Hybrid Ni–Al layered double hydroxide/graphene composite supported gold nanoparticles for aerobic selective oxidation of benzyl alcohol

A NiAl-LDH/RGO composite-supported Au catalyst was synthesized and exhibited high activity and stability in the selective oxidation of benzyl alcohol.

Lower free testosterone level is correlated with left ventricular diastolic dysfunction in asymptomatic middle-aged men with type 2 diabetes mellitus

AIMS

Low testosterone (T) level is associated with cardiovascular risk factors. However, the relationship between T level and heart function in asymptomatic men with type 2 diabetes mellitus (T2DM) is unknown.

METHODS

A total of 325 men were recruited who had no history, symptoms, or signs of heart disease.

RESULTS

T2DM had significantly lower free T (FT) levels than those with normal glucose metabolism (NGM) (428 ± 38 pmol/l vs. 444 ± 38 pmol/l, p = 0.0002), and had an increased risk of LVDD (66.1% vs. 31.8%). There was a significant difference in FT level between subjects with and without LVDD among those with T2DM (421 ± 37 pmol/l vs. 442 ± 40 pmol/l, p = 0.0007), but not among those with NGM (439 ± 37 pmol/l vs. 447 ± 39 pmol/l, p = 0.247) or in the group overall (426 ± 38 pmol/l vs. 445 ± 38 pmol/l, p = 0.156). Lower FT level was significantly associated with LVDD [univariate odds ratio (OR) = 0.63, p = 0.032; multivariate OR = 0.71, p = 0.039]. Receiver operating characteristic curve analysis of the usefulness of FT level for predicting LVDD showed an area under the curve (AUC) of 0.85 for T2DM (p < 0.001) and 0.66 for NGM (p < 0.05). FT level had a high predictive value for LVDD in T2DM (83% for FT < 414 pmol/l), but a low predictive value in NGM (61% for FT < 423 pmol/l). Comparison of the AUCs showed that FT level was more strongly correlated with LVDD in T2DM than in NGM.

CONCLUSIONS

Lower FT level is correlated with LVDD in asymptomatic middle-aged men with T2DM.

Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer

BACKGROUND

Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.

AIM

To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.

METHODS

Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.

RESULTS

A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).

CONCLUSIONS

Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.

The Bionanoprobe: hard X-ray fluorescence nanoprobe with cryogenic capabilities

Hard X-ray fluorescence microscopy is one of the most sensitive techniques for performing trace elemental analysis of biological samples such as whole cells and tissues. Conventional sample preparation methods usually involve dehydration, which removes cellular water and may consequently cause structural collapse, or invasive processes such as embedding. Radiation-induced artifacts may also become an issue, particularly as the spatial resolution increases beyond the sub-micrometer scale. To allow imaging under hydrated conditions, close to the `natural state', as well as to reduce structural radiation damage, the Bionanoprobe (BNP) has been developed, a hard X-ray fluorescence nanoprobe with cryogenic sample environment and cryo transfer capabilities, dedicated to studying trace elements in frozen-hydrated biological systems. The BNP is installed at an undulator beamline at sector 21 of the Advanced Photon Source. It provides a spatial resolution of 30 nm for two-dimensional fluorescence imaging. In this first demonstration the instrument design and motion control principles are described, the instrument performance is quantified, and the first results obtained with the BNP on frozen-hydrated whole cells are reported.

Polymorphism of rs1836882 in NOX4 gene modifies associations between dietary caloric intake and ROS levels in peripheral blood mononuclear cells

