TAp63 suppress metastasis via miR-133b in colon cancer cells

BACKGROUND

TAp63 is a tumour-suppressor protein that is often underexpressed in various types of cancer. It has been shown to activate gene transcription depending on the transcription domain and to be closely related with metastasis. In this study, we demonstrate that TAp63 suppresses metastasis in colon cancer cells through microRNA-133b.

METHODS

We evaluated the correlation of TAp63 and miR-133b with HT-29 and SW-620 cells and investigated the roles of TAp63 in the expression of RhoA, E-cadherin and vimentin. We further investigated the roles of TAp63-mediated invasion and migration of colon cancer cells.

RESULTS

TAp63 expression is downregulated in colon cancer, and microRNA-133b is a transcriptional target of TAp63. Furthermore, microRNA-133b is essential for the inhibitory effects of TAp63 on RhoA, E-cadherin and vimentin. Moreover, TAp63 inhibits cell migration and invasion through microRNA-133b. Correspondingly, the inhibitory effect of TAp63 on RhoA, E-cadherin, vimentin, migration and invasion can be blocked by the microRNA-133b inhibitor.

CONCLUSIONS

TAp63 and microRNA-133b were able to suppress the metastasis of colon cancer. Both TAp63 and microRNA-133b may be potential biomarkers for diagnosis in colon cancer metastasis and may provide unique therapeutic targets for this common malignancy.

Abstract P2-06-02: Pparg deacetylation by SIRT1 determines breast tumor lipid synthesis and growth

Peroxisome proliferator-activated receptorg (Pparγ) is a member of the nuclear receptor (NR) superfamily, which regulates diverse biological functions including lipogenesis and differentiation, anti-inflammation, insulin sensitivity, cellular proliferation, and autophagy. Independent lines of evidence support a role for Pparγ as either a collaborative oncogene or as a tumor suppressor. Heterozygous mutations of Pparγ have been detected in 4/55 patients with colon cancer and a chromosomal translocation between PAX8 and Pparγ in follicular thyroid cancer appeared to serve as a dominant inhibitor of endogenous Pparγ expression. Pparγ agonists reduced tumorigenesis in several in vivo models. In contrast, several studies suggest Pparγ may enhance tumor growth. Pparγ ligands increased polyp numbers in the Apc mouse model of familial adenomatosis. Pparγ and its ligands inhibit breast tumor growth; however, constitutively active Pparγ collaborated in mammary oncogenesis with polyoma middle T antigen or oncogenic ErbB2.

Pparγ activation involves post-translational modifications including phosphorylation and sumoylation upon growth factor or ligand stimulus. Mutation of the Pparγ1 sumoylation site at K77 and K365 demonstrated that K77 may either reduce Pparγ-dependent gene induction and enhance repression or reduce repression, depending upon the synthetic reporter gene used. Lysine residues of nuclear receptors also serve as substrates for acetylation and Pparγ binds co-activators and co-repressors with intrinsic or associated histone acetylase or deacetylase activity including NCoR, SMRT, SIRT1, and p300. Initially characterized for the ERα, AR and, subsequently, the orphan nuclear receptor steroidogenic factor 1 (SF-1), acetylation occurs at a conserved lysine motif shared amongst evolutionarily related nuclear receptors. Several nuclear receptors and co-integrators involved in lipid metabolism are regulated by acetylation including p300, PGC1α, FXR, LXR and RAR. Both TSA- and NAD-sensitive HDACs (e.g. SIRT1) regulate Pparγ function and SIRT1 inhibits Pparγ-dependent adipocyte differentiation. Whether Pparγ is acetylated in cancer cells and how Pparγ exerts it's crucial, though controversial, function in tumorigenesis have not been established.

Pparγ induces gene transcription through binding specific NR half-sites and through non-canonical binding sequences (such as CREB/AP-1 sites). Transcriptional repression involves Pparγ sumoylation at lysine 77 (K77). Herein, Pparγ was shown to be acetylated at nine distinct lysine residues. SIRT1 bound and deacetylated Pparγ at K154/155. ChIP-Seq analysis for genome-wide DNA binding demonstrated the acetylation site was required for binding NR half-sites, but was not required for non-canonical site binding. Breast tumor growth, de novo lipid synthesis, induction of autophagy and evasion of apoptosis was promoted by K154/155 and inhibited by K77 in vivo. Pparγ acetylation induced a gene signature that was increased in breast cancer, associated with a reduction in SIRT1 abundance and poor outcome. The Pparγ acetylation site determines binding to autophagy and apoptosis signaling to regulate breast tumor lipid metabolism and growth.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-06-02.

Abstract P5-11-04: Post-translational modification of the cell-fate factor Dachshund determines p53 binding and signaling modules in breast cancer

Breast cancer is a leading form of cancer in the world. Initially cloned as a dominant inhibitor of the hyperactive EGFR, Ellipse, in Drosophila, the mammalian DACH1 regulates expression of target genes in part through interacting with DNA-binding transcription factors (c-Jun, Smads, Six, ERα), and in part through intrinsic DNA-sequence specific binding to Forkhead binding sites. The Drosophila dac gene is a key member of the retinal determination gene network (RDGN), which also includes eyes absent (eya), ey, twin of eyeless (toy), teashirt (tsh) and sin oculis (so), that specifies eye tissue identity.

