Circulating levels of MCP-1 and IL-8 are elevated in human obese subjects and associated with obesity-related parameters

BACKGROUND

Chemotactic cytokines, referred to as chemokines, play an important role in leukocyte trafficking. The circulating levels of chemokines have been shown to increase in inflammatory processes including obesity-related pathologies (e.g. atherosclerosis and diabetes). However, little is currently known about the relationship between chemokines and human obesity. In the present study, we investigated the circulating levels of selected chemokines (monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha), leukotactin-1, interleukin-8 (IL-8)) and the association between the chemokine levels and obesity-related parameters: body mass index (BMI), waist circumference, fasting glucose and insulin levels, lipids profile, and the level of C-reactive protein (CRP).

METHODS

A total of 100 subjects, 50 obese (BMI>or=25 kg/m2) and 50 who were not obese (BMI<25 kg/m2) participated in the present study. The levels of chemokines and CRP were measured in a fasting state serum by sandwich enzyme-linked immunosorbent assay. Total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, glucose, and insulin levels were measured by enzymatic analysis and immunoassay.

RESULTS

The circulating levels of MCP-1 and IL-8 in the serum were significantly (P<0.05) higher in obese subjects (BMI>30 kg/m2) compared with those of nonobese controls (BMI<25 kg/m2). The levels of CRP were positively correlated with BMI (P<0.001) or waist circumference (P<0.0001). The levels of MCP-1 and IL-8 were positively related to BMI (MCP-1, P<0.02; IL-8, P<0.01) and/or waist circumference (MCP-1, P<0.009; IL-8, P<0.03). The levels of MCP-1 were positively related to the levels of CRP (P<0.007) or interleukin-6 (IL-6) (P<0.0001), and negatively related to the levels of HDL-cholesterol (P<0.01). Homeostasis model assessment (HOMA) score was positively related to the levels of MCP-1 (P<0.02) or IL-8 (P<0.03) in obese subject.

DISCUSSION

Our data demonstrated that the circulating levels of MCP-1 and IL-8 are related to obesity-related parameters such as BMI, waist circumference, CRP, IL-6, HOMA and HDL-cholesterol. These findings suggest that the circulating MCP-1 and/or IL-8 may be a potential candidate linking obesity with obesity-related metabolic complications such as atherosclerosis and diabetes.

DAX-1 inhibits SF-1-mediated transactivation via a carboxy-terminal domain that is deleted in adrenal hypoplasia congenita

X-linked adrenal hypoplasia congenita (AHC) with hypogonadotropic hypogonadism was recently shown to be caused by mutations in a gene referred to as DAX-1, which encodes a novel member of the orphan nuclear receptor family. DAX-1 is homologous to other nuclear receptors in its carboxy-terminal region, but it lacks the characteristic zinc finger DNA-binding domain. The tissue distribution of DAX-1 (adrenal cortex, gonads, hypothalamus, and pituitary) is the same as that of another orphan nuclear receptor, steroidogenic factor 1 (SF-1), that is required for development of the adrenal glands and gonads. We examined whether DAX-1 and SF-1 might interact in the regulation of SF-1-responsive target genes. Coexpression of DAX-1 and SF-1 inhibited SF-1-mediated transactivation. DAX-1 was shown to interact directly with SF-1 in in vitro protein binding studies; however, it did not interfere with SF-1 binding to DNA in gel mobility shift assays. Transactivation by GAL4-SF-1 constructs was inhibited by DAX-1, indicating that neither the SF-1 DNA-binding domain nor the SF-1 binding sites are required for inhibition by DAX-1. A series of DAX-1 deletion mutants localized the inhibitory domain to the carboxy-terminal region of the protein. Deletion of this domain also reduced basal transcriptional silencing by GAL4-DAX-1. This inhibitory domain has been deleted in all naturally occurring AHC deletion mutants described to date. In addition, two naturally occurring point mutations in DAX-1 exhibited impaired inhibition of SF-1. We conclude that DAX-1 can inhibit SF-1 transcriptional activity and suggest that the loss of this inhibitory property in DAX-1 may account in part for the phenotype of AHC.

Nilotinib vs imatinib in patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase: ENESTnd 3-year follow-up

Evaluating Nilotinib Efficacy and Safety in Clinical Trials Newly Diagnosed Patients compares nilotinib and imatinib in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP). With a minimum follow-up of 3 years, major molecular response, molecular response of BCR-ABL≤ 0.01% expressed on the international scale (BCR-ABL(IS); MR(4)) and BCR-ABL(IS)≤ 0.0032% (MR(4.5)) rates were significantly higher with nilotinib compared with imatinib, and differences in the depth of molecular response between nilotinib and imatinib have increased over time. No new progressions occurred on treatment since the 2-year analysis. Nilotinib was associated with a significantly lower probability of progression to accelerated phase/blast crisis vs imatinib (two (0.7%) progressions on nilotinib 300 mg twice daily, three (1.1%) on nilotinib 400 mg twice daily and 12 (4.2%) on imatinib). When considering progressions occurring after study treatment discontinuation, the advantage of nilotinib over imatinib in preventing progression remained significant (nine (3.2%) progressions on nilotinib 300 mg twice daily, six (2.1%) on nilotinib 400 mg twice daily and 19 (6.7%) on imatinib). Both nilotinib and imatinib were well tolerated, with minimal changes in safety over time. Nilotinib continues to demonstrate superior efficacy in all key response and outcome parameters compared with imatinib for the treatment of patients with newly diagnosed CML-CP.

