Fucoidan induces G1 arrest of the cell cycle in EJ human bladder cancer cells through down-regulation of pRB phosphorylation

A Fucose-Containing Sulfated Polysaccharide from Spatoglossum schröederi Potentially Targets Tumor Growth Rather Than Cytotoxicity: Distinguishing Action on Human Melanoma Cell Lines

Natural substances are strategic candidates for drug development in cancer research. Marine-derived molecules are of special interest due to their wide range of biological activities and sustainable large-scale production. Melanoma is a type of skin cancer that originates from genetic mutations in melanocytes. BRAF, RAS, and NF1 mutations are described as the major melanoma drivers, but approximately 20% of patients lack these mutations and are included in the triple wild-type (tripleWT) classification. Recent advances in targeted therapy directed at driver mutations along with immunotherapy have only partially improved patients' overall survival, and consequently, melanoma remains deadly when in advanced stages. Fucose-containing sulfated polysaccharides (FCSP) are potential candidates to treat melanoma; therefore, we investigated Fucan A, a FCSP from Spatoglossum schröederi brown seaweed, in vitro in human melanoma cell lines presenting different mutations. Up to 72 h Fucan A treatment was not cytotoxic either to normal melanocytes or melanoma cell lines. Interestingly, it was able to impair the tripleWT CHL-1 cell proliferation (57%), comparable to the chemotherapeutic cytotoxic drug cisplatin results, with the advantage of not causing cytotoxicity. Fucan A increased CHL-1 doubling time, an effect attributed to cell cycle arrest. Vascular mimicry, a close related angiogenesis process, was also impaired (73%). Fucan A mode of action could be related to gene expression modulation, in special β-catenin downregulation, a molecule with protagonist roles in important signaling pathways. Taken together, results indicate that Fucan A is a potential anticancer molecule and, therefore, deserves further investigation.

Opportunities and challenges of fucoidan for tumors therapy

The large-scale collections, screening and discovery of biologically active and pharmacologically significant marine-derived natural products have garnered tremendous attraction. Edible brown algae are rich in fucoidan. Importantly, fucoidan has been reported to inhibit carcinogenesis and metastasis mainly through the regulation of deregulated cell signaling pathways. This review summarizes the structural features of fucoidan, including monosaccharide type, sulfate content, and main chain structure. We have set spotlight on fucoidan-mediated tumor suppressive effects in cell cultures studies and tumor-bearing rodent models. Fucoidan exerts anti-tumor effects primarily through the inhibition of tumor cell viability, proliferation and metastatic dissemination of cancer cells from primary tumor sites to distant secondary sites. Fucoidan not only promotes immunological responses in tumor microenvironment but also induces apoptotic death in cancer cells. In addition, fucoidan can be used as a dietary supplement for preventive purposes, in combination with other drugs as complementary and alternative medicine or with nanoparticle modifications will be the future of fucoidan use. Cutting-edge research related to fucoidan has catalyzed the transition of fucoidan from preclinical studies to different phases of clinical trials. Rationally designed clinical trials for the critical evaluation of fucoidan against different cancers will be valuable to reap full benefits.

Seaweed-Derived Sulfated Polysaccharides; The New Age Chemopreventives: A Comprehensive Review

Seaweed-derived bioactive compounds are regularly employed to treat human diseases. Sulfated polysaccharides are potent chemotherapeutic or chemopreventive medications since it has been discovered. They have exhibited anti-cancer properties by enhancing immunity and driving apoptosis. Through dynamic modulation of critical intracellular signalling pathways, such as control of ROS generation and preservation of essential cell survival and death processes, sulfated polysaccharides' antioxidant and immunomodulatory potentials contribute to their disease-preventive effectiveness. Sulfated polysaccharides provide low cytotoxicity and good efficacy therapeutic outcomes via dynamic modulation of apoptosis in cancer. Understanding how sulfated polysaccharides affect human cancer cells and their molecular involvement in cell death pathways will showcase a new way of chemoprevention. In this review, the significance of apoptosis and autophagy-modulating sulfated polysaccharides has been emphasized, as well as the future direction of enhanced nano-formulation for greater clinical efficacy. Moreover, this review focuses on the recent findings about the possible mechanisms of chemotherapeutic use of sulfated polysaccharides, their potential as anti-cancer drugs, and proposed mechanisms of action to drive apoptosis in diverse malignancies. Because of their unique physicochemical and biological properties, sulfated polysaccharides are ideal for their bioactive ingredients, which can improve function and application in disease. However, there is a gap in the literature regarding the physicochemical properties and functionalities of sulfated polysaccharides and the use of sulfated polysaccharide-based delivery systems in functional cancer. Furthermore, the preclinical and clinical trials will reveal the drug's efficacy in cancer.

