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1.  Osteopontin (OPN) Is an Important Protein to Mediate Improvements in the Biocompatibility of C Ion-Implanted Silicone Rubber 
PLoS ONE  2014;9(6):e98320.
Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface.
PMCID: PMC4049582  PMID: 24911051
2.  Enhancement of radiotherapy efficacy by miR-200c-loaded gelatinase-stimuli PEG-Pep-PCL nanoparticles in gastric cancer cells 
Radiotherapy is the main locoregional control modality for many types of unresectable tumors, including gastric cancer. However, many patients fail radiotherapy due to intrinsic radioresistance of cancer cells, which has been found to be strongly associated with cancer stem cell (CSC)-like properties. In this study, we developed a nanoparticle formulation to deliver miR-200c, which is reported to inhibit CSC-like properties, and then evaluated its potential activity as a radiosensitizer. miR-200c nanoparticles significantly augmented radiosensitivity in three gastric cancer cell lines (sensitization enhancement ratio 1.13–1.25), but only slightly in GES-1 cells (1.06). In addition to radioenhancement, miR-200c nanoparticles reduced the expression of CD44, a putative CSC marker, and the percentage of CD44+ BGC823 cells. Meanwhile, other CSC-like properties, including invasiveness and resistance to apoptosis, could be suppressed by miR-200c nanoparticles. CSC-associated radioresistance mechanisms, involving reactive oxygen species levels and DNA repair capacity, were also attenuated. We have demonstrated that miR-200c nanoparticles are an effective radiosensitizer in gastric cancer cells and induce little radiosensitization in normal cells, which suggests that they are as a promising candidate for further preclinical and clinical evaluation.
PMCID: PMC4026568  PMID: 24872697
radiosensitizer; miR-200c; gelatinase-stimuli nanoparticles; cancer stem cell-like properties; gastric cancer
3.  Planar-defect-rich zinc oxide nanoparticles assembled on carbon nanotube films as ultraviolet emitters and photocatalysts 
Scientific Reports  2014;4:4728.
Structural defects in zinc oxide (ZnO) nanoparticles are complex and hard to be controlled during the synthesis, however, diversifying the chemical and physical performances. Here we report a rapid and low-temperature deposition method to fabricate planar-defect-rich ZnO nanoparticles on freestanding and aligned carbon nanotube films, different from common treatments which remove structural defects as many as possible. The defect energy states are very close to the valence band of ZnO and serve as recombination centers for a nearly monochromatic ultraviolet luminescence within a wavelength range of 373–376 nm. The absence of point defects, especially of oxygen vacancies whose energy level is <1 eV below the conduction band, allows photoinduced electrons and holes to take parts in possible photocatalytic reactions rather than to recombine at the shallow energy levels of planar defects.
PMCID: PMC3989556  PMID: 24740315
4.  Contamination of Medical Charts: An Important Source of Potential Infection in Hospitals 
PLoS ONE  2014;9(2):e78512.
This prospective study aims to identify and compare the incidence of bacterial contamination of hospital charts and the distribution of species responsible for chart contamination in different units of a tertiary hospital.
All beds in medical, surgical, pediatric, and obstetric-gynecologic general wards (556) and those in corresponding special units (125) including medical, surgical, pediatric intensive care units (ICUs), the obstetric tocolytic unit and delivery room were surveyed for possible chart contamination. The outer surfaces of included charts were sampled by one experienced investigator with sterile cotton swabs rinsed with normal saline.
For general wards and special units, the overall sampling rates were 81.8% (455/556) and 85.6% (107/125) (p = 0.316); the incidence of chart contamination was 63.5% and 83.2%, respectively (p<0.001). Except for obstetric-gynecologic charts, the incidence was significantly higher in each and in all ICUs than in corresponding wards. Coagulase-negative staphylococci was the most common contaminant in general wards (40.0%) and special units (34.6%) (p>0.05). Special units had a significantly higher incidence of bacterial contamination due to Staphylococcus aureus (17.8%), Methicillin-resistant Staphylococcus aureus (9.3%), Streptococcus viridans (9.4%), Escherichia coli (11.2%), Klebsiella pneumoniae (7.5%), and Acinetobacter baumannii (7.5%). Logistic regression analysis revealed the incidence of chart contamination was 2- to 4-fold higher in special units than in general wards [odds ratios: 1.97–4.00].
Noting that most hospital charts are contaminated, our study confirms that a hospital chart is not only a medical record but also an important source of potential infection. The plastic cover of the medical chart can harbor potential pathogens, thus acting as a vector of bacteria. Additionally, chart contamination is more common in ICUs. These findings highlight the importance of effective hand-washing before and after handling medical charts. However, managers and clinical staff should pay more attention to the issue and may consider some interventions.
PMCID: PMC3928153  PMID: 24558355
5.  Cancer risk of incremental exposure to polycyclic aromatic hydrocarbons in electrocautery smoke for mastectomy personnel 
Electrocautery applications in surgical operations produce evasive odorous smoke in the cleanest operation rooms. Because of the incomplete combustion of electrical current in the tissues and blood vessels during electrocautery applications, electrocautery smoke (ES) containing significant unknown chemicals and biological forms is released. The potential hazards and cancer risk should be further investigated from the perspective of the occupational health of surgical staff.