Activation of mitogen-activated protein kinase pathways induces antioxidant response element-mediated gene expression via a Nrf2-dependent mechanism

Antioxidant response element (ARE) regulates the induction of a number of cellular antioxidant and detoxifying enzymes. However, the signaling pathways that lead to ARE activation remain unknown. Here, we report that the expression of mitogen-activated protein (MAP) kinase/extracellular signal-regulated kinase kinase kinase 1 (MEKK1), transforming growth factor-beta-activated kinase (TAK1), and apoptosis signal-regulating kinase (ASK1) in HepG2 cells activated the ARE reporter gene, whereas the expression of their dominant-negative mutants impaired ARE activation by the chemicals sodium arsenite and mercury chloride. Coexpression of downstream kinases, MAP kinase kinase 4, MAP kinase kinase 6, and c-Jun NH(2)-terminal kinase-1, but not MAP kinase kinase 3 and p38, augmented ARE activation by MEKK1, TAK1, and ASK1. The coexpression of a basic leucine zipper transcription factor Nrf2 but not c-Jun also greatly enhanced the activation of reporter gene by MEKK1, TAK1, and ASK1; however, a dominant-negative mutant of Nrf2 (NF-E2-related factor 2) blocked this event. Furthermore, when overexpressed, MEKK1, TAK1, and ASK1 induced the expression of heme oxygenase-1, a gene regulated by ARE, and the cotransfection with the dominant-negative mutant of Nrf2 abolished the induction. Taken together, these results suggest that MAP kinase pathways that are activated by MEKK1, TAK1, and ASK1 may link chemical signals to Nrf2, leading to the activation of ARE-dependent genes.

Activation of antioxidant-response element (ARE), mitogen-activated protein kinases (MAPKs) and caspases by major green tea polyphenol components during cell survival and death

Green tea polyphenols (GTP) have been demonstrated to suppress tumorigenesis in several chemical-induced animal carcinogenesis models, and predicted as promising chemopreventive agents in human. Recent studies of GTP extracts showed the involvement of mitogen-activated protein kinases (MAPKs) in the regulation of Phase II enzymes gene expression and induction of apoptosis. In the current work we compared the biological actions of five green tea catechins: (1) induction of ARE reporter gene, (2) activation of MAP kinases, (3) cytotoxicity in human hepatoma HepG2-C8 cells, and (4) caspase activation in human cervical squamous carcinoma HeLa cells. For the induction of phase II gene assay, (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) potently induced antioxidant response element (ARE)-mediated luciferase activity, with induction observed at 25 microM with EGCG. The induction of ARE reporter gene appears to be structurally related to the 3-gallate group. Comparing the activation of MAPK by the five polyphenols, only EGCG showed potent activation of all three MAPKs (ERK, JNK and p38) in a dose- and time-dependent manner, whereas EGC activated ERK and p38. In the concentration range of 25 microM to 1 mM, EGCG and ECG strongly suppressed HepG2-ARE-C8 cell-growth. To elucidate the mechanisms of green tea polyphenol-induced apoptosis, we measured the activation of an important cell death protein, caspase-3 induced by EGCG, and found that caspase-3 was activated in a dose- and time-dependent manner. Interestingly, the activation of caspase-3 was a relatively late event (peaked at 16 h), whereas activation of MAPKs was much earlier (peaked at 2 h). It is possible, that at low concentrations of EGCG, activation of MAPK leads to ARE-mediated gene expression including phase II detoxifying enzymes. Whereas at higher concentrations of EGCG, sustained activation of MAPKs such as JNK leads to apoptosis. These mechanisms are currently under investigation in our laboratory. As the most abundant catechin in GTP extract, we found that EGCG potently induced ARE-mediated gene expression, activated MAP kinase pathway, stimulated caspase-3 activity, and induced apoptosis. These mechanisms together with others, may contribute to the overall chemopreventive function of EGCG itself as well as the GTP

Clonal genetic alterations in the lungs of current and former smokers

BACKGROUND AND PURPOSE

Genetic damage has been identified at multiple chromosomal sites (i.e., loci) in lung cancer cells. We questioned whether similar damage could be detected in the bronchial epithelial cells of chronic smokers who do not have this disease.

METHODS

Biopsy specimens from six different bronchial regions were obtained from 54 chronic smokers (40 current smokers and 14 former smokers). The presence of squamous metaplasia and dysplasia (abnormal histologic changes) in the specimens was documented by examination of hematoxylin-eosin-stained sections, and a metaplasia index ([number of biopsy specimens with metaplasia/total number of biopsy specimens] x 100%) was calculated for each subject. Loss of heterozygosity (i.e., loss of DNA sequences from one member of a chromosome pair) involving microsatellite DNA at three specific loci-chromosome 3p14, chromosome 9p21, and chromosome 17p13-was evaluated by means of the polymerase chain reaction. Fisher's exact test and logistic regression analysis were used to assess the data. Reported P values are two-sided.