The Therapeutic Potential of the Anticancer Activity of Fucoidan: Current Advances and Hurdles

Several types of cancers share cellular and molecular behaviors. Although many chemotherapy drugs have been designed to weaken the defenses of cancer cells, these drugs may also have cytotoxic effects on healthy tissues. Fucoidan, a sulfated fucose-based polysaccharide from brown algae, has gained much attention as an antitumor drug owing to its anticancer effects against multiple cancer types. Among the anticancer mechanisms of fucoidan are cell cycle arrest, apoptosis evocation, and stimulation of cytotoxic natural killer cells and macrophages. Fucoidan also protects against toxicity associated with chemotherapeutic drugs and radiation-induced damage. The synergistic effect of fucoidan with existing anticancer drugs has prompted researchers to explore its therapeutic potential. This review compiles the mechanisms through which fucoidan slows tumor growth, kills cancer cells, and interacts with cancer chemotherapy drugs. The obstacles involved in developing fucoidan as an anticancer agent are also discussed in this review.

Present Status, Limitations and Future Directions of Treatment Strategies Using Fucoidan-Based Therapies in Bladder Cancer

Bladder cancer (BC) is a common urological cancer, with poor prognosis for advanced/metastatic stages. Various intensive treatments, including radical cystectomy, chemotherapy, immune therapy, and radiotherapy are commonly used for these patients. However, these treatments often cause complications and adverse events. Therefore, researchers are exploring the efficacy of natural product-based treatment strategies in BC patients. Fucoidan, derived from marine brown algae, is recognized as a multi-functional and safe substrate, and has been reported to have anti-cancer effects in various types of malignancies. Additionally, in vivo and in vitro studies have reported the protective effects of fucoidan against cancer-related cachexia and chemotherapeutic agent-induced adverse events. In this review, we have introduced the anti-cancer effects of fucoidan extracts in BC and highlighted its molecular mechanisms. We have also shown the anti-cancer effects of fucoidan therapy with conventional chemotherapeutic agents and new treatment strategies using fucoidan-based nanoparticles in various malignancies. Moreover, apart from the improvement of anti-cancer effects by fucoidan, its protective effects against cancer-related disorders and cisplatin-induced toxicities have been introduced. However, the available information is insufficient to conclude the clinical usefulness of fucoidan-based treatments in BC patients. Therefore, we have indicated the aspects that need to be considered regarding fucoidan-based treatments and future directions for the treatment of BC.

Putting the Brakes on Tumorigenesis with Natural Products of Plant Origin: Insights into the Molecular Mechanisms of Actions and Immune Targets for Bladder Cancer Treatment

Bladder cancer is the 10th most commonly diagnosed cancer worldwide. Although the incidence in men is 4 times higher than that in women, the diagnoses are worse for women. Over the past 30 years, the treatment for bladder cancer has not achieved a significant positive effect, and the outlook for mortality rates due to muscle-invasive bladder cancer and metastatic disease is not optimistic. Phytochemicals found in plants and their derivatives present promising possibilities for cancer therapy with improved treatment effects and reduced toxicity. In this study, we summarize the promising natural products of plant origin with anti-bladder cancer potential, and their anticancer mechanisms—especially apoptotic induction—are discussed. With the developments in immunotherapy, small-molecule targeted immunotherapy has been promoted as a satisfactory approach, and the discovery of novel small molecules against immune targets for bladder cancer treatment from products of plant origin represents a promising avenue of research. It is our hope that this could pave the way for new ideas in the fields of oncology, immunology, phytochemistry, and cell biology, utilizing natural products of plant origin as promising drugs for bladder cancer treatment.

