Search tips
Search criteria

Results 1-25 (241)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  The triterpenoid pristimerin induces U87 glioma cell apoptosis through reactive oxygen species-mediated mitochondrial dysfunction 
Oncology Letters  2012;5(1):242-248.
It has become evident that some of the natural or synthetic triterpenoids are natural proteasome inhibitors that have great potential for use in cancer prevention and treatment. However, the mechanisms for the antitumor activity of triterpenoids remain to be elucidated. In the present study, we investigated the anticancer activities of a natural triterpenoid, pristimerin, and the signaling pathways affected. Pristimerin was found to possess potent cytotoxic effects, inducing apoptosis and inhibiting proliferation in U87 human glioma cells. Hoechst 33258 staining and Annexin V/PI double staining exhibited the typical nuclear features of apoptosis and increased the proportion of apoptotic Annexin V-positive cells in a dose-dependent manner, respectively. Moreover, western blotting assay revealed that this apoptotic induction was associated with activated caspase-9, caspase-3, PARP cleavage and downregulation of Bcl-xl/Bax in a concentration-dependent manner. Pristimerin also increased the generation of reactive oxygen species and induced the subsequent release of cytochrome c from the mitochondria into the cytosol. Additionally, pristimerin downregulated EGFR protein expression and inhibited downstream signaling pathways in U87 cells. Our results suggest that pristimerin may have potential as a new targeting therapeutic strategy in the treatment of EGFR-overexpressing gliomas.
PMCID: PMC3525416  PMID: 23255929
pristimerin; glioma; apoptosis; reactive oxygen species; U87 cells
2.  Bullatacin Triggered ABCB1-Overexpressing Cell Apoptosis via the Mitochondrial-Dependent Pathway 
This paper was to explore bullatacin-mediated multidrug-resistant cell apoptosis at extremely low concentration. To investigate its precise mechanisms, the pathway of cell apoptosis induced by bullatacin was examined. Bullatacin causes an upregulation of ROS and a downregulation of ΔΨm in a concentration-dependent manner in ABCB1-overexpressing KBv200 cells. In addition, cleavers of caspase-9, caspase-3, and PARP were observed following the release of cytochrome c from mitochondria after bullatacin treatment. However, neither cleavage of caspase-8 nor change of expression level of bcl-2, bax and Fas was observed by the same treatment. Pretreating KBv200 cells with N-acetylcysteine, an antioxidant modulator, resulted in a significant reduction of ROS generation and cell apoptosis induced by bullatacin. Bullatacin-induced apoptosis was antagonized by z-LEHD-fmk, a caspase-9 inhibitor, but not by z-IETD-fmk, a caspase-8 inhibitor. These implied that apoptosis of KBv200 cells induced by bullatacin was associated with the mitochondria-dependent pathway that was limited to activation of apical caspase-9.
PMCID: PMC2715821  PMID: 19639048
3.  Vandetanib (Zactima, ZD6474) Antagonizes ABCC1- and ABCG2-Mediated Multidrug Resistance by Inhibition of Their Transport Function 
PLoS ONE  2009;4(4):e5172.
ABCC1 and ABCG2 are ubiquitous ATP-binding cassette transmembrane proteins that play an important role in multidrug resistance (MDR). In this study, we evaluated the possible interaction of vandetanib, an orally administered drug inhibiting multiple receptor tyrosine kinases, with ABCC1 and ABCG2 in vitro.
Methodology and Principal Findings
MDR cancer cells overexpressing ABCC1 or ABCG2 and their sensitive parental cell lines were used. MTT assay showed that vandetanib had moderate and almost equal-potent anti-proliferative activity in both sensitive parental and MDR cancer cells. Concomitant treatment of MDR cells with vandetanib and specific inhibitors of ABCC1 or ABCG2 did not alter their sensitivity to the former drug. On the other hand, clinically attainable but non-toxic doses of vandetanib were found to significantly enhance the sensitivity of MDR cancer cells to ABCC1 or ABCG2 substrate antitumor drugs. Flow cytometric analysis showed that vandetanib treatment significantly increase the intracellular accumulation of doxorubicin and rhodamine 123, substrates of ABCC1 and ABCG2 respectively, in a dose-dependent manner (P<0.05). However, no significant effect was shown in sensitive parental cell lines. Reverse transcription-PCR and Western blot analysis showed that vandetanib did not change the expression of ABCC1 and ABCG2 at both mRNA and protein levels. Furthermore, total and phosphorylated forms of AKT and ERK1/2 remained unchanged after vandetanib treatment in both sensitive and MDR cancer cells.
Vandetanib is unlikely to be a substrate of ABCC1 or ABCG2. It overcomes ABCC1- and ABCG2-mediated drug resistance by inhibiting the transporter activity, independent of the blockade of AKT and ERK1/2 signal transduction pathways.
PMCID: PMC2669214  PMID: 19390592
4.  Reduced growth and proliferation dynamics of nasal epithelial stem/progenitor cells in nasal polyps in vitro 
Scientific Reports  2014;4:4619.
Basal cells in nasal epithelium have stemness/progenitor characters and play essential roles in the epithelial remodeling in nasal polyps (NP). We investigate whether the human nasal epithelial stem/progenitor cells (hNESPCs) from patients with NP are inherently distinct from those obtained from healthy controls. Epithelial basal cells were isolated and cultured for four passages from NP tissues and control nasal mucosa. hNESPCs from controls were stained positively with stem cell marker p63 and KRT5 and presented a consistent high Ki67 expression level over four passages. In contrast, hNESPCs from NP patients showed: i). a reduced growth and proliferation rate at each passage by evaluating colony-forming efficiency and doubling time; ii). a lower percentage of Ki67+ cells among p63+ cells in the colonies in late passages, which was also confirmed by immunostaining in the NP tissues. Thus reduced growth/proliferation dynamics in hNESPCs from NP could be an important pathological phenomenon in NP development.
PMCID: PMC3980221  PMID: 