Therapeutic potential of GW501516 and the role of Peroxisome proliferator-activated receptor β/δ and B-cell lymphoma 6 in inflammatory signaling in human pancreatic cancer cells.

Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is a member of the nuclear receptor superfamily and a ligand-activated transcription factor that is involved in the regulation of the inflammatory response via activation of anti-inflammatory target genes and ligand-induced disassociation with the transcriptional repressor B-cell lymphoma 6 (BCL6). Chronic pancreatitis is considered to be a significant etiological factor for pancreatic cancer development, and a better understanding of the underlying mechanisms of the transition between inflammation and carcinogenesis would help further elucidate chemopreventative options. The aim of this study was to determine the role of PPARβ/δ and BCL6 in human pancreatic cancer of ductal origin, as well as the therapeutic potential of PPARβ/δ agonist, GW501516.

Effects of cranberry extracts on gene expression in THP-1 cells.

Cranberry contains high levels of nutrients and bioactive molecules that have health-promoting properties. The purpose of the present studies was to determine if cranberry extracts (CEs) contain phytochemicals that exert anti-inflammatory effects. The human monocytic cell line THP-1 was treated with two CEs (CE and 90MX) and subsequently challenged with Lipopolysaccharides (LPS).

Differential nucleobase protection against 5-fluorouracil toxicity for squamous and columnar cells: implication for tissue function and oncogenesis.

Purpose: The goal of these studies was to test if local excess of a normal nucleobase substrate prevents the toxicity of protracted 5FU exposure used in human cancer treatment.

Methods: Messenger RNA expression studies were performed of 5FU activating enzymes in human colon cancer cells lines (CaCo-2, HT-29), primary human gingival cells (HEGP), and normal esophageal and gastric clinical tissue samples. Excess nucleobase was then used in vitro to protect cells from 5FU toxicity.

Marine- and plant-derived ω-3 fatty acids differentially regulate prostate cancer cell proliferation.

Fish oil contains the marine ω-3 polyunsaturated fatty acids (ω-3 PUFAs) docosahexaenoic (DHA) and eicosapentaenoic acid (EPA). The consumption of diets rich in these fatty acids is associated with a decreased incidence of prostate cancer. However, there is limited knowledge regarding the non-marine ω-3 PUFA α-linolenic acid (ALA).

Evidence for triclosan-induced activation of human and rodent xenobiotic nuclear receptors.

The bacteriostat triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether) (TCS) decreases rat serum thyroxine via putative nuclear receptor (NR) interaction(s) and subsequent transcriptional up-regulation of hepatic catabolism and clearance. However, due to the evolutionary divergence of the constitutive androstane and pregnane-X receptors (CAR, PXR), TCS-mediated downstream effects may be species-dependent. To test the hypothesis that TCS activates xenobiotic NRs across species, cell-based NR reporter assays were employed to assess potential activation of rat, mouse, and human PXR, and rat, mouse, and three splice variants of human CAR.

Role of Peroxisome Proliferator-Activated Receptor β/δ and B-Cell Lymphoma-6 in Regulation of Genes Involved in Metastasis and Migration in Pancreatic Cancer Cells.

PPARβ/δ is a ligand-activated transcription factor that regulates various cellular functions via induction of target genes directly or in concert with its associated transcriptional repressor, BCL-6. Matrix remodeling proteinases are frequently over-expressed in pancreatic cancer and are involved with metastasis. The present study tested the hypothesis that PPARβ/δ is expressed in human pancreatic cancer cells and that its activation could regulate MMP-9, decreasing cancer cells ability to transverse the basement membrane.

Mechanistic examination of walnuts in prevention of breast cancer.

Walnuts contain bioactive molecules that may contribute to their beneficial effects, including alpha-linolenic acid (ALA) and phytosterols. In these studies, extracts of walnut, purified compounds, or postprandial serum were examined for effects on breast cancer cell proliferation and gene expression. Extracts derived from walnut oil decreased proliferation of MCF-7 cells, as did ALA and β-sitosterol.

The dietary fatty acid 10E12Z-CLA induces epiregulin expression through COX-2 dependent PGF(2α) synthesis in adipocytes.

Conjugated linoleic acids (CLAs) are a group of dietary fatty acids that are widely marketed as weight loss supplements. The isomer responsible for this effect is the trans-10, cis-12 CLA (10E12Z-CLA) isomer. 10E12Z-CLA treatment during differentiation of 3T3-L1 adipocytes induces expression of prostaglandin-endoperoxide synthase-2 (Cyclooxygenase-2; COX-2).

Regulation of inflammatory and lipid metabolism genes by eicosapentaenoic acid-rich oil.

