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1.  An Efficient Strategy for Heterologous Expression and Purification of Active Peptide Hainantoxin-IV 
PLoS ONE  2015;10(2):e0117099.
Hainantoxin-IV (HNTX-IV) from the venom of the spider Selenocosmia hainana is a potent antagonist that specifically inhibits the tetrodotoxin-sensitive (TTX-S) sodium channels. The toxin peptide consists of 35 amino acids and adopts a typical inhibitory cystine knot (ICK) motif. To obtain adequate HNTX-IV peptides for further insight into the structure-activity relationships of the toxin, a novel strategy including cloning, expression and purification was developed in an E. coli expression system. For this purpose, a seamless restriction-free (RF) cloning method was employed for the construction of an expression vector to avoid introducing unwanted sequences into the target gene. Furthermore, the solubility of recombinant HNTX-IV could be promoted efficiently by the combination of a glutathione S-transferase (GST) tag and a small ubiquitin-related modifier (SUMO) tag. Finally, an affinity-chromatography-free purification strategy was developed by cut-off dialysis tubing combined with trichloroacetic acid (TCA) extraction. Further HPLC purification yielded recombinant, tag-free HNTX-IV with high yield and purity. The molecular weight of recombinant HNTX-IV (rHNTX-IV) is identical to its theoretical value according to Matrix-Assisted Laser Desorption / Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) analysis. The recombinant toxin has similar activity (IC50 value of 120 nM) on the tetrodotoxin-sensitive (TTX-S) sodium channels in adult rat dorsal root ganglion (DRG) neurons to native toxins. In the report, an efficient and cost-effective strategy for producing rHNTX-IV was developed, which paved the way for the further study of structure-activity relationships of rHNTX-IV and its pharmaceutical applications.
PMCID: PMC4315428  PMID: 25647561
2.  Loss of p53 and altered miR15-a/16-1→MCL-1 pathway in CLL: insights from TCL1-Tg:p53−/− mouse model and primary human leukemia cells 
Leukemia  2013;28(1):118-128.
Chronic lymphocytic leukemia (CLL) patients with deletion of chromosome 17p, where the tumor suppressor p53 gene is located, often develop more aggressive disease with poor clinical outcomes. To investigate the underlying mechanisms responsible for the highly malignant phenotype of 17p- CLL and to facilitate the in vivo evaluation of potential drugs against CLL with p53 deletion, we have created a mouse model with TCL1-Tg:p53−/− genotype. The TCL1-Tg:p53−/− mice develop B-cell leukemia at very early age and follow an aggressive path of disease development that resembles human CLL with 17p deletion, with an early appearance of CD5+/IgM+ B cells in the peritoneal cavity, spleen and bone marrow. These TCL1-Tg:p53−/− leukemia cells exhibit higher survival capacity and are more resistant to drug treatment than the leukemia cells from the TCL1-Tg:p53wt (TCL1-Tg) mice. Analysis of microRNA expression reveals that the p53 deletion resulted in a significant decrease of miR-15a and miR-16-1, leading to a substantial elevated expression of Mcl-1. Primary leukemia cells from CLL patients with 17p deletion also show a decrease in miR-15a/miR-16-1 and an increase in Mcl-1 expression. Our study has created a novel CLL mouse model, and suggests that the p53/miR15a/16-Mcl-1 axis may contribute to the aggressive phenotype and drug resistance in CLL cells with loss of p53.
PMCID: PMC3806892  PMID: 23608884
Leukemia; p53; TCL1; mouse model; Drug resistance
3.  Biodegradable Gold Nanovesicles with Ultra-Strong Plasmonic Coupling Effect for Photoacoustic Imaging and Photothermal Therapy** 
Hierarchical assembling of gold nanoparticles (GNPs) allows one to engineer the localized surface plasmon resonance (LSPR) peaks to the near-infrared (NIR) region for enhanced photothermal Therapy (PTT). Herein we report a novel theranostic platform based on biodegradable plasmonic gold nanovesicles for photoacoustic (PA) Imaging and PTT. The disulfide bond (S-S) termed PEG-b-PCL block copolymer graft allows dense packing of GNPs during the assembly process and induces ultra-strong plasmonic coupling effect between adjacent GNPs. The strong NIR absorption induced by plasmon coupling and very high photothermal conversion efficiency (η= 37 %) enable simultaneous thermal/PA imaging and enhanced PTT efficacy with improved clearance of the dissociated particles after the completion of PTT. These vesicle-architectures assembling of various nanocrystals with tailored optical, magnetic, and electronic properties opens new possibilities for constructing multifunctional biodegradable platforms for biomedical applications, particularly in cancer theranotics.
PMCID: PMC4058316  PMID: 24318645
Theranostics; Biodegradable block co-polymer; Gold Nanovesicles; Plasmonic Coupling Effect; Photoacoustic Imaging; Photothermal Therapy
4.  HIV Prevalence and Associated Factors among Foreign Brides from Burma in Yunnan Province, China 
PLoS ONE  2014;9(12):e115599.