Several lines of evidence suggest DACH1 may function as a tumor suppressor. Clinical studies have demonstrated a correlation between poor prognosis and reduced expression of the cell-fate determination factor DACH1 in breast cancer, and loss of DACH1 expression has been observed in prostate and endometrial cancer. DACH1 inhibits breast cancer tumor metastasis and reduces breast cancer stem cell expansion via Sox2/Nanog. Although these studies suggest DACH1 may function as a tumor suppressor, the molecular mechanisms remain poorly defined. Herein, endogenous DACH1 co-localized with p53 in a nuclear, extranucleolar compartment and bound to p53 in human breast cancer cell lines, p53 and DACH1 bound common genes in ChIP-Seq. Full inhibition of breast cancer contact-independent growth by DACH1 required p53. The p53 breast cancer mutants R248Q and R273H, evaded DACH1 binding. DACH1 phosphorylation at serine residue (S439) inhibited p53 binding and phosphorylation at p53 amino-terminal sites (S15, S20) enhanced DACH1 binding. DACH1 binding to p53 was inhibited by NAD-dependent deacetylation via DACH1 K628. DACH1 repressed p21CIP1 and induced RAD51, an association found in basal breast cancer. DACH1 inhibits breast cancer cellular growth in an NAD and p53 dependent manner through direct protein-protein association.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-11-04.

Cognitive trio: relationship with major depression and clinical predictors in Han Chinese women

BACKGROUND

Previous studies support Beck's cognitive model of vulnerability to depression. However, the relationship between his cognitive triad and other clinical features and risk factors among those with major depression (MD) has rarely been systematically studied.

METHOD

The three key cognitive symptoms of worthlessness, hopelessness and helplessness were assessed during their lifetime worst episode in 1970 Han Chinese women with recurrent MD. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression.

RESULTS

Compared to patients who did not endorse the cognitive trio, those who did had a greater number of DSM-IV A criteria, more individual depressive symptoms, an earlier age at onset, a greater number of episodes, and were more likely to meet diagnostic criteria for melancholia, postnatal depression, dysthymia and anxiety disorders. Hopelessness was highly related to all the suicidal symptomatology, with ORs ranging from 5.92 to 6.51. Neuroticism, stressful life events (SLEs) and a protective parental rearing style were associated with these cognitive symptoms.

CONCLUSIONS

During the worst episode of MD in Han Chinese women, the endorsement of the cognitive trio was associated with a worse course of depression and an increased risk of suicide. Individuals with high levels of neuroticism, many SLEs and high parental protectiveness were at increased risk for these cognitive depressive symptoms. As in Western populations, symptoms of the cognitive trio appear to play a central role in the psychopathology of MD in Chinese women.

Postantibiotic effect and postantibiotic sub-minimum inhibitory concentration effect of valnemulin against Staphylococcus aureus isolates from swine and chickens

The postantibiotic effect (PAE) and postantibiotic sub-minimum inhibitory concentration (MIC) effect (PA-SME) of valnemulin against Staphylococcus aureus were investigated in vitro using a spectrophotometric technique and classic viable count method. A standard curve was constructed by regression analysis of the number of colonies and the corresponding optical density (OD) at 630 nm of the inoculum. After exposure to valnemulin at different concentrations for an hour, the antibiotic was removed by centrifuging and washing. The PA-SMEs were measured after initial exposure to valnemulin at 4 × the MIC, and then, valnemulin was added to reach corresponding desired concentrations in the resuspended culture. Samples were collected hourly until the culture became turbid. The results were calculated by converting the OD values into the counts of bacteria in accordance with the curve. The MIC of valnemulin against eight strains was identically 0.125 μg ml(-1) . The mean PAEs were 2.12 h (1 × MIC) and 5.06 h (4 × MIC), and the mean PA-SMEs were 6.85 h (0.1 × MIC), 9.12 h (0.2 × MIC) and 10.8 h (0.3 × MIC). The results showed that the strains with identical MICs exhibited different PAEs and PA-SMEs. Valnemulin produced prolonged PAE and PA-SME periods for Staph. aureus, supporting a longer dosing interval while formulating a daily administration dosage.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, valnemulin demonstrated prolonged postantibiotic effects and postantibiotic sub-MIC effects on strains of Staphylococcus aureus. The strains with identical MICs of valnemulin exhibited different PAEs and PA-SMEs. Staphylococcus aureus isolated from different species has little impact on the postantibiotic effect of valnemulin. The result suggests a longer dosing interval while formulating a daily administration dosage, and it may play a valuable role of valnemulin in treating Staph. aureus infections in animals.

CpG7909 adjuvant enhanced immunogenicity efficacy in mice immunized with ESAT6-Ag85A fusion protein, but does not confer significant protection against Mycobacterium tuberculosis infection

AIMS

This study aimed to investigate the ability of CpG7909 adjuvant to enhance immunogenicity and protective efficacy of a subunit vaccine composed of ESAT6-Ag85A fusion protein (Pe685a) of Mycobacterium tuberculosis.

