2014
Advances in molecular biology, emergence of novel techniques and huge amount of information generated in the post-Human Genome Project era have fostered the emergence of new disciplines in the field of nutritional research: Nutrigenomics deals with the effect of diet on gene expression whereas nutrigenetics refers to the impact of inherited traits on the response to a specific dietary pattern, functional food or supplement. Understanding the role of micronutrient supplementation with specific genetic backgrounds may provide an important contribution to a new optimum health strategy based on individualized nutritional treatment and may provide the strategies for the development of safer and more effective dietary interventions. This overview of the various aspects of supplementation of micronutrients in the era of nutrigenetics and nutrigenomics may provide a better understanding of novel nutritional research approach and provide an additional insight that can be applied to the daily dietary practice.
Since ancient times, medicinal mushrooms have been traditionally used as a health food or supplement for the prevention and cure of a range of health-statuses or diseases, such as overt inflammation, atherosclerosis, cancer, hypertension, diabetes and others. We concentrate in this review on the effect and putative mechanism of action of glucans harvested from fungi on inflammatory bowel disease (IBD) and colitis associated cancer. Many scientists including our own group have examined the immunomodulating effect of isolated polysaccharides-glucans in general and specifically in inflammation associated with cancer. In this manuscript we reviewed the sources, the chemical composition and medicinal properties of polysaccharides extracted from edible mushrooms. In addition we brought insights into their putative mechanisms of action behind each health-promoting activity of these interesting biomolecules. The preventive and therapeutic effects of the medicinal mushrooms and their components have been well documented in mouse and rat model systems and in cancer cell lines being the most striking effects reported to their anti-inflammatory and antitumor effect. Their anticancer effects were demonstrated mainly in in vitro and in vivo experimental systems but a very limited number of studies have been conducted in human populations. We can summarize that oral consumption of several mushrooms glucans is an efficient treatment to prevent colitis-associated dysplasias through modulation of mucosal inflammation and cell proliferation. Identifying new food-derived isolates and understanding their mechanisms of action are the main challenges in using mushrooms glucans for therapeutic purposes in the field of IBD and associated cancer. Only an in-depth understanding of the mechanism of action and cross-talk between the inflammatory cell, epithelial cell and fungi derived glucans on which we have a based structural knowledge will lead to well designed intervention clinical human studies to test the efficacy of these molecules on intestinal inflammation and colitis associated cancer.
A. Algamas-Dimantov, Yehuda-Shnaidman, E. , Hertz, R. , Peri, I. , Bar-Tana, J. , and Schwartz, B. . 2014.
“Prevention Of Diabetes-Promoted Colorectal Cancer By (N-3) Polyunsaturated Fatty Acids And (N-3) Pufa Mimetic”. Oncotarget, 5, 20, Pp. 9851-63. doi:10.18632/oncotarget.2453.
Publisher's Version Abstract The global obesity / diabetes epidemic has resulted in robust increase in the incidence of colorectal cancer (CRC). Epidemiological, animal and human studies have indicated efficacy of (n-3) PUFA in chemoprevention of sporadic and genetic-driven CRC. However, diabetes-promoted CRC presents a treatment challenge that surpasses that of sporadic CRC. This report analyzes the efficacy of (n-3) PUFA generated by the fat-1 transgene that encodes an (n-6) to (n-3) PUFA desaturase, and of synthetic (n-3) PUFA mimetic (MEDICA analog), to suppress CRC development in carcinogen-induced diabetes-promoted animal model. Carcinogen-induced CRC is shown here to be promoted by the diabetes context, in terms of increased aberrant crypt foci (ACF) load, cell proliferation and epithelial dedifferentiation, being accompanied by increase in the expression of HNF4alpha, beta-catenin, and beta-catenin-responsive genes. Incorporating the fat-1 transgene in the diabetes context, or oral MEDICA treatment, resulted in ameliorating the diabetic phenotype and in abrogating CRC, with decrease in ACF load, cell proliferation and the expression of HNF-4alpha, beta-catenin, and beta-catenin-responsive genes. The specificity of (n-3) PUFA in abrogating CRC development, as contrasted with enhancing CRC by (n-6) PUFA, was similarly verified in CRC cell lines. These findings may indicate prospective therapeutic potential of (n-3) PUFA or MEDICA in the management of CRC, in particular diabetes-promoted CRC.