Fucoidan Inhibition of Osteosarcoma Cells Is Species and Molecular Weight Dependent

Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anti-cancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula, and effects of low (LMW, 10-50 kDa), medium (MMW, 50-100 kDa) and high (HMW, >100 kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had the highest levels of sugars, acids and sulphation among molecular weight fractions. There was a dose-dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in the sub-G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress-induced apoptosis-like cell death for F. vesiculosus fucoidan and features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment.

Isobolographic Analysis Demonstrates the Additive and Synergistic Effects of Gemcitabine Combined with Fucoidan in Uterine Sarcomas and Carcinosarcoma Cells

Background: Uterine sarcomas and carcinosarcoma are associated with unfavorable prognosis. The regimens that are used in chemotherapy are associated with high incidence of side effects and usually do not significantly increase patients’ survival rates. In this study we investigated the activity and interactions between gemcitabine and fucoidan, the natural compound known for its anti-tumor properties, in human sarcomas and carcinosarcoma cell models. Methods: SK-UT-1, SK-UT1-B (carcinosarcoma), MES-SA (leiomyosarcoma), and ESS-1 (endometrial stromal sarcoma) cell lines were used for the experiments. Cells were incubated in the presence of gemcitabine, fucoidan, and mixtures, after the incubation the MTT tests were performed. In order to assess the interactions between tested compounds isobolographic analysis was performed. Additional assessments of apoptosis and cell cycle were done. Results: Additive effect of combined treatment with gemcitabine and fucoidan was observed in ESS-1 and SK-UT-1 cell line. Although the supra-additive (synergistic) effect noticed in SK-UT-1B cell line. It was not possible to determine the interactions of fucoidan and gemcitabine in MES-SA cell line due to insufficient response to treatment. Addition of fucoidan to gemcitabine enhances its proapoptotic activity, what was observed especially in ESS-1 and SK-UT-1B cell lines. The arrest of cell cycle induced by mixture of gemcitabine and fucoidan, superior comparing gemcitabine alone was observed in SK-UT-1B. Conclusions: Obtained data showed that a combination of fucoidan and gemcitabine in uterine endometrial stromal sarcoma and carcinosarcoma cell lines has additive or even synergistic effect in decreasing cell viability. Furthermore, this drug combination induces apoptosis and arrest of cell cycle. The resistance of uterine leiomyosarcoma cell line, justifies searching for other drugs combinations to improve therapy efficacy.

Molecular Mechanisms Underlying Cancer Preventive and Therapeutic Potential of Algal Polysaccharides

Background:

Algal polysaccharide and oligosaccharide derivatives have been shown to possess a variety of therapeutic potentials and drug delivery applications. Algal polysaccharides contain sulfated sugar monomers derived from seaweed including brown, red, and green microalgae. Here, in this review, the recent progress of algal polysaccharides’ therapeutic applications as anticancer agents, as well as underlying cellular and molecular mechanisms was investigated. Moreover, recent progress in the structural chemistry of important polysaccharides with anticancer activities were illustrated.

Methods:

Electronic databases including “Scopus”, “PubMed”, and “Cochrane library” were searched using the keywords “cancer”, or “tumor”, or “malignancy” in title/abstract, along with “algae”, or “algal” in the whole text until July 2018. Only English language papers were included.

Results:

The most common polysaccharides involved in cancer management were sulfated polysaccharides, Fucoidans, Carageenans, and Ulvan from different species of algae that have been recognized in vitro and in vivo. The underlying anticancer mechanisms of algal polysaccharides included induction of apoptosis, cell cycle arrest, modulation of transduction signaling pathways, suppression of migration and angiogenesis, as well as activation of immune responses and antioxidant system. VEGF/VEGFR2, TGFR/Smad/Snail, TLR4/ROS/ER, CXCL12/ CXCR4, TGFR/Smad7/Smurf2, PI3K/AKT/mTOR, PBK/TOPK, and β-catenin/Wnt are among the main cellular signaling pathways which have a key role in the preventive and therapeutic effects of algal polysaccharides against oncogenesis.

Conclusion:

Algal polysaccharides play a crucial role in the management of cancer and may be considered the next frontier in pharmaceutical research. Further well-designed clinical trials are mandatory to evaluate the efficacy and safety of algal polysaccharides in patients with cancer.