The particle number concentration and the concentration of polycyclic aromatic hydrocarbons (PAHs) in ES were thoroughly investigated in 10 mastectomies to estimate the cancer risk for surgical staff. The particle number concentration and gaseous/particle PAHs at the surgeons’ and anesthetic technologists’ (AT) breathing heights were measured with a particle counter and filter/adsorbent samplers. PAHs were soxhlet-extracted, cleaned, and analyzed by gas chromatography/mass spectrometry.
Abundant submicron particles and high PAH concentrations were found in ES during regular surgical mastectomies. Most particles in ES were in the size range of 0.3 to 0.5 μm, which may potentially penetrate through the medical masks into human respiration. The average particle/gaseous phase PAH concentrations at the surgeon’s breathing height were 131 and 1,415 ng/m3, respectively, which is 20 to 30 times higher than those in regular outdoor environments. By using a toxicity equivalency factor, the cancer risk for the surgeons and anesthetic technologists was calculated to be 117 × 10-6 and 270 × 10-6, respectively; the higher cancer risk for anesthetic technologists arises due to the longer working hours in operation rooms.
The carcinogenic effects of PAHs in ES on the occupational health of surgical staff should not be neglected. The use of an effective ES evacuator or smoke removal apparatus is strongly suggested to diminish the ES hazards to surgical staff.
PMCID: PMC3922599  PMID: 24499532
Cancer risk; Electrocautery smoke; Polycyclic aromatic hydrocarbons; Surgical staff; Toxicity equivalency factor
6.  Endocardial Cushion Morphogenesis and Coronary Vessel Development Require Chicken Ovalbumin Upstream Promoter-Transcription Factor II 
Septal defects and coronary vessel anomalies are common congenital heart defects, yet their ontogeny and the underlying genetic mechanisms are not well understood. Here, we investigated the role of chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, NR2F2) in cardiac organogenesis.
Methods and Results
We analyzed embryos deficient in COUP-TFII and observed a spectrum of cardiac defects, including atrioventricular septal defect, thin-walled myocardium, and abnormal coronary morphogenesis. We show by expression analysis that COUP-TFII is expressed in the endocardium and the epicardium but not in the myocardium of the ventricle. Using endothelial-specific COUP-TFII mutants and molecular approaches, we show that COUP-TFII deficiency resulted in endocardial cushion hypoplasia. This was attributed to the reduced growth and survival of atrioventricular cushion mesenchymal cells and defective epithelial-mesenchymal transformation (EMT) in the underlying endocardium. In addition, the endocardial EMT defect was accompanied by downregulation of Snai1, one of the master regulators of EMT, and upregulation of vascular endothelial-cadherin. Furthermore, we show that although COUP-TFII does not play a major role in the formation of epicardial cell cysts, it is critically important for the formation of epicardium. Ablation of COUP-TFII impairs epicardial EMT and coronary plexus formation.
Our results reveal that COUP-TFII plays cell-autonomous roles in the endocardium and the epicardium for endocardial and epicardial EMT, which are required for proper valve and coronary vessel formation during heart development.
PMCID: PMC3598627  PMID: 22962329
atrioventricular septal defect; cardiac morphogenesis; chicken ovalbumin upstream promoter-transcription factor II; epicardium; epithelial-mesenchymal transformation
7.  The Effects of Hematopoietic Growth Factors on Neurite Outgrowth 
PLoS ONE  2013;8(10):e75562.
Stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) are initially discovered as the essential hematopoietic growth factors regulating bone marrow stem cell proliferation and differentiation, and SCF in combination with G-CSF (SCF+G-CSF) has synergistic effects on bone marrow stem cell mobilization. In this study we have determined the effect of SCF and G-CSF on neurite outgrowth in rat cortical neurons. Using molecular and cellular biology and live cell imaging approaches, we have revealed that receptors for SCF and G-CSF are expressed on the growth core of cortical neurons, and that SCF+G-CSF synergistically enhances neurite extension through PI3K/AKT and NFκB signaling pathways. Moreover, SCF+G-CSF induces much greater NFκB activation, NFκB transcriptional binding and brain-derived neurotrophic factor (BDNF) production than SCF or G-CSF alone. In addition, we have also observed that BDNF, the target gene of NFκB, is required for SCF+G-CSF-induced neurite outgrowth. These data suggest that SCF+G-CSF has synergistic effects to promote neurite growth. This study provides new insights into the contribution of hematopoietic growth factors in neuronal plasticity.