METHODS AND RESULTS

ELISA was used to detect specific antibody and IFN-γ expression in sera; ELISPOT, to detect IFN-γ expression in splenocytes; MTT assay and FACS, to detect T-lymphocytes proliferation in spleens; and RT-PCR, to detect cytokines expression in lungs of mice after immunization. Bacterial load and histopathological lesions in lungs or spleens of mice challenged with Myco. tuberculosis H37Rv strain were analysed. Compared with incomplete Freund's adjuvant, CpG7909 induced more potent production of Pe685a-specific IgG2a/IgG1 antibody and higher expression of IFN-γ in sera, stimulated more generation of antigen-specific IFN-γ-secreting splenocytes, enhanced frequencies of CD3(+) CD4(+) and CD3(+) CD8(+) T-lymphocytes in spleen and increased transcription of TNF-α, IFN-γ, IL-6 and TLR9 in lung. However, lower bacterial load in lung and less severe lung pathology were not observed in CpG7909 group mice.

CONCLUSIONS

CpG7909 is able to enhance immunological effects of Pe685a subunit vaccine, but does not confer significant protective efficacy against Myco. tuberculosis infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

CpG7909 as an adjuvant of subunit vaccine against Myco. tuberculosis is worthy of further investigation.

Diabetes as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies

This study examined the association of diabetes with the onset of dementia (including Alzheimer's disease (AD), vascular dementia (VD) and any dementia) and mild cognitive impairment (MCI) by using a quantitative meta-analysis of longitudinal studies. EMBASE and MEDLINE were searched for articles published up to December 2010. All studies that examined the relationship between diabetes and the onset of dementia or MCI were included. Pooled relative risks were calculated using fixed and random effects models. Nineteen studies met our inclusion criteria for this meta-analysis, and 6184 subjects with diabetes and 38 530 subjects without diabetes were included respectively. All subjects were without dementia or MCI at baseline. The quantitative meta-analysis showed that subjects with diabetes had higher risk for AD (relative risk (RR):1.46, 95% confidence interval (CI): 1.20-1.77), VD (RR: 2.48, 95% CI: 2.08-2.96), any dementia (RR: 1.51, 95% CI: 1.31-1.74) and MCI (RR: 1.21, 95% CI: 1.02-1.45) than those without. The quantitative meta-analysis showed that diabetes was a risk factor for incident dementia (including AD, VD and any dementia) and MCI.

Growth factor receptor-bound protein 10-mediated negative regulation of the insulin-like growth factor-1 receptor-activated signalling pathway results in cognitive disorder in diabetic rats

Growth factor receptor-bound protein 10 (Grb10) is a Src homology 2 domain-containing protein and one of the binding partners for several transmembrane tyrosine kinase receptors, including insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1-R). The hippocampus, which is critical for cognitive functions, is one of the main distribution areas of Grb10 in the central nervous system. In recent years, diabetic encephalopathy has been defined as a third type of diabetes and the IGF1-IR pathway was shown to be critical for the neuropathogenic process of cognitive disorder in diabetes. However, the role of endogenous Grb10 in regulating the IGF1-IR pathway and neurobehavioural changes is not explicit. The present study aimed to determine the in vivo function of endogenous Grb10 in diabetic encephalopathy and the underlying mechanisms. Using stereotaxic surgical techniques and lentiviral vectors expressing specific short hairpin RNA, we could steadily knockdown Grb10 expression in the hippocampus. More importantly, we demonstrated that hippocampus-specific modulation of Grb10 protein levels led to a prominent remission of cognitive disorder, including improvements in both ultrastructural pathology and abnormal neurobehavioural changes. Our findings indicate that endogenous overexpression of Grb10 functions as a suppressor of the IGF1-IR pathway, which may represent an important mechanism for regulating cognitive disorder in diabetes.

Mycoplasma gallisepticum and Escherichia coli mixed infection model in broiler chickens for studying valnemulin pharmacokinetics

A Mycoplasma gallisepticum-Escherichia coli mixed infection model was developed in broiler chickens, which was applied to pharmacokinetics of valnemulin in the present experiment. The velogenic M. gallisepticum standard strain S6 was rejuvenated to establish the animal model, and the wild E. coli strain O78 was injected as supplementary inoculum to induce chronic respiratory disease in chickens. The disease model was evaluated based on its clinical signs, histopathological examination, bacteriological assay, and serum plate agglutination test. The pharmacokinetics of valnemulin in infected chickens was determined by intramuscular (i.m.) injection and oral administration (per os, p.o.) of a single dose of 10 mg/kg body weight (BW). Plasma samples were analyzed by liquid chromatography-tandem mass spectrometry. The plasma concentration-time curve of valnemulin was analyzed using the noncompartmental method. After the i.m. administration, the mean values of Cmax , Tmax , AUClast , MRT, CLβ /F, Vz /F, and t1⁄2β , were 27.94 μg/mL, 1.57 h, 171.63 μg·h/mL, 4.51 h, 0.06 L/h/kg, 0.56 L/kg, and 6.50 h, respectively. By contrast, the corresponding values after p.o. administration were 5.93 μg/mL, 7.14 h, 47.60 μg·h/mL, 9.80 h, 0.22 L/h/kg, 3.35 L/kg, and 10.60 h. The disposition of valnemulin was retarded in infected chickens after both modes of extravascular administration as compared to the healthy controls. More attention should be given to monitoring the therapeutic efficacy and adverse effects of mixed infection because of higher required plasma drug concentration and enlarged AUC with valnemulin treatment.