RESULTS

Data on microsatellite DNA status at chromosomes 3p14, 9p21, and 17p13 were available for 54, 50, and 44 subjects, respectively. The numbers of individuals who were actually informative (i.e., able to be evaluated for a loss of heterozygosity) at the three loci were 36 (67%), 37 (74%), and 34 (77%), respectively. DNA losses were detected in 27 (75%), 21 (57%), and six (18%) of the informative subjects at chromosomes 3p14, 9p21, and 17p13, respectively. Fifty-one subjects were informative for at least one of the three loci, and 39 (76%) exhibited a loss of heterozygosity. Forty-two subjects were informative for at least two of the loci, and 13 (31%) exhibited losses at a minimum of two loci. Loss of heterozygosity at chromosome 3p14 was more frequent in current smokers (22 [88%] of 25 informative) than in former smokers (five [45%] of 11 informative) (P = .01) and in subjects with a metaplasia index greater than or equal to 15% (21 [91%] of 23 informative) than in subjects with a metaplasia index of less than 15% (six [46%] of 13 informative) (P = .003). In five informative individuals among nine tested nonsmokers, a loss of heterozygosity was detected in only one subject at chromosome 3p14 (P = .03), and no losses were detected at chromosome 9p21 (P = .05).

CONCLUSIONS

Genetic alterations at chromosomal sites containing putative tumor-suppressor genes (i.e., 3p14 and the FHIT gene, 9p21 and the p16 gene [also known as CDKN2], and 17p13 and the p53 gene [also known as TP53]) occur frequently in the histologically normal or minimally altered bronchial epithelium of chronic smokers.

Induction of xenobiotic enzymes by the MAP kinase pathway and the antioxidant or electrophile response element (ARE/EpRE)

Cellular responses to xenobiotic-induced stress can signal proliferation, differentiation, homeostasis, apoptosis, or necrosis. To better understand the underlying molecular mechanisms after exposure to xenobiotics or drugs, we studied the signal transduction pathways, the mitogen-activated protein kinase (MAPK), and the basic leucine zipper transcription factor Nrf2, activated by different agents in the induction of Phase II drug metabolizing enzymes (DMEs). The MAPKs, characterized as proline-directed serine/threonine kinases, are essential components of signaling pathways that convert various extracellular signals into intracellular responses through serial phosphorylation cascades. Once activated, MAPKs can phosphorylate many transcription factors, such as c-Jun, ATF-2, and ultimately lead to changes in gene expression. Two classes of Phase II gene inducers, which are also cancer chemopreventive agents, were studied: (1) the phenolic antioxidants, namely butylated hydroxyanisole (BHA) and its active de-methylated metabolite t-butylhydroquinone (tBHQ), and phenolic flavonoids such as green tea polyphenols (GTP) and (-)-epigallocatechin-3-gallate (EGCG); and (2) the naturally occurring isothiocyanates, namely phenethyl isothiocyanate (PEITC), and sulforaphane. BHA and tBHQ are both well-known phenolic antioxidants used as food preservatives, and strongly activate c-Jun N-terminal kinase 1 (JNK1), extracellular signal-regulated protein kinase 2 (ERK2), or p38, in a time- and dose-dependent fashion. Free radical scavengers N-acetyl-L-cysteine (NAC), or glutathione (GSH), inhibited ERK2 activation and, to a much lesser extent, JNK1 activation by BHA/tBHQ, implicating the role of oxidative stress. Under conditions where MAPKs were activated, BHA or GTP also activated ARE/EpRE (antioxidant/electrophile response element), with the induction of Phase II genes such as NQO. Transfection studies with various cDNAs encoding wild-type or dominant-negative mutants of MAPKs and/or transcription factor Nrf2, substantially modulated ARE-mediated luciferase reporter activity in the presence or absence of phenolic compounds. Other phytochemicals including PEITC, and sulforaphane, also differentially regulated the activities of MAPKs, Nrf2, and ARE-mediated luciferase reporter gene activity and Phase II enzyme induction. A model is proposed where these xenobiotics (BHA, tBHQ, GTP, EGCG, PEITC, sulforaphane) activate the MAPK pathway via an electrophilic-mediated stress response, leading to the transcription activation of Nrf2/Maf heterodimers on ARE/EpRE enhancers, with the subsequent induction of cellular defense/detoxifying genes including Phase II DMEs, which may protect the cells against toxic environmental insults and thereby enhance cell survival. The studies of these signaling pathways may yield insights into the fate of cells upon exposure to xenobiotics.