Excessive caloric intake is a contributing risk factor for human metabolic disorders. Caloric restriction may prolong a person's life by lowering the incidence of deadly diseases. Reactive oxygen species (ROS) in peripheral blood mononuclear cells (PBMC) have been associated with the biochemical basis of the relationship between caloric intake and pathophysiologic processes. Polymorphisms associated with ROS generation genes are being increasingly implicated in inter-individual responses to daily caloric intake alterations. In the current study, a single nucleotide polymorphism, rs1836882, in the nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) gene's promoter region was found to modulate associations between dietary caloric intake and ROS levels in PBMC. Based on rs1836882, 656 Chinese Han participants were classified into CC, CT and TT genotypes. ROS levels in PBMC were significantly higher in the CC or CT genotypes compared with the TT genotype with the same increases in daily caloric intake. Using an electrophoretic mobility shift assay, NOX4 promoter region with rs1836882 (T) was observed to have a higher affinity for hepatocyte nuclear factor gamma (HNF3γ) protein than rs1836882 (C). HNF3γ protein over-expression decreased NOX4 gene transcriptional activity in the TT genotype more than in the CC genotype (5.68% vs. 2.12%, P<0.05) in a dual luciferase reporter assay. By silencing the NOX4 gene using small interfering RNA or over-expressing HNF3γ using an expression plasmid, serum from high dietary caloric intake participants decreased ROS levels in PBMC of the TT genotype more than in the CC or CT genotype via HNF3γ down-regulating the NOX4 gene expression signaling pathway. This is the first study to report on the functions of phenotypes of rs1836882 in the NOX4 gene, and it suggests rs1836882 as a candidate gene for interpreting inter-individual ROS levels differences in PBMC induced by alterations in daily caloric intake.

Development and characterization of new microsatellites for walnut (Juglans regia)

The expressed sequence tag (EST) database represents a potentially valuable resource for the development of simple sequence repeat (SSR) markers for use in evolutionary studies. EST-SSRs reveal polymorphisms not only within the source taxon, but in related taxa as well. In this paper, we describe a case study in which the publicly available walnut (Juglans regia) EST database was used to develop SSR markers for use in the genetic analysis of the widespread Juglans nigra and Carya cathayensis and an endangered species Annamocarya sinensis. A total of 7262 unigenes, including 1911 contigs and 5351 singletons, were obtained from 13,559 ESTs retrieved from the NCBI database. The 7262 unigenes were further reduced to 706 EST-SSR sequences containing 805 SSR loci. Then, 309 EST-SSR primers were randomly designed, and 77 were identified with five high across-species transferability cross-species: namely, J. regia, J. nigra, C. cathayensis, Carya dabieshanensis, and A. sinensis. Thirteen highly polymorphic EST-SSRs were further used for genetic analyses in these above five species.

Low Serum retinol-binding protein-4 levels in acute exacerbations of chronic obstructive pulmonary disease at intensive care unit admission is a predictor of mortality in elderly patients

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are thought to be associated with increased mortality in elderly patients. Low retinol-binding protein-4 (RBP4) is associated with a high risk of respiratory infections in the general population. Therefore, we hypothesized that low RBP4 levels are associated with an increased risk of AECOPD and can be used as a biomarker for AECOPD in elderly patients.

METHODS

Enzyme-linked immunosorbent assays were used to assess RBP4 levels in elderly with AECOPD within the first 24 hours after intensive care unit admission. Forty-six elderly patients with stable COPD in outpatient clinics and 50 healthy elderly persons who had physical examinations as outpatients were controls.

RESULTS

In AECOPD patients, RBP4 levels were lower than those in stable COPD patients and healthy controls (59.7 vs 91.2 and 113.6 mg/L, p < 0.001). RBP4 levels were decreased by 30.6% in non-survivors compared with survivors (51.5 vs 74.2 mg/L, p < 0.001). A higher Acute Physiology and Chronic Health Enquiry II (APACHE II) score and Simplified Acute Physiology score (SAPS II) were associated with lower RBP4 levels (r = -0.692, p = 0.024 and r = -0.670, p = 0.015, respectively). RBP4 was positively correlated with creatinine and body mass index, and negatively correlated with C-reactive protein and Global Initiative for Chronic Obstructive Lung Disease stage. Multivariate logistic regression showed that RBP4 was an independent mortality predictor of AECOPD (odds ratio: 0.926, p = 0.007). Analysis of the area under the receiver operating characteristic (AUC) curve showed that RBP4 showed good discrimination (AUC: 0.88; 95% confidence interval: 0.78-0.94; p = 0.008) in predicting mortality. RBP4 improved the prognostic accuracy of mortality for the APACHE II and SAPS II scores.

CONCLUSIONS

Serum RBP4 levels are significantly reduced in elderly AECOPD patients. RBP4 might be a good predictive biomarker for mortality in elderly AECOPD patients in the intensive care unit.

