Determination of Bifidobacterium and Lactobacillus in breast milk of healthy women by digital PCR

Breast milk is one of the most important sources of postnatal microbes. Quantitative real-time polymerase chain reaction (qRT-PCR) is currently used for the quantitative analysis of bacterial 16S rRNA genes in breast milk. However, this method relies on the use of standard curves and is imprecise when quantitating target DNA of low abundance. In contrast, droplet digital PCR (DD-PCR) provides an absolute quantitation without the need for calibration curves. A comparison between DD-PCR and qRT-PCR was conducted for the quantitation of Bifidobacterium and Lactobacillus 16S RNA genes in human breast milk, and the impacts of selected maternal factors were studied on the composition of these two bacteria in breast milk. From this study, DD-PCR reported between 0-34,460 16S rRNA gene copies of Bifidobacterium genera and between 1,108-634,000 16S rRNA gene copies of Lactobacillus genera in 1 ml breast milk. The 16S rRNA gene copy number of Lactobacillus genera was much greater than that of Bifidobacterium genera in breast milk. DD-PCR showed a 10-fold lower limit of quantitation as compared to qRT-PCR. A higher correlation and agreement was observed between qRT-PCR and DD-PCR in Lactobacillus quantitation as compared to Bifidobacterium quantitation. Based on our DD-PCR quantitation, a low abundance of Bifidobacterium bacteria in breast milk was correlated to higher pre-pregnancy body mass index (BMI). However, no significant difference was observed for these two bacteria in breast milk between mothers who had vaginal deliveries and caesarean deliveries. This study suggests that DD-PCR is a better tool to quantitate the bacterial load of breast milk compared to the conventional qRT-PCR method. The number of breast milk Bifidobacterium bacteria is influenced by maternal pre-pregnancy BMI.

IL10 inhibits starvation-induced autophagy in hypertrophic scar fibroblasts via cross talk between the IL10-IL10R-STAT3 and IL10-AKT-mTOR pathways

Hypertrophic scar (HS) is a serious skin fibrotic disease characterized by excessive hypercellularity and extracellular matrix (ECM) component deposition. Autophagy is a tightly regulated physiological process essential for cellular maintenance, differentiation, development, and homeostasis. Previous studies show that IL10 has potential therapeutic benefits in terms of preventing and reducing HS formation. However, no studies have examined IL10-mediated autophagy during the pathological process of HS formation. Here, we examined the effect of IL10 on starvation-induced autophagy and investigated the molecular mechanism underlying IL10-mediated inhibition of autophagy in HS-derived fibroblasts (HSFs) under starvation conditions. Immunostaining and PCR analysis revealed that a specific component of the IL10 receptor, IL10 alpha-chain (IL10Rα), is expressed in HSFs. Transmission electron microscopy and western blot analysis revealed that IL10 inhibited starvation-induced autophagy and induced the expression of p-AKT and p-STAT3 in HSFs in a dose-dependent manner. Blocking IL10R, p-AKT, p-mTOR, and p-STAT3 using specific inhibitors (IL10RB, LY294002, rapamycin, and cryptotanshinone, respectively) showed that IL10 inhibited autophagy via IL10Rα-mediated activation of STAT3 (the IL10R-STAT3 pathway) and by directly activating the AKT-mTOR pathway. Notably, these results suggest that IL10-mediated inhibition of autophagy is facilitated by the cross talk between STAT3, AKT, and mTOR; in other words, the IL10-IL10R-STAT3 and IL10-AKT-mTOR pathways. Finally, the results also indicate that mTOR-p70S6K is the molecule upon which these two pathways converge to induce IL10-mediated inhibition of autophagy in starved HSFs. In summary, the findings reported herein shed light on the molecular mechanism underlying IL10-mediated inhibition of autophagy and suggest that IL10 is a potential therapeutic agent for the treatment of HS.

Direct sequencing and analysis of the genomes of newly emerging GII.17 norovirus strains in South China

AIMS

This study aims to develop a quick and sensitive method for obtaining GII.17 norovirus genome sequences based on a novel amplification strategy.

METHODS AND RESULTS

Based on multiple alignments of GII.17 norovirus genome sequences available in GenBank, a set of primer pairs were first rationally designed, which could amplify six overlapping fragments encompassing the whole genome. Two sequencing primers II.17-Seq1R and II.17-Seq6F were also designed to complement sequences at both ends. The sensitivity of new primers was then evaluated by end-point dilution RT-PCR that was comparable to detection primers G2SKF/G2SKR. In practice, genome sequences of nine Guangzhou GII.17 strains were successfully obtained by the new method in one working day. All genomes comprised 7495 nucleotides with three complete ORFs, and their phylogenetic relationships were verified with other GII norovirus reference strains.