Role of a mitogen-activated protein kinase pathway in the induction of phase II detoxifying enzymes by chemicals

Mitogen-activated protein kinase (MAPK) cascades are activated by diverse extracellular signals and participate in the regulation of an array of cellular programs. In this study, we investigated the roles of MAPKs in the induction of phase II detoxifying enzymes by chemicals. Treatment of human hepatoma (HepG2) and murine hepatoma (Hepa1c1c7) cells with tert-butylhydroquinone (tBHQ) or sulforaphane (SUL), two potent phase II enzyme inducers, stimulated the activity of extracellular signal-regulated protein kinase 2 (ERK2) but not c-Jun N-terminal kinase 1. tBHQ and SUL also activated MAPK kinase. Inhibition of MAPK kinase with its inhibitor, PD98059, abolished ERK2 activation and impaired the induction of quinone reductase, a phase II detoxifying enzyme, and antioxidant response element (ARE)-linked reporter gene by tBHQ and SUL. Overexpression of a dominant-negative mutant of ERK2 also attenuated tBHQ and SUL induction of ARE reporter gene activity. Interestingly, although expression of Ras and its mutant forms showed distinct effects on basal ARE reporter gene activity, they did not affect the activation of reporter gene by the inducers. Furthermore, a dominant-negative mutant of Ras had little effect on ERK2 activation by tBHQ and SUL, implicating a Ras-independent mechanism. Indeed, both tBHQ and SUL were able to stimulate Raf-1 kinase activity in vivo as well as in vitro. Thus, our results indicate that the induction of ARE-dependent phase II detoxifying enzymes is mediated by a MAPK pathway, which may involve direct activation of Raf-1 by the inducers.

Reduction of liver Fas expression by an antisense oligonucleotide protects mice from fulminant hepatitis

Aberrant apoptosis-mediated cell death is believed to result in a number of different human diseases. For example, excessive apoptosis in the liver can result in fulminant and autoimmune forms of hepatitis. We have explored the possibility that inhibition of Fas expression in mice would reduce the severity of fulminant hepatitis. To do this, we have developed a chemically modified 2'-O-(2-methoxy)ethyl antisense oligonucleotide (ISIS 22023) inhibitor of mouse Fas expression. In tissue culture, this oligonucleotide induced a reduction in Fas mRNA expression that was both concentration- and sequence-specific. In Balb/c mice, dosing with ISIS 22023 reduced Fas mRNA and protein expressions in liver by 90%. The ID50 for this response was 8-10 mg kg-1 daily dosing, and the reduction was highly dependent on oligonucleotide sequence, oligonucleotide concentration in liver, and treatment time. Pretreatment with ISIS 22023 completely protected mice from fulminant hepatitis induced by agonistic Fas antibody, by a mechanism entirely consistent with an oligonucleotide antisense mechanism of action. In addition, oligonucleotide-mediated suppression of Fas expression reduced the severity of acetaminophen-mediated fulminant hepatitis, but was without effect on concanavalin A-mediated hepatitis. Our results demonstrate that 2'-O-(2-methoxy)ethyl containing antisense oligonucleotides targeting Fas can exert in vivo pharmacological activity in liver, and suggest that oligonucleotide inhibitors of Fas may be useful in the treatment of human liver disease.

Direct observation of the spin texture in SmB6 as evidence of the topological Kondo insulator

Topological Kondo insulators have been proposed as a new class of topological insulators in which non-trivial surface states reside in the bulk Kondo band gap at low temperature due to strong spin-orbit coupling. In contrast to other three-dimensional topological insulators, a topological Kondo insulator is truly bulk insulating. Furthermore, strong electron correlations are present in the system, which may interact with the novel topological phase. By applying spin- and angle-resolved photoemission spectroscopy, here we show that the surface states of SmB6 are spin polarized. The spin is locked to the crystal momentum, fulfilling time reversal and crystal symmetries. Our results provide strong evidence that SmB6 can host topological surface states in a bulk insulating gap stemming from the Kondo effect, which can serve as an ideal platform for investigating of the interplay between novel topological quantum states with emergent effects and competing orders induced by strongly correlated electrons.

Docosahexaenoic acid ingestion inhibits natural killer cell activity and production of inflammatory mediators in young healthy men

The purpose of this study was to examine the effects of feeding docosahexaenoic acid (DHA) as triacylglycerol on the fatty acid composition, eicosanoid production, and select activities of human peripheral blood mononuclear cells (PBMNC). A 120-d study with 11 healthy men was conducted at the Metabolic Research Unit of Western Human Nutrition Reach Center. Four subjects (control group) were fed the stabilization diet throughout the study; the remaining seven subjects were fed the basal diet for the first 30 d, followed by 6 g DHA/d for the next 90 d. DHA replaced an equivalent amount of linoleic acid; the two diets were comparable in their total fat and all other nutrients. Both diets were supplemented with 20 mg D alpha-tocopherol acetate per day. PBMNC fatty acid composition and eicosanoid production were examined on day 30 and 113; immune cell functions were tested on day 22, 30, 78, 85, 106, and 113. DHA feeding increased its concentration from 2.3 to 7.4 wt% in the PBMNC total lipids, and decreased arachidonic acid concentration from 19.8 to 10.7 wt%. It also lowered prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) production, in response to lipopolysaccharide, by 60-75%. Natural killer cell activity and in vitro secretion of interleukin-1beta and tumor necrosis factor alpha were significantly reduced by DHA feeding. These parameters remained unchanged in the subjects fed the control diet. B-cell functions as reported here and T-cell functions that we reported previously were not altered by DHA feeding. Our results show that inhibitory effects of DHA on immune cell functions varied with the cell type, and that the inhibitory effects are not mediated through increased production of PGE2 and LTB4.