Many Burmese women have migrated to Yunnan Province and married local residents over the past few decades; however, limited information is available on their HIV prevalence and ability to cope with HIV. This study aims to assess the prevalence of HIV and knowledge related to AIDS, as well as to discover possible risk factors of HIV infection among foreign brides from Burma in Yunnan Province.
A cross-sectional study was taken of all Burmese cross-border wives residing in Tengchong County using standardized questionnaires. HIV and syphilis testing was conducted at the same time.
Among 600 Burmese brides, the HIV prevalence was 2.17%. Those aged 21–30, those with higher education levels and those who had resided in China less than one year had higher infection rates. The AIDS awareness rate of 39.50% was very low in this population. Only 28.67% of participants had ever been involved in prevention services. The rate of condom use was low. Classification by age, education, occupation, prior HIV testing and prior use of HIV prevention services showed a statistically significant association with mean knowledge score (p<0.05). Residing in China less than one year (OR = 3.86, 95% CI = 1.09–13.70) and having casual sex in the last year (OR = 10.49, 95% CI = 1.20–91.59) were risk factors for HIV infection.
Burmese brides in China are not only exposed to a high risk of HIV infection, but also seriously lack response capabilities. Educational interventions and control efforts are practical approaches that need to be strengthened among this population.
PMCID: PMC4275213  PMID: 25536087
5.  Genetic variants in antigen presentation-related genes influence susceptibility to hepatitis C virus and viral clearance: a case control study 
BMC Infectious Diseases  2014;14(1):3837.
Genes related to antigen presentation pathway, which are in the non-classical class-II region of human leukocyte antigen (HLA), play a vital role during the infection of hepatitis C virus (HCV).
The current study determined the genotypes of 34 tagging-SNPs (single nucleotide polymorphisms) from 9 candidate genes (HLA-DMA, HLA-DMB, HLA-DOA, HLA-DOB, TAP1, TAP2, LMP2, LMP7, and tapasin) in a Chinese population of paid blood donors with high risk of HCV infection. The distributions of those SNPs were compared among the 1207 former paid blood donors with different HCV infection outcomes.
HLA-DMA rs1063478 and HLA-DOA rs2284191 were independent factors of acquiring HCV infection. Carrying three favorable alleles of rs1063478-T and rs2284191-G offered the highest protective effect (odds ratio = 0.46, 95% confidence intervals = 0.27-0.78). HLA-DOB rs7383287 and LMP2 rs17587 were independent factors of infection chronicity. Subjects carrying two favorable alleles of rs7383287-G and rs17587-A had a decreased risk of HCV chronicity (odds ratio = 0.42, 95% confidence intervals = 0.26-0.66). The interaction analysis showed that experience of plasma donation interacted with the combined effects of rs1063478 and rs2284191 for HCV susceptibility, and the experience of whole blood donation interacted with the association of rs7383287 with HCV clearance.
Our results suggested that genetic variants in antigen presentation pathway had influence on susceptibility to HCV infection and viral clearance. HLA-DMA rs1063478, HLA-DOA rs2284191, and HLA-DOB rs7383287 were identified as novel loci in Chinese population that were involved in HCV infection.
Electronic supplementary material
The online version of this article (doi:10.1186/s12879-014-0716-8) contains supplementary material, which is available to authorized users.
PMCID: PMC4279674  PMID: 25528575
Hepatitis C; Genetic polymorphism; Human leukocyte antigen; Infection outcomes; Chinese population
6.  l-Isocorypalmine reduces behavioral sensitization and rewarding effects of cocaine in mice by acting on dopamine receptors* 
Drug and alcohol dependence  2013;133(2):693-703.
We previously reported isolation of l-isocorypalmine (l-ICP), a mono-demethylated analog of l-tetrahydropalmatine (l-THP), from the plant Corydalis yanhusuo. Here we characterized its in vitro pharmacological properties and examined its effects on cocaine-induced behaviors in mice.
Receptor binding, cAMP and [35S]GTPγS assays were used to examine pharmacological actions of l-ICP in vitro. Effects of I-ICP on cocaine-induced locomotor hyperactivity and sensitization and conditioned place preference (CPP) in mice were investigated. HPLC was employed to analyze metabolites of I-ICP in mouse serum.
Among more than 40 targets screened, l-ICP and l-THP bound only to dopamine (DA) receptors. l-ICP was a high-affinity partial agonist of D1 and D5 receptors and a moderate-affinity antagonist of D2, D3 and D4 receptors, whereas l-THP bound to only D1 and D5 receptors, with lower affinities than l-ICP. At 10 mg/kg (i.p.), l-ICP inhibited spontaneous locomotor activity for a shorter time than l-THP. Pretreatment with l-ICP reduced cocaine-induced locomotor hyperactivities. Administration of l-ICP before cocaine once a day for 5 days reduced cocaine-induced locomotor sensitization on days 5 and 13 after 7 days of withdrawal. Pretreatment with l-ICP before cocaine daily for 6 days blocked cocaine-induced CPP, while l-ICP itself did not cause preference or aversion. HPLC analysis showed that l-ICP was the main compound in mouse serum following i.p. injection of l-ICP.
l-ICP likely acts as a D1 partial agonist and a D2 antagonist to produce its in vivo effects and may be a promising agent for treatment of cocaine addiction.