Newly emerging data highlight obesity as an important risk factor for developing certain types of cancer, including colorectal cancer. Although evidence supports a link between the two, the mechanisms responsible for this relationship have not yet been fully elucidated. Hypertrophied and dysfunctional adipose tissue of the obese state is characterized by low-grade inflammation. Adipokines and cytokines secreted from adipocytes, together with the abundant availability of lipids from adipocytes in the tumor microenvironment, promote adhesion, migration, and invasion of tumor cells and support tumor progression and uncontrolled growth. One of the predisposed targets of the deleterious effects exerted by secretions from adipose tissue in obesity is the activities associated with the cellular mitochondria. Mitochondrial oxidative metabolism plays a key role in meeting cells' energetic demands by oxidative phosphorylation (OxPhos). Here we discuss: (a) the dynamic relationship between glycolysis, the tricarboxylic acid cycle, and OxPhos; (b) the evidence for impaired OxPhos (i.e., mitochondrial dysfunction) in colon cancer; (c) the mechanisms by which mitochondrial dysfunction can predispose to cancer. We propose that impaired OxPhos increases susceptibility to colon cancer since OxPhos is sensitive to a large number of factors that are intrinsic to the host (e.g., inflammation). Given that adipocytes are a major source of adipokines and energy for the cancer cell, understanding the mechanisms of metabolic symbiosis between cancer cells and adipocytes should reveal new therapeutic possibilities.
2013
BACKGROUND: We previously found that enhanced expression of hepatocyte nuclear factor 4alpha (HNF-4alpha) is associated with hyper-proliferation of colon carcinoma cells. Here, the effect of histone deacetylase (HDAC) inhibitors on proliferation and the expression of HNF-4alpha and its downstream target genes were assessed in HM7, LS174T, HT29 and Caco-2 colon carcinoma cell lines. RESULTS: HNF-4alpha expression was found to vary in the different colon carcinoma cell lines tested, being highest in HM7. Additionally, a direct correlation with proliferation was observed. In HM7 cells, the weak HDAC inhibitor butyrate significantly inhibited the transcription of HNF-4alpha, its downstream target gene MUC4, and genes associated with proliferation, including the proliferating cell nuclear antigen gene PCNA. siRNA-mediated silencing of HNF-4alpha exerted an effect similar to butyrate on HM7 cell proliferation. The stronger HDAC inhibitor trichostatin A (TSA) exerted an effect similar to that of siRNA-mediated HNF-4alpha silencing and, concomitantly, inhibited the expression of the transcription factor gene SP1. Also, siRNA-mediated silencing of HDAC3 and HDAC4 reduced HNF-4alpha expression. Chromatin immunoprecipitation (ChIP) assays revealed that TSA induces hyperacetylation of histones H3 and H4 and, concomitantly, inhibits SP1 binding to the HNF-4alpha promoter. Subsequent electromobility shift assays supported these latter findings. CONCLUSIONS: HNF-4alpha transcriptional expression and activity are tightly controlled by epigenetic mechanisms. HDAC inhibitor targeting of HNF-4alpha may serve as an effective treatment for advanced colon carcinomas, since downstream cancer-associated target genes such as MUC4 are significantly down-regulated by this treatment.
L. Nimri, Barak, H. , Graeve, L. , and Schwartz, B. . 2013.
“Restoration Of Caveolin-1 Expression Suppresses Growth, Membrane-Type-4 Metalloproteinase Expression And Metastasis-Associated Activities In Colon Cancer Cells”. Mol Carcinog, 52, 11, Pp. 859-70. doi:10.1002/mc.21927.
