Irradiation Induced Injury Reduces Energy Metabolism in Small Intestine of Tibet Minipigs

Background

The radiation-induced energy metabolism dysfunction related to injury and radiation doses is largely elusive. The purpose of this study is to investigate the early response of energy metabolism in small intestinal tissue and its correlation with pathologic lesion after total body X-ray irradiation (TBI) in Tibet minipigs.

Methods and Results

30 Tibet minipigs were assigned into 6 groups including 5 experimental groups and one control group with 6 animals each group. The minipigs in these experimental groups were subjected to a TBI of 2, 5, 8, 11, and 14 Gy, respectively. Small intestine tissues were collected at 24 h following X-ray exposure and analyzed by histology and high performance liquid chromatography (HPLC). DNA contents in this tissue were also examined. Irradiation causes pathologic lesions and mitochondrial abnormalities. The Deoxyribonucleic acid (DNA) content-corrected and uncorrected adenosine-triphosphate (ATP) and total adenine nucleotides (TAN) were significantly reduced in a dose-dependent manner by 2–8 Gy exposure, and no further reduction was observed over 8 Gy.

Conclusion

TBI induced injury is highly dependent on the irradiation dosage in small intestine and inversely correlates with the energy metabolism, with its reduction potentially indicating the severity of injury.     

Gli as a Novel Therapeutic Target in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor with poor prognosis. Current treatment is rarely curative, thus novel meaningful therapies are urgently needed. Inhibition of Hedgehog (Hh) signaling at the cell membrane level in several cancers has shown anti-cancer activity in recent clinical studies. Evidence of Hh-independent Gli activation suggests Gli as a more potent therapeutic target. The current study is aimed to evaluate the potential of Gli as a therapeutic target to treat MPM. The expression profiles of Gli factors and other Hh signaling components were characterized in 46 MPM patient tissue samples by RT-PCR and immunohistochemistry. Cultured cell lines were employed to investigate the requirement of Gli activation in tumor cell growth by inhibiting Gli through siRNA or a novel small molecule Gli inhibitor (Gli-I). A xenograft model was used to evaluate Gli-I in vivo. In addition, a side by side comparison between Gli and Smoothened (Smo) inhibition was conducted in vitro using siRNA and small molecule inhibitors. Our study reported aberrant Gli1 and Gli2 activation in a large majority of tissues. Inhibition of Gli by siRNAs or Gli-I suppressed cell growth dramatically both in vitro and in vivo. Inhibition of Gli exhibited better cytotoxicity than that of Smo by siRNA and small molecule inhibitors vismodegib and cyclopamine. Combination of Gli-I and pemetrexed, as well as Gli-I and vismodegib demonstrated synergistic effects in suppression of MPM proliferation in vitro. In summary, Gli activation plays a critical role in MPM. Inhibition of Gli function holds strong potential to become a novel, clinically effective approach to treat MPM.     

Metabonomic Profiling of Serum and Urine by 1H NMR-Based Spectroscopy Discriminates Patients with Chronic Obstructive Pulmonary Disease and Healthy Individuals

Chronic obstructive pulmonary disease (COPD) has seriously impacted the health of individuals and populations. In this study, proton nuclear magnetic resonance (¹H NMR)-based metabonomics combined with multivariate pattern recognition analysis was applied to investigate the metabolic signatures of patients with COPD. Serum and urine samples were collected from COPD patients (n = 32) and healthy controls (n = 21), respectively. Samples were analyzed by high resolution ¹H NMR (600 MHz), and the obtained spectral profiles were then subjected to multivariate data analysis. Consistent metabolic differences have been found in serum as well as in urine samples from COPD patients and healthy controls. Compared to healthy controls, COPD patients displayed decreased lipoprotein and amino acids, including branched-chain amino acids (BCAAs), and increased glycerolphosphocholine in serum. Moreover, metabolic differences in urine were more significant than in serum. Decreased urinary 1-methylnicotinamide, creatinine and lactate have been discovered in COPD patients in comparison with healthy controls. Conversely, acetate, ketone bodies, carnosine, m-hydroxyphenylacetate, phenylacetyglycine, pyruvate and α-ketoglutarate exhibited enhanced expression levels in COPD patients relative to healthy subjects. Our results illustrate the potential application of NMR-based metabonomics in early diagnosis and understanding the mechanisms of COPD.     