PMCID: PMC3792965  PMID: 24116056
8.  Upregulated MicroRNA-155 Expression in Peripheral Blood Mononuclear Cells and Fibroblast-Like Synoviocytes in Rheumatoid Arthritis 
Objective. This study was to screen for the miRNAs differently expressed in peripheral blood mononuclear cells (PBMC) of RA, to further identify the expression of miR-155 in RA PBMC and fibroblast-like synoviocytes (FLS), and to evaluate the function of miR-155 in RA-FLS. Methods. Microarray was used to screen for differentially expressed miRNAs in RA PBMC. miR-155 expression in PBMC and FLS of RA were identified by real-time PCR. Enforced overexpression and downexpression of miR-155 were used to investigate the function of miR-155 in RA-FLS. Expression of IKBKE which was previously identified as the actual target of miR-155 was examined by Western blot and real-time PCR in RA-FLS. Results. miR-155 levels were increased in both PBMC and FLS of RA and could be induced by TNF-α. Upregulation of miR-155 decreased MMP-3 levels and suppressed proliferation and invasion of RA-FLS. Inverse relationship between the expressions of miR-155 and the MMPs production-related protein IKBKE was found. Conclusion. An inflammatory milieu may alter miRNA expression profiles in rheumatoid arthritis. miR-155 is upregulated in RA-FLS, and it may be a protective factor against the inflammatory effect in part by attenuating expression of IKBKE.
PMCID: PMC3789322  PMID: 24151514
9.  Reestablishing Neuronal Networks in the Aged Brain by Stem Cell Factor and Granulocyte-Colony Stimulating Factor in a Mouse Model of Chronic Stroke 
PLoS ONE  2013;8(6):e64684.
Stroke has a high incidence in the elderly. Stroke enters the chronic phase 3 months after initial stroke onset. Currently, there is no pharmaceutical treatment available for chronic stroke. We have demonstrated the therapeutic effects of the combination of stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF) (SCF+G-CSF) on chronic stroke. However, it remains unclear how SCF+G-CSF repairs the brain in chronic stroke. In this study, we determined the effects of SCF+G-CSF on neuronal network remodeling in the aged brain of chronic stroke. Cortical brain ischemia was produced in 16–18 month-old transgenic mice expressing yellow fluorescent protein in layer V pyramidal neurons. SCF+G-CSF was subcutaneously injected for 7 days beginning at 3.5 months post-ischemia. Using both live brain imaging and immunohistochemistry, we observed that SCF+G-CSF increased the mushroom-type spines on the apical dendrites of layer V pyramidal neurons adjacent to the infarct cavities 2 and 6 weeks after treatment. SCF+G-CSF also augmented dendritic branches and post-synaptic density protein 95 puncta in the peri-infarct cortex 6 weeks after treatment. These data suggest that SCF+G-CSF treatment in chronic stroke remodels neural circuits in the aged brain. This study provides evidence to support the development of a new therapeutic strategy for chronic stroke.
PMCID: PMC3672166  PMID: 23750212
10.  Overexpression of Cystatin SN positively affects survival of patients with surgically resected esophageal squamous cell carcinoma 
BMC Surgery  2013;13:15.
Cystatin SN is a secreted protein and a cysteine proteinase inhibitor. It has been considered to be a tumor marker for gastrointestinal tract cancer in several functional researches. However, the clinicopathological and prognostic significance of Cystatin SN expression in esophageal squamous cell carcinoma (ESCC) has not been elucidated.
In our study, the expression of Cystatin SN was detected in 209 surgically resected ESCC tissues and 170 peritumoral normal esophageal mucosae by immunohistochemistry. The prognostic significance of Cystatin SN expression was analysed with Kaplan-Meier plots and the Cox proportional hazards regression models.
The results showed that the immunostaining of Cystatin SN in ESCC tissues was less intense than that in the normal control tissue (P < 0.001). Compared with patients with low tumoral Cystatin SN expression, ESCC patients with tumors high-expression Cystatin SN exhibited increased disease-free survival (DFS) and overall survival (OS) (P < 0.001 and P < 0.001, respectively). Furthermore, the expression level of Cystatin SN could further stratify the ESCC patients by survival (DFS and OS) in the stage II subgroup (P < 0.001 and P < 0.001, respectively). Multivariate analyses showed that Cystatin SN expression, N status and differentiation were independent and significant predictors of survival.
We concluded that ESCC patients whose tumors express high levels of Cystatin SN have favourable survival compared with those patients with low Cystatin SN expression. Tumoral Cystatin SN expression may be an independent predictor of survival for patients with resectable ESCCs.
PMCID: PMC3699386  PMID: 23711283
Esophageal squamous cell carcinoma; Cystatin SN; Immunohistochemistry; Prognosis
11.  Regulated Expression of Lentivirus-Mediated GDNF in Human Bone Marrow-Derived Mesenchymal Stem Cells and Its Neuroprotection on Dopaminergic Cells In Vitro 
PLoS ONE  2013;8(5):e64389.