Publisher's Version Abstract Caveolin-1 (cav-1) and flotillin-1 are two major structural proteins associated with lipid rafts in mammalian cells. The membrane-type matrix metalloproteinases (MT-MMPs) are expressed at the cell surface, hydrolyze extracellular matrix, and play an important role in cancer cell migration and metastasis. Expression of cav-1, flotillin-1, and MT4-MMP in lysates and lipid rafts of LS174T and HM-7 colon cancer cells was determined. The impact of restoration of cav-1 expression on proliferation, adhesion, motility in vitro, and growth of implanted tumors in vivo was characterized. Cav-1 is not expressed in lipid rafts of the highly metastatic colon cancer cell line (HM-7), but expressed in cytosolic fractions of the parental lower metastatic cell line (LS174T). In contrast, MT4-MMP was expressed in lipid rafts of HM-7 cells but not in LS174T cells. Overexpression of cav-1 in HM-7 cells down-regulate proliferation, viability, wound closure, adhesion to laminin, invasion, and development of filopodial and lamellipodial structures in a dose-dependent manner. Cav-1 positive HM-7 clones ceased to express MT4-MMP in their lipid rafts. Comparative proteomic analyses of lipid rafts from cav-1 positive and cav-1 negative cells demonstrated de novo expression of flotillin-1 only on the cells expressing cav-1. Xenografting control cells devoid of cav-1 in nude mice induced development of bigger tumors expressing higher levels of proliferating cell nuclear antigen as compared to mice injected with cells expressing the highest cav-1 levels. We conclude that cav-1 orchestrates and reorganize several proteins in lipid rafts, activities directly associated with reduced tumorigenic and metastatic ability of colon cancer cells.
E. Yehuda-Shnaidman, Nimri, L. , Tarnovscki, T. , Kirshtein, B. , Rudich, A. , and Schwartz, B. . 2013.
“Secreted Human Adipose Leptin Decreases Mitochondrial Respiration In Hct116 Colon Cancer Cells”. Plos One, 8, 9, Pp. e74843. doi:10.1371/journal.pone.0074843.
Publisher's Version Abstract Obesity is a key risk factor for the development of colon cancer; however, the endocrine/paracrine/metabolic networks mediating this connection are poorly understood. Here we hypothesize that obesity results in secreted products from adipose tissue that induce malignancy-related metabolic alterations in colon cancer cells. Human HCT116 colon cancer cells, were exposed to conditioned media from cultured human adipose tissue fragments of obese vs. non-obese subjects. Oxygen consumption rate (OCR, mostly mitochondrial respiration) and extracellular acidification rate (ECAR, mostly lactate production via glycolysis) were examined vis-a-vis cell viability and expression of related genes and proteins. Our results show that conditioned media from obese (vs. non-obese) subjects decreased basal (40%, p<0.05) and maximal (50%, p<0.05) OCR and gene expression of mitochondrial proteins and Bax without affecting cell viability or expression of glycolytic enzymes. Similar changes could be recapitulated by incubating cells with leptin, whereas, leptin-receptor specific antagonist inhibited the reduced OCR induced by conditioned media from obese subjects. We conclude that secreted products from the adipose tissue of obese subjects inhibit mitochondrial respiration and function in HCT116 colon cancer cells, an effect that is at least partly mediated by leptin. These results highlight a putative novel mechanism for obesity-associated risk of gastrointestinal malignancies, and suggest potential new therapeutic avenues.
The use of dietary components having protective and/or preventive effects on chronic diseases is an important emerging field of research. Identifying new food supplements and understanding their mechanisms of action are some of the main challenges in using functional foods. In this manuscript we reviewed the sources, the chemical composition and medicinal properties of polysaccharides extracted from edible mushrooms. In addition we brought insights into the putative mechanisms of action behind each health-promoting activity of these interesting biomolecules.
2012
M. De Leeuw, Gonzalez, A. , Lanir, A. , Roiz, L. , Smirnoff, P. , Schwartz, B. , Shoseyov, O. , and Almog, O. . 2012.
“The 1.8 A Crystal Structure Of Actibind Suggests A Mode Of Action For T2 Ribonucleases As Antitumorigenic Agents”. J Med Chem, 55, 3, Pp. 1013-20. doi:10.1021/jm1015507.