Small-molecule inducer of β cell proliferation identified by high-throughput screening

The identification of factors that promote β cell proliferation could ultimately move type 1 diabetes treatment away from insulin injection therapy and toward a cure. We have performed high-throughput, cell-based screens using rodent β cell lines to identify molecules that induce proliferation of β cells. Herein we report the discovery and characterization of WS6, a novel small molecule that promotes β cell proliferation in rodent and human primary islets. In the RIP-DTA mouse model of β cell ablation, WS6 normalized blood glucose and induced concomitant increases in β cell proliferation and β cell number. Affinity pulldown and kinase profiling studies implicate Erb3 binding protein-1 and the IκB kinase pathway in the mechanism of action of WS6.

A suppository for treating cervical erosion and its preparation method

OBJECTIVE

To study a suppository for treating cervical erosion, its preparation method, and to observe its therapeutic effect on cervical erosion in animal models.

METHODS

Twenty rats were divided into five groups: blank control group, model group, and three different therapeutic concentration groups. Phenol slurry was injected through the vagina to create cervical erosion animal models. After seven days of drug treatment, the difference of cervical histopathology was observed and compared between different groups.

RESULTS

Compared with the control group, the model group showed obvious cervical erosion, inflammatory cell infiltration, vascular dilatation, and congestion. Among the administration group, the high administration group had the least inflammation and cell infiltration in the mucous membrane.

CONCLUSIONS

There is a significant effect of therapeutic drugs in rats with cervical erosion, which is related to the concentration of drugs.

Inhibitory activities of baicalin against renin and angiotensin-converting enzyme

CONTEXT

Baicalin has been characterized as the active compound and quality control marker in Scutellaria baicalensis Georgi, traditionally used as a hypotensive herb.

OBJECTIVES

To investigate the inhibitory activities of baicalin against renin and angiotensin-I converting enzyme (ACE) and their molecule mechanism of interactions.

METHODS

The fluorescence method using renin substrate 1(R-2932) and the spectroscopy method by Cushman were used to determine renin and ACE activities, respectively. The fluorescence quench techniques were used to characterize their interactions.

RESULTS

The results showed that baicalin inhibited renin activity with an IC(50) value of 120.36 µM and inhibited ACE activity with an IC(50) value of 2.24 mM in vitro. The fluorescence emission of both renin and ACE were efficiently quenched by baicalin and a complete quenching was achieved at a high concentration of baicalin. Furthermore, baicalin was more effective in quenching the fluorescence of renin (K(SV) = 60 × 10(3) M(-1)) than ACE (K(SV) = 17.1 × 10(3) M(-1)). The quenching of fluorescence of renin and ACE involved static interactions, which was characterized by the formation of quencher-enzyme complex. The baicalin-renin complex formed through three-sites binding including the active site with a binding constant of 796.15 × 10(13) M(-1), but there was only one binding site for the baicalin-ACE complex with a much smaller binding constant of 6.8 × 10(5) M(-1).

CONCLUSION

The inhibition activity of baicalin against renin was a result of the formation of stable complex through multisites binding including the active site, which could explain the higher inhibitory efficiency.

IL28B genetic variants and gender are associated with spontaneous clearance of hepatitis C virus infection

Single nucleotide polymorphisms (SNPs) near the IL28B gene have been shown to be associated with response to treatment for chronic hepatitis C and also with spontaneous clearance of hepatitis C virus (HCV) infection. We analysed the association between IL28B genetic variants and spontaneous clearance of HCV infection in 376 HCV-infected Chinese paid plasma donors. Genotyping of eight SNPs near the IL28B region was performed by the iPLEX system (MassARRAY(®) SNP Genotyping; Sequenom) in all donors, and sequencing was performed on all 80 donors who cleared HCV and on 160 of 296 donors who did not clear HCV to validate the genotypes. Eighty (21.3%) donors spontaneously cleared HCV. Four SNPs were significantly associated with spontaneous HCV clearance: rs8099917 TT (vs GT), rs8105790 TT (vs CT), rs12980275 AA (vs AG) and rs10853728 CC (vs CG or GG) with OR (95% CI) 15.27 (2.07-112.50), 14.88 (2.02-109.72), 7.92 (1.88-33.32) and 2.32 (1.22-4.42) respectively. No association between the other four IL28B SNPs including rs12979860 and spontaneous HCV clearance was found. Women had a higher rate of spontaneous HCV clearance than men [56/213 (26.3%) vs 24/163 (14.6%), P = 0.007], and this was true even after stratification for IL28B genotypes with OR of 1.9-2.2 among those with favourable genotypes. Our results confirmed that IL28B polymorphism is associated with spontaneous clearance of HCV in Chinese subjects, but the SNPs that predict HCV clearance in Chinese subjects were different from those reported in Caucasians. Women were more likely to clear HCV infection regardless of IL28B genotypes.