Omega-3-PUFAs, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), are associated with prevention of various aspects of metabolic syndrome. In the present studies, the effects of oil rich in EPA on gene expression and activation of nuclear receptors was examined and compared with other ω3-PUFAs. The EPA-rich oil (EO) altered the expression of FA metabolism genes in THP-1 cells, including stearoyl CoA desaturase (SCD) and FA desaturase-1 and -2 (FASDS1 and -2).

Δ12-prostaglandin J3, an omega-3 fatty acid-derived metabolite, selectively ablates leukemia stem cells in mice.

Targeting cancer stem cells is of paramount importance in successfully preventing cancer relapse. Recently, in silico screening of public gene-expression datasets identified cyclooxygenase-derived cyclopentenone prostaglandins (CyPGs) as likely agents to target malignant stem cells. We show here that Δ(12)-PGJ(3), a novel and naturally produced CyPG from the dietary fish-oil ω-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA; 20:5) alleviates the development of leukemia in 2 well-studied murine models of leukemia.

Walnut oil increases cholesterol efflux through inhibition of stearoyl CoA desaturase 1 in THP-1 macrophage-derived foam cells.

Background: Walnuts significantly decrease total and low-density lipoprotein cholesterol in normo- and hypercholesterolemic individuals. No study to date has evaluated the effects of walnuts on cholesterol efflux, the initial step in reverse cholesterol transport, in macrophage-derived foam cells (MDFC). The present study was conducted to investigate the mechanisms by which walnut oil affects cholesterol efflux.

10e12z CLA alters adipocyte differentiation and adipocyte cytokine expression and induces macrophage proliferation.

The trans-10, cis-12 (10e12z) conjugated linoleic acid (CLA) isomer of CLA is responsible for loss of lipid storage or adipose tissue in vitro or in vivo. This isomer also induces inflammatory signaling in both mouse and human adipocytes in vitro. However, when these events occur and whether they are significant enough to affect other cell types are unclear.

Alpha-linolenic acid increases cholesterol efflux in macrophage-derived foam cells by decreasing stearoyl CoA desaturase 1 expression: evidence for a farnesoid-X-receptor mechanism of action.

Increased cholesterol efflux from macrophage-derived foam cells (MDFCs) is an important protective mechanism to decrease lipid load in the atherosclerotic plaque. Dietary alpha-linolenic acid (ALA), an omega-3 polyunsaturated fatty acid (PUFA), decreases circulating cholesterol, but its role in cholesterol efflux has not been extensively studied. Stearoyl CoA desaturase 1 (SCD1) is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids (MUFAs).

15-Deoxy-delta12,14-prostaglandin J2-glycerol ester, a putative metabolite of 2-arachidonyl glycerol, activates peroxisome proliferator activated receptor gamma.

2-Arachidonyl glycerol (2-AG) is an endogenous arachidonic acid derivative capable of suppressing interleukin (IL)-2 production by activated T cells. 2-AG-mediated IL-2 suppression is dependent on cyclooxygenase-2 (COX-2) metabolism and peroxisome proliferator activated receptor γ (PPARγ) activation. The objective of the present studies was to examine whether 15-deoxy-Δ(12,14)-PGJ(2)-glycerol ester (15d-PGJ(2)-G), a putative metabolite of 2-AG, can mimic the actions of 2-AG on IL-2 regulation through PPARγ activation.

Effect of pistachio oil on gene expression of IFN-induced protein with tetratricopeptide repeats 2: a biomarker of inflammatory response.

When incorporated into the diet, pistachios have a beneficial effect on lipid and lipoprotein profiles. However, little is known about potential anti-inflammatory properties. This study was conducted to determine whether pistachio oil and an organic extract from pistachio oil extract (PE) regulated expression of inflammation-related genes.

Dasatinib inhibits both osteoclast activation and prostate cancer PC-3-cell-induced osteoclast formation.

Purpose: Therapies to target prostate cancer bone metastases have only limited effects. New treatments are focused on the interaction between cancer cells, bone marrow cells and the bone matrix. Osteoclasts play an important role in the development of bone tumors caused by prostate cancer.

9E,11E-conjugated linoleic acid increases expression of the endogenous antiinflammatory factor, interleukin-1 receptor antagonist, in RAW 264.7 cells.

Despite having a similar structure, various conjugated linoleic acid (CLA) isomers have a distinct gene expression pattern in RAW 264.7 (RAW) cells, a mouse macrophage cell line. Among the 5 CLA isomers tested [9cis(Z),11trans(E)-, 9Z,11Z-, 9E,11E-, 10E,12Z-, and 11Z,13E-CLA], only 9E,11E-CLA induced the endogenous antiinflammatory molecule, interleukin (IL)-1 receptor antagonist (IL-1Ra), in RAW cells.

Isomer-specific effects of conjugated linoleic acid on gene expression in RAW 264.7.