PMCID: PMC3954112  PMID: 24080315
tetrahydropalmatine; isocorypalmine; cocaine; conditioned place preference; sensitization; dopamine receptor
7.  Nucleus pulposus cells derived IGF-1 and MCP-1 enhance osteoclastogenesis and vertebrae disruption in lumbar disc herniation 
Study design: Chronic strained lumbar disc herniation (LDH) cases were classified into bulging LDH, herniated LDH and prolapse LDH types according to imaging examination, and vertebrae disruptions were evaluated. Cytokines derived from the nucleus pulposus cells were detected, and their effects on osteoclastogenesis, as well as the mechanisms involved, were studied via an in vitro osteoclast differentiation system. Objective: To clarify the mechanisms of lumbar vertebrae resorption induced by lumbar herniation. Summary and background data: Chronic strained lumbar disc herniation induced vertebrae erosion exacerbates quality of patients’ life and clinical outcome. Although nucleus pulposus cells derived cytokines were reported to play an important role in this pathogenesis, the fundamental mechanisms underlying this process are still unclear. Methods: Chronic strained lumbar disc herniation patients were diagnosed with CT scan and T2-weighted magnetic resonance imaging. RNA was extracted from 192 surgical specimens of the herniated lumbar disc and 29 surgical excisions of the lumbar disc from spinal injury patients. The expressions of osteoclastogenesis related cytokines and chemokines were examined using real time PCR. Monocytes were induced into osteoclast with M-CSF and RANKL in vitro, while the IGF-1 and MCP-1 were added into the differentiation procedure in order to evaluate the effects and explore the molecular mechanisms. Results: Vertebrae erosion had a positive relationship with lumbar disc herniation severity types. In all of the osteoclastogenesis related cytokines, the IGF-1 and MCP-1 were the most highly expressed in the nucleus pulposus cells. IGF-1 enhances activation of NF-kB signaling directly, but MCP-1 upregulated the expression of RANK, so that enhanced cellular sensitivity to RANKL resulted in increasing osteoclastogenesis and activity. Conclusion: Lumbar herniation induced overexpression of IGF-1 and MCP-1 in nucleus pulposus cells aggravated vertebral erosions. Hence, this study suggests that targeting osteoclastogenesis related cytokines has potential clinical significance in the treatment of lumbar disc herniation patients.
PMCID: PMC4313999
Lumbar disc herniation; vertebra disruption; IGF-1; MCP-1; osteoclast
8.  Impact of lattice distortion and electron doping on α-MoO3 electronic structure 
Scientific Reports  2014;4:7131.
Band structure of transition metal oxides plays a critical role in many applications such as photo-catalysis, photovoltaics, and electroluminescent devices. In this work we report findings that the band structure of MoO3 can be significantly altered by a distortion in the octahedral coordination structure. We discovered that, in addition to epitaxial type of structural strain, chemical force such as hydrogen inclusion can also cause extended lattice distortion. The lattice distortion in hydrogenated MoO3 led to a significant reduction of the energy gap, overshadowing the Moss-Burstein effect of band filling. Charge doping simulations revealed that filling of conduction band drives the lattice distortion. This suggests that any charge transfer or n-type electron doping could lead to lattice distortion and consequentially a reduction in energy gap.
PMCID: PMC4238012  PMID: 25410814
9.  Acute stress responses in Chinese soldiers performing various military tasks 
To examine Chinese soldiers’ acute stress responses, we did this study.
The soldiers completed the Acute Stress Response Scale (ASRS) when engaged in major tasks, such as earthquake rescue in Wenchuan, Sichuan, and maintaining social stability in Urumchi, Xinjiang. The ASRS has good reliability and validity. The study enrolled 1,832 male soldiers.
The results showed significant differences among five dimensions and the overall response index when comparing four diverse military tasks. Further analysis found that reduced work efficiency and 24 symptom clusters were significantly positively correlated.
The acute stress response of soldiers performing various tasks was influenced by many factors, including the task characteristics and external factors. In addition, the acute stress response affected their work efficiency.