Signal transduction events elicited by natural products: role of MAPK and caspase pathways in homeostatic response and induction of apoptosis

Many natural products elicit diverse pharmacological effects. Using two classes of potential chemopreventive compounds, the phenolic compounds and the isothiocyanates, we review the potential utility of two signaling events, the mitogen-activated protein kinases (MAPKs) and the ICE/Ced-3 proteases (caspases) stimulated by these agents in mammalian cell lines. Studies with phenolic antioxidants (BHA, tBHQ), and natural products (flavonoids; EGCG, ECG, and isothiocyanates; PEITC, sulforaphane), provided important insights into the signaling pathways induced by these compounds. At low concentrations, these chemicals may activate the MAPK (ERK2, JNK1, p38) leading to gene expression of survival genes (c-Fos, c-Jun) and defensive genes (Phase II detoxifying enzymes; GST, QR) resulting in survival and protective mechanisms (homeostasis response). Increasing the concentrations of these compounds will additionally activate the caspase pathway, leading to apoptosis (potential cytotoxicity). Further increment to suprapharmacological concentrations will lead to nonspecific necrotic cell death. The wider and narrow concentration ranges between the activation of MAPK/gene induction and caspases/cell death exhibited by phenolic compounds and isothiocyanates, respectively, in mammalian cells, may reflect their respective therapeutic windows in vivo. Consequently, the studies of signaling pathways elicited by natural products will advance our understanding of their efficacy and safety, of which many may become important therapeutic drugs of the future.

p38 mitogen-activated protein kinase negatively regulates the induction of phase II drug-metabolizing enzymes that detoxify carcinogens

Phase II drug-metabolizing enzymes, such as glutathione S-transferase and quinone reductase, play an important role in the detoxification of chemical carcinogens. The induction of these detoxifying enzymes by a variety of agents occurs at the transcriptional level and is regulated by a cis-acting element, called the antioxidant response element (ARE) or electrophile-response element. In this study, we identified a signaling kinase pathway that negatively regulates ARE-mediated gene expression. Treatment of human hepatoma HepG2 and murine hepatoma Hepa1c1c7 cells with tert-butylhydroquinone (tBHQ) stimulated the activity of p38, a member of mitogen-activated protein kinase family. Inhibition of p38 activation by its inhibitor, SB203580, enhanced the induction of quinone reductase activity and the activation of ARE reporter gene by tBHQ. In contrast, SB202474, a negative analog of SB203580, had little effect. Consistent with this result, interfering with the p38 kinase pathway by overexpression of a dominant-negative mutant of p38 or MKK3, an immediate upstream regulator of p38, potentiated the activation of the ARE reporter gene by tBHQ, whereas the wild types of p38 and MKK3 diminished such activation. In addition, inhibition of p38 activity augmented the induction of ARE reporter gene activity by tert-butylhydroxyanisole, sulforaphane, and beta-naphthoflavone. Thus, p38 kinase pathway functions as a negative regulator in the ARE-mediated induction of phase II detoxifying enzymes.

Heavy metal pollution in intertidal sediments from Quanzhou Bay, China

The concentrations of eight heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As) in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows: 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100.9 mg/kg for Pb, 0.28-0.89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index (Igeo) show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.

Double blind, placebo controlled trial of the remission inducing and steroid sparing properties of an ICAM-1 antisense oligodeoxynucleotide, alicaforsen (ISIS 2302), in active steroid dependent Crohn's disease

BACKGROUND AND AIMS

To evaluate the safety and efficacy of the intercellular adhesion molecule 1 (ICAM-1) antisense phosphorothioate oligonucleotide alicaforsen (ISIS 2302) in Crohn's disease.

METHODS

Active (Crohn's disease activity index (CDAI) 200-350), steroid dependent (prednisone 10-40 mg) Crohn's patients were randomised into three treatment groups: placebo versus ISIS 2302 (2 mg/kg intravenously three times a week) for two or four weeks. Patients were treated in months 1 and 3, with steroid withdrawal attempted by week 10. The primary end point (steroid free remission) was a CDAI <150 off steroids at the end of week 14.

RESULTS

A total of 299 patients were enrolled, with a mean baseline CDAI of 276 and steroid dose of 23 mg/day. Rates of steroid free remission were equivalent for the two and four week ISIS 2302 groups (20.2% and 21.2%) and the placebo group (18.8%). At week 14, steroid withdrawal was successful in more ISIS 2302 patients compared with placebo treated patients (78% v 64%; p=0.032). Steroid free remission was highly correlated with exposure (p=0.0064). Other clinical responses were correlated with exposure, with significant results versus placebo being observed in the highest area under the curve subgroup. CDAI scores decreased by 136 (112) at week 14 versus 52 (107) for placebo (p=0.027) and inflammatory bowel disease score questionnaire improved by 43 (31) versus 15 (36) for placebo (p=0.027).