Population pharmacokinetics of valnemulin in swine

This study was carried out in 121 pigs to develop a population pharmacokinetic (PPK) model by oral (p.o.) administration of valnemulin at a single dose of 10 mg/kg. Serum biochemistry parameters of each pig were determined prior to drug administration. Three to five blood samples were collected at random time points, but uniformly distributed in the absorption, distribution, and elimination phases of drug disposition. Plasma concentrations of valnemulin were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration-time data were fitted to PPK models using nonlinear mixed effect modeling (NONMEM) with G77 FORTRAN compiler. NONMEM runs were executed using Wings for NONMEM. Fixed effects of weight, age, sex as well as biochemistry parameters, which may influence the PK of valnemulin, were investigated. The drug concentration-time data were adequately described by a one-compartmental model with first-order absorption. A random effect model of valnemulin revealed a pattern of log-normal distribution, and it satisfactorily characterized the observed interindividual variability. The distribution of random residual errors, however, suggested an additive model for the initial phase (<12 h) followed by a combined model that consists of both proportional and additive features (≥ 12 h), so that the intra-individual variability could be sufficiently characterized. Covariate analysis indicated that body weight had a conspicuous effect on valnemulin clearance (CL/F). The featured population PK values of Ka , V/F and CL/F were 0.292/h, 63.0 L and 41.3 L/h, respectively.

Efficacy of sequential use of telbivudine in hepatitis B e antigen-positive chronic hepatitis B patients with partial responses to pegylated interferon: a pilot study

The aim of this study was to investigate the efficacy of sequential use of telbivudine in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients with partial responses to pegylated interferon. Patients with partial responses to 48 weeks of pegylated interferon treatment were divided into two groups. In group A, patients stopped pegylated interferon directly without sequential treatment. In group B, patients received sequential treatment with telbivudine 600 mg/day. HBeAg, HBeAb, hepatitis B virus (HBV) DNA, alanine aminotransferase (ALT) and creatine kinase levels were determined at baseline and at weeks 12, 24, 36 and 48. Responses and safety were assessed after 48 weeks of telbivudine treatment. Thirty-six patients were recruited. Eighteen of these patients stopped pegylated interferon without sequential treatment (group A). After 48 weeks of follow-up, five patients (28%) had undergone HBeAg seroconversion, nine patients (50%) had undetectable levels of HBV DNA, and 11 patients (61%) achieved normal alanine aminotransferase (ALT) levels. The other 18 patients received sequential telbivudine treatment (group B). After 48 weeks of treatment, 11 patients (61%) had undergone HBeAg seroconversion, and all patients had undetectable levels of HBV DNA and normal ALT levels. All patients tolerated sequential telbivudine treatment, and only slightly elevated creatine kinase levels were observed. Switching to telbivudine therapy was efficient and safe in HBeAg-positive chronic hepatitis B patients with partial responses to 48 weeks of pegylated interferon. Sequential treatment with telbivudine resulted in an HBeAg seroconversion rate of 61% and an HBV DNA loss rate of 100% after 48 weeks. This promising strategy warrants further investigation.

Administration of PLGA nanoparticles carrying shRNA against focal adhesion kinase and CD44 results in enhanced antitumor effects against ovarian cancer

The two membrane-bound proteins, focal adhesion kinase (FAK) and CD44, are involved in processes critical to cancer progression. FAK has an active role in angiogenesis, cell proliferation and cell apoptosis, whereas the heavily glycosylated CD44 has been implicated in cancer metastasis. Here, using short hairpin RNA (shRNA) against FAK and CD44, we demonstrate that simultaneous knockdown of both these genes inhibits cancer growth more efficiently than knockdown of either gene individually. Plasmids targeting these genes or non-relative control sequences were constructed and delivered to ovarian cancer targets by biodegradable poly D,L-lactide-co-glycolide acid nanoparticles (PLGANPs). Nude mice were utilized in an intraperitoneal model of ovarian carcinomatosis to assess antitumor efficacy in vivo. Single gene knockdown resulted in significantly smaller tumors than those observed in the empty-vector control (P's<0.001). More importantly, knockdown of both genes resulted in tumors smaller than both the empty-vector group (P<0.0001) and the single gene knockdown groups (P's<0.001). Knockdown of both FAK and CD44 resulted in tumors with inhibited angiogenesis, reduced proliferation and increased apoptosis as compared with controls (P's<0.001) and single knockdown groups (P's<0.05). These results indicate that dual knockdown of FAK and CD44 in the tumors of patients with ovarian cancer may have an enhanced therapeutic effect, and point toward a mechanism involving the inhibition of angiogenesis, cellular proliferation and the induction of apoptosis.

Population pharmacokinetics of cefquinome in pigs

This study was performed in 145 pigs to develop a population pharmacokinetics (PPK) model by i.m. administration of cefquinome (CEQ) at the dose of 2 mg/kg in the neck muscle. Serum physiological and biochemical parameters for each pig were determined before administration. After administration, 2-4 samples were collected at random, with the sampling point evenly distributed in the three periods (<1 h, 1-4 h and >4 h). The plasma concentration of CEQ was determined by high performance liquid chromatography with UV detector. The pharmacostatistical analyses of concentration-time data, weight, age, gender, serum physiological and biochemical parameters were performed with nonlinear mixed effect modeling (NONMEM). A one-compartmental model with first-order absorption and elimination adequately described the data from the study group. The optimal random effect model of pharmacokinetics parameters was of log-normal distribution and the residual errors assumed a mixed-type model (proportional and additive) to best explain intra-individual variability. Covariate analysis showed that body weight is positively correlated with apparent volume of distribution (V/F) and body clearance (CL/F). The typical PPK parameters of Ka , CL, and V were 0.564/h, 5.15 L/h, and 1.36 L, respectively.