PMCID: PMC4247674  PMID: 25435903
Chinese soldiers; Major tasks; Acute stress
10.  Efficacy of intravesical Bacillus Calmette-Guérin therapy against tumor immune escape in an orthotopic model of bladder cancer 
The aim of this study was to evaluate the antitumor immune response of the Bacillus Calmette-Guérin (BCG) in an orthotopic bladder cancer model. The murine bladder cancer cell line MBT-2 was transurethrally implanted in the bladder of syngeneic female C3H/He mice. The animals were randomly divided into three treatment groups: Phosphate-buffered saline (PBS), low-dose BCG and high-dose BCG. The analyses of luciferin-stained tumor images 28 days after each treatment showed significant tumor growth inhibition in the high-dose group in comparison with that in the low-dose- or PBS-treated groups. In addition, the percentage of myeloid-derived suppressor cells in the high-dose group was significantly suppressed in comparison with that in the PBS and low-dose agent treatment groups. These findings are notable in terms of the clinical evaluations of this therapy for patients with bladder cancer. The outcomes of this study also provide important implications regarding antitumor immune responses in human cancer.
PMCID: PMC4247304  PMID: 25452795
Bacillus Calmette-Guérin; bladder cancer; immune-escape; myeloid-derived suppressor cells
11.  A G protein-coupled receptor (GPCR) in red: live cell imaging of the kappa opioid receptor-tdTomato fusion protein (KOPR-tdT) in neuronal cells 
In contrast to green fluorescent protein and variants (GFPs), red fluorescent proteins (RFPs) have rarely been employed for generation of GPCR fusion proteins, likely because of formation of aggregates and cell toxicity of some RFPs. Among all the RFPs available, tdTomato (tdT), one of the non-aggregating RFP, has the highest brightness score (about 3 times that of eGFP) and unsurpassed photostability.
We fused tdT to the KOPR C-terminus. The KOPR-tdT cDNA construct was transfected into Neuro2A mouse neuroblastoma cell line (Neuro2A cells) and rat cortical primary neurons for characterization of pharmacological properties and imaging studies on KOPR trafficking.
KOPR-tdT retained KOPR properties (cell surface expression, ligand binding, agonist-induced signaling and internalization) when expressed in Neuro2A cells and rat primary cortical neurons. Live cell imaging of KOPR-tdT enables visualization of time course of agonist-induced internalization of KOPR in real time for 60 min, without photobleaching and apparent cell toxicity. U50,488H-induced KOPR internalization occurred as early as 4 min and plateaued at about 30 min. A unique pattern of internalized KOPR in processes of primary neurons was induced by U50,488H.
tdT is an alternative to, or even a better tool than, GFPs for fusing to GPCR for trafficking studies, because tdT has higher brightness and thus better resolution and less photobleaching problems due to reduced laser power used. It also has advantages associated with its longer-wavelength emission including spectral separation from autofluorescence and GFPs, reduced cell toxicity the laser may impose, and greater tissue penetration. These advantages of tdT over GPFs may be critical for live cell imaging studies of GPCRs in vitro and for studying GPCRs in vivo because of their low abundance.
PMCID: PMC3954113  PMID: 23856011
GPCR; tdTomato; red fluorescent protein; live cell imaging; neurons; GFP
12.  A Sequence Variant in the Phospholipase C Epsilon C2 Domain Is Associated With Esophageal Carcinoma and Esophagitis 
Molecular carcinogenesis  2013;52(0 1):E80-E86.
A single-nucleotide polymorphism (rs2274223: A5780G:His1927Arg) in the phospholipase C epsilon gene (PLCε) was recently identified as a susceptibility locus for esophageal cancer in Chinese subjects. To determine the underlying mechanisms of PLCε and this SNP in esophageal carcinogenesis, we analyzed PLCε genotypes, expression, and their correlation in esophageal cancer cell lines, non-transformed esophageal cells, 58 esophageal squamous cell carcinomas and 10,614 non-cancer subjects from China. We found that the G allele (AG or GG) was associated with increased PLCε mRNA and protein expression in esophageal cancer tissues and in esophageal cancer cell lines. G allele was also associated with higher enzyme activity, which might be associated with increased protein expression. Quantitative analysis of the C2 domain sequences revealed that A:G allelic imbalance was strongly linked to esophageal malignancy. Moreover, the analysis of 10,614 non-cancer subjects demonstrated that the G allele was strongly associated with moderate to severe esophagitis in the subjects from the high-incidence areas of China (OR 6.03, 95% CI 1.59–22.9 in high-incidence area vs. OR 0.74, 95% CI 0.33–1.64 in low-incidence area; P = 0.008). In conclusion, the PLCε gene, particularly the 5780G allele, might play a pivotal role in esophageal carcinogenesis via upregulating PLCε mRNA, protein, and enzyme activity, and augmenting inflammatory process in esophageal epithelium. Thus, 5780G allele may constitute a promising biomarker for esophageal squamous cell carcinoma risk stratification, early detection, and progression prediction.
PMCID: PMC3931523  PMID: 23390063
phospholipase C epsilon; esophageal cancer; esophagitis
13.  Host genetic variations are associated with virological response to interferon therapy of chronic HCV in Han Chinese patients 
Journal of Biomedical Research  2014;28(6):476-483.