CONCLUSIONS

Based on the new amplification strategy, a quick and sensitive method for direct sequencing of GII.17 norovirus genomes was successfully established.

SIGNIFICANCE AND IMPACT OF THE STUDY

The newly developed method can be used as an important tool to collect genetic information of GII.17 noroviruses, and new obtained viral genomes in Guangzhou also provide reference data for norovirus research in future.

Abstract P4-08-03: DEAD-box RNA helicase DP103 as a novel regulator of Wnt/β-catenin signaling pathway and promotes cancer stem cell-like behavior in triple negative breast cancers

Despite recent advances in breast cancer therapeutics, mortality of metastatic triple negative breast cancer (TNBC) subtype remains high; due to their lack of hormone receptors expression for targeted therapy. Aberrant activation of Wnt/β-catenin signaling has been associated with breast cancers; where 40% of total breast cancers have elevated β-catenin levels with increased Wnt activity. Recently, we identified DEAD-box RNA helicase DP103 as a novel prognostic biomarker and metastasis-driving oncogene; highly expressed in TNBC subtype. Interestingly, we found high DP103 expression to be positively correlated with high β-catenin expression in clinical specimens (n=400). This led us to hypothesize a possible role of DP103 in modulating the Wnt/β-catenin pathway in TNBCs. Depletion of DP103 in metastatic TNBC cells decreases Wnt/β-catenin activity and expression of downstream Wnt target genes, while overexpression of DP103 increases Wnt activity. Depletion of DP103 also decreases phosphorylation of LRP6 and several important Wnt modulators required for downstream Wnt activation. Moreover, induction of Wnt/β-catenin signaling in Wnt responsive TNBC cells also significantly increased DP103 expression, indicating a possible positive feedback loop. Both canonical and non-canonical Wnt signaling is known to independently promote stem cell growth in mammospheres. Herein, we will also provide evidence on the role of DP103 in promoting breast cancer stem cell-like properties. Collectively, our data show a novel regulatory role of DP103 in the Wnt/β-catenin signaling pathway and in promoting breast cancer stem cell-like behavior, presenting itself as a potential drug target in TNBC patients.

Citation Format: Cai W, Cheong JK, Edison E, Banerjee A, Tan TZ, Gaboury L, Yousef EM, Thiery JP, Lobie PE, Virshup DM, Yap CT, Kumar AP. DEAD-box RNA helicase DP103 as a novel regulator of Wnt/β-catenin signaling pathway and promotes cancer stem cell-like behavior in triple negative breast cancers. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-08-03.

Long-term association between dairy consumption and risk of childhood obesity: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND/OBJECTIVES

Data from small-scale, short-term, clinical trials suggest a beneficial effect of dairy consumption on the risk of childhood obesity; however, the long-term association is unclear. Therefore, we aim to examine the longitudinal association between dairy consumption and the risk of overweight/obesity in children and adolescents by conducting a systematic review and meta-analysis of prospective cohort studies.

SUBJECTS/METHODS

Eligible studies were identified by searching PubMed and EMBASE through March 2015. Additional studies were retrieved via Google Scholar or a hand review of the reference lists from relevant articles. Pooled associations of interest were estimated by using a random-effects model. The heterogeneity for each pooled analysis was evaluated by I(2) statistic as well as by Cochran's Q test. Publication bias was assessed by using both Egger's and Begg's tests.

RESULTS

Ten studies comprising 46,011 children and adolescents with an average 3-year follow-up were included. As compared with those who were in the lowest group of dairy consumption, children in the highest intake group were 38% less likely to have childhood overweight/obesity (pooled odds ratio (OR)=0.62; 95% confidence interval (CI): 0.49, 0.80). With each 1 serving/day increment in dairy consumption, the percentage of body fat was reduced by 0.65% (β=0.65; 95% CI: -1.35, 0.06; P=0.07), and the risk of overweight/obesity was 13% lower (OR=0.87; 95% CI: 0.74, 0.98).

CONCLUSIONS

Accumulated evidence from prospective cohort studies suggests that dairy consumption is inversely and longitudinally associated with the risk of childhood overweight/obesity. Further studies are warranted to examine the types of dairy products in relation to the risk of childhood overweight/obesity.

Spectral properties and highly efficient continuous-wave laser operation in Nd-doped Sr(1-x)Y(x)F(2+x) crystals

Spectral properties of Nd:Sr(1-x)Y(x)F(2+x) crystals were investigated. Compared with Nd:SrF2, the spectral parameters of Nd:Sr(1-x)Y(x)F(2+x) (x=0.05,0.1) were altered in a large scale. LD-pumped true CW laser has been demonstrated in the crystals. The slope efficiency up to 43.5% in 0.43% Nd:Sr0.95Y0.05F2.05 was achieved. The system is a promising candidate for highly efficient lasers.