LIM domain protein-3 (LMP3) cooperates with BMP7 to promote tissue regeneration by ligament progenitor cells

Gene transfer of key regulators of osteogenesis for mesenchymal stem cells represents a promising strategy to regenerate bone. It has been reported that LMP3, a transcription variant of LIM domain mineralization protein (LMP) lacking LIM domains, can induce osteogenesis in vitro and in vivo. As little is known about the effects of LMP3 gene therapy on periodontal ligament (PDL) cell osteogenic differentiation, this study sought to explore whether gene delivery of LMP3 can promote PDL cell mineralization and bone formation. Our results showed that adenoviral mediated gene transfer of LMP3 (AdLMP3) significantly upregulated ALP (Alkaline Phosphatase), BSP (Bone Sialoprotein) and BMP2 gene expression and increased in vitro matrix mineralization in human PDL. Although AdLMP3 gene delivery to PDL cells did not induce ectopic bone formation in vivo, we found that AdLMP3 augments new bone formation, which co-delivered with AdBMP7 gene transfer. Our study provides the evidence that there is a synergistic effect between LMP3 and BMP-7 in vivo, suggesting that LMP3 delivery may be used to augment BMP-mediated osteogenesis. LMP3 and BMP-7 combinatory gene therapy may also have specific applications for oral and periodontal regenerative medicine.

P2-01-14: High Level of CD44 Expression and Soluble CD44 Secretion Mediate Trastuzumab Resistance in HER2 Positive Breast Cancer

Background: Overexpression of HER2 occurs in 15–25% of invasive breast cancer. Trastuzumab, a humanized monoclonal antibody targeting the extracellular domain of HER2, markedly improves disease-free and overall survival in patients with HER2−positive breast cancer. However, resistance to trastuzumab develops in most patients with HER2−overexpressing metastatic breast cancer. Breast cancer stem cells have been shown to express HER2, although its role in the development or maintenance of stem cells is not well characterized. CD44 is one of the proposed markers for breast cancer stem cells. We investigated the role of CD44 in acquired trastuzumab resistance in HER2 positive breast cancer.

Methods: CD44 mRNA expression was measured by quantitative real-time PCR. The proportion of CD44 positive cells was measured by fluorescence-activated cell sorting (FACS). Soluble CD44 level was detected by enzyme-linked immunosorbent assay (ELISA). In vitro tumorigenicity was evaluated by soft agar colony formation assay. Cell invasion was tested by using a matrigel invasion assay. In vivo tumor growth was evaluated using a mammary fat pad xenograft mouse model.

Results: CD44 mRNA expression, CD44 positive cell population by FACS, and CD44 secretion were significantly increased in both SKBR3 derived trastuzumab resistant SKBR3 clone 3 and BT474 derived trastuzumab resistant HR20 cells compared to parental, trastuzumab sensitive cells. Consistent with the increase in CD44, trastuzumab resistant cells showed an increase in soft agar colony formation and cell invasion, which were blocked by siRNA-induced downregulation of CD44 expression. Tumor growth and incidence were enhanced in mice injected with trastuzumab resistant HR20 cells compared to the mice injected with trastuzumab sensitive parental BT474 cells. Knock-down of CD44 expression by the transfection with CD44-specific siRNA suppressed in vivo tumor growth in the mice injected with trastuzumab resistant HR20 cells. Finally, we found high serum CD44 levels correlated with advanced tumor progression in HER2 positive breast cancer.

Conclusion: Our findings indicate that high levels of CD44 mediate trastuzumab resistance in HER2 positive breast cancer cells as well as tumor progression in mice. Circulating CD44 is prognostic in patients with HER2 positive breast cancer. CD44 may be a therapeutic target for HER2 positive breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-01-14.