Porous Tantalum Coatings Prepared by Vacuum Plasma Spraying Enhance BMSCs Osteogenic Differentiation and Bone Regeneration In Vitro and In Vivo

Tantalum, as a potential metallic implant biomaterial, is attracting more and more attention because of its excellent anticorrosion and biocompatibility. However, its significantly high elastic modulus and large mechanical incompatibility with bone tissue make it unsuitable for load-bearing implants. In this study, porous tantalum coatings were first successfully fabricated on titanium substrates by vacuum plasma spraying (VPS), which would exert the excellent biocompatibility of tantalum and alleviate the elastic modulus of tantalum for bone tissue. We evaluated cytocompatibility and osteogenesis activity of the porous tantalum coatings using human bone marrow stromal cells (hBMSCs) and its ability to repair rabbit femur bone defects. The morphology and actin cytoskeletons of hBMSCs were observed via electron microscopy and confocal, and the cell viability, proliferation and osteogenic differentiation potential of hBMSCs were examined quantitatively by PrestoBlue assay, Ki67 immunofluorescence assay, real-time PCR technology and ALP staining. For in vivo detection, the repaired femur were evaluated by histomorphology and double fluorescence labeling 3 months postoperation. Porous tantalum coating surfaces promoted hBMSCs adhesion, proliferation, osteogenesis activity and had better osseointegration and faster new bone formation rate than titanium coating control. Our observation suggested that the porous tantalum coatings had good biocompatibility and could enhance osseoinductivity in vitro and promote new bone formation in vivo. The porous tantalum coatings prepared by VPS is a promising strategy for bone regeneration.     

Protective Effects of Andrographolide Analogue AL-1 on ROS-Induced RIN-mβ Cell Death by Inducing ROS Generation

Oxidative stress is considered to be a major factor contributing to pathogenesis and progression of many diseases. A novel andrographolide-lipoic acid conjugate (AL-1) could protect pancreatic β-cells from reactive oxygen species (ROS)-induced oxidative injury. However, its protective mechanism is still unclear. In this work, we used proteomics to identify AL-1-regulated proteins in β-cells and found that 13 of the 71 proteins regulated by AL-1 were closely associated with antioxidation. These differential proteins were mainly involved in the ERK1/2 and AKT1 signaling pathways. Functional investigation demonstrated that AL-1 exerted its protective effects on H₂O₂-induced cell death of β-cells by generating NADPH oxidase-dependent ROS to activate ERK1/2 and AKT1 signaling pathways. As a consequence, the expressions of antioxidant proteins including Trx1, Prx1 and Prx5, and anti-apoptotic proteins including PDCD6IP, prohibitin, galectin-1 and HSP were upregulated. AL-1 probably worked as a “vaccinum” to activate the cellular antioxidant system by inducing the generation of low concentration ROS which then reciprocally protected β-cells from oxidative damage caused by high-level ROS from H₂O₂. To the best of our knowledge, this is the first comprehensive proteomic analysis illustrating a novel molecular mechanism for the protective effects of antioxidants on β-cells from H₂O₂-induced cell death.     

Prognostic Significance of EBV Latent Membrane Protein 1 Expression in Lymphomas: Evidence from 15 Studies

Background

Epstein-Barr virus (EBV) infection has been associated with lymphoma development. EBV latent membrane protein 1 (LMP1) is essential for EBV-mediated transformation and progression of different human cells, including lymphocytes. This meta-analysis investigated LMP1 expression with prognosis of patients with lymphoma.