Previous studies have suggested that host genetic polymorphisms may affect virological response to pegylated-interferon and ribavirin (PEG-IFN/ ribavirin) therapy in chronic HCV infection. IL28B and MxA are the most intensively studied genes in Chinese Han population. The current research is to summarize published data and evaluate the overall association of meaningful SNPs in these two genes with virological response to interferon-based therapy. Literature search was performed in online database and a systematic review was conducted based on the search results. Meaningful single nucleotide polymorphisms (SNPs) were summarized and analyzed for odds ratio (OR) and 95% confidence intervals (95% CI). Data manipulation and statistical analyses were performed by using STATA 12.0 and Review Manager version 5.1. Eighteen papers were included for final data analysis. Three SNPs of IL28B and two SNPs of MxA were found to be associated with higher sustained virological response (SVR) to interferon therapy. The ORs and 95% CIs of each variant were: IL28B rs8099917 TT (OR: 4.35, 95% CI: 3.10∼6.12), IL28B rs12979860 CC (OR: 5.37, 95% CI: 3.95∼7.31), IL28B rs7248668 CC (OR: 3.50, 95% CI: 2.30∼5.35), MxA rs2071430 GT (OR: 2.03, 95% CI: 1.31∼3.13), and MxA rs17000900 AC/AA (OR: 1.82, 95% CI: 1.17∼2.83). The genotypes of IL28B rs8099917, rs12979860, rs7248668, MxA rs2071430, and MxA rs17000900 were strong SVR predictors for PEG-IFN/ ribavirin -treated HCV patients in Han Chinese population. Our findings suggest that host genetic variations are associated with virological response to interferon therapy of chronic HCV in Han Chinese patients.
PMCID: PMC4250526  PMID: 25469117
hepatitis C virus; therapy; virological response; IL28B; MxA; meta-analysis
14.  A cytoplasmic RNA virus generates functional viral small RNAs and regulates viral IRES activity in mammalian cells 
Nucleic Acids Research  2014;42(20):12789-12805.
The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (>105 copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced viral yield and viral protein synthesis. We also present evidence that vsRNA1 targets stem-loop II of the viral 5′ untranslated region and inhibits the activity of the IRES through this sequence-specific targeting. Our study demonstrates the ability of a cytoplasmic RNA virus to generate functional vsRNA in mammalian cells. In addition, we also demonstrate a potential novel mechanism for a positive-stranded RNA virus to regulate viral translation: generating a vsRNA that targets the IRES.
PMCID: PMC4227785  PMID: 25352551
15.  The PCP Protein Vangl2 Regulates Migration of Hindbrain Motor Neurons by Acting in Floor Plate Cells, and Independently of Cilia Function 
Developmental biology  2013;382(2):10.1016/j.ydbio.2013.08.017.
Vangl2, a core component of the Planar Cell Polarity pathway, is necessary for the caudal migration of Facial Branchiomotor (FBM) neurons in the vertebrate hindbrain. Studies in zebrafish suggest that vangl2 functions largely non-cell autonomously to regulate FBM neuron migration out of rhombomere 4 (r4), but the cell-type within which it acts is not known. Here, we demonstrate that vangl2 functions largely in floor plate cells to regulate caudal neuronal migration. Furthermore, FBM neurons fail to migrate caudally in the mouse Gli2 mutant that lacks the floor plate, suggesting an evolutionarily conserved role for this cell type in neuronal migration. Although hindbrain floor plate cilia are disorganized in vangl2 mutant embryos, cilia appear to be dispensable for neuronal migration. Notably, Vangl2 is enriched in the basolateral, but not apical, membranes of floor plate cells. Taken together, our data suggest strongly that Vangl2 regulates FBM neuron migration by acting in floor plate cells, independently of cilia function.
PMCID: PMC3864009  PMID: 23988578
Hindbrain; Facial Branchiomotor Neuron; Floor plate cells; Van gogh-like 2; Neuronal migration; Cilia
16.  Crystal structure of 4-methyl-2-oxo-2H-chromen-7-yl ferrocene­carboxyl­ate 
The title mol­ecule, [Fe(C5H5)(C16H11O4)], consists of a ferrocenyl moiety and a 4-methyl­coumarin group linked through an ester unit to one of the cyclo­penta­dienyl (Cp) rings. The two Cp rings are virually parallel, with an angle between the two least-squares planes of 0.74 (16)°. The distances between the FeII atom and the centroids of the two Cp rings are 1.639 (2) and 1.652 (2) Å. The conformation of the ferrocenyl moiety is slightly away from eclipsed. The dihedral angle between the coumarin ring system and the ferrocenyl ester moiety is 69.17 (19)°. π–π stacking inter­actions involving the benzene rings of neighbouring coumarin moieties, with centroid–centroid distances of 3.739 (2) Å, consolidate the crystal packing.
