Transcriptomically Revealed Oligo-Fucoidan Enhances the Immune System and Protects Hepatocytes via the ASGPR/STAT3/HNF4A Axis.

Oligo-fucoidan, a sulfated polysaccharide extracted from brown seaweed, exhibits anti-inflammatory and anti-tumor effects. However, the knowledge concerning the detailed mechanism of oligo-fucoidan on liver cells is obscure. In this study, we investigate the effect of oligo-fucoidan in normal hepatocytes by transcriptomic analysis. Using an oligo-fucoidan oral gavage in wild-type adult zebrafish, we find that oligo-fucoidan pretreatment enhances the immune system and anti-viral genes in hepatocytes. Oligo-fucoidan pretreatment also decreases the expression of lipogenic enzymes and liver fibrosis genes. Using pathway analysis, we identify hepatocyte nuclear factor 4 alpha (HNF4A) to be the potential driver gene. We further investigate whether hepatocyte nuclear factor 4 alpha (HNF4A) could be induced by oligo-fucoidan and the underlying mechanism. Therefore, a normal hepatocyte clone 9 cell as an in vitro model was used. We demonstrate that oligo-fucoidan increases cell viability, Cyp3a4 activity, and Hnf4a expression in clone 9 cells. We further demonstrate that oligo-fucoidan might bind to asialoglycoprotein receptors (ASGPR) in normal hepatocytes through both in vitro and in vivo competition assays. This binding, consequently activating the signal transducer and activator of transcription 3 (STAT3), increases the expression of the P1 isoform of HNF4A. According to our data, we suggest that oligo-fucoidan not only enhances the gene expression associated with anti-viral ability and immunity, but also increases P1-HNF4A levels through ASGPR/STAT3 axis, resulting in protecting hepatocytes.

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

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.

In-phantom neutron dose measurement using Gafchromic film dosimeter for QA of BNCT beams.

In order to improve the quality assurance (QA) procedure for beams of boron neutron capture therapy (BNCT), this study introduced using the Gafchromic film dosimeter for neutron dose measurement of BNCT beams. The crucial part of this study was investigating an approach to employ the Gafchromic film dosimeter placed inside a PMMA phantom irradiated by a BNCT beam. The spatial distribution of neutron dose of the film was determined using measurements and Monte Carlo calculations. By employing the present approach, the two-dimensional distributions of the neutron dose component of the film at specific depths in the phantom were successfully obtained. The determined neutron dose profiles were in good agreement with the calculated ones. This study also confirmed the finding that the film dosimeter is sensitive to thermal neutrons by comparing the depth-capture-reaction-rate and depth-dose distributions. Results of this work not only proved the feasibility of using the proposed method for the QA measurement of beam delivery but also revealed the advantages of easy-handling and remarkable spatial resolution of the film dosimeter when applied to BNCT fields. The present work can help to verify the dose uniformity and output stability of BNCT beams prior to clinical irradiation.

Computational study of room scattering influence in the THOR BNCT treatment room.

BNCT dosimetry has often employed heavy Monte Carlo calculations for the beam characterization and the dose determination. However, these calculations commonly ignored the scattering influence between the radiations and the room structure materials in order to facilitate the calculation speed. The aim of this article attempts to explore how the room scattering affects the physical quantities such as the capture reaction rate and the gamma-ray dose rate under in-phantom and free-air conditions in the THOR BNCT treatment room. The geometry and structure materials of the treatment room were simulated in detail. The capture reaction rates per atom, as well as the gamma-ray dose rate were calculated in various sizes of phantoms and in the free-air condition. Results of this study showed that the room scattering has significant influence on the physical quantities, whether in small phantoms or in the free-air condition. This paper may be of importance in explaining the discrepancies between measurements and calculations in the BNCT dosimetry using small phantoms, in addition to provide a useful consideration with a better understanding of how the room scattering influence acts in a BNCT facility.

Neutron response of GafChromic® EBT2 film.

Neutron and gamma-ray mixed field dosimetry remains one of the most challenging topics in radiation dosimetry studies. However, the requirement for accurate mixed field dosimetry is increasing because of the considerable interest in high-energy radiotherapy machines, medical ion beams and BNCT epithermal neutron beams. Therefore, this study investigated the GafChromic® EBT2 film. The linearity, reproducibility, energy dependence and homogeneity of the film were tested in a (60)Co medical beam, 6-MV LINAC and 10-MV LINAC. The linearity and self-developing effect of the film irradiated in an epithermal neutron beam were also examined. These basic detector characteristics showed that EBT2 film can be effectively applied in mixed field dosimetry. A general detector response model was developed to determine the neutron relative effectiveness (RE) values. The RE value of fast neutrons varies with neutron spectra. By contrast, the RE value of thermal neutrons was determined as a constant; it is only 32.5% in relation to gamma rays. No synergy effect was observed in this study. The lithium-6 capture reaction dominates the neutron response in the thermal neutron energy range, and the recoil hydrogen dose becomes the dominant component in the fast neutron energy region. Based on this study, the application of the EBT2 film in the neutron and gamma-ray mixed field is feasible.

Macro- and microdistributions of boron drug for boron neutron capture therapy in an animal model.

BACKGROUND: The boron concentration (BC) in the blood, rather than in normal tissue, is often used as the reference to calculate the BC in tumor for boron neutron capture therapy (BNCT). The aims of this study were to justify whether BC in the blood is equal to that of normal tissue, and to verify the macro- and microdistributions of boron in tumor. MATERIALS AND METHODS: BALB/c nude mice bearing SAS human oral carcinoma xenografts were intravenously injected with 400 mg/kg of boronophenylalanine (BPA). Macro- and microdistributions of boron in the tumor were assayed with (18)F-fluoro-L-boronophenylalanine-fructose (FBPA-Fr)/micro-positron-emission tomography (PET) and alpha track autoradiography, respectively. RESULTS: The BCs assayed from the blood, normal tissue and tumor varied even on sampling at the same time points post-BPA administration. The ratio of BC in normal tissue to that in blood, i.e. N/B ratio, remains about 1.31 at 30 to 45 min post-BPA administration. Furthermore, (18)F-FBPA-Fr/micro-PET imaging and autoradiography also showed heterogeneous boron distribution in the tumor. CONCLUSION: The heterogeneous distribution of boron in the tumor is a limiting factor for the precise calculation of BC in the tumor. Here we suggest that the N/B ratio could be used to calculate the true BC in the tumor and in normal tissue for BNCT. (18)F-FBPA-Fr/PET imaging is useful to justify the N/B ratio for BNCT treatment.

A preliminary study on using the radiochromic film for 2D beam profile QC/QA at the THOR BNCT facility.

The GAFCHROMIC(®) EBT2 dosimetry film has been studied as a rapid QC/QA tool for 2D dose profile mapping in the BNCT beam at THOR. The pixel values of the EBT2 film image were converted to the 2D dose profile using a dose calibration curve obtained by 6-MV X-ray. The reproducibility of the 2D dose profile measured using the EBT2 film in the PMMA phantom was preliminarily found to be acceptable with uncertainties within about ±2 to ±3.5%. It is found that the EBT2 measured dose profile consisted of both gamma-ray components and neutron contributions. Therefore, the dose profile measured using the EBT2 film is significantly different from the neutron flux profile measured using the indirect neutron radiography method. Further study of the influence of neutrons to the response of the EBT2 film is indispensible for the absolute dose profile determination in a BNCT beam.