Publisher's Version Abstract ACTIBIND and its human homologue RNASET2 are T2 ribonucleases (RNases). RNases are ubiquitous and efficient enzymes that hydrolyze RNA to 3' mononucleotides and also possess antitumorigenic and antiangiogenic activities. Previously, we have shown that ACTIBIND and RNASET2 bind actin and interfere with the cytoskeletal network structure, thereby inhibiting cell motility and invasiveness in cancer and in endothelial cells. We also showed that ACTIBIND binds actin in a molar ratio of 1:2. Here, we further characterize ACTIBIND and determine its crystal structure at 1.8 A resolution, which enables us to propose two structural elements that create binding sites to actin. We suggest that each of these binding sites is composed of one cysteine residue and one conserved amino acid region. These binding sites possibly interfere with the cytoskeleton network structure and as such may be responsible for the antitumorigenic and antiangiogenic activities of ACTIBIND and its human analogue RNASET2.
A. Algamas-Dimantov, Davidovsky, D. , Ben-Ari, J. , Kang, J.X. , Peri, I. , Hertz, R. , Bar-Tana, J. , and Schwartz, B. . 2012.
“Amelioration Of Diabesity-Induced Colorectal Ontogenesis By Omega-3 Fatty Acids In Mice”. J Lipid Res, 53, 6, Pp. 1056-70. doi:10.1194/jlr.M021949.
Publisher's Version Abstract Postnatal intestinal ontogenesis in an animal model of diabesity may recapitulate morphological and transduction features of diabesity-induced intestinal dysplasia and its amelioration by endogenous (n-3) polyunsaturated fatty acids (PUFA). Proliferation, differentiation, and transduction aspects of intestinal ontogenesis have been studied here in obese, insulin-resistant db/db mice, in fat-1 transgene coding for desaturation of (n-6) PUFA into (n-3) PUFA, in db/db crossed with fat-1 mice, and in control mice. Diabesity resulted in increased colonic proliferation and dedifferentiation of epithelial colonocytes and goblet cells, with increased colonic beta-catenin and hepatocyte nuclear factor (HNF)-4alpha transcriptional activities accompanied by enrichment in HNF-4alpha-bound (n-6) PUFA. In contrast, in fat-1 mice, colonic proliferation was restrained, accompanied by differentiation of crypt stem cells into epithelial colonocytes and goblet cells and by decrease in colonic beta-catenin and HNF-4alpha transcriptional activities, with concomitant enrichment in HNF-4alpha-bound (n-3) PUFA at the expense of (n-6) PUFA. Colonic proliferation and differentiation, the profile of beta-catenin and HNF-4alpha-responsive genes, and the composition of HNF-4alpha-bound PUFA of db/db mice reverted to wild-type by introducing the fat-1 gene into the db/db context. Suppression of intestinal HNF-4alpha activity by (n-3) PUFA may ameliorate diabesity-induced intestinal ontogenesis and offer an effective preventive modality for colorectal cancer.
M. Theilla, Schwartz, B. , Zimra, Y. , Shapiro, H. , Anbar, R. , Rabizadeh, E. , Cohen, J. , and Singer, P. . 2012.
“Enteral N-3 Fatty Acids And Micronutrients Enhance Percentage Of Positive Neutrophil And Lymphocyte Adhesion Molecules: A Potential Mediator Of Pressure Ulcer Healing In Critically Ill Patients”. Br J Nutr, 107, 7, Pp. 1056-61. doi:10.1017/S0007114511004004.