PMCID: PMC4257315  PMID: 25484779
crystal structure; ferrocene; coumarin; pharmacological activity 4-methyl-2-oxo-2H-chromene-7-yl ferrocene­carboxyl­ate
17.  Bayesian Hierarchical Modeling and Selection of Differentially Expressed Genes for the EST Data 
Biometrics  2011;67(1):142-150.
Expressed sequence tag (EST) sequencing is a one-pass sequencing reading of cloned cDNAs derived from a certain tissue. The frequency of unique tags among different unbiased cDNA libraries is used to infer the relative expression level of each tag. In this paper, we propose a hierarchical multinomial model with a nonlinear Dirichlet prior for the EST data with multiple libraries and multiple types of tissues. A novel hierarchical prior is developed and the properties of the proposed prior are examined. An efficient Markov chain Monte Carlo algorithm is developed for carrying out the posterior computation. We also propose a new selection criterion for detecting which genes are differentially expressed between two tissue types. Our new method with the new gene selection criterion is demonstrated via several simulations to have low false negative and false positive rates. A real EST data set is used to motivate and illustrate the proposed method.
PMCID: PMC4171397  PMID: 20560937
Dirichlet distribution; Gene expression; Mixture distributions; Multinomial distribution; Shrinkage estimators
18.  Dual-factor triggered fluorogenic nanoprobe for ultrahigh contrast and subdiffraction fluorescence imaging 
Biomaterials  2013;34(26):6194-6201.
Ultrahigh contrast fluorescence molecular imaging has long been pursued over the past few decades from basic sciences to clinics. Although new classes of near-infrared (NIR) molecular probes are emerging, the requirement of fluorophores with high quantum yield, high signal to noise (S/N) ratio, and being activatable to microenvironment changes can hardly be fulfilled. In this study, a new NIR dye embedded fluorogenic nanoprobe (fg-nanoprobe) was developed for ultrahigh contrast in vitro and in vivo imaging with negligible background interference. The achieved S/N ratio was found to be attributed to the synergistic effects of the cellular compartmental triggered fluorogenicity and pH tunable fluorescence on/off character. In addition, this constructed fluorogenic nanoprobe could be coupled with image processing method for super-resolution subdiffraction imaging. The developed fg-nanoprobe integrated photophysical merits of the synthesized NIR fluorophore and advantages of engineered nanoparticle for enhanced fluorescence molecular imaging. This probe may open another avenue for ultrahigh contrast fluorescence molecular imaging in the future.
PMCID: PMC4167587  PMID: 23721793
Fluorescence imaging; Subdiffraction imaging; Fluorogenic PLGA nanoparticle; BODIPY NIR dye; pH sensitive; Molecular binding
19.  Mitochondrial dysfunction in some triple-negative breast cancer cell lines: role of mTOR pathway and therapeutic potential 
Triple-negative breast cancer (TNBC) is a subtype of highly malignant breast cancer with poor prognosis. TNBC is not amenable to endocrine therapy and often exhibit resistance to current chemotherapeutic agents, therefore, further understanding of the biological properties of these cancer cells and development of effective therapeutic approaches are urgently needed.
We first investigated the metabolic alterations in TNBC cells in comparison with other subtypes of breast cancer cells using molecular and metabolic analyses. We further demonstrated that targeting these alterations using specific inhibitors and siRNA approach could render TNBC cells more sensitive to cell death compared to other breast cancer subtypes.
We found that TNBC cells compared to estrogen receptor (ER) positive cells possess special metabolic characteristics manifested by high glucose uptake, increased lactate production, and low mitochondrial respiration which is correlated with attenuation of mTOR pathway and decreased expression of p70S6K. Re-expression of p70S6K in TNBC cells reverses their glycolytic phenotype to an active oxidative phosphorylation (OXPHOS) state, while knockdown of p70S6K in ER positive cells leads to suppression of mitochondrial OXPHOS. Furthermore, lower OXPHOS activity in TNBC cells renders them highly dependent on glycolysis and the inhibition of glycolysis is highly effective in targeting TNBC cells despite their resistance to other anticancer agents.
Our study shows that TNBC cells have profound metabolic alterations characterized by decreased mitochondrial respiration and increased glycolysis. Due to their impaired mitochondrial function, TNBC cells are highly sensitive to glycolytic inhibition, suggesting that such metabolic intervention may be an effective therapeutic strategy for this subtype of breast cancer cells.
Electronic supplementary material
The online version of this article (doi:10.1186/s13058-014-0434-6) contains supplementary material, which is available to authorized users.
PMCID: PMC4303115  PMID: 25209360
20.  Radiobiological Optimization of Combination Radiopharmaceutical Therapy Applied to Myeloablative Treatment of Non-Hodgkin’s Lymphoma 
Combination treatment is a hallmark of cancer therapy. Although the rationale for combination radiopharmaceutical therapy was described in the mid ‘90s, such treatment strategies have only been implemented clinically recently, and without a rigorous methodology for treatment optimization. Radiobiological and quantitative imaging-based dosimetry tools are now available that enable rational implementation of combined targeted radiopharmaceutical therapy. Optimal implementation should simultaneously account for radiobiological normal organ tolerance while optimizing the ratio of two different radiopharmaceuticals required to maximize tumor control. We have developed such a methodology and applied it to hypothetical myeloablative treatment of non-hodgkin’s lymphoma (NHL) patients using 131I-tositumomab and 90Y-ibritumomab tiuxetan.