Anticancer effect of fucoidan on cell proliferation, cell cycle progression, genetic damage and apoptotic cell death in HepG2 cancer cells

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The centre of the attraction of this article is inevitably associated with fucoidan polymers in terms of brown seaweed such as Turbinaria conoides.

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Fucoidan in various cancer types exhibited by targeting apoptotic molecules and mitigate the toxicity of chemotherapeutic agents and radiation.

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To treat deadly liver cancer by identifying bioactive compounds available in the dietary supplement that rekindles the direction of research against cancer diseases.

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Fucoidan in a HepG2 cell line was studied with typical techniques such as cell viability, colony formation, cell migration, cell cycle progression, genetic damage and apoptosis along with their nuclear morphology and mitochondrial membrane potential.

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This study concluded that the fucoidan contain brown seaweeds consumed as dietary supplement not predispose to liver cancer.

The centre of the attraction of this article is inevitably associated with fucoidan polymers in terms of brown seaweed such as Turbinaria conoides. Fucoidan is a sulphated polysaccharide constitutes fucose as a major principle sugar along with other monosugars such as glucuronic acid, xylose and galactose. The core value of fucoidan in terms of various cancer types were substantially exhibited through targeting the key apoptotic molecules and subsequently mitigate the toxicity that are essentially included in the chemotherapeutic agents and radiation. The pragmatic investigation about the anti-cancer effect of fucoidan in a hepatoblastoma-derived (HepG2) cell line was thoroughly analyzed by the typical techniques such as cell viability, colony formation, cell migration, cell cycle progression, genetic damage and apoptosis along with their nuclear morphology and mitochondrial membrane potential. Following the analyzes, the cell viability was precisely evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. And hence, cell cycle arrest and apoptosis was appropriately examined staining with propidium iodide (PI) and annexin V-fluorescein isothiocyante (FITC) by flowcytometer, respectively. Primarily, genetic damage by fucoidan in HepG2 cell line was evaluated by following Trevigen’s comet assay kit. In addition, alteration of nuclear content and mitochondrial membrane potential were also detected with Hoechst and mitochondrial membrane potential dye (JC-1: 5,5′6,6′-tetrachloro-1,1′3,3′tetraethylbenzimi-dazolycarbocyanine iodide) by fluorescence microscopy, respectively. The results of the present study showed that cells constituted with fucoidan/quercetin standard at 50, 100 and 200 μg/ml exhibited cell viability about 71, 60 & 40/80, 65 & 45%, respectively. The above recorded effect of fucoidan was a concentration-dependant inhibition on the basis of decline in colony forming and cell migration potential of HepG2 cancer cells. Compared with untreated control, fucoidan consituted cells were significantly (p ≤  0.05) accumulated proliferative cells in the G₀/G₁ phase of the cell cycle in a concentration dependent manner. Increasing concentration of fucoidan (50,100 and 200 μg/ml) was remarkably enhanced the DNA damage which reflected through tail moment value of 3.8, 7.1 & 12.8 folds with respect to the untreated control. Fucoidan induced total apoptotic cells were observed ∼20–40% at 50–200 μg/ml concentrations. The apoptotic cell formation effected by change in the nuclear content and mitochondrial membrane potential was confirmed in HepG2 cancer cells under fluorescence microscopy. It was eventually concluded that the fucoidan display promising anti-cancer activity against HepG2 cancer cells by promoting the inhibition of cell proliferation, migration and cell arrest on concentration dependent-manner that was well correlated with genetic damage and apoptosis.

Clinical applications of fucoidan in translational medicine for adjuvant cancer therapy