Electrochemical polymerization of aniline investigated using on-line electrochemistry/electrospray mass spectrometry

A thin-layer electrochemical flow cell coupled on-line with electrospray mass spectrometry (EC/ES-MS) was used to investigate the soluble products from the controlled-potential anodic polymerization of aniline in H(2)O and H(2)O/CH(3)OH (1/1 v/v) with ammonium acetate and acetic acid or ammonium hydroxide as electrolytes (pH 4, 6.5, or 9). At a working electrode (glassy carbon) potential of 1.0 V versus Ag/AgCl, singly protonated aniline oligomers containing as many as 10 aniline units (10-mer) were observed in the ES mass spectra when the polymerization in H(2)O/CH(3)OH at pH 4 was carried out. The abundance of the higher n-mers decreased at higher solution pH and in 100% H(2)O at pH 4. Most of the oligomers were observed in more than one redox state ranging from fully oxidized (all imine nitrogens) to fully reduced (all amine nitrogens). The number of different redox states observed for the n-mers increased with increasing n. The structures of the reduced (m/z 185) and oxidized (m/z 183) aniline dimer ions (head-to-tail, tail-to-tail, or head-to-head) produced from the polymerization of aniline at pH 4, 6.5, and 9 in H(2)O/CH(3)OH were revealed to vary as a function of pH by comparison of their tandem mass spectrometry product ion spectra with the product ion spectra of the dimer standards. EC/ES-MS potential scan experiments, in which the working electrode current and major n-mer ions for n = 2, 3, and 4 were monitored as a function of electrode potential, were used to probe the growth mechanism to higher aniline oligomers. Under the conditions used, the controlled-current electrolytic process inherent to the operation of the ES ion source did not significantly influence the formation or nature of the oligomers observed. Beyond the current application, the results presented here serve to demonstrate the utility of EC/ES-MS as a tool in identifying the initial products of electropolymerization and in studying the products of electrode reactions in general.

SKLB1002, a novel inhibitor of VEGF receptor 2 signaling, induces vascular normalization to improve systemically administered chemotherapy efficacy

Vascular endothelial growth factor receptor (VEGFR) or vascular endothelial growth factor (VEGF) inhibitors have shown only modest clinical activity for most tumor types when used as single agents. However, present evidence indicates that these antiangiogenic drugs can cause transient "normalization" of the tumor vasculature, thereby improving the delivery of systemic chemotherapy. We examined temporal changes in tumor vascular function in response to the novel VEGFR2 inhibitor, SKLB1002. Established tumor-bearing animals were evaluated at serial time points for treatment-associated changes in tumor vascular architecture and function. As a result, blocking VEGF signaling by SKLB1002 produced a morphologically and functionally "normalized" vascular network. Consistent with our observations, a 2.2 fold increase in intratumoral doxorubicin levels was determined with SKLB1002 pretreatment compared with administration of doxorubicin alone. Finally, combined SKLB1002 and doxorubicin exhibited significant antitumor (49% of control size) and antimetastatic effects (12% of control metastatic nodules) in vivo. Our results showed SKLB1002 induced vascular normalization and enhanced anticancer drug delivery, which were associated with the observed synergistic effect in vivo.

Lead contamination and source in Shanghai in the past century using dated sediment cores from urban park lakes

Lead contamination becomes of importance to urban resident health worldwide, especially for child health and growth. Undisturbed lake sediment cores are increasingly employed as a useful tool to backdate environmental contamination history. Five intact sediment cores collected from lakes in five urban parks were dated using (210)Pb and analyzed for total Pb content and isotope ratio to reconstruct the Pb contamination history over the last century in Shanghai, China. Total Pb content in the sediment cores increased by about 2- to 3-fold since 1900s. The profile of Pb flux in each sediment core revealed a remarkable increase of Pb contamination in Shanghai over the past century, especially in the latest three decades when China was experiencing a rapid economic and industrial development. Significant correlations were found between Pb fluxes in sediment cores and Pb emission from coal combustion in Shanghai. Coal combustion emission dominated anthropogenic Pb sources during the past century contributing from 52% to 69% of total Pb in cores, estimated by a three-end member model of Pb isotope ratios. Leaded gasoline emission generally contributed <30% of total Pb, which was banned by 1997 in the Shanghai region. Our results implicate that coal combustion-based energy consumption should be replaced, or at least partially replaced, to reduce health risks of Pb contamination in Shanghai.

Genetic analysis of NR4A2 gene in a large population of Han Chinese patients with Parkinson's disease

BACKGROUND

NR4A2 gene is a transcription factor crucial for differentiation and survival of midbrain dopamine (DA) neurons, and several variants have been eported to be associated with Parkinson's disease (PD) in the Caucasian population.

METHODS

To determine whether there is any association of NR4A2 mutation or variation with PD in the Han Chinese population, we performed a genetic analysis of all the exons and exon-intron boundaries in 689 PD patients and 672 controls from mainland China using direct sequencing analysis.

RESULTS

We identified four novel variants and two previously reported variants. Two novel variants (exon 2 c.-20 C>G and exon 3 c.711 C>A) were only found in PD. The others (exon 2 c.-35 A>G; exon 8 c.1615 G>A; intron 4 IVS4-16 G>T; and intron 6 IVS6 + 18 insG) were found in both PD and controls at different frequencies.