Publisher's Version Abstract n-3 Fatty acids are recognised as influencing both wound healing and immunity. We assessed the impact of a fish oil- and micronutrient-enriched formula (study formula) on the healing of pressure ulcers and on immune function in critically ill patients in an intensive care unit. A total of forty patients with pressure ulcers and receiving nutritional support were enrolled (intervention group, n 20, received study formula; and a control group, n 20, received an isoenergetic formula). Total and differential leucocyte count and percentage of adhesion molecule positive granulocyte and lymphocyte cells (CD11a, CD11b, CD18 and CD49b) were measured on days 0, 7 and 14. Percentage of positive lymphocytes for CD54, CD49b, CD49d and CD8 were also measured on days 0, 7 and 14. The state of pressure ulcers was assessed by using the pressure ulcer scale for healing tool score on days 7, 14 and 28 of treatment. No between-group differences in patient demographics, anthropometry or diagnostic class were observed. Patients who received the study formula showed significant increases in the percentage of positive CD18 and CD11a lymphocytes and of CD49b granulocytes as compared to controls (P < 0.05). While the severity of pressure ulcers was not significantly different between the two groups on admission, severity increased significantly over time for the control group (P < 0.05), but not for the study group. The present study suggests that a fish oil- and micronutrient-enriched formula may prevent worsening of pressure ulcers and that this effect may be mediated by an effect on adhesion molecule expression.
I. Lavi, Nimri, L. , Levinson, D. , Peri, I. , Hadar, Y. , and Schwartz, B. . 2012.
“Glucans From The Edible Mushroom Pleurotus Pulmonarius Inhibit Colitis-Associated Colon Carcinogenesis In Mice”. J Gastroenterol, 47, 5, Pp. 504-18. doi:10.1007/s00535-011-0514-7.
Publisher's Version Abstract BACKGROUND: We have recently demonstrated that polysaccharides from fruiting body extract (FBE) or mycelia extract (ME) of the edible mushroom Pleurotus pulmonarius exert antiproliferative effects in intestinal cells and an anti-inflammatory effect in a dextran sulfate sodium (DSS) mouse model of acute colitis. The aim of this study was to assess the role of fungal FBE and ME in colon carcinogenesis. METHODS: In vitro, human colorectal cancer cells were treated with FBE and ME and analyzed for inflammation response, for markers of apoptosis, and for cell-cycle progression. In vivo, FBE and ME were tested in a mouse model of colitis-associated colorectal carcinogenesis induced by cyclic treatments with DSS and azoxymethane. Treated mice were fed a daily diet containing 2 or 20 mg FBE or ME per mouse for 80 days. RESULTS: In vitro, FBE and ME induced apoptosis in a dose-responsive manner and modulated the expression of Bcl-2, Bax, and cytochrome c, and blocked tumor necrosis factor (TNF)-alpha-induced inhibitor of nuclear factor (NF) (Ikappa)-Balpha degradation and NF-kappaB nuclear translocation. In vivo, dietary administration of FBE and ME significantly reduced the formation of aberrant crypt foci, which precedes colorectal cancer, and of microadenomas. The treatments significantly lowered the expression of proliferating cell nuclear antigen and increased the number of cells undergoing apoptosis in the colon. Additionally, FBE and ME inhibited the expression of the proinflammatory cytokine TNF-alpha in colonic tissue. CONCLUSIONS: We conclude that P. pulmonarius FBE and ME inhibit colitis-associated colon carcinogenesis induced in mice through the modulation of cell proliferation, induction of apoptosis, and inhibition of inflammation.
M. Theilla, Schwartz, B. , Cohen, J. , Shapiro, H. , Anbar, R. , and Singer, P. . 2012.
“Impact Of A Nutritional Formula Enriched In Fish Oil And Micronutrients On Pressure Ulcers In Critical Care Patients”. Am J Crit Care, 21, 4, Pp. e102-9. doi:10.4037/ajcc2012187.