Effect of exercise combined with dietary intervention on obese children and adolescents associated with the FTO rs9939609 polymorphism

OBJECTIVE

Aim of this study was to investigate the association of the FTO rs9939609 polymorphism with the effects of the exercise and dietary intervention on obese adolescents and children in China.

PATIENTS AND METHODS

Total 138 chinese children and adolescents (77 males and 61 females, aged 10-18 years) were recruited in the 2012 summer camp in Shanghai. Dietary and exercise intervention was performed for four weeks. Obesity related parameters were detected by the physical examination before and after four-week's intervention. Genotyping of the FTO rs9939609 was performed by using a TaqMan SNP Genotyping Assay. SPSS 19.0 were used to do the statistical analysis.

RESULTS

Finally, 135 campers were investigated in this study. The AA, AT and TT genotype frequencies of rs9939609 were 5.2%, 33.3% and 61.5%, respectively. The BMI in individuals with the genotype AA (or AT) was significantly higher compared with their with TT genotype (p = 0.044). The levels of body mass index (BMI), insulin (INS), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), red blood cell (RBC), Hemoglobin (HB) and hematocrit (HCT) in campers were significantly declined by the combined intervention (p < 0.05). Moreover, the levels of TC, low-density lipoprotein (LDL), RBC, HB, and HCT in the camper with genotype AA (or AT) were significantly decreased by the combined intervention compared with the camper with genotype TT (p < 0.05).

CONCLUSIONS

The effects of exercise combined with dietary intervention on obesity were associated with the FTO rs9939609 polymorphism in chinese adolescents and children.

Lack of association between the hOGG1 gene Ser326Cys polymorphism and gastric cancer risk: evidence from a case-control study and a meta-analysis

The association between the human 8-oxoguanine glycosylase 1 (hOGG1) gene Ser326Cys polymorphism (rs1052133) and gastric cancer has been widely evaluated, yet a definitive answer to whether this association exists is lacking. We first conducted a case-control study to assess this association in a large Han Chinese population, and then performed a meta-analysis to further address this issue. This case-control study involved 448 patients clinically diagnosed with gastric cancer and 372 cancer-free control individuals from China. Genotyping was conducted using the polymerase chain reaction-ligase detection reaction method. Meta-analysis was performed by the STATA software. Data and study quality were assessed in duplicate. Our case-control association study indicated that there were no significant differences in the genotype and allele distributions of the Ser326Cys polymorphism between gastric cancer patients and controls (P = 0.8026 for genotype, and P = 0.5857 for allele), consistent with the results of the subsequent meta-analysis involving 2745 patients and 4588 controls under both allelic [odds ratio (OR) = 1.02; 95% confidence interval (CI) = 0.91-1.14; P = 0.739] and dominant (OR = 0.97; 95%CI = 0.78-1.21; P = 0.803) models. Further subgroup analyses by ethnicity, source of controls, and sample size also did not detect any positive associations in this meta-analysis. Overall, our study in the Han Chinese population, along with the meta-analysis, failed to confirm the association of the hOGG1 gene Ser326Cys polymorphism with gastric cancer risk, even across different ethnic populations.

Synthesis and molecular characterization of acrylate liquid crystalline resin monomers (ALCRM)

A novel biocompatible resin monomer 4&mdash;3&mdash;(acryloyloxy)&mdash;2&mdash;hydroxypropoxy) phenyl 4&mdash;(3&mdash;(acryloyloxy)&mdash;2&mdash;hydroxypropoxy) benzoate, as an oral restorative &mdash; acrylate liquid crystalline resin monomer (ALCRM) was synthesized. The intermediate product and the final product were characterized by differential scanning calorimetry (DSC), polarized optical microscope (POM), and nuclear magnetic resonance (NMR). A resin matrix which has a potential application in dental composites was prepared by photopolymerizing ALCRM and triethylene glycol dimethacrylate (TEGDMA) as a primary and diluted monomer with a photosensitizer of camphorquinone (CQ) and 2&mdash;(Dimethylamino)ethyl methacrylate (DMAEMA) mixture. The molar ratio of ALCRM and TEGDMA was 7:3. The properties such as the curing depth, curing time, and the volumetric shrinkage of the resin matrix were investigated and compared with a traditional composite resin matrix Bis&mdash;GMA. After photocuring polymerization, the conversion degree of the resin matrix is 68.06%, higher than Bis&mdash;GMA/TEGDMA; the curing time is 4.08±0.20min, the curing depth is 2.10±0.17mm, and the volumetric shrinkage is 3.62%±0.26%. All the properties exhibit a better performance of the prepared resin matrix than Bis&mdash;GMA.