Gene regulation remains one of the major challenges for gene therapy in clinical trials. In the present study, we first generated a binary tetracycline-on (Tet-On) system based on two lentivirus vectors, one expressing both human glial cell line-derived neurotrophic factor (hGDNF) and humanized recombinant green fluorescent protein (hrGFP) genes under second-generation tetracycline response element (TRE), and the other expressing the advanced reverse tetracycline-controlled transactivator - rtTA2S-M2 under a human minimal cytomegalovirus immediate early (CMV-IE) promoter. This system allows simultaneous expression of hGDNF and hrGFP genes in the presence of doxycycline (Dox). Human bone marrow-derived mesenchymal stem cells (hMSCs) were transduced with the binary Tet-On lentivirus vectors and characterized in vitro in the presence (On) or absence (Off) of Dox. The expression of hGDNF and hrGFP transgenes in transduced hMSCs was tightly regulated as determined by flow cytometry (FCM), GDNF enzyme-linked immunosorbent assay (ELISA) and quantitative real time-polymerase chain reaction (qRT-PCR). There was a dose-dependent regulation for hrGFP transgene expression. The levels of hGDNF protein in culture medium were correlated with the mean fluorescence intensity (MFI) units of hrGFP. The levels of transgene background expression were very low in the absence of Dox. The treatment of the conditioned medium from cultures of transduced hMSCs in the presence of Dox protected SH-SY5Y cells against 6-hydroxydopamine (6-OHDA) toxicity as determined by cell viability using 3, [4,5-dimethylthiazol-2-yl]- diphenyltetrazolium bromide (MTT) assay. The treatment of the conditioned medium was also found to improve the survival of dopaminergic (DA) neurons of ventral mesencephalic (VM) tissue in serum-free culture conditions as assessed by cell body area, the number of neurites and dendrite branching points, and proportion of tyrosine hydroxylase (TH)-immunoreactive (IR) cells. Our inducible lentivirus-mediated hGDNF gene delivery system may provide useful tools for basic research on gene therapy for chronic neurological disorders such as Parkinson’s disease (PD).
PMCID: PMC3661514  PMID: 23717608
12.  Pre-immunization with an Intramuscular Injection of AAV9-Human Erythropoietin Vectors Reduces the Vector-Mediated Transduction following Re-Administration in Rat Brain 
PLoS ONE  2013;8(5):e63876.
We have recently demonstrated that adeno-associated virus serotype 9 (AAV9)-mediated human erythropoietin (hEPO) gene delivery into the brain protects dopaminergic (DA) neurons in the substantia nigra in a rat model of Parkinson's disease. In the present study, we examined whether pre-exposure to AAV9-hEPO vectors with an intramuscular or intrastriatal injection would reduce AAV9-mediated hEPO transduction in rat brain. We first characterized transgene expression and immune responses against AAV9-hEPO vectors in rat striatum at 4 days, 3 weeks and 6 months, and with doses ranging from 1011 to 1013 viral genomes. To sensitize immune system, rats received an injection of AAV9-hEPO into either the muscle or the left striatum, and then sequentially an injection of AAV9-hEPO into the right striatum 3 weeks later. We observed that transgene expression exhibited in a time course and dose dependent manner, and inflammatory and immune responses displayed in a time course manner. Intramuscular, but not intrastriatal injections of AAV9-hEPO resulted in reduced levels of hEPO transduction and increased levels of the major histocompatibility complex (MHC) class I and class II antigen expression in the striatum following AAV9-hEPO re-administration. There were infiltration of the cluster of differentiation 4 (CD4)-and CD8-lymphacytes, and accumulation of activated microglial cells and astrocytes in the virally injected striatum. In addition, the sera from the rats with intramuscular injections of AAV9-hEPO contained greater levels of antibodies against both AAV9 capsid protein and hEPO protein than the other treatment groups. hEPO gene expression was negatively correlated with the levels of circulating antibodies against AAV9 capsid protein. Intramuscular and intrastriatal re-administration of AAV9-hEPO led to increased numbers of red blood cells in peripheral blood. Our results suggest that pre-immunization with an intramuscular injection can lead to the reduction of transgene expression in the striatal re-administration.
PMCID: PMC3648480  PMID: 23667683
13.  Pyrosequencing Reveals the Influence of Organic and Conventional Farming Systems on Bacterial Communities 
PLoS ONE  2012;7(12):e51897.
It has been debated how different farming systems influence the composition of soil bacterial communities, which are crucial for maintaining soil health. In this research, we applied high-throughput pyrosequencing of V1 to V3 regions of bacterial 16S rRNA genes to gain further insight into how organic and conventional farming systems and crop rotation influence bulk soil bacterial communities. A 2×2 factorial experiment consisted of two agriculture management systems (organic versus conventional) and two crop rotations (flax-oat-fababean-wheat versus flax-alfalfa-alfalfa-wheat) was conducted at the Glenlea Long-Term Crop Rotation and Management Station, which is Canada’s oldest organic-conventional management study field. Results revealed that there is a significant difference in the composition of bacterial genera between organic and conventional management systems but crop rotation was not a discriminator factor. Organic farming was associated with higher relative abundance of Proteobacteria, while Actinobacteria and Chloroflexi were more abundant in conventional farming. The dominant genera including Blastococcus, Microlunatus, Pseudonocardia, Solirubrobacter, Brevundimonas, Pseudomonas, and Stenotrophomonas exhibited significant variation between the organic and conventional farming systems. The relative abundance of bacterial communities at the phylum and class level was correlated to soil pH rather than other edaphic properties. In addition, it was found that Proteobacteria and Actinobacteria were more sensitive to pH variation.