Publisher's Version Abstract BACKGROUND: Pressure ulcers are an important source of morbidity and suffering for patients and a formidable burden on caregivers. OBJECTIVES: To assess the impact of a feeding formula enriched with fish oil on healing of preexisting pressure ulcers and serum levels of C-reactive protein in critical care patients. METHODS: Adult patients with pressure ulcers grade II or higher were randomly allocated to receive either a formula enriched with fish oil or an isocaloric control formula. Wound healing was assessed by using the Pressure Ulcer Scale for Healing tool on days 7, 14, and 28. Blood levels of C-reactive protein were measured on days 0, 7, and 14. RESULTS: Baseline demographics did not differ between the study (n = 20) and the control (n = 20) groups. The mean score on the ulcer healing tool increased significantly (P = .02) from day 0 to day 28 in the control group (from 9.25 [SD, 2.12] to 10.75 [SD, 3.41]) compared with the study group (from 9.10 [SD, 2.84] to 9.40 [SD, 3.72]). Mean levels of C-reactive protein decreased significantly (P= .02) from day 0 to day 14 in the study group (from 191 [SD, 104.4] mg/L to 111.7 [SD, 97.8] mg/L) compared with the control group (from 145 [SD, 90] mg/L to 139 [SD, 62] mg/L). CONCLUSION: Administration of a feeding formula enriched with fish oil was associated with decreased progression of pressure ulcers and a decrease in blood concentrations of C-reactive protein.
Due to its prevalence, obesity is now considered a global epidemic. It is linked to increased risk of colorectal cancer, the third most common cancer and the second leading cause of death among adults in Western countries. Obese adipose tissue differs from lean adipose tissue in its immunogenic profile, body fat distribution and metabolic profile. Obese adipose tissue releases free fatty acids, adipokines and many pro-inflammatory chemokines. These factors are known to play a key role in regulating malignant transformation and cancer progression. Obese adipose tissue is infiltrated by macrophages that participate in inflammatory pathways activated within the tissue. Adipose tissue macrophages consist of two different phenotypes. M1 macrophages reside in obese adipose tissue and produce pro-inflammatory cytokines, and M2 macrophages reside in lean adipose tissue and produce anti-inflammatory cytokines, such as interleukin-10 (IL-10). The metabolic networks that confer tumour cells with their oncogenic properties, such as increased proliferation and the ability to avoid apoptosis are still not well understood. We review the interactions between adipocytes and immune cells that may alter the metabolism towards promotion of colorectal cancer.
V. Yashunsky, Lirtsman, V. , Zilbershtein, A. , Bein, A. , Schwartz, B. , Aroeti, B. , Golosovsky, M. , and Davidov, D. . 2012.
“Surface Plasmon-Based Infrared Spectroscopy For Cell Biosensing”. J Biomed Opt, 17, 8, Pp. 081409-1. doi:10.1117/1.JBO.17.8.081409.
Publisher's Version Abstract Cell morphology is often used as a valuable indicator of the physical condition and general status of living cells. We demonstrate a noninvasive method for morphological characterization of adherent cells. We measure infrared reflectivity spectrum at oblique angle from living cells cultured on thin Au film, and utilize the unique properties of the confined infrared waves (i.e., surface plasmon and guided modes) traveling inside the cell layer. The propagation of these waves strongly depends on cell morphology and connectivity. By tracking the resonant wavelength and attenuation of the surface plasmon and guided modes we measure the kinetics of various cellular processes such as (i) cell attachment and spreading on different substrata, (ii) modulation of the outer cell membrane with chlorpromazine, and (iii) formation of intercellular junctions associated with progressive cell polarization. Our method enables monitoring of submicron variations in cell layer morphology in real-time, and in the label-free manner.
2010
W. Bat-Chen, Golan, T. , Peri, I. , Ludmer, Z. , and Schwartz, B. . 2010.
“Allicin Purified From Fresh Garlic Cloves Induces Apoptosis In Colon Cancer Cells Via Nrf2”. Nutr Cancer, 62, 7, Pp. 947-57. doi:10.1080/01635581.2010.509837.