Relationship between serum levels of endogenous secretory RAGE and blood pressure in male nondiabetic patients with obstructive sleep apnea

The interaction of advanced glycation end products (AGE) and their specific cell-surface receptor (RAGE) has an important role in the pathogenesis of cardiovascular disease and diabetic complications. Two isoforms of C-truncated RAGE, soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE), may prevent activation of RAGE signaling by acting as decoys. This study investigated whether serum esRAGE and sRAGE levels are associated with blood pressure in nondiabetic patients with obstructive sleep apnea (OSA). Male nondiabetic patients (n=139) with OSA were enrolled. Serum esRAGE and sRAGE levels were examined using enzyme-linked immunosorbent assay. Three consecutive seated systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements were obtained at 5-min intervals in the morning. In univariate analysis, there was a significant correlation between serum esRAGE and SBP or DBP, but not between serum sRAGE and SBP or DBP. Multiple regression analysis showed that SBP was independently associated with waist circumference, HbA1c, minimum SaO2 and serum esRAGE, and that DBP was independently associated with low-density lipoprotein cholesterol, apnea-hypopnea index, serum AGE and body mass index, but not with serum esRAGE. These results indicated that serum esRAGE levels were inversely associated with blood pressure, especially SBP, in male nondiabetic patients with OSA. esRAGE may have a protective role against hypertension in patients with OSA, and it may be a novel biomarker for OSA patients at high risk of developing cardiovascular diseases.

3D fluoroscopic image estimation using patient-specific 4DCBCT-based motion models

3D fluoroscopic images represent volumetric patient anatomy during treatment with high spatial and temporal resolution. 3D fluoroscopic images estimated using motion models built using 4DCT images, taken days or weeks prior to treatment, do not reliably represent patient anatomy during treatment. In this study we developed and performed initial evaluation of techniques to develop patient-specific motion models from 4D cone-beam CT (4DCBCT) images, taken immediately before treatment, and used these models to estimate 3D fluoroscopic images based on 2D kV projections captured during treatment. We evaluate the accuracy of 3D fluoroscopic images by comparison to ground truth digital and physical phantom images. The performance of 4DCBCT-based and 4DCT-based motion models are compared in simulated clinical situations representing tumor baseline shift or initial patient positioning errors. The results of this study demonstrate the ability for 4DCBCT imaging to generate motion models that can account for changes that cannot be accounted for with 4DCT-based motion models. When simulating tumor baseline shift and patient positioning errors of up to 5 mm, the average tumor localization error and the 95th percentile error in six datasets were 1.20 and 2.2 mm, respectively, for 4DCBCT-based motion models. 4DCT-based motion models applied to the same six datasets resulted in average tumor localization error and the 95th percentile error of 4.18 and 5.4 mm, respectively. Analysis of voxel-wise intensity differences was also conducted for all experiments. In summary, this study demonstrates the feasibility of 4DCBCT-based 3D fluoroscopic image generation in digital and physical phantoms and shows the potential advantage of 4DCBCT-based 3D fluoroscopic image estimation when there are changes in anatomy between the time of 4DCT imaging and the time of treatment delivery.

A microfluidic device enabling high-efficiency single cell trapping

Single cell trapping increasingly serves as a key manipulation technique in single cell analysis for many cutting-edge cell studies. Due to their inherent advantages, microfluidic devices have been widely used to enable single cell immobilization. To further improve the single cell trapping efficiency, this paper reports on a passive hydrodynamic microfluidic device based on the "least flow resistance path" principle with geometry optimized in line with corresponding cell types. Different from serpentine structure, the core trapping structure of the micro-device consists of a series of concatenated T and inverse T junction pairs which function as bypassing channels and trapping constrictions. This new device enhances the single cell trapping efficiency from three aspects: (1) there is no need to deploy very long or complicated channels to adjust flow resistance, thus saving space for each trapping unit; (2) the trapping works in a "deterministic" manner, thus saving a great deal of cell samples; and (3) the compact configuration allows shorter flowing path of cells in multiple channels, thus increasing the speed and throughput of cell trapping. The mathematical model of the design was proposed and optimization of associated key geometric parameters was conducted based on computational fluid dynamics (CFD) simulation. As a proof demonstration, two types of PDMS microfluidic devices were fabricated to trap HeLa and HEK-293T cells with relatively significant differences in cell sizes. Experimental results showed 100% cell trapping and 90% single cell trapping over 4 × 100 trap sites for these two cell types, respectively. The space saving is estimated to be 2-fold and the cell trapping speed enhancement to be 3-fold compared to previously reported devices. This device can be used for trapping various types of cells and expanded to trap cells in the order of tens of thousands on 1-cm(2) scale area, as a promising tool to pattern large-scale single cells on specific substrates and facilitate on-chip cellular assay at the single cell level.