PMCID: PMC3526490  PMID: 23284808
14.  The combination of stem cell factor and granulocyte-colony stimulating factor for chronic stroke treatment in aged animals 
Stroke occurs more frequently in the elderly population and presents the number one leading cause of persistent disability worldwide. Lack of effective treatment to enhance brain repair and improve functional restoration in chronic stroke, the recovery phase of stroke, is a challenging medical problem to be solved in stroke research. Our early study has revealed the therapeutic effects of stem cell factor (SCF) in combination with granulocyte-colony stimulating factor (G-CSF) (SCF+G-CSF) on chronic stroke in young animals. However, whether this treatment is effective and safe to the aged population remains to be determined.
Cortical brain ischemia was produced in aged C57BL mice or aged spontaneously hypertensive rats. SCF+G-CSF or equal volume of vehicle solution was subcutaneously injected for 7 days beginning at 3–4 months after induction of cortical brain ischemia. Using the approaches of biochemistry assays, flow cytometry, pathology, and evaluation of functional outcome, several doses of SCF+G-CSF have been examined for their safety and efficiency on chronic stroke in aged animals.
All tested doses did not show acute or chronic toxicity in the aged animals. Additionally, SCF+G-CSF treatment in chronic stroke of aged animals mobilized bone marrow stem cells and improved functional outcome in a dose-dependent manner.
SCF+G-CSF treatment is a safe and effective approach to chronic stroke in the aged condition. This study provides important information needed for developing a new therapeutic strategy to improve the health of older adults with chronic stroke.
PMCID: PMC3552930  PMID: 23254113
Hematopoietic growth factor; SCF; G-CSF; Chronic stroke; Treatment; Elderly
15.  Nimotuzumab promotes radiosensitivity of EGFR-overexpression esophageal squamous cell carcinoma cells by upregulating IGFBP-3 
Epidermal growth factor receptor (EGFR) is suggested to predict the radiosensitivity and/or prognosis of human esophageal squamous cell carcinoma (ESCC). The objective of this study was to investigate the efficacy of Nimotuzumab (an anti-EGFR monoclonal antibody) on ESCC radiotherapy (RT) and underlying mechanisms.
Nimotuzumab was administrated to 2 ESCC cell lines KYSE30 and TE-1 treated with RT. Cell growth, colony formation and apoptosis were used to measure anti-proliferation effects. The method of RNA interference was used to investigate the role of insulin-like growth factor binding protein-3 (IGFBP-3) in ESCC cells radiosensitivity treated with Nimotuzumab. In vivo effect of Nimotuzumab on ESCC radiotherapy was done using a mouse xenograft model.
Nimotuzumab enhanced radiation response of KYSE30 cells (with high EGFR expression) in vitro, as evidenced by increased radiation-inhibited cell growth and colony formation and radiation-mediated apoptosis. Mechanism study revealed that Nimotuzumab inhibited phosphorylated EGFR (p-EGFR) induced by EGF in KYSE30 cells. In addition, knockdown of IGFBP-3 by short hairpin RNA significantly reduced KYSE30 cells radiosensitivity (P<0.05), and even after the administration of Nimotuzumab, the RT response of IGFBP-3 silenced KYSE30 cells was not enhanced (P>0.05). In KYSE30 cell xenografts, Nimotuzumab combined with radiation led to significant tumor growth delay, compared with that of radiation alone (P=0.029), and also with IGFBP-3 up-regulation in tumor tissue.
Nimotuzumab could enhance the RT effect of ESCC cells with a functional active EGFR pathway. In particular, the increased ESCC radiosensitivity by Nimotuzumab might be dependent on the up-regulation of IGFBP-3 through EGFR-dependent pathway.
PMCID: PMC3540017  PMID: 23232108
EGFR; Esophageal squamous carcinoma cell; IGFBP-3; Nimotuzumab; Radiosensitivity
16.  Dual Function of Sox1 in Telencephalic Progenitor Cells 
Developmental biology  2007;310(1):85-98.
The transcription factor, Sox1 has been implicated in the maintenance of neural progenitor cell status, but accumulating evidence suggests that this is only part of its function. This study examined the role of Sox1 expression in proliferation, lineage commitment, and differentiation by telencephalic neural progenitor cells in vitro and in vivo, and further clarified the pattern of Sox1 expression in postnatal and adult mouse brain. Telencephalic neural progenitor cells isolated from Sox1 null embryos formed neurospheres normally, but were specifically deficient in neuronal differentiation. Conversely, overexpression of Sox1 in the embryonic telencephalon in vivo both expanded the progenitor pool and biased neural progenitor cells towards neuronal lineage commitment. Sox1 mRNA and protein were found to be persistently expressed in the postnatal and adult brain in both differentiated and neurogenic regions. Importantly, in differentiated regions Sox1 co-labeled only with neuronal markers. These observations, coupled with previous studies, suggest that Sox1 expression by early embryonic progenitor cells initially helps to maintain the cells in cell cycle, but that continued expression subsequently promotes neuronal lineage commitment.