The range of potential administered activities (AA) is limited by the normal organ maximum tolerated biologic effective doses (MTBEDs) arising from the combined radiopharmaceuticals. Dose limiting normal organs are expected to be the lungs for 131I-tositumomab and the liver for 90Y-ibritumomab tiuxetan in myeloablative NHL treatment regimens. By plotting the limiting normal organ constraints as a function of the AAs and calculating tumor biological effective dose (BED) along the normal organ MTBED limits, the optimal combination of activities is obtained. The model was tested using previously acquired patient normal organ and tumor kinetic data and MTBED values taken from the literature.
The average AA values based solely on normal organ constraints was (19.0 ± 8.2) GBq with a range of 3.9 – 36.9 GBq for 131I-tositumomab, and (2.77 ± 1.64) GBq with a range of 0.42 – 7.54 GBq for 90Y-ibritumomab tiuxetan. Tumor BED optimization results were calculated and plotted as a function of AA for 5 different cases, established using patient normal organ kinetics for the two radiopharmaceuticals. Results included AA ranges which would deliver 95 % of the maximum tumor BED, which allows for informed inclusion of clinical considerations, such as a maximum allowable 131I administration.
A rational approach for combination radiopharmaceutical treatment has been developed within the framework of a proven 3-dimensional personalized dosimetry software, 3D-RD, and applied to the myeloablative treatment of NHL. We anticipate combined radioisotope therapy will ultimately supplant single radioisotope therapy, much as combination chemotherapy has substantially replaced single agent chemotherapy.
PMCID: PMC4142210  PMID: 23918734
Radiopharmaceutical therapy; Dosimetry; Treatment planning; BED; Lymphoma
21.  Single Continuous Wave Laser Induced Photodynamic/Plasmonic Photothermal Therapy Using Photosensitizer-Functionalized Gold Nanostars 
PMCID: PMC4138877  PMID: 23404693
Gold nanostar; chlorin e6; continuous wave laser; photodynamic therapy; plasmonic photothermal therapy
22.  Incidence and risk factors for AIDS-related mortality in HIV patients in China: a cross-sectional study 
BMC Public Health  2014;14(1):831.
To estimate the incidence and risk factors for mortality in HIV-1-infected patients in China.
Information on AIDS-related deaths was collected from the Chinese Center for Disease Control and Prevention’s Disease Surveillance Information Reporting System and AIDS Prevention and Control Information System.
A total of 379,348 HIV cases were recorded in the databases from 2006. Among those, 138,288 patients were reported as having developed AIDS and 72,616 (19%) died of AIDS after data was extracted from the databases in January 2011. Mortality was higher among those patients aged 50 years old or older (AOR: 3.41, CI: 1.47-7.91) who had been infected by intravenous drug use (AOR: 1.65, CI: 1.28-2.14) or blood transfusion/donation (AOR: 2.18: 1.18-3.99). Compared to patients who had not initiated highly active antiretroviral therapy (HAART), those who had initiated HAART were more likely to have a long interval of time between infection confirmation and AIDS-related death.
The effective reduction of AIDS mortality could be improved through timely treatment.
PMCID: PMC4137099  PMID: 25113245
HIV/AIDS; Highly active antiretroviral treatment; Mortality; China
23.  Adjuvant Leuprolide With or Without Docetaxel in Patients With High-Risk Prostate Cancer After Radical Prostatectomy (TAX-3501) 
Cancer  2013;119(20):3610-3618.
The current trial evaluated 2 common therapies for patients with advanced prostate cancer, docetaxel and hormonal therapy (HT), in the surgical adjuvant setting.
TAX-3501 was a randomized, phase 3, adjuvant study post-radical prostatectomy (RP) in high-risk patients with prostate cancer (n = 228) comparing 18 months of HT with (CHT) without docetaxel chemotherapy either immediately (I) or deferred (D). High-risk disease was defined as a 5-year freedom-from-disease-progression rate of ≤60% as predicted by a post-RP nomogram. Progression-free survival (PFS), including prostate-specific antigen disease recurrence, was the primary endpoint. The authors also assessed the accuracy of the nomogram and analyzed testosterone recovery in 108 patients treated with HT who had at least 1 posttreatment testosterone value.