Separation of cyclotron-produced 44Sc from a natural calcium target using a dipentyl pentylphosphonate functionalized extraction resin

Significant interest in ⁴⁴Sc as a radioactive synthon to label small molecules for positron emission tomography (PET) imaging has been recently observed. Despite the efforts of several research groups, the ideal ⁴⁴Sc production and separation method remains elusive. Herein, we propose a novel separation method to obtain ⁴⁴Sc from the proton irradiation of calcium targets based on extraction chromatography, which promises to greatly simplify current production methodologies. Using the commercially available Uranium and Tetravalent Actinides (UTEVA) extraction resin we were able to rapidly (<20min) recover >80% of the activity generated at end of bombardment (EoB) in small ~1M HCl fractions (400μL). The chemical purity of the ⁴⁴Sc eluates was evaluated through chelation with DOTA and DTPA, and by trace metal analysis using microwave induced plasma atomic emission spectrometry. The distribution coefficients (K_d) of Sc(III) and Ca(II) in UTEVA were determined in HCl medium in a range of concentrations from zero to 12.1M. The ⁴⁴Sc obtained with our method proved to be suitable for the direct labeling of small biomolecules for PET imaging, with excellent specific activities and radiochemical purity.

Screening genes crucial for pediatric pilocytic astrocytoma using weighted gene coexpression network analysis combined with methylation data analysis

To identify novel genes associated with pediatric pilocytic astrocytoma (PA) for better understanding the molecular mechanism underlying the pediatric PA pathogenesis. Gene expression profile data of GSE50161 and GSE44971 and the methylation data of GSE44684 were downloaded from Gene Expression Omnibus. The differentially expressed genes (DEGs) between PA and normal control samples were screened using the limma package in R, and then used to construct weighted gene coexpression network (WGCN) using the WGCN analysis (WGCNA) package in R. Significant modules of DEGs were selected using the clustering analysis. Function enrichment analysis of the DEGs in significant modules were performed using the WGCNA package and clusterprofiler package in R. Correlation between methylation sites of DEGs and PA was analyzed using the CpGassoc package in R. Totally, 3479 DEGs were screened in PA samples. Thereinto, 3424 DEGs were used to construct the WGCN. Several significant modules of DEGs were selected based on the WGCN, in which the turquoise module was positively related to PA, whereas blue module was negatively related to PA. DEGs (for example, DOCK2 (dedicator of cytokinesis 2), DOCK8 and FCGR2A (Fc fragment of IgG, low affinity IIa)) in blue module were mainly involved in Fc gamma R-mediated phagocytosis pathway and natural killer cell-mediated cytotoxicity pathway. Methylations of 14 DEGs among the top 30 genes in blue module were related to PA. Our data suggest that DOCK2, DOCK8 and FCGR2A may represent potential therapeutic targets in PA that merits further investigation.

Biological effect of audible sound control on mung bean (Vigna radiate) sprout

Audible sound (20-20000 Hz) widely exists in natural world. However, the interaction between audible sound and the growth of plants is usually neglected in biophysics research. Not much effort has been put forth in studying the relation of plant and audible sound. In this work, the effect of audible sound on germination and growth of mung bean (Vigna radiate) was studied under laboratory condition. Audible sound ranging 1000-1500 Hz, 1500-2000 Hz, and 2000-2500 Hz and intensities [80 dB (A), 90 dB (A), 100 dB (A)] were used to stimulate mung bean for 72 hours. The growth of mung bean was evaluated in terms of mean germination time, total length, and total fresh weight. Experimental results indicated that the sound wave can reduce the germination period of mung bean and the mung bean under treatments of sound with intensity around 90 dB and frequency around 2000 Hz and significant increase in growth. Audible sound treatment can promote the growth of mung bean differently for distinct frequency and intensity. The study provides us with a way to understand the effects and rules of sound field on plant growth and a new way to improve the production of mung bean.

Quantum dot-based nanoprobes for in vivo targeted imaging

Fluorescent semiconductor quantum dots (QDs) have attracted tremendous attention over the last decade. The superior optical properties of QDs over conventional organic dyes make them attractive labels for a wide variety of biomedical applications, whereas their potential toxicity and instability in biological environment have puzzled scientific researchers. Much research effort has been devoted to surface modification and functionalization of QDs to make them versatile probes for biomedical applications, and significant progress has been made over the last several years. This review article aims to describe the current state-of-the-art of the synthesis, modification, bioconjugation, and applications of QDs for in vivo targeted imaging. In addition, QD-based multifunctional nanoprobes are also summarized.