PMCID: PMC3437622  PMID: 17719572
Sox1; neural progenitor cells; neural stem cells; neurogenesis; differentiation
17.  A Replication Study Confirms the Association of Dendritic Cell Immunoreceptor (DCIR) Polymorphisms with ACPA - Negative RA in a Large Asian Cohort 
PLoS ONE  2012;7(7):e41228.
Dendritic cell immunoreceptor (DCIR) has been implicated in development of autoimmune disorders in rodent and DCIR polymorphisms were associated with anti-citrullinated proteins antibodies (ACPA)-negative rheumatoid arthritis (RA) in Swedish Caucasians. This study was undertaken to further investigate whether DCIR polymorphisms are also risk factors for the development of RA in four Asian populations originated from China and Malaysia.
We genotyped two DCIR SNPs rs2377422 and rs10840759 in Han Chinese population (1,193 cases, 1,278 controls), to assess their association with RA. Subsequently, rs2377422 was further genotyped in three independent cohorts of Malaysian-Chinese subjects (MY_Chinese, 254 cases, 206 controls), Malay subjects (MY_ Malay, 515 cases, 986 controls), and Malaysian-Indian subjects (MY_Indian, 378 cases, 285 controls), to seek confirmation of association in various ethnic groups. Meta-analysis was preformed to evaluate the contribution of rs2377422 polymorphisms to the development of ACPA-negative RA in distinct ethnic groups. Finally, we carried out association analysis of rs2377422 polymorphisms with DCIR mRNA expression levels.
DCIR rs2377422 was found to be significantly associated with ACPA -negative RA in Han Chinese (OR 1.92, 95% CI 1.27–2.90, P = 0.0020). Meta-analysis confirms DCIR rs2377422 as a risk factor for ACPA-negative RA across distinct ethnic groups (ORoverall = 1.17, 95% CI 1.06–1.30, P = 0.003). The SNP rs2377422 polymorphism showed significant association with DCIR mRNA expression level, i.e. RA-risk CC genotype exhibit a significant increase in the expression of DCIR (P = 0.0023, Kruskal–Wallis).
Our data provide evidence for association between DCIR rs2377422 and RA in non-Caucasian populations and confirm the influence of DCIR polymorphisms on RA susceptibility, especially on ACPA-negative RA.
PMCID: PMC3400585  PMID: 22829930
18.  Human Albumin Prevents 6-Hydroxydopamine-Induced Loss of Tyrosine Hydroxylase in In Vitro and In Vivo 
PLoS ONE  2012;7(7):e41226.
Human albumin has recently been demonstrated to protect brain neurons from injury in rat ischemic brain. However, there is no information available about whether human albumin can prevent loss of tyrosine hydroxylase (TH) expression of dopaminergic (DA) neurons induced by 6-hydroxydopamine (6-OHDA) toxicity that is most commonly used to create a rat model of Parkinson's disease (PD). In the present study, two microliters of 1.25% human albumin were stereotaxically injected into the right striatum of rats one day before or 7 days after the 6-OHDA lesion in the same side. D-Amphetamine-induced rotational asymmetry was measured 7 days, 3 and 10 weeks after 6-OHDA lesion. We observed that intrastriatal administration of human albumin significantly reduced the degree of rotational asymmetry. The number of TH-immunoreactive neurons present in the substantia nigra was greater in 6-OHDA lesioned rats following human albumin-treatment than non-human albumin treatment. TH-immunoreactivity in the 6-OHDA-lesioned striatum was also significantly increased in the human albumin-treated rats. To examine the mechanisms underlying the effects of human albumin, we challenged PC12 cells with 6-OHDA as an in vitro model of PD. Incubation with human albumin prevented 6-OHDA-induced reduction of cell viability in PC12 cell cultures, as measured by MTT assay. Furthermore, human albumin reduced 6-OHDA-induced formation of reactive oxygen species (ROS) and apoptosis in cultured PC12 cells, as assessed by flow cytometry. Western blot analysis showed that human albumin inhibited 6-OHDA-induced activation of JNK, c-Jun, ERK, and p38 mitogen-activated protein kinases (MAPK) signaling in PC12 cultures challenged with 6-OHDA. Human albumin may protect against 6-OHDA toxicity by influencing MAPK pathway followed by anti-ROS formation and anti-apoptosis.
PMCID: PMC3398951  PMID: 22815976
19.  Characterizing criticality of proteins by systems dynamics: Escherichia coli central carbon metabolism as a working example 
BMC Systems Biology  2012;6(Suppl 1):S11.