CONCLUSIONS

Although the primary outcomes failed to demonstrate efficacy, pharmacodynamic modelling suggests that alicaforsen (ISIS 2302) may be an effective therapy for steroid dependent Crohn's disease.

Randomized Trial of First-Line Tyrosine Kinase Inhibitor With or Without Radiotherapy for Synchronous Oligometastatic EGFR-Mutated Non-Small Cell Lung Cancer

BACKGROUND

Adding radiotherapy (RT) to systemic therapy improves progression-free survival (PFS) and overall survival (OS) in oligometastatic non-small cell lung cancer (NSCLC). Whether these findings translate to epidermal growth factor receptor (EGFR)-mutated NSCLC remains unknown. The SINDAS trial (NCT02893332) evaluated first-line tyrosine kinase inhibitor (TKI) therapy for EGFR-mutated synchronous oligometastatic NSCLC and randomized to upfront RT vs no RT; we now report the prespecified interim analysis at 68% accrual.

METHODS

Inclusion criteria were biopsy-proven EGFR-mutated adenocarcinoma (per amplification refractory mutation system or next generation sequencing), with synchronous (newly diagnosed, treatment naïve) oligometastatic (≤5 metastases; ≤2 lesions in any one organ) NSCLC without brain metastases. All patients received a first-generation TKI (gefitinib, erlotinib, or icotinib), and randomization was between no RT vs RT (25-40 Gy in 5 fractions depending on tumor size and location) to all metastases and the primary tumor/involved regional lymphatics. The primary endpoint (intention to treat) was PFS. Secondary endpoints included OS and toxicities. All statistical tests were 2-sided.

RESULTS

A total of 133 patients (n = 65 TKI only, n = 68 TKI with RT) were enrolled (2016-2019). The median follow-up was 23.6 months. The respective median PFS was 12.5 months vs 20.2 months (P < .001), and the median OS was 17.4 months vs 25.5 months (P < .001) for TKI only vs TKI with RT. Treatment yielded no grade 5 events and a 6% rate of symptomatic grade 3-4 pneumonitis in the TKI with RT arm. Based on the efficacy results of this prespecified interim analysis, the ethics committee recommended premature cessation of this trial.

CONCLUSIONS

As compared with a first-line TKI alone, addition of upfront local therapy using RT statistically significantly improved PFS and OS for EGFR-mutated NSCLC.

Validation of the Bowel Function Index to detect clinically meaningful changes in opioid-induced constipation

OBJECTIVE

The Bowel Function Index (BFI) is a clinician-administered, patient-reported, 3-item questionnaire to evaluate opioid-induced constipation in cancer and non-cancer chronic pain patients. The objective of the present analysis was to evaluate the psychometric characteristics of the BFI using data from clinical studies of oral prolonged release (PR) oxycodone/naloxone.

METHODS

OXN2401 was a multicenter, controlled, randomized, double-blind, parallel-group study including oral PR oxycodone combined with oral PR naloxone as well as oral PR oxycodone combined with corresponding naloxone placebo. OXN3401 and OXN3001 were 12-week multicenter, controlled, randomized, double-blind, parallel-group studies of a fixed combination of oral PR oxycodone/naloxone versus PR oxycodone. In addition, a placebo group was included in study OXN3401. BFI psychometric characteristics (reliability, reproducibility, convergent/known groups validity, and responsiveness) were evaluated.

RESULTS

Demographic data (n=985) were comparable and analyses indicated a high degree of internal consistency (Cronbach's alpha >0.7). Change of less than 5 points in BFI was indicative of high reproducibility. Correlations between BFI item and total scores to stool frequency were statistically significant and in the low-to-moderate range (OXN2401 -0.23 to -0.29, p < 0.001; OXN3401 range -0.26 to -0.40, p < 0.001; OXN3001 -0.14 to -0.15, p < 0.05). Data indicate that a BFI score change of ≥12 points represents a clinically meaningful change in constipation.

LIMITATIONS

This publication for validation of BFI only includes data from three clinical trials. However, another publication of an additional specifically designed cross-sectional validation study is in preparation.

CONCLUSION

The BFI is a valid and reliable instrument for the assessment of opioid-induced constipation in chronic pain patients. Psychometric analyses from clinical trials support the BFI's psychometric properties.

Polymorphisms of the DNA repair gene XRCC1 and risk of gastric cancer in a Chinese population