Functionalized upconversion nanoparticles: versatile nanoplatforms for translational research

The design, application, and translation of targeted multimodality molecular imaging probes based on nanotechnology have attracted increasing attentions during the last decade and will continue to play vital roles in cancer diagnosis and personalized medicine. With the growing awareness of drawbacks of traditional organic dyes and quantum dots, biocompatible lanthanide ion doped upconversion nanoparticles have emerged as promising candidates for clinically translatable imaging probes, owing to their unique features that are suitable for future targeted multimodal imaging in living subjects. In this review, we summarized the recent advances in the field of functionalized upconversion nanoparticles (f-UCNP) for biological imaging and therapy in vivo, and discussed the future research directions, obstacles ahead, and the potential use of f-UCNP in translational research.

Antibody-based imaging of HER-2: moving into the clinic

Human epidermal growth factor receptor-2 (HER-2) mediates a number of important cellular activities, and is up-regulated in a diverse set of cancer cell lines, especially breast cancer. Accordingly, HER-2 has been regarded as a common drug target in cancer therapy. Antibodies can serve as ideal candidates for targeted tumor imaging and drug delivery, due to their inherent affinity and specificity. Advanced by the development of a wide variety of imaging techniques, antibody-based imaging of HER-2 can allow for early detection and localization of tumors, as well as monitoring of drug delivery and tissue's response to drug treatment. In this review article, antibody-based imaging of HER-2 are summarized and discussed, with an emphasis on the involved imaging methods.

Multimodality imaging of CXCR4 in cancer: current status towards clinical translation

CXCR4 has gained tremendous attention over the last decade, since it was found to be up-regulated in a wide variety of cancer types, in addition to its role in human immunodeficiency virus infection. Molecular imaging of CXCR4 with small molecules, peptides, and antibodies has been a vibrant research area over the last several years. In this review article, we will summarize the current status of imaging CXCR4 with fluorescence, bioluminescence, positron emission tomography, and single-photon emission computed tomography techniques. Since each molecular imaging modality has its own strengths and weaknesses, dualmodality probes that can be detected by more than one imaging techniques have also been investigated. Noninvasive visualization of CXCR4 expression has potential clinical applications in multiple facets of patient management. While big strides have been made over the last several years in the development of CXCR4- targeted imaging probes, clinical translation and investigation of these agents in cancer patients are eagerly awaited. Since CXCR4 is also involved in many other diseases beyond cancer, these clinically translatable probes can also play multiple roles in other pathological disorders such as myocardial infarction and several immunodeficiency disorders.

Dual-source CT versus single-source 64-section CT angiography for coronary artery disease: A meta-analysis

AIM

To perform a meta-analysis to compare the diagnostic performance of single-source 64-section computed tomography (CT) versus dual-source CT angiography for diagnosis of coronary artery disease (CAD).

MATERIALS AND METHODS

The Cochrane Library, MEDLINE, and EMBASE were searched for relevant original papers. Inclusion criteria were (1) significant CAD defined as ≥50% reduction in luminal diameter by invasive coronary angiography as reference standard; (2) single-source 64-section CT or dual-source CT was used; (3) results were reported in absolute numbers of true-positive, false-positive, true-negative, and false-negative results or sufficiently detailed data for deriving these numbers were presented. A random-effects model was used for the meta-analysis.

RESULTS

Fifty-one papers including 3966 patients who underwent single-source 64-section CT and 2047 patients who underwent dual-source CT at a per-patient level were pooled. The diagnostic values of single-source 64-section CT versus dual-source CT were 97% versus 97% for sensitivity (p = 0.386), 78% versus 86% for specificity (p < 0.001), 90% versus 85% for positive predictive value (PPV; p < 0.001), 93% versus 97% for negative predictive value (NPV; p = 0.001), 6.8 versus 6.5 for positive likelihood ratio (p = 0.018), 0.04 versus 0.04 for negative likelihood ratio (p = 0.625), and 191.59 versus 207.37 for diagnostic odds ratio (p = 0.043), respectively.

CONCLUSION

Dual-source CT and single-source 64-section CT have similar negative likelihood ratios and, therefore, there was no significant difference in their utility to rule out CAD in intermediate-risk patients. However, compared to single-source 64-section CT, dual-source CT has significantly higher specificity, so that CT-based decisions for subsequent coronary catheter angiography are more accurate.