Methods

The electronic databases of PubMed, Embase, and Chinese Biomedicine Databases were searched. There were 15 published studies available for a random effects model analysis. Quality assessment was performed using the Newcastle-Ottawa Quality Assessment Scale for cohort studies. A funnel plot was used to investigate publication bias, and sources of heterogeneity were identified by meta-regression analysis. The combined hazard ratios (HR) and their corresponding 95% confidence intervals of LMP1 expression were calculated by comparison to the overall survival.

Results

Overall, there was no statistical significance found between LMP1 expression and survival of lymphoma patients (HR 1.25 [95% CI, 0.92–1.68]). In subgroup analyses, LMP1 expression was associated with survival in patients with non-Hodgkin lymphoma (NHL) (HR  = 1.84, 95% CI: 1.02–3.34), but not with survival of patients with Hodgkin disease (HD) (HR  =  1.03, 95% CI: 0.74–1.44). In addition, significant heterogeneity was present and the meta-regression revealed that the outcome of analysis was mainly influenced by the cutoff value.

Conclusions

This meta-analysis demonstrated that LMP1 expression appears to be an unfavorable prognostic factor for overall survival of NHL patients. The data suggested that EBV infection and LMP1 expression may be an important factor for NHL development or progression.     

A Novel Anti-Tumor Inhibitor Identified by Virtual Screen with PLK1 Structure and Zebrafish Assay

Polo-like kinase 1 (PLK1), one of the key regulators of mitosis, is a target for cancer therapy due to its abnormally high activity in several tumors. Plk1 is highly conserved and shares a nearly identical 3-D structure between zebrafish and humans. The initial 10 mitoses of zebrafish embryonic cleavages occur every∼30 minutes, and therefore provide a rapid assay to evaluate mitosis inhibitors including those targeting Plk1. To increase efficiency and specificity, we first performed a computational virtual screen of∼60000 compounds against the human Plk1 3-D structure docked to both its kinase and Polo box domain. 370 candidates with the top free-energy scores were subjected to zebrafish assay and 3 were shown to inhibit cell division. Compared to general screen for compounds inhibiting zebrafish embryonic cleavage, computation increased the efficiency by 11 folds. One of the 3 compounds, named I2, was further demonstrated to effectively inhibit multiple tumor cell proliferation in vitro and PC3 prostate cancer growth in Xenograft mouse model in vivo. Furthermore, I2 inhibited Plk1 enzyme activity in a dose dependent manner. The IC₅₀ values of I2 in these assays are compatible to those of ON-01910, a Plk1 inhibitor currently in Phase III clinic trials. Our studies demonstrate that zebrafish assays coupled with computational screening significantly improves the efficiency of identifying specific regulators of biological targets. The PLK1 inhibitor I2, and its analogs, may have potential in cancer therapeutics.     

A Novel 99mTc-Labeled Molecular Probe for Tumor Angiogenesis Imaging in Hepatoma Xenografts Model: A Pilot Study

Introduction

Visualization of tumor angiogenesis using radionuclide targeting provides important diagnostic information. In previous study, we proved that an arginine-arginine-leucine (RRL) peptide should be a tumor endothelial cell specific binding sequence. The overall aim of this study was to evaluate whether ^99mTc-radiolabeled RRL could be noninvasively used for imaging of malignant tumors in vivo, and act as a new molecular probe targeting tumor angiogenesis.

Methods

The RRL peptide was designed and radiosynthesized with ^99mTc by a one-step method. The radiolabeling efficiency and radiochemical purity were then characterized in vitro. ^99mTc-RRL was injected intravenously in HepG2 xenograft-bearing BALB/c nude mice. Biodistribution and in vivo imaging were performed periodically. The relationship between tumor size and %ID uptake of ^99mTc-RRL was also explored.