Gastric cancer remains the leading cause of cancer death in China and other countries in eastern Asia. Studies of gastric cancer have revealed that it is a disease of complex etiology involving dietary, infectious, environmental, occupational and genetic factors. DNA repair capacity has been suggested as a genetic factor contributing to variation in susceptibility to cancer. In the present study, we described an association between 2 polymorphisms of the DNA repair gene XRCC1 and risk of gastric cancer in a Chinese population. We used a polymerase chain reaction-based assay to detect Pvu II and Nci I restriction fragment length polymorphisms (XRCC1 26304 C-->T and XRCC1 28152 G-->A, respectively) in 188 patients with gastric cancer and 166 healthy controls. The XRCC1 26304 T allele (194Trp) frequency (34.6%) was higher and the XRCC1 28152 A allele (399Gln) frequency (25.6%) was lower in healthy Chinese controls than previously reported healthy U.S. Caucasian controls (7.2% and 34.1%, respectively). Multivariate logistic regression analysis revealed that the putative high-risk genotypes XRCC1 26304 CC and XRCC1 28152 GA/AA were associated with a non-significant increased risk for gastric cancer (adjusted odds ratio [OR]=1.45, 95% confidence interval [CI]= 0.93-2.25 and OR=1.53, 95% CI= 0.98-2.39, respectively) compared with other genotypes. However, the XRCC1 26304 CC genotype was associated with a significantly increased risk for gastric cardia cancer (adjusted OR=1.86, 95% CI=1.09-3.20). Individuals with both putative high-risk genotypes (CC and GA/AA) had a significantly higher risk (adjusted OR=1.73, 95% CI=1.12-2.69), particularly for gastric cardia cancer (adjusted OR=2.18, 95% CI=1.21-3.94) than individuals with other genotypes. These findings support the hypothesis that these 2 XRCC1 variants may contribute to the risk of developing gastric cancer, particularly gastric cardia cancer.

Mice lacking pituitary tumor transforming gene show testicular and splenic hypoplasia, thymic hyperplasia, thrombocytopenia, aberrant cell cycle progression, and premature centromere division

Tumorigenic pituitary tumor transforming gene (PTTG) is a mammalian homolog of Xenopus securin that inhibits chromatid separation, is overexpressed in many human tumor types, and mediates transcriptional activation. Loss of yeast securin Pds1p or Drosophila securin pimples is lethal. Here we show that mice lacking PTTG (PTTG -/-) are, surprisingly, viable and fertile; but they have testicular and splenic hypoplasia, thymic hyperplasia, and thrombocytopenia. PTTG -/- mouse embryo fibroblasts exhibited aberrant cell cycle progression with prolonged G2-M phase and binucleated and multinucleated nuclei with increased aneuploidy. PTTG -/- mouse embryo fibroblast metaphases contained quadriradial, triradial, and chromosome breaks, as well as premature centromere division. The results show that PTTG functions to maintain chromosome stability, cell cycle progression, and appropriate cell division. Moreover, mammalian sister chromatid separation, an important transition in the cell cycle, is likely regulated by mechanisms in addition to securin.

Differential regulation of mitogen-activated protein kinases by microtubule-binding agents in human breast cancer cells

Drug design targeted at microtubules has led to the advent of some potent anti-cancer drugs. In the present study, we demonstrated that microtubule-binding agents (MBAs) taxol and colchicine induced immediate early gene (c-jun and ATF3) expression, cell cycle arrest, and apoptosis in the human breast cancer cell line MCF-7. To elucidate the signal transduction pathways that mediate such biological activities of MBAs, we studied the involvement of mitogen-activated protein (MAP) kinases. Treatment with taxol, colchicine, or other MBAs (vincristine, podophyllotoxin, nocodazole) stimulated the activity of c-jun N-terminal kinase 1 (JNK1) in MCF-7 cells. In contrast, p38 was activated only by taxol and none of the MBAs changed the activity of extracellular signal-regulated protein kinase 2 (ERK2). Activation of JNK1 or p38 by MBAs occurred subsequent to the morphological changes in the microtubule cytoskeleton induced by these compounds. Furthermore, baccatine III and beta-lumicolchicine, inactive analogs of taxol and colchicine, respectively, did not activate JNKI or p38. These results suggest that interactions between microtubules and MBAs are essential for the activation of these kinases. Pretreatment with the antioxidants N-acetyl-L-cysteine (NAC), ascorbic acid or vitamin E, blocked H2O2- or doxorubicin-induced JNKI activity, but had no effect on JNKI activation by MBAs, excluding a role for oxidative stress. However, BAPTA/AM, a specific intracellular Ca2+ chelator, attenuated JNK1 activation by taxol but not by colchicine, and had no effect on microtubule changes induced by taxol. Thus, stabilization or depolymerization of microtubules may regulate JNK1 activity via distinct downstream signaling pathways. The differential activation of MAP kinases opens up a new avenue for addressing the mechanism of action of antimicrotubule drugs.

Prevention of vaginal SHIV transmission in macaques by a live recombinant Lactobacillus

Most human immunodeficiency virus (HIV) transmissions in women occur through the cervicovaginal mucosa, which is coated by a bacterial biofilm including Lactobacillus. This commensal bacterium has a role in maintaining a healthy mucosa and can be genetically engineered to produce antiviral peptides. Here, we report a 63% reduction in transmission of a chimeric simian/HIV (SHIV(SF162P3)) after repeated vaginal challenges of macaques treated with Lactobacillus jensenii expressing the HIV-1 entry inhibitor cyanovirin-N. Furthermore, peak viral loads in colonized macaques with breakthrough infection were reduced sixfold. Colonization and prolonged antiviral protein secretion by the genetically engineered lactobacilli did not cause any increase in proinflammatory markers. These findings lay the foundation for an accessible and durable approach to reduce heterosexual transmission of HIV in women, which is coitally independent, inexpensive, and enhances the natural protective effects of the vaginal microflora.