Multimodality imaging of RNA interference

The discovery of small interfering RNAs (siRNAs) and their potential to knock down virtually any gene of interest has ushered in a new era of RNA interference (RNAi). Clinical use of RNAi faces severe limitations due to inefficiency delivery of siRNA or short hairpin RNA (shRNA). Many molecular imaging techniques have been adopted in RNAi-related research for evaluation of siRNA/shRNA delivery, biodistribution, pharmacokinetics, and the therapeutic effect. In this review article, we summarize the current status of in vivo imaging of RNAi. The molecular imaging techniques that have been employed include bioluminescence/fluorescence imaging, magnetic resonance imaging/ spectroscopy, positron emission tomography, single-photon emission computed tomography, and various combinations of these techniques. Further development of non-invasive imaging strategies for RNAi, not only focusing on the delivery of siRNA/shRNA but also the therapeutic efficacy, is critical for future clinical translation. Rigorous validation will be needed to confirm that biodistribution of the carrier is correlated with that of siRNA/shRNA, since imaging only detects the label (e.g. radioisotopes) but not the gene or carrier themselves. It is also essential to develop multimodality imaging approaches for realizing the full potential of therapeutic RNAi, as no single imaging modality may be sufficient to simultaneously monitor both the gene delivery and silencing effect of RNAi.

ROS1 fusions in Chinese patients with non-small-cell lung cancer

BACKGROUND

To determine the prevalence and clinicopathological features of ROS1 fusions in Chinese patients with non-small-cell lung cancer (NSCLC).

METHODS

Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 392 patients with NSCLC were screened for ROS1 fusions by multiplex RT-PCR and all ROS1 fusions were validated by direct sequencing. The relationship between ROS1 fusions and clinicopathological features and the prognostic effect of the ROS1 fusion status on survival were analyzed.

RESULTS

In this study, 8 of 392 (2.0%) evaluable samples were found to harbor ROS1 fusions. Of the ROS1-positive patients, seven presented with adenocarcinoma, and one with adenosquamous carcinoma. The ratio of female to male and never smoker to smokers in a ROS1 fusion-positive group was 5:3. There was no statistically significant difference in age, sex, smoking history, histological type and pathological stage between ROS1 fusion-positive and ROS1 fusion-negative patients. ROS1 fusion-negative patients had a significantly longer survival when compared with ROS1 fusion-positive patients (P = 0.041). Lower pathological stage, younger age and ROS1 fusion-negative status were significantly associated with better prognosis on multivariate analysis.

CONCLUSIONS

ROS1 fusions occurred in ∼2.0% of Chinese patients with NSCLC and had no specific clinicopathological feature. ROS1 fusion-negative patients may have a better survival than ROS1 fusion-positive patients.

The prognostic value of CDKN2A hypermethylation in colorectal cancer: a meta-analysis

Background:

The prognostic value of CDKN2A promoter hypermethylation in colorectal cancer remains controversial. We systematically reviewed the evidence for assessment of CDKN2A methylation in colorectal cancer to elucidate this issue.

Methods:

Pubmed, Embase and ISI web of knowledge were searched to identify eligible studies to evaluate the association of CDKN2A hypermethylation and overall survival and clinicopathological features of colorectal cancer patients. Combined hazard ratios (HRs) or odds ratios (ORs) with 95% confidence interval (95% CI) were pooled using a random-effects model.

Results:

A total of 11 studies encompassing 3440 patients were included in the meta-analysis. CDKN2A hypermethylation had an unfavourable impact on OS of patients with colorectal cancer (HR 1.65, 95% CI 1.29–2.11). Subgroup analysis indicated that CDKN2A hypermethylation was significantly correlated with OS in Europe (HR 1.49; 95% CI 1.28–1.74) and Asia (HR 3.30; 95% CI 1.68–6.46). Furthermore, there was a significant association between CDKN2A hypermethylation and lymphovascular invasion (OR 1.68, 95% CI 1.15–2.47), lymph node metastasis (OR 1.68, 95% CI 1.09–2.59) and proximal tumour location (OR 2.09, 95% CI 1.34–3.26) of colorectal cancer.

Conclusion:

This meta-analysis indicated that CDKN2A hypermethylation might be a predictive factor for unfavourable prognosis of colorectal cancer patients.