The chemical composition of fucoidan, a kind of sulfated polysaccharide mainly derived from brown seaweed, includes a substantial percentage of l-fucose. Fucoidan has various biological and pharmacological activities, such as anti-cancer/anti-tumor, anti-proliferation, anti-inflammatory and immune-modulatory functions, and fucoidan-related dietary supplements and nutraceuticals have recently drawn considerable attention. In this review, we aim to provide a current view of different aspects of fucoidan biological activity, with a focus on the anti-cancer regulatory effects of fucoidan on growth signaling mechanisms. First, we discuss historical aspects of fucoidan and fucoidan products, as well as the anti-cancer effects of fucoidan on various cancer cells. Second, we discuss fucoidan’s biological activities and induction of cell death in cancer cells, including multiple mechanisms and signal transduction pathways related to its anti-cancer effects. Next, we focus on fucoidan and fucoidan-derived products that have been marketed as dietary supplements or nutraceuticals for cancer, including anti-cancer effects of fucoidan when combined as an adjuvant with clinical drugs. Finally, case studies of fucoidan in complementary therapy and as an alternative medicine in animal and mouse models and human clinical trials to alleviate side effects of anti-cancer chemotherapy are discussed. Combining fucoidan with clinical therapeutic agents in the treatment of cancer patients, dissecting the related signal transduction pathways and investigating their dynamic interactions may reveal potential molecular targets in cancer prevention, therapies and key obstacles in the current development of anti-cancer strategies.

The potential of brown-algae polysaccharides for the development of anticancer agents: An update on anticancer effects reported for fucoidan and laminaran

In recent decades, attention to cancer-preventive treatments and studies on the development of anticancer drugs have sharply increased owing to the increase in cancer-related death rates in every region of the world. However, due to the adverse effects of synthetic drugs, much attention has been given to the development of anticancer drugs from natural sources because of fewer side effects of natural compounds than those of synthetic drugs. Recent studies on compounds and crude extracts from marine algae have shown promising anticancer properties. Among those compounds, polysaccharides extracted from brown seaweeds play a principal role as anticancer agents. Especially, a number of studies have revealed that polysaccharides isolated from brown seaweeds, such as fucoidan and laminaran, have promising effects against different cancer cell types in vitro and in vivo. Herein, we reviewed in vitro and in vivo anticancer properties reported for fucoidan and laminaran toward various cancer cells from 2013 to 2016.

Differences in cell death and cell cycle following fucoidan treatment in high-density HT-29 colon cancer cells

Fucoidan, a sulfated polysaccharide present in marine brown seaweed, has been demonstrated to inhibit in vivo and in vitro growth of cells. The present study was conducted in HT-29 human colon cancer cells cultured at a high density, and examined the potential underlying mechanisms by which fucoidan exerts its anti-proliferative effects, which remain poorly understood. Fucoidan treatment of high-density HT-29 cells resulted in the inhibition of cell growth and increased apoptotic cell death. Flow cytometric analysis revealed that fucoidan treatment led to sub-G1 phase cell cycle arrest. This was associated with decreased protein expression levels of Retinoblastoma protein and E2 factor protein. In conclusion, the results of the present study demonstrated that fucoidan possesses anticancer activity against high density HT-29 cells by inhibiting cell growth and cell cycle progression.

Sulfated Galactans from Red Seaweed Gracilaria fisheri Target EGFR and Inhibit Cholangiocarcinoma Cell Proliferation

Cholangiocarcinoma (CCA) is increasing in incidence worldwide and is resistant to chemotherapeutic agents, making treatment of CCA a major challenge. Previous studies reported that natural sulfated polysaccharides (SPs) disrupted growth factor receptor activation in cancer cells. The present study, therefore, aimed at investigating the antiproliferation effect of sulfated galactans (SG) isolated from the red seaweed Gracilaria fisheri (G. fisheri) on CCA cell lines. Direct binding activity of SG to CCA cells, epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) were determined. The effect of SG on proliferation of CCA cells was investigated. Cell cycle analyses and expression of signaling molecules associated with proliferation were also determined. The results demonstrated that SG bound directly to EGFR. SG inhibited proliferation of various CCA cell lines by inhibiting EGFR and extracellular signal-regulated kinases (ERK) phosphorylation, and inhibited EGF-induced increased cell proliferation. Cell cycle analyses showed that SG induced cell cycle arrest at the G0/G1 phase, down-regulated cell cycle genes and proteins (cyclin-D, cyclin-E, cdk-4, cdk-2), and up-regulated the tumor suppressor protein P53 and the cyclin-dependent kinase inhibitor P21. Taken together, these data demonstrate that SG from G. fisheri inhibited proliferation of CCA cells, and its mechanism of inhibition is mediated, to some extent, by inhibitory effects on EGFR activation and EGFR/ERK signaling pathway. SG presents a potential EGFR targeted molecule, which may be further clinically developed in a combination therapy for CCA treatment.