Systems biology calls for studying system-level properties of genes and proteins rather than their individual chemical/biological properties, regarding the bio-molecules as system components. By characterizing how critical the components are to the system and classifying them accordingly, we can study the underlying complex mechanisms, facilitating researches in drug target selection, metabolic engineering, complex disease, etc. Up to date, most studies aiming at this goal are confined to the topology-based or flux-analysis approaches. However, proteins have tertiary structures and specific functions, especially in metabolic systems. Thus topological properties such as connectivity, path length, etc., are not good surrogates for protein properties. Also, the manner of individual sensitivity analysis in most flux-analysis approaches cannot reveal the simultaneous impacts on collateral components as well as the overall impact on the system, thus lacking in system-level perspective.
In the present work, we developed a method to directly assess protein system-level properties based on system dynamics and in silico knockouts, regarding to the conceptual term "criticality". Applying the method to E. coli central carbon metabolic system, we found that multiple enzymes including phosphoglycerate kinase, enolase, transketolase-b, etc., had critical roles in the system in terms of both system states and dynamical stability. In contrast, another set of enzymes including glucose-6-phosphate isomerise, pyruvate kinase, phosphoglucomutase, etc., exerted very little influences when deleted. The finding is consistent with experimental characterization of metabolic essentiality and other studies on E. coli gene essentiality and functions. We also found that enzymes could affect distant metabolites or enzymes even greater than a close neighbour and asymmetry in system-level properties of enzymes catalyzing alternative pathways could give rise to local flux compensation.
Our method creates a different angle for evaluating protein criticality to a biological system from the conventional methodologies. Moreover, the method leads to consistent results with experimental references, showing its efficiency in studying protein system-level properties. Besides working on metabolic systems, the application of the method can be extended to other kinds of bio-systems to reveal the constitutive/functional properties of system building blocks.
PMCID: PMC3402961  PMID: 23046715
20.  Pyrosequencing the Bemisia tabaci Transcriptome Reveals a Highly Diverse Bacterial Community and a Robust System for Insecticide Resistance 
PLoS ONE  2012;7(4):e35181.
Bemisia tabaci (Gennadius) is a phloem-feeding insect poised to become one of the major insect pests in open field and greenhouse production systems throughout the world. The high level of resistance to insecticides is a main factor that hinders continued use of insecticides for suppression of B. tabaci. Despite its prevalence, little is known about B. tabaci at the genome level. To fill this gap, an invasive B. tabaci B biotype was subjected to pyrosequencing-based transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes.
Methodology and Principal Findings
Using Roche 454 pyrosequencing, 857,205 reads containing approximately 340 megabases were obtained from the B. tabaci transcriptome. De novo assembly generated 178,669 unigenes including 30,980 from insects, 17,881 from bacteria, and 129,808 from the nohit. A total of 50,835 (28.45%) unigenes showed similarity to the non-redundant database in GenBank with a cut-off E-value of 10–5. Among them, 40,611 unigenes were assigned to one or more GO terms and 6,917 unigenes were assigned to 288 known pathways. De novo metatranscriptome analysis revealed highly diverse bacterial symbionts in B. tabaci, and demonstrated the host-symbiont cooperation in amino acid production. In-depth transcriptome analysis indentified putative molecular markers, and genes potentially involved in insecticide resistance and nutrient digestion. The utility of this transcriptome was validated by a thiamethoxam resistance study, in which annotated cytochrome P450 genes were significantly overexpressed in the resistant B. tabaci in comparison to its susceptible counterparts.
This transcriptome/metatranscriptome analysis sheds light on the molecular understanding of symbiosis and insecticide resistance in an agriculturally important phloem-feeding insect pest, and lays the foundation for future functional genomics research of the B. tabaci complex. Moreover, current pyrosequencing effort greatly enriched the existing whitefly EST database, and makes RNAseq a viable option for future genomic analysis.
PMCID: PMC3340392  PMID: 22558125
22.  Gelatinase-stimuli strategy enhances the tumor delivery and therapeutic efficacy of docetaxel-loaded poly(ethylene glycol)-poly(ɛ-caprolactone) nanoparticles 
Nanoscale drug carriers have been extensively developed to improve drug therapeutic efficiency. However, delivery of chemotherapeutic agents to tumor tissues and cells has not been favorably managed. In this study, we developed a novel “intelligent” nanoparticle, consisting of a gelatinase-cleavage peptide with poly(ethylene glycol) (PEG) and poly(ɛ-caprolactone) (PCL)-based structure for tumor-targeted docetaxel delivery (DOC-TNPs). The docetaxel-loaded PEG-PCL nanoparticles (DOC-NPs) that did not display gelatinase-stimuli behaviors were used as a control. We found clear evidence that the DOC-TNPs were transformed by gelatinases, allowing drug release and enhancing the cellular uptake of DOC (P < 0.01). In vivo biodistribution study demonstrated that targeted DOC-TNPs could accumulate and remain in the tumor regions, whereas non-targeted DOC-NPs rapidly eliminated from the tumor tissues. DOC-TNPs exhibited higher tumor growth suppression than commercialized Taxotere® (docetaxel; Jiangsu Hengrui Medicine Company, Jiangsu, China) and DOC-NPs on hepatic H22 tumor model via intravenous administration (P < 0.01). Both in vitro and in vivo experiments suggest that the gelatinase-mediated nanoscale delivery system is promising for improvement of antitumor efficacy in various overexpressed gelatinase cancers.