S2-7: Mechanisms of Action and Biological Significance of HER2 Mutations in HER2−Overexpressing Breast Cancer

Background: Trastuzumab is the most successful HER2−directed therapy in patients with early-stage and advanced HER2 positive breast cancer. Although trastuzumab improves survival in the adjuvant setting, 15–20% of the patients develop metastasis. Lapatinib is currently the only tyrosine kinase inhibitor approved for the treatment of patients with metastatic breast cancer after trastuzumab progression. However, progression eventually occurs and the disease remains incurable for the majority of patients. Recently, somatic mutations in the HER2 kinase domain have been reported in lung adenocarcinomas which result in constitutive phosphorylation of HER2, EGFR and cellular substrates. Activation of these receptors and pathways in lung cancer was associated with tumor progression and trastuzumab resistance, but tumors remained sensitive to a tyrosine kinase inhibitor. Because there are many different types of breast cancer that respond differently to treatments, more approaches are needed to predict which patients will most likely respond to a given therapy.

Material and Methods: Using gene sequencing on 78 HER2 positive breast tumors, our laboratory identified 4 novel missense variants in the kinase domain of HER2. None of the patients whose tumors carried one of these mutations achieved objective response to trastuzumab. Mutants were created using directed mutagenesis, inserted in a lentiviral expression plasmid and stably expressed in different breast cancer or non-tumorigenic cell lines. An ATP-based assay was used for cell survival studies. Migration studies were performed using Boyden-chambers coated with Matrigel. Anchorage-independent colony formation was assessed in soft-agar. Signaling pathways and phosphorylation status were analyzed by Western blot. Localization results were obtained by immunofluorescence and confocal microscopy followed by deconvolution analysis.

Results: Two of the mutants were dramatically under-phosphorylated and presented an altered cellular localization revealed by immunofluorescence studies in both cell lines and patient surgical samples. Also, cells expressing HER2 mutants showed an increased ability to invade Matrigel and migrate and to form colonies in soft-agar, suggesting the induction of a more aggressive behavior. In particular, one of the mutations was strongly associated with resistance to lapatinib treatment in cell survival and soft-agar assays, and higher doses of lapatinib were necessary to inhibit the ERK and AKT pathways. Computational analysis revealed that the mechanism of lapatinib resistance could be explained by a sterical obstruction of the ATP-binding pocket of the protein kinase domain that would impede the binding of lapatinib.

Conclusion: HER2 mutations confer a more aggressive phenotype. A specific mutation directly interacts with Lapatinib binding to HER2 and predicts resistance to Lapatinib in HER2−overexpressing breast cancer cells. Further characterization of novel HER2 mutations may have a direct implication in the development of novel markers for early diagnostics, patient selection and characterization of more appropriate and personalized treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr S2-7.

Small molecule antagonists in distinct binding modes inhibit drug-resistant mutant of smoothened

Several small molecule antagonists for Smoothened (Smo) have been developed, and achieved promising preclinical efficacy in cancers that are dependent on Hedgehog (Hh) signaling. However, in a recent clinical study, a drug-resistant D473H SMO mutant was identified that is thought to be responsible for cancer relapse in a patient with medulloblastoma. Here, we report two Smo antagonists that bind to distinct sites, as compared to known antagonists and agonists, and inhibit both wild-type and mutant Smo. These findings provide an insight of the ligand-binding sites of Smo and a basis for the development of potential therapeutics for tumors with drug-resistant Smo mutations.

Direct pathogen detection from swab samples using a new high-throughput sequencing technology

The detection of emerging infectious diseases has been a continuing concern, especially with the novel influenza A (H1N1) viral pandemic of 2009. In the present study, we validated a ‘second-generation’ parallel sequencing platform for viral detection in swab samples collected during recent influenza virus infections in Beijing. This operation yielded millions of valid reads per sample and resulted in an almost complete spectrum of nucleotide information. Importantly, novel A (H1N1) and seasonal A (H3N2) influenza virus-derived sequences were detected without prior knowledge or use of genetic information in advance, suggesting that this approach could be a valuable tool for diagnosing emerging infectious diseases.