Conjugated linoleic acid (CLA) is a mixture of dietary fatty acids that has various beneficial effects including decreasing cancer, atherosclerosis, diabetes and inflammation in animal models. Some controversy exists on the specific isomers of CLA that are responsible for the benefits observed. This study was conducted to examine how different CLA isomers regulate gene expression in RAW 264.

The anti-inflammatory effects of selenium are mediated through 15-deoxy-Delta12,14-prostaglandin J2 in macrophages.

Selenium is an essential micronutrient that suppresses the redox-sensitive transcription factor NF-kappaB-dependent pro-inflammatory gene expression. To understand the molecular mechanisms underlying the anti-inflammatory property of selenium, we examined the activity of a key kinase of the NF-kappaB cascade, IkappaB-kinase beta (IKKbeta) subunit, as a function of cellular selenium status in murine primary bone marrow-derived macrophages and RAW264.7 macrophage-like cell line.

The oxidative stress mediator 4-hydroxynonenal is an intracellular agonist of the nuclear receptor peroxisome proliferator-activated receptor-beta/delta (PPARbeta/delta).

Liver insufficiency and damage are major causes of death and disease worldwide and may result from exposure to environmental toxicants, specific combinations or dosages of pharmaceuticals, and microbial metabolites. The generation of reactive intermediates, in particular 4-hydroxynonenal (4-HNE), is a common event in liver damage caused by a variety of hepatotoxic drugs and solvents. The peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that are involved in the transcriptional regulation of lipid metabolism as well as other biological functions.

Examination of Ligand-Dependent Coactivator Recruitment by Peroxisome Proliferator-Activated Receptor-alpha (PPARalpha).

The ligand-dependent recruitment of coactivators to peroxisome proliferator-activated receptor-alpha (PPARalpha) was examined. PPAR-binding protein (PBP), PPARgamma coactivator-1alpha (PGC-1alpha), steroid receptor coactivator-1 (SRC-1), and CBP/p300-interacting transactivator with ED-rich tail 2 (CITED2) affected PPARalpha activity in the presence of Wy-14,643. The effects on PPARalpha activity in light of increased or decreased expression of these coactivators were qualitatively different depending on the ligand examined.

Differential activation of nuclear receptors by perfluorinated fatty acid analogs and natural fatty acids: a comparison of human, mouse, and rat peroxisome proliferator-activated receptor-alpha, -beta, and -gamma, liver X receptor-beta, and retinoid X receptor-alpha.

Administration of ammonium salts of perfluorooctanoate (PFOA) to rats results in peroxisome proliferation and benign liver tumors, events associated with activation of the nuclear receptor (NR) peroxisome proliferator-activated receptor-alpha (PPARalpha). Due to its fatty acid structure, PFOA may activate other NRs, such as PPARbeta, PPARgamma, liver X receptor (LXR), or retinoid X receptor (RXR). In this study, the activation of human, mouse, and rat PPARalpha, PPARbeta, PPARgamma, LXRbeta, and RXRalpha by PFOA (including its linear and branched isomers) and perfluorooctane sulfonate (PFOS) was investigated and compared to several structural classes of natural fatty acids and appropriate positive control ligands.

Interleukin-2 suppression by 2-arachidonyl glycerol is mediated through peroxisome proliferator-activated receptor gamma independently of cannabinoid receptors 1 and 2.

2-Arachidonyl glycerol (2-AG) is an endogenous arachidonic acid derivative that binds cannabinoid receptors CB1 and CB2 and is hence termed an endocannabinoid. 2-AG also modulates a variety of immunological responses, including expression of the autocrine/paracrine T cell growth factor interleukin (IL)-2. The objective of the present studies was to determine the mechanism responsible for IL-2 suppression by 2-AG.

Activation of mouse and human peroxisome proliferator-activated receptors (PPARs) by phthalate monoesters.

Administration of phthalates is known to cause toxicity and liver cancer in rodents through the activation of peroxisome proliferator-activated receptors (PPARs), and the monoesters appear to be the active metabolites that function as ligands of PPARs. There is evidence that PPARs exhibit significant species differences in response to ligand activation. In this study, the activation of mouse and human PPARalpha, PPARbeta, and PPARgamma by a broad class of phthalate monoesters was investigated using a trans-activation assay, functional analysis of PPARalpha target gene expression, and a PPARgamma-mediated differentiation assay.

Differential regulation of the cardiac sodium calcium exchanger promoter in adult and neonatal cardiomyocytes by Nkx2.5 and serum response factor.

Nkx2.5 and serum response factor (SRF) are critically important transcription factors in cardiac morphogenesis. They are also widely expressed in adult cardiomyocytes, but there is little data to indicate their possible role in adult cardiac cells.