His-His-Leu, an angiotensin I converting enzyme inhibitory peptide derived from Korean soybean paste, exerts antihypertensive activity in vivo

It has been reported that soybean peptide fractions isolated from Korean fermented soybean paste exert angiotensin I converting enzyme (ACE) inhibitory activity in vitro. In this study, further purification and identification of the most active fraction inhibiting ACE activity were performed, and its antihypertensive activity in vivo was confirmed. Subsequently, a novel ACE inhibitory peptide was isolated by preparative HPLC. The amino acid sequence of the isolated peptide was identified as His-His-Leu (HHL) by Edman degradation. The IC(50) value of the HHL for ACE activity was 2.2 microg/mL in vitro. Moreover, the synthetic tripeptide HHL (spHHL) resulted in a significant decrease of ACE activity in the aorta and led to lowered systolic blood pressure (SBP) in spontaneously hypertensive (SH) rats compared to control. Triple injections of spHHL, 5 mg/kg of body weight/injection resulted in a significant decrease of SBP by 61 mmHg (p < 0.01) after the third injection. These results demonstrated that the ACE inhibitory peptide HHL derived from Korean fermented soybean paste exerted antihypertensive activity in vivo.

Environmental occurrence, fate, impact, and potential solution of tire microplastics: Similarities and differences with tire wear particles

Tire microplastics (TMPs) are identified as one of the most abundant types of microplastics, which originate from rubber with intended or unintended release. While increasing knowledge about TMPs concentrates on tire wear particles (TWPs), TMPs from other potential sources like recycled tire crumb (RTC) and tire repair-polished debris (TRD) are much less understood. Excessive levels of TMPs and their additives have been fragmentarily reported in the environment. The accumulating environmental TMPs from different sources may directly or indirectly cause adverse impacts on the environment and human health. The objectives of this review are to (1) summarize the properties, abundance, and sources of TMPs in the environment; (2) analyze the environmental fates and behaviors of TMPs, including their roles in carrying abiotic and biotic co-contaminants; (3) evaluate the potential impacts of TMPs on terrestrial and aquatic organisms, as well as human; and (4) discuss the potential solutions to mitigate the TMP pollution. By collecting and analyzing the up-to-date literature, this review enhances our better understanding of the environmental occurrence, fates, impacts, and potential solutions of TMPs, and further highlights critical knowledge gaps and future research directions that require cooperative efforts of scientists, policymakers, and public educators.

Signal transduction events elicited by cancer prevention compounds

Many chemopreventive agents have been shown to modulate gene expression including induction of phase II detoxifying enzymes, such as glutathione S-transferases (GST) and quinone reductases (QR). Induction of phase II enzymes in general leads to protection of cells/tissues against exogenous and/or endogenous carcinogenic intermediates. The antioxidant or electrophile response element (ARE/EpRE) found at the 5'-flanking region of these phase II genes may play important role in mediating their induction by xenobiotics including chemopreventive agents. Members of the basic leucine zipper (bZIP) transcription factor, Nrf2 which heterodimerizes with Maf G/K, are found to bind to the ARE, and transcriptionally-activated ARE. Recently, we showed that the mitogen-activated protein kinases (MAPK) were activated by phase II gene inducers such as phenolic antioxidant butylated hydroxyanisol (BHA) and isothiocyanate sulforaphane (SUL), and involved in the transcription activation of ARE-mediated reporter gene. Transfection studies with wild-type and dominant negative mutants of Nrf2 and MAPK showed synergistic response during co-transfection as well as to phase II gene inducers. However, increasing the concentrations of these compounds such as BHA, the activities of cell death signaling molecules, caspases, were stimulated and resulted in apoptotic cell death. At these concentrations, BHA stimulated loss of mitochondrial membrane potential, cytochrome c release, and activation of caspase 3, 8 and 9 preceding apoptosis. Further increase in concentrations led to rapid cell necrosis. A model is proposed for BHA and SUL, in that at low concentrations, these potential chemopreventive agents may modulate MAPK pathway leading to transcription activation of Nrf2 and ARE with subsequent induction of cellular defensive enzymes including phase II detoxifying enzymes as well as other defensive genes, which may protect the cells against cellular injury, which is a homeostatic response. At higher concentrations, these agents may activate the caspase pathways, leading to apoptosis, a potential beneficial effect if occurs at preneoplastic/neoplastic tissues, but a potential cytotoxic response if occurs in normal tissues. On the other hand, some phenolic compounds such as resveratrol inhibits TPA- or UV-induced AP-1-mediated activity through the inhibition of c-Src non-receptor tyrosine kinase and MAPK pathways. It is possible that in proliferating or stimulated cells, these chemopreventive compounds may block proliferation by inhibiting these signaling kinases, whereas in non-proliferating or quiescent cells, some of these compounds may activate these signaling kinases leading to gene expression of cellular defensive enzymes such as phase II detoxifying enzymes. The studies of these and other signaling pathways may yield insights into the development of potential chemopreventive compounds.