Publisher's Version Abstract Allicin (diallyl thiosulfinate) is the best-known biologically active component in freshly crushed garlic extract. We developed a novel, simple method to isolate active allicin, which yielded a stable compound in aqueous solution amenable for use in in vitro and in vivo studies. We focused on the in vitro effects of allicin on cell proliferation of colon cancer cell lines HCT-116, LS174T, HT-29, and Caco-2 and assessed the underlying mechanisms. This allicin preparation exerted a time- and dose-dependent cytostatic effect on these cells at concentrations ranging from 6.2 to 310 muM. Treatment with allicin resulted in HCT-116 apoptotic cell death as demonstrated by enhanced hypodiploid DNA content, decreased levels of B-cell non-Hodgkin lymphoma-2 (Bcl-2), increased levels of bax and increased capability of releasing cytochrome c from mitochondria to the cytosol. Allicin also induced translocation of NF-E2-related factor-2 (Nrf2) to the nuclei of HCT-116 cells. Luciferase reporter gene assay showed that allicin induces Nrf2-mediated luciferase transactivation activity. SiRNA knock down of Nrf2 significantly affected the capacity of allicin to inhibit HCT-116 proliferation. These results suggest that Nrf2 mediates the allicin-induced apoptotic death of colon cancer cells.
Publisher Summary Different studies have shown that the consumption of olive oil may have a potential role in lowering the risk of malignant neoplasms, especially breast and stomach cancer and also ovary, colon and endometrium cancer. Different mechanisms for the modulatory actions of olive oil and other dietary lipids on cancer have been proposed. Among them, there is experimental evidence about an influence on the hormonal status, cell membrane structure and function, signal transduction pathways, gene expression, and the immune system. Nevertheless, the definite mechanisms by which the effects of olive oil are mediated are not well understood and require further elucidation. Colomer and Menendez suggested that the molecular explanation concerning the anticancer actions of olive oil might relate to the ability of oleic acid (OA) to specifically regulate cancer-related oncogenes. Exogenous supplementation of cultured breast cancer cells with physiological concentrations of oleic acid was found to suppress the overexpression of Her-2, a well-characterized oncogene playing a key role in the etiology, progression and response to chemotherapy and endocrine therapy in approximately 20% of breast carcinomas. Exogenous supplementation with oleic acid dramatically down-regulates Her-2/neu-coded p185Her-2/neu oncoprotein in human breast cancer cell lines, bearing amplification of the Her-2/neu oncogene. Importantly, oleic-acid–induced suppression of Her-2/neu overexpression was not significantly prevented by the effective scavenger of reactive oxygen species vitamin E, thus ruling out that lipid peroxidation may be involved in this effect.
I. Lavi, Levinson, D. , Peri, I. , Tekoah, Y. , Hadar, Y. , and Schwartz, B. . 2010.
“Chemical Characterization, Antiproliferative And Antiadhesive Properties Of Polysaccharides Extracted From Pleurotus Pulmonarius Mycelium And Fruiting Bodies”. Appl Microbiol Biotechnol, 85, 6, Pp. 1977-90. doi:10.1007/s00253-009-2296-x.
Publisher's Version Abstract Mushroom polysaccharides are potent substances that exhibit antitumor and immunomodulatory properties. Studies comparing the chemical composition and antitumor-related activities of polysaccharides released by fungal strains under different growth conditions are not available. Thus, the present study compared polysaccharides extracts produced by Pleurotus pulmonarius from mycelium grown in liquid culture (ME) or fruiting bodies (FBE). Polysaccharides of both ME and FBE had a relatively high molecular mass. NMR spectroscopy indicated that ME glucan is an alpha-glucan whereas FBE glucan is a mixture of both alpha- and beta-glucans. Glucose and galactose where the most prominent monosaccharide in both glucans. Treatment of several colon cancer cell lines expressing varying amounts of galectin-3 with the two fungal glucans inhibited their viability and significantly reduced their ability to adhere to the key component of the extracellular matrix, fibronectin, and to a human umbilical vein endothelial cell monolayer, in a time- and dose-dependent manner mainly in those cell lines expressing high amounts of galectin-3. We conclude that ME and FBE glucans may exert a direct antiproliferative effect on cancer cells expressing high galectin-3 concentrations and concomitantly downregulate tumor cell adherence, the latter being directly related to cancer progression and metastasis.