CONCLUSIONS

Collectively, our results suggest that NR4A2 may be a susceptibility gene for PD in the Chinese population.

Association of genetic variation in FTO with risk of obesity and type 2 diabetes with data from 96,551 East and South Asians

AIMS/HYPOTHESIS

FTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians.

METHODS

All studies published on the association between FTO-rs9939609 (or proxy [r (2) > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes.

RESULTS

The FTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 10(-19)), overweight by 1.13-fold/allele (p = 1.0 × 10(-11)) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 10(-8)). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 10(-5)). The FTO-rs9939609 minor allele increased BMI by 0.26 kg/m(2) per allele (p = 2.8 × 10(-17)), WHR by 0.003/allele (p = 1.2 × 10(-6)), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12-20%) than South Asians (30-33%), the effect of FTO variation on obesity-related traits and type 2 diabetes was similar in the two populations.

CONCLUSIONS/INTERPRETATION

FTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTO is also associated with type 2 diabetes independently of BMI.

A cryogen-free dilution refrigerator based Josephson qubit measurement system

We develop a small-signal measurement system on cryogen-free dilution refrigerator which is suitable for superconducting qubit studies. Cryogen-free refrigerators have several advantages such as less manpower for system operation and large sample space for experiment, but concern remains about whether the noise introduced by the coldhead can be made sufficiently low. In this work, we demonstrate some effective approaches of acoustic isolation to reduce the noise impact. The electronic circuit that includes the current, voltage, and microwave lines for qubit coherent state measurement is described. For the current and voltage lines designed to have a low pass of dc-100 kHz, we show that the measurements of Josephson junction's switching current distribution with a width down to 1 nA, and quantum coherent Rabi oscillation and Ramsey interference of the superconducting qubit can be successfully performed.

Decreased NURR1 and PITX3 gene expression in Chinese patients with Parkinson's disease

BACKGROUND AND PURPOSE

The preferential degeneration of midbrain dopaminergic (mDA) neurons in the substantia nigra pars compacta is the pathological hallmark in Parkinson's disease (PD). The transcription factors NURR1 and PITX3 have been shown to play a crucial role in the maturation and survival of mDA neurons, and both of them were potential susceptibility genes for PD.

METHODS

  To determine whether NURR1 and PITX3 gene expression are altered in Chinese patients with PD, we measured their gene expression in human peripheral blood lymphocytes (PBL) in 255 patients with PD and 211 age- and gender-matched healthy controls by quantitative real-time PCR technique.

RESULTS

 We found that both NURR1 and PITX3 gene expression in PBL were significantly decreased in patients with PD as compared with controls (P < 0.0001). Lower levels of NURR1 and PITX3 gene expression were significantly associated with the increased risk for PD in male and older subjects, respectively.

CONCLUSIONS

  Our results provide useful information that the NURR1 and PITX3 gene expression is decreased in the PBL of Chinese patients with PD, indicating their possible systemic involvement in PD.

Altered cerebrospinal fluid index of prealbumin, fibrinogen, and haptoglobin in patients with Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy

OBJECTIVES

Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are autoimmune diseases of the peripheral nervous system. A clinical hallmark of GBS and CIDP is the albumino-cytologic dissociation in the cerebrospinal fluid (CSF). Changes in the CSF levels of proteins other than albumin in patients with GBS and CIDP are not as well studied. If altered, aberrant levels of CSF proteins may render it possible to establish useful biomarkers for GBS and CIDP.

MATERIALS AND METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of prealbumin, fibrinogen, haptoglobin, apolipoprotein E, apolipoprotein A4 in both CSF and plasma samples from 19 patients with GBS and eight with CIDP, 24 controls with multiple sclerosis (MS) as well as 20 patients with other non-inflammatory neurological disorders (OND).

RESULTS

The levels of prealbumin in both the plasma and the CSF were elevated in patients with GBS and MS compared with the controls. The higher levels of fibrinogen were seen in the CSF of patients with GBS and CIDP, but not in the plasma. The levels of CSF prealbumin and fibrinogen, measured by the CSF index of these proteins, were lower in patients with GBS and that of fibrinogen in patients with CIDP compared with controls with OND. Haptoglobin levels in the CSF rather than in the plasma were higher in patients with GBS and CIDP than in controls. The CSF haptoglobin index was higher in patients with CIDP and MS, but not in those with GBS. No correlation was found between levels of CSF proteins and clinical parameters in patients with GBS and CIDP.

CONCLUSIONS

Our data provide preliminary evidence that GBS is associated with low CSF index levels of prealbumin and fibrinogen, but normal levels of haptoglobin, whereas CIDP is associated with normal CSF index levels of prealbumin, low fibrinogen, and high levels of haptoglobin. Further studies are needed to identify the underlying mechanisms behind these CSF protein alterations and to clarify whether prealbumin, fibrinogen, and haptoglobin can serve as useful biomarkers for GBS and CIDP.

Childhood sexual abuse and the risk for recurrent major depression in Chinese women

BACKGROUND

Studies in Western countries have repeatedly shown that women with a history of childhood sexual abuse (CSA) are at increased risk for developing major depression (MD). Would this relationship be found in China?

METHOD

Three levels of CSA (non-genital, genital, and intercourse) were assessed by self-report in two groups of Han Chinese women: 1970 clinically ascertained with recurrent MD and 2597 matched controls. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression and regression coefficients by linear or Poisson regression.