Between December 2005 and September 2007, 228 patients were randomized between the treatment cohorts. TAX-3501 was terminated prematurely because of enrollment challenges, leaving it underpowered to detect differences in PFS. After a median follow-up of 3.4 years (interquartile range, 2.3–3.8 years), 39 of 228 patients (17%) demonstrated PSA disease progression, and metastatic disease progression occurred in 1 patient. The median time to baseline testosterone recovery after the completion of treatment was prolonged at 487 days (95% confidence interval, 457–546 days). The nomogram’s predicted versus observed freedom from disease progression was significantly different for the combination D(HT) and D(CHT) group (P < .00001).
TAX-3501 illustrated several difficulties involved in conducting postoperative adjuvant systemic trials in men with high-risk prostate cancer: the lack of consensus regarding patient selection and treatment, the need for long follow-up time, nonvalidated intermediate endpoints, evolving standard approaches, and the need for long-term research support. Except for selected patients at very high-risk of disease recurrence and death, surgical adjuvant trials in patients with prostate cancer may not be feasible.
PMCID: PMC4124610  PMID: 23943299
prostate cancer; adjuvant therapy; docetaxel; leuprolide; testosterone recovery
24.  Cooperativity of Oncogenic K-Ras and Downregulated p16/INK4A in Human Pancreatic Tumorigenesis 
PLoS ONE  2014;9(7):e101452.
Activation of K-ras and inactivation of p16 are the most frequently identified genetic alterations in human pancreatic epithelial adenocarcinoma (PDAC). Mouse models engineered with mutant K-ras and deleted p16 recapitulate key pathological features of PDAC. However, a human cell culture transformation model that recapitulates the human pancreatic molecular carcinogenesis is lacking. In this study, we investigated the role of p16 in hTERT-immortalized human pancreatic epithelial nestin-expressing (HPNE) cells expressing mutant K-ras (K-rasG12V). We found that expression of p16 was induced by oncogenic K-ras in these HPNE cells and that silencing of this induced p16 expression resulted in tumorigenic transformation and development of metastatic PDAC in an orthotopic xenograft mouse model. Our results revealed that PI3K/Akt, ERK1/2 pathways and TGFα signaling were activated by K-ras and involved in the malignant transformation of human pancreatic cells. Also, p38/MAPK pathway was involved in p16 up-regulation. Thus, our findings establish an experimental cell-based model for dissecting signaling pathways in the development of human PDAC. This model provides an important tool for studying the molecular basis of PDAC development and gaining insight into signaling mechanisms and potential new therapeutic targets for altered oncogenic signaling pathways in PDAC.
PMCID: PMC4100754  PMID: 25029561
25.  Cytoplasmic Viral RNA-Dependent RNA Polymerase Disrupts the Intracellular Splicing Machinery by Entering the Nucleus and Interfering with Prp8 
PLoS Pathogens  2014;10(6):e1004199.
The primary role of cytoplasmic viral RNA-dependent RNA polymerase (RdRp) is viral genome replication in the cellular cytoplasm. However, picornaviral RdRp denoted 3D polymerase (3Dpol) also enters the host nucleus, where its function remains unclear. In this study, we describe a novel mechanism of viral attack in which 3Dpol enters the nucleus through the nuclear localization signal (NLS) and targets the pre-mRNA processing factor 8 (Prp8) to block pre-mRNA splicing and mRNA synthesis. The fingers domain of 3Dpol associates with the C-terminal region of Prp8, which contains the Jab1/MPN domain, and interferes in the second catalytic step, resulting in the accumulation of the lariat form of the splicing intermediate. Endogenous pre-mRNAs trapped by the Prp8-3Dpol complex in enterovirus-infected cells were identified and classed into groups associated with cell growth, proliferation, and differentiation. Our results suggest that picornaviral RdRp disrupts pre-mRNA splicing processes, that differs from viral protease shutting off cellular transcription and translation which contributes to the pathogenesis of viral infection.
Author Summary
RNA-dependent RNA polymerase (RdRp) is an enzyme that catalyzes the replication from an RNA template and is encoded in the genomes of all RNA viruses. RNA viruses in general replicate in cytoplasm and interfere host cellular gene expression by utilizing proteolytic destruction of cellular targets as the primary mechanism. However, several cytoplasmic RNA viral proteins have been found in the nucleus. What do they do in the nucleus? This study utilized picornaviral polymerase to probe the function of RdRp in the nucleus. Our findings reveal a novel mechanism of viruses attacking hosts whereby picornaviral 3D polymerase (3Dpol) enters the nucleus and targets the central pre-mRNA processing factor 8 (Prp8) to block pre-mRNA splicing and mRNA synthesis. The 3Dpol inhibits the second catalytic step of the splicing process, resulting in the accumulation of the lariat-form and the reduction of the mRNA. These results provide new insights into the strategy of a cytoplasmic RNA virus attacking host cell, that differs from viral shutting off cellular transcription and translation which contributes to the viral pathogenesis. To our knowledge, this study shows for the first time that a cytoplasmic RNA virus uses its polymerase to alter cellular gene expression by hijacking the splicing machinery.
PMCID: PMC4072778  PMID: 24968230

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