86 research outputs found

    Arginase I in myeloid suppressor cells is induced by COX-2 in lung carcinoma

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    Myeloid suppressor cells (MSCs) producing high levels of arginase I block T cell function by depleting l-arginine in cancer, chronic infections, and trauma patients. In cancer, MSCs infiltrating tumors and in circulation are an important mechanism for tumor evasion and impair the therapeutic potential of cancer immunotherapies. However, the mechanisms that induce arginase I in MSCs in cancer are unknown. Using the 3LL mouse lung carcinoma, we aimed to characterize these mechanisms. Arginase I expression was independent of T cell–produced cytokines. Instead, tumor-derived soluble factors resistant to proteases induced and maintained arginase I expression in MSCs. 3LL tumor cells constitutively express cyclooxygenase (COX)-1 and COX-2 and produce high levels of PGE2. Genetic and pharmacological inhibition of COX-2, but not COX-1, blocked arginase I induction in vitro and in vivo. Signaling through the PGE2 receptor E-prostanoid 4 expressed in MSCs induced arginase I. Furthermore, blocking arginase I expression using COX-2 inhibitors elicited a lymphocyte-mediated antitumor response. These results demonstrate a new pathway of prostaglandin-induced immune dysfunction and provide a novel mechanism that can help explain the cancer prevention effects of COX-2 inhibitors. Furthermore, an addition of arginase I represents a clinical approach to enhance the therapeutic potential of cancer immunotherapies

    Recommendations for myeloid-derived suppressor cell nomenclature and characterization standards

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    Myeloid-derived suppressor cells (MDSCs) have emerged as major regulators of immune responses in cancer and other pathological conditions. In recent years, ample evidence supports key contributions of MDSC to tumour progression through both immune-mediated mechanisms and those not directly associated with immune suppression. MDSC are the subject of intensive research with >500 papers published in 2015 alone. However, the phenotypic, morphological and functional heterogeneity of these cells generates confusion in investigation and analysis of their roles in inflammatory responses. The purpose of this communication is to suggest characterization standards in the burgeoning field of MDSC research

    Regulation of SPDEF expression by DNA methylation in advanced prostate cancer

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    IntroductionProstate cancer (PCa) presents a significant health challenge in men, with a substantial number of deaths attributed to metastatic castration resistant PCa (mCRPC). Moreover, African American men experience disproportionately high mortality rates due to PCa. This study delves into the pivotal role of SPDEF, a prostate specific Ets transcription factor, and its regulation by DNA methylation in the context of PCa progression.MethodsWe performed Epigenetic reprogramming using daily treatment with non-toxic dose of 5Aza-2-deoxycytidine (5Aza-dC) for two weeks to assess its impact on PDEF expression in prostate cancer cells. Next, we conducted functional studies on reprogrammed cells, including cell migration (wound-healing assay), invasion (Boyden-Chamber test), and proliferation (MTT assay) to comprehensively evaluate the consequences of altered PDEF expression. We used bisulfite sequencing (BSP) to examine DNA methylation at SPDEF promoter. Simultaneously, we utilized siRNA-mediated targeting of key DNMTs (DNMT1, DNMT3A, and DNMT3B) to elucidate their specific role in regulating PDEF. We measured mRNA and protein expressions using qRT-PCR and immune-blotting techniques, respectively.ResultsIn this report, we observed that: a) there is a gradual decrease in SPDEF expression with a concomitant increase in methylated CpG sites within the SPDEF gene during prostate cancer progression from lower to higher Gleason grade; b) Expression of DNMT’s (DNMT1, 3a and 3b) is increased during prostate cancer progression, and there is an inverse correlation between SPDEF and DNMT expression; c) SPDEF levels are decreased in RC77/T, a line of PCa cells from African American origin similar to PC3 and DU145 cells (CRPC cells), as compared to LNCaP cells , a line of androgen dependent cells,; d) the 5′ CpG island of SPDEF gene are hypermethylated in SPDEF-negative CRPC ( PC3, DU145 and RC77/T) cell lines but the same regions are hypomethylated in SPDEF-positive castrate sensitive (LNCaP) cell line ; (e) expression of SPDEF in PCa cells lacking SPDEF decreases cell migration and invasion, but has no significant effect on cell proliferation, and; (f) treatment with the demethylating agent, 5-aza-2′-deoxycytidine, or silencing of the DNMT’s by siRNA, partially restores SPDEF expression in SPDEF-negative PCa cell lines, and decreases cell migration and invasion.DiscussionThese results indicate hypermethylation is a prevalent mechanism for decreasing SPDEF expression during prostate cancer progression. The data demonstrate that loss of SPDEF expression in prostate cancer cells, a critical step in cellular plasticity, results from a potentially reversible process of aberrant DNA methylation. These studies suggest DMNT activity as a potential therapeutic vulnerability that can be exploited for limiting cellular plasticity, tumor progression, and therapy resistance in prostate cancer

    Impact of Federal, State, and Local Housing Policies on Disparities in Cardiovascular Disease in Black/African American Men and Women: From Policy to Pathways to Biology

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    Racist and discriminatory federal, state, and local housing policies significantly contribute to disparities in cardiovascular disease incidence and mortality for individuals that self-identify as Black or African American. Here we highlight three key housing policies – “redlining,” zoning, and the construction of highways – which have wrought a powerful, sustained, and destructive impact on cardiovascular health in Black/African American communities. Redlining and highway construction policies have restricted access to quality health care, increased exposure to carcinogens such as PM2.5, and increased exposure to extreme heat. At the root of these policy decisions are longstanding, toxic societal factors including racism, segregation, and discrimination, which also serve to perpetuate racial inequities in cardiovascular health. Here, we review these societal and structural factors and then link them with biological processes such as telomere shortening, allostatic load, oxidative stress, and tissue inflammation. Lastly, we focus on the impact of inflammation on the immune system and the molecular mechanisms by which the inflamed immune microenvironment promotes the formation of atherosclerotic plaques. We propose that racial residential segregation and discrimination increases tissue inflammation and cytokine production, resulting in dysregulated immune signaling, which promotes plaque formation and cardiovascular disease. This framework has the power to link structural racism not only to cardiovascular disease, but also to cancer

    Inhibition of ERβ Induces Resistance to Cisplatin by Enhancing Rad51–Mediated DNA Repair in Human Medulloblastoma Cell Lines

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    Cisplatin is one of the most widely used and effective anticancer drugs against solid tumors including cerebellar tumor of the childhood, Medulloblastoma. However, cancer cells often develop resistance to cisplatin, which limits therapeutic effectiveness of this otherwise effective genotoxic drug. In this study, we demonstrate that human medulloblastoma cell lines develop acute resistance to cisplatin in the presence of estrogen receptor (ER) antagonist, ICI182,780. This unexpected finding involves a switch from the G2/M to G1 checkpoint accompanied by decrease in ATM/Chk2 and increase in ATR/Chk1 phosphorylation. We have previously reported that ERβ, which is highly expressed in medulloblastomas, translocates insulin receptor substrate 1 (IRS-1) to the nucleus, and that nuclear IRS-1 binds to Rad51 and attenuates homologous recombination directed DNA repair (HRR). Here, we demonstrate that in the presence of ICI182,780, cisplatin-treated medulloblastoma cells show recruitment of Rad51 to the sites of damaged DNA and increase in HRR activity. This enhanced DNA repair during the S phase preserved also clonogenic potential of medulloblastoma cells treated with cisplatin. In conclusion, inhibition of ERβ considered as a supplemental anticancer therapy, has been found to interfere with cisplatin–induced cytotoxicity in human medulloblastoma cell lines

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
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