Results

The labeling efficiencies of ^99mTc-RRL reached 76.9%±4.5% (n = 6) within 30–60 min at room temperature, and the radiochemical purity exceeded 96% after purification. In vitro stability experiment revealed the radiolabeled peptide was stable. Biodistribution data showed that ^99mTc-RRL rapidly cleared from the blood and predominantly accumulated in the kidneys and tumor. The specific uptake of ^99mTc-RRL in tumor was significantly higher than that of unlabeled RRL blocking and free pertechnetate control test after injection (p<0.05). The ratio of the tumor-to-muscle exceeded 6.5, tumor-to-liver reached 1.98 and tumor-to-blood reached 1.95. In planar gamma imaging study, the tumors were imaged clearly at 2–6 h after injection of ^99mTc-RRL, whereas the tumor was not imaged clearly in blocking group. The tumor-to-muscle ratio of images with ^99mTc-RRL was comparable with that of ¹⁸F-FDG PET images. Immunohistochemical analysis verified the excessive vasculature of tumor. There was a linear relationship between the tumor size and uptake of ^99mTc-RRL with R² = 0.821.

Conclusion

^99mTc-RRL can be used as a potential candidate for visualization of tumor angiogenesis in malignant carcinomas.     

Lagged Effect of Diurnal Temperature Range on Mortality in a Subtropical Megacity of China

Background

Many studies have found extreme temperature can increase the risk of mortality. However, it is not clear whether extreme diurnal temperature range (DTR) is associated with daily disease-specific mortality, and how season might modify any association.

Objectives

To better understand the acute effect of DTR on mortality and identify whether season is a modifier of the DTR effect.

Methods

The distributed lag nonlinear model (DLNM) was applied to assess the non-linear and delayed effects of DTR on deaths (non-accidental mortality (NAD), cardiovascular disease (CVD), respiratory disease (RD) and cerebrovascular disease (CBD)) in the full year, the cold season and the warm season.

Results

A non-linear relationship was consistently found between extreme DTR and mortality. Immediate effects of extreme low DTR on all types of mortality were stronger than those of extreme high DTR in the full year. The cumulative effects of extreme DTRs increased with the increment of lag days for all types of mortality in cold season, and they were greater for extreme high DTRs than those of extreme low DTRs. In hot season, the cumulative effects for extreme low DTRs increased with the increment of lag days, but for extreme high DTR they reached maxima at a lag of 13 days for all types of mortality except for CBD(at lag6 days), and then decreased.

Conclusions

Our findings suggest that extreme DTR is an independent risk factor of daily mortality, and season is a modifier of the association of DTR with daily mortality.     

Eight Functional Polymorphisms in the Estrogen Receptor 1 Gene and Endometrial Cancer Risk: A Meta-Analysis

Background and Objective

Emerging evidence indicates that common functional polymorphisms in the estrogen receptor 1 (ESR1) gene may have an impact on an individual’s susceptibility to endometrial cancer, but individually published results are inconclusive. The aim of this meta-analysis is to derive a more precise estimation of the associations between eight polymorphisms in the ESR1 gene and endometrial cancer risk.

Methods

A literature search of PubMed, Embase, Web of Science and China Biology Medicine (CBM) databases was conducted on publications published before November 1^st, 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Statistical analyses were performed using the STATA 12.0 software.

Results

Thirteen case-control studies were included with a total of 7,649 endometrial cancer cases and 16,855 healthy controls. When all the eligible studies were pooled into the meta-analysis, the results indicated that PvuII (C>T) polymorphism was associated with an increased risk of endometrial cancer, especially among Caucasian populations. There were also significant associations between rs3020314 (C>T) polymorphism and an increased risk of endometrial cancer. Furthermore, rs2234670 (S/L) polymorphism may decrease the risk of endometrial cancer. However, no statistically significant associations were found in XbaI (A>G), Codon 325 (C>G), Codon 243 (C>T), VNTR (S/L) and rs2046210 (G>A) polymorphisms.

Conclusion

The current meta-analysis suggests that PvuII (C>T) and rs3020314 (C>T) polymorphisms may be risk factors for endometrial cancer, especially among Caucasian populations.