RESULTS

Any form of CSA was significantly associated with recurrent MD [OR 3.26, 95% confidence interval (CI) 1.95-5.45]. This association strengthened with increasing CSA severity: non-genital (OR 2.47, 95% CI 1.17-5.23), genital (OR 2.77, 95% CI 1.32-5.83) and intercourse (OR 13.35, 95% CI 1.83-97.42). The association between any form of CSA and MD remained significant after accounting for parental history of depression, childhood emotional neglect (CEN), childhood physical abuse (CPA) and parent-child relationship. Among the depressed women, those with CSA had an earlier age of onset, longer depressive episodes and an increased risk for generalized anxiety disorder (GAD; OR 1.92, 95% CI 1.39-2.66) and dysthymia (OR 2.16, 95% CI 1.52-3.09).

CONCLUSIONS

In Chinese women CSA is strongly associated with MD and this association increases with greater severity of CSA. Depressed women with CSA have an earlier age of onset, longer depressive episodes and increased co-morbidity with GAD and dysthymia. Although reporting biases cannot be ruled out, our results are consistent with the hypothesis that, as in Western countries, CSA substantially increases the risk for MD in China.

The treatment of oral cancer: an overview for dental professionals

Oral cancer is a serious life-threatening disease. Dental professionals may be the first individuals to identify/suspect these lesions before referring to oral and maxillofacial surgeons and oral medicine specialists. Because the general dentist will likely follow on with the patient's future oral health, it is important that he or she has a basic understanding of the various treatments involved in treating oral malignancies and their respective outcomes. The four main modalities discussed in this review include surgery alone, radiotherapy alone, surgery with radiotherapy, and chemotherapy with or without surgery and radiotherapy. Chemotherapy has become an area of great interest with the introduction of new 'targeted therapies' demonstrating promising results in conjunction with surgery. Despite these results, the toxicities associated with chemotherapy regimens are frequent and can be severe, and therefore may not be suitable for all patients. Treatment modalities have improved significantly over the decades with overall decreases in recurrence rates, improved disease-free and overall survival, and an improved quality of life. Prognosis, however, is still ultimately dependent on the clinical stage of the tumour at the initial diagnosis with respect to size, depth, extent, and metastasis as recurrence rates and survival rates plummet with disease progression.

LINGO1 variants in essential tremor and Parkinson's disease

The leucine-rich repeat and Ig domain containing 1 gene (LINGO1), recently considered to be conferred increased risk of essential tremor (ET), has been also implicated in Parkinson disease (PD). As the two common movement disorders have overlapping clinical and pathological features, it has been postulated that the LINGO1 gene may play a role in the pathogenesis of the two diseases. Here, we review published reports of the LINGO1 variants in ET and PD in an attempt to better understand the molecular and pathogenic relationship of LINGO1 to the two disorders.

Enhanced chemosensitivity to CPT-11 in colorectal carcinoma xenografts by small hairpin RNA interference targeting PLK1

Commonly used drugs for the treatment of colon{} cancer patients like CPT-11 shows severe side effects or induces resistance in clinical settings. Thus, we analyzed a combination of PLK1 (polo-like kinase 1)-specific short hair RNA (shRNA), a potent tool to destroy mitosis in cancer cells, together with CPT-11 to enhance drug sensitivity. Cellular proliferation and apoptosis were determined in SW620 colorectal carcinoma cells. Knockdown of cellular PLK1 led to the decreased mRNA and PLK1 protein in RT-PCR and western blot assay. The viability declined (p<0.001) in MTT assay and colony formation assay, and the number of apoptotic cells was clearly increased (p<0.01) in flow cytometric analysis and Hoechst 33258 staining compared with control cells after incubation with PLK1-specific shRNA and SN-38. We found the level of cleaved PARP was also increased in vitro. In vivo, employment of shRNA targeting PLK1 improved the sensitivity to treat SW620 nude mouse model toward CPT-11. The combination therapy inhibited cellular proliferation and promoted apoptosis observed at the percentage of PCNA and caspase3 by immunohistochemistry, accompanied with TUNEL assay. As we expect, the combination treatment delayed tumor growth (p<0.01) and simultaneously reduced tumor weight (p<0.01) compared with control group. Taken together, combination of PLK1-specific shRNA interference with low-dose CPT-11 triggered a antitumor efficacy and represented a potential strategy to treat colon cancer.

Azithromycin in periodontal treatment: more than an antibiotic

Azithromycin is a macrolide antibiotic used extensively in medicine for the treatment of a wide range of infections such as upper respiratory tract infections, middle ear infections, sexually transmitted infections and trachoma. It is also effective against the most common periodontopathogens. The versatility of the macrolides extends beyond their antibiotic properties as a result of their well-documented immune-modulating/anti-inflammatory effects. Macrolides, including azithromycin, are therefore used to treat diseases not associated with bacteria, such as severe asthma, chronic obstructive pulmonary diseases and, more recently, cystic fibrosis. Azithromycin is concentrated in neutrophils, macrophages and particularly fibroblasts; all of these cells are central players in the pathogenesis of most periodontal diseases. This paper reviews the diverse properties of azithromycin and the clinical periodontal studies of its effects in both the treatment of periodontitis and in resolving drug-related gingival overgrowth. Evidence exists to support the use of a single course of azithromycin in the treatment of advanced periodontal diseases. Azithromycin could have a triple role in the treatment and resolution of periodontal diseases: suppressing periodontopathogens, anti-inflammatory activity and healing through persistence at low levels in macrophages and fibroblasts in periodontal tissues, even after a single course of three tablets. If future periodontal research confirms these properties, it could become a valuable host-modulator in periodontal treatment.