PMCID: PMC3265997  PMID: 22287839
drug delivery; stimuli-responsive; gelatinase; antitumor; docetaxel
23.  Gene Expression Profiling in the Thiamethoxam Resistant and Susceptible B-biotype Sweetpotato Whitefly, Bemisia tabaci  
Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based on their gene ontology annotation. Some categories such as cell communication, response to abiotic stimulus, lipid particle, and nuclear envelope were identified only in the forward library of thiamethoxam-resistant strains. In contrast, categories such as behavior, cell proliferation, nutrient reservoir activity, sequence-specific DNA binding transcription factor activity, and signal transducer activity were identified solely in the reverse library.
To study the validity of the SSH method, 16 differentially expressed genes from both forward and reverse SSH libraries were selected randomly for further analyses using quantitative realtime PCR (qRT-PCR). The qRT-PCR results were fairly consistent with the SSH results; however, only 50% of the genes showed significantly different expression profiles between the thiamethoxam-resistant and thiamethoxam-susceptible whiteflies. Among these genes, a putative NAD-dependent methanol dehydrogenase was substantially over-expressed in the thiamethoxamresistant adults compared to their susceptible counterparts. The distributed profiles show that it was highly expressed during the egg stage, and was most abundant in the abdomen of adult females.
PMCID: PMC3476951  PMID: 22957505
insecticide resistance; quantitative real-time PCR; NAD-dependent methanol dehydrogenase; sap-sucking insect; suppression subtractive hybridization
24.  Prognosticators and Risk Grouping in Patients with Lung Metastasis from Nasopharyngeal Carcinoma: A more accurate and appropriate assessment of prognosis 
Lung metastases arising from nasopharyngeal carcinomas (NPC) have a relatively favourable prognosis. The purpose of this study was to identify the prognostic factors and to establish a risk grouping in patients with lung metastases from NPC.
A total of 198 patients who developed lung metastases from NPC after primary therapy were retrospectively recruited from January 1982 to December 2000. Univariate and multivariate analyses of clinical variables were performed using Cox proportional hazards regression models. Actuarial survival rates were plotted against time using the Kaplan-Meier method, and log-rank testing was used to compare the differences between the curves.
The median overall survival (OS) period and the lung metastasis survival (LMS) period were 51.5 and 20.9 months, respectively. After univariate and multivariate analyses of the clinical variables, age, T classification, N classification, site of metastases, secondary metastases and disease-free interval (DFI) correlated with OS, whereas age, VCA-IgA titre, number of metastases and secondary metastases were related to LMS. The prognoses of the low- (score 0-1), intermediate- (score 2-3) and high-risk (score 4-8) subsets based on these factors were significantly different. The 3-, 5- and 10-year survival rates of the low-, intermediate- and high-risk subsets, respectively (P < 0.001) were as follows: 77.3%, 60% and 59%; 52.3%, 30% and 27.8%; and 20.5%, 7% and 0%.
In this study, clinical variables provided prognostic indicators of survival in NPC patients with lung metastases. Risk subsets would help in a more accurate assessment of a patient's prognosis in the clinical setting and could facilitate the establishment of patient-tailored medical strategies and supports.
PMCID: PMC3179719  PMID: 21871101
lung metastasis; nasopharyngeal carcinoma; prognosis; risk subset
25.  Factors determining the survival of nasopharyngeal carcinoma with lung metastasis alone: does combined modality treatment benefit? 
BMC Cancer  2011;11:370.
Nasopharyngeal carcinoma (NPC) with lung metastasis alone has been reported as a relatively favorable prognostic group, and combined modality treatment might be indicated for selected cases. However, the prognostic factors determining survival of this group and the indication of combined therapy have not been thoroughly studied.
We retrospectively reviewed 246 patients of NPC with lung metastasis(es) alone presented at diagnosis or as the first failure after primary treatment from 1993 to 2008 in an academic tertiary hospital. Univariate and multivariate survival analyses of post-metastasis survival (PMS) and overall survival (OS) were carried out to determine the prognostic factors.
The 3-year, 5-year, and 10-year of PMS and OS for the whole cohort were 34.3%, 17.0%, 8.6% and 67.8%, 45.4%, 18.5%, respectively. The median PMS (45.6 months vs. 23.7 months) and OS (73.7 months vs. 46.2 months) of patients treated with combined therapy was significantly longer than that of those treated with chemotherapy alone (P < 0.001). Age, disease-free interval (DFI) and treatment modality were evaluated as independent prognostic factors of OS, while only age and treatment modality retain their independent significance in PMS analysis. In stratified survival analysis, compared to chemotherapy alone, combined therapy could benefit the patients with DFI > 1 year, but not those with DFI ≤ 1 year.
Age ≤ 45 years, DFI > 1 year, and the combined therapy were good prognostic factors for NPC patients with lung metastasis(es) alone. The combination of local therapy and the basic chemotherapy should be considered for these patients with DFI > 1 year.
PMCID: PMC3170652  PMID: 21864397

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