ERK and AKT signaling cooperate to translationally regulate survivin expression for metastatic progression of colorectal cancer

The MEK/ERK and PI3K/AKT pathways are often concurrently activated by separate genetic alterations in colorectal cancer (CRC), which is associated with CRC progression and poor survival. However, how activating both pathways is required for CRC metastatic progression remains unclear. Our recent study showed that both ERK and AKT signaling are required to activate eIF4E-initiated cap-dependent translation via convergent regulation of the translational repressor 4E-BP1 for maintaining CRC transformation. Here, we identified that the activation of cap-dependent translation by cooperative ERK and AKT signaling is critical for promotion of CRC motility and metastasis. In CRC cells with coexistent mutational activation of ERK and AKT pathways, inhibition of either MEK or AKT alone showed limited activity in inhibiting cell migration and invasion, but combined inhibition resulted in profound effects. Genetic blockade of the translation initiation complex by eIF4E knockdown or expression of a dominant active 4E-BP1 mutant effectively inhibited migration, invasion and metastasis of CRC cells, whereas overexpression of eIF4E or knockdown of 4E-BP1 had the opposite effect and markedly reduced their dependence on ERK and AKT signaling for cell motility. Mechanistically, we found that these effects were largely dependent on the increase in mTORC1-mediated survivin translation by ERK and AKT signaling. Despite the modest effect of survivin knockdown on tumor growth, reduction of the translationally-regulated survivin profoundly inhibited motility and metastasis of CRC. These findings reveal a critical mechanism underlying the translational regulation of CRC metastatic progression, and suggest that targeting cap-dependent translation may provide a promising treatment strategy for advanced CRC.

Lack of association between Cyclin D1 gene G870A polymorphism and esophageal cancer: evidence from a meta-analysis

The association between the Cyclin D1 gene (CCND1) G870A polymorphism and esophageal cancer has been widely evaluated, with conflicting results. As meta-analysis is a reliable approach to resolving discrepancies, we aimed to evaluate this association. Data were available from 9 study populations incorporating 1898 cases and 3046 controls. Overall, the allelic/genotypic association between the G870A polymorphism and esophageal cancer was nonsignificant [for allele: odds ratio (OR) = 1.14, 95% confidence interval (95%CI) = 0.94-1.38, P = 0.184; for genotype homozygous comparison: OR = 1.36, 95%CI = 0.90-2.06, P = 0.140; for dominant model: OR = 1.24, 95%CI = 0.88-1.75, P = 0.222; for recessive model: OR = 1.13, 95%CI = 0.90-1.43, P = 0.292]. Moreover, subgroup analyses according to study designs, geographic areas, types of esophageal cancer, genotyping methods, and ethnicities failed to demonstrate a significant association between this polymorphism and esophageal cancer. In addition, there was significant publication bias as reflected by funnel plots and the Egger test (P = 0.042). Taken together, our results suggest that the CCND1 G870A polymorphism might not be a potential candidate for predicting esophageal cancer risk.

Anthrax among heroin users in Europe possibly caused by same Bacillus anthracis strain since 2000

Injection anthrax was described first in 2000 in a heroin-injecting drug user in Norway. New anthrax cases among heroin consumers were detected in the United Kingdom (52 cases) and Germany (3 cases) in 2009-10. In June 2012, a fatal case occurred in Regensburg, Bavaria. As of December 2012, 13 cases had been reported in this new outbreak from Germany, Denmark, France and the United Kingdom. We analysed isolates from 2009-10 and 2012 as well as from the first injection anthrax case in Norway in 2000 by comparative molecular typing using a high resolution 31 marker multilocus variable-number tandem repeat analysis (MLVA) and a broad single nucleotide polymorphism (SNP) analysis. Our results show that all cases may be traced back to the same outbreak strain. They also indicate the probability of a single source contaminating heroin and that the outbreak could have lasted for at least a decade. However, an additional serological pilot study in two German regions conducted in 2011 failed to discover additional anthrax cases among 288 heroin users.

Anthrax among heroin users in Europe possibly caused by same Bacillus anthracis strain since 2000

Injection anthrax was described first in 2000 in a heroin-injecting drug user in Norway. New anthrax cases among heroin consumers were detected in the United Kingdom (52 cases) and Germany (3 cases) in 2009-10. In June 2012, a fatal case occurred in Regensburg, Bavaria. As of December 2012, 13 cases had been reported in this new outbreak from Germany, Denmark, France and the United Kingdom. We analysed isolates from 2009-10 and 2012 as well as from the first injection anthrax case in Norway in 2000 by comparative molecular typing using a high resolution 31 marker multilocus variable-number tandem repeat analysis (MLVA) and a broad single nucleotide polymorphism (SNP) analysis. Our results show that all cases may be traced back to the same outbreak strain. They also indicate the probability of a single source contaminating heroin and that the outbreak could have lasted for at least a decade. However, an additional serological pilot study in two German regions conducted in 2011 failed to discover additional anthrax cases among 288 heroin users.