The effects of fucosylated chondroitin sulfate isolated from Isostichopus badionotus on antimetastatic activity via down-regulation of Hif-1α and Hpa

Exploring the Target Genes of Fucosylated Chondroitin Sulfate in Treating Lung Adenocarcinoma Based on the Integration of Bioinformatics Analysis, Molecular Docking, and Experimental Verification

Fucosylated chondroitin sulfate (FCS), extracted from sea cucumbers' body walls, has been found to inhibit the proliferation of lung adenocarcinoma (LUAD) cells. However, there have been few studies of the associated drug targets. This study combined bioinformatics analysis and molecular docking to screen the main targets of FCS intervention in LUAD. Moreover, an experimental validation was performed. First, we downloaded the LUAD gene data set from The Cancer Genome Atlas (TCGA) database and the cisplatin (DDP) resistance gene data set of LUAD A549 cells from the Gene Expression Omnibus (GEO) database. Nine significant genes (PLK1, BUB1, CDK1, CDC20, CCNB1, BUB1B, KIF11, CCNB2, and DLAGP5) were identified by bioinformatics analysis, and these nine genes overlapped in both data sets. Then, molecular docking results showed that FCS had a better affinity with target proteins BUB1 and PLK1. Further experimental verification revealed that FCS inhibited the growth of A549 cells and increased the sensitivity of A549 cells to DDP. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that A549 cells treated with FCS exhibited down-regulated BUB1 and PLK1 mRNA expression. At the same time, FCS+DDP treatment resulted in a more significant reduction in BUB1 and PLK1 mRNA expression than DDP or FCS treatment alone. These findings reveal potential targets of FCS for LUAD and provide clues for the development of FCS as a potential anticancer agent.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

A Highly Active Chondroitin Sulfate Lyase ABC for Enzymatic Depolymerization of Chondroitin Sulfate

Enzymatic preparation of low-molecular-weight chondroitin sulfate (LMWCS) has received increasing attention. In this work, a chondroitin sulfate lyase ABC (Chon-ABC) was successfully cloned, expressed, and characterized. The K_m and V_max of the Chon-ABC were 0.54 mM and 541.3 U mg⁻¹, respectively. The maximal activity was assayed as 500.4 U mg⁻¹ at 37 °C in pH 8.0 phosphate buffer saline. The half-lives of the Chon-ABC were 133 d and 127 min at 4 °C and 37 °C, respectively. Enzymatic preparation of LMWCS was performed at room temperature for 30 min. The changes between the substrate and product were analyzed with mass spectrometry (MS), high-performance liquid chromatography (HPLC), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR). Overall, the Chon-ABC from Bacteroides thetaiotaomicron is competitive in large-scale enzymatic preparation of LMWCS for its high activity, stability, and substrate specificity.

Galactosaminoglycans: Medical Applications and Drawbacks

Galactosaminoglycans (GalAGs) are sulfated glycans composed of alternating N-acetylgalactosamine and uronic acid units. Uronic acid epimerization, sulfation patterns and fucosylation are modifications observed on these molecules. GalAGs have been extensively studied and exploited because of their multiple biomedical functions. Chondroitin sulfates (CSs), the main representative family of GalAGs, have been used in alternative therapy of joint pain/inflammation and osteoarthritis. The relatively novel fucosylated chondroitin sulfate (FCS), commonly found in sea cucumbers, has been screened in multiple systems in addition to its widely studied anticoagulant action. Biomedical properties of GalAGs are directly dependent on the sugar composition, presence or lack of fucose branches, as well as sulfation patterns. Although research interest in GalAGs has increased considerably over the three last decades, perhaps motivated by the parallel progress of glycomics, serious questions concerning the effectiveness and potential side effects of GalAGs have recently been raised. Doubts have centered particularly on the beneficial functions of CS-based therapeutic supplements and the potential harmful effects of FCS as similarly observed for oversulfated chondroitin sulfate, as a contaminant of heparin. Unexpected components were also detected in CS-based pharmaceutical preparations. This review therefore aims to offer a discussion on (1) the current and potential therapeutic applications of GalAGs, including those of unique features extracted from marine sources, and (2) the potential drawbacks of this class of molecules when applied to medicine.

Chondroitin Sulfate-Degrading Enzymes as Tools for the Development of New Pharmaceuticals

Chondroitin sulfates are linear anionic sulfated polysaccharides found in biological tissues, mainly within the extracellular matrix, which are degraded and altered by specific lyases depending on specific time points. These polysaccharides have recently acquired relevance in the pharmaceutical industry due to their interesting therapeutic applications. As a consequence, chondroitin sulfate (CS) lyases have been widely investigated as tools for the development of new pharmaceuticals based on these polysaccharides. This review focuses on the major breakthrough represented by chondroitin sulfate-degrading enzymes and their structures and mechanisms of function in addition to their major applications.

Ultrasound-assisted fast preparation of low molecular weight fucosylated chondroitin sulfate with antitumor activity

Fucosylated chondroitin sulfate from sea cucumber Isostichopus badionotus (fCS-Ib) was depolymerized with an ultrasound-accelerated, metal-free Fenton chemistry, relying on H₂O₂/ascorbic acid redox system. Fragments of different molecular weights were obtained at different reaction temperatures, ascorbic acid concentrations and ultrasonic intensities. The structures of two typical depolymerized fragments were evaluated using high-performance liquid chromatography (HPLC), infrared spectroscopy (IR), and nuclear magnetic resonance spectroscopy (NMR). The results showed that ultrasound enhanced the degradation efficiency of H₂O₂/ascorbic acid system mainly by disaggregating sulfated polysaccharide clusters and that free radicals induced depolymerization with no significant chemical changes in the backbone of fCS-Ib and with no obvious loss of fucose branches. The antitumor activity, using A549 lung cancer cells, showed that the ultrasound treated low molecular weight sulfated fragment enhanced proliferation-inhibitory and anti-migration effects, compared to native fCS-Ib. This was different from the anticoagulant activity of fCS-Ib, suggesting that the molecular weight change may cause a conformational transition and affect biological activity. We propose that combining ultrasound with non-metal Fenton chemistry as an effective method to prepare low molecular weight fCS fragments with potential applications as functional foods, antitumor drugs, and that these fCS fragments display negligible bleeding risk.