepatocyte protection and anti-radiation induced fibrosis and secondary tumor. 30,31,34…”

“…29 Previously, we have demonstrated OF protects the liver through binding to ASGR and activates STAT3 in normal liver cells, 30 and prevents radiation induced firbosis and secondary tumor. 31 In this study, we investigated whether OF would be capable of reducing cancer incidence in different transgenic zebrafish HCC models including [HBx,src,p53 −/+ ] transgenic zebrafish under diet induced obesity (DIO) developed HCC at 5 months of age, 14 and CD36 transgenic zebrafish under high-fat diet induced HCC at 1 month. Thus, we used those models to evaluate the efficacy of OF for anti-HCC treatment for both HBV-associate HCC and NBNC-HCC.…”