Generation of pancreatic insulin-producing cells from rhesus monkey induced pluripotent stem cells

AIMS/HYPOTHESIS

The generation of induced pluripotent stem cells (iPSCs) provides a promising possibility for type 1 diabetes therapy. However, the generation of insulin-producing cells from iPSCs and evaluation of their efficacy and safety should be achieved in large animals before clinically applying iPSC-derived cells in humans. Here we try to generate insulin-producing cells from rhesus monkey (RM) iPSCs.

METHODS

Based on the knowledge of embryonic pancreatic development, we developed a four-stage protocol to generate insulin-producing cells from RM iPSCs. We established a quantitative method using flow cytometry to analyse the differentiation efficiency. In addition, to evaluate the differentiation competence and function of RM iPSC-derived cells, transplantation of stage 3 and 4 cells into immunodeficient mice was performed.

RESULTS

RM iPSCs were sequentially induced to definitive endoderm (DE), pancreatic progenitors (PP), endocrine precursors (EP) and insulin-producing cells. PDX1(+) PP cells were obtained efficiently from RM iPSCs (over 85% efficiency). The TGF-β inhibitor SB431542 promoted the generation of NGN3(+) EP cells, which can generate insulin-producing cells in vivo upon transplantation. Finally, after this four-stage differentiation in vitro, insulin-producing cells that could secrete insulin in response to glucose stimulation were obtained. When transplanted into mouse models for diabetes, these insulin-producing cells could decrease blood glucose levels in approximately 50% of the mice.

CONCLUSIONS/INTERPRETATION

We demonstrate for the first time that RM iPSCs can be differentiated into functional insulin-producing cells, which will provide the basis for investigating the efficacy and safety of autologous iPSC-derived insulin-producing cells in a rhesus monkey model for type 1 diabetes therapy.

Growth, Structure and Stress of DC Magnetron Sputtered TiB2 Thin Films

TiB2 is a very hard refractory compound that strongly resists erosion and shows metallic luster and good electrical conductivity. It has potential applications in protective coating systems. This paper investigates the microstructure and stresses of as-deposited TiB2 thin films ranging from 2000 °A to 4000 °A thick produced by dc magnetron sputtering as a function of sputtering power and Ar pressure. Three power levels: 100, 400, 600 W, and four pressures: 3, 5, 8, and 12 mTorr were used. X-ray diffraction studies indicate that two types of crystalline structure are formed: a randomly oriented fine crystalline structure and a coarser grained (001) textured structure, depending on the sputtering power and pressure. As-deposited stresses at different powers all show a transition from compression to tension as the Ar pressure increases. The relationship between the processing parameters, microstructure and residual stresses is discussed. The effects of the deposition power and pressure on the residual stress transition of TiB2 thin films are clearly mapped out by 3-D and contour maps.

Exposure-response (E-R) analysis to facilitate phase III (P3) dose selection for AMG 479 (A479) in combination with gemcitabine (G) to treat metastatic pancreatic cancer (mPC)

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Background: A479 is an investigational, fully human monoclonal antibody against IGF1R. In a phase II study, 125 pts with mPC were randomized 1:1:1 to A479, placebo (P), or conatumumab in combination with G. Addition of A479 (12 mg/kg IV, Q2W) to G (1000 mg/m2) showed evidence of improved OS and PFS (Kindler, JCO 2010:28 abstr 4035). An E-R analysis was done to inform P3 dose selection for A479.

Methods: A population PK model of A479 was constructed using data from multiple studies. An E-R analysis was performed with pts from the A479+G and P+G arms (∼40 pts/arm). The effect of estimated steady-state area under the curve (AUCss) on OS and PFS was evaluated with a Cox proportional hazard model. Effects of potential confounding factors on OS- AUCss and PFS-AUCss associations were assessed by multivariate analysis. Exposure-safety data were analyzed with descriptive statistics and linear regression. P3 doses for A479 were explored with Monte Carlo simulations using population PK and parametric survival models.

Results: There was a positive association between OS or PFS and higher AUCss in the A479+G arm (P<0.001, <0.001) that remained even when data from the A479+G and P+G arms were combined (P=0.033, 0.022). Pts with AUCss ≥ median (19.2 mg·h/μL) had longer median OS and PFS (16.0, 7.6 months) than pts with AUCss < median (4.7, 1.9 months). OS-AUCss and PFS-AUCss associations were significant after adjusting for potential confounding factors. Sensitivity E-R analyses were done to confirm the modeling results. The incidence of most adverse events was similar between the AUCss < and ≥ median groups, although the incidence of grade ≥3 hyperglycemia, neutropenia, and thrombocytopenia trended higher in pts with AUCss ≥ median. Population PK indicated 1.7-fold higher clearance of A479 in mPC than non-mPC pts. No G-A479 PK interactions were identified. PK simulations showed similar AUCss of A479 in mPC pts at 20 mg/kg and in non-mPC pts at 12 mg/kg. Simulations projected improved OS and PFS with 20 mg/kg vs 12 mg/kg A479.

Conclusions: Increased exposure to A479 is associated with improved clinical outcomes in mPC. This supports the evaluation of 20 mg/kg A479 in P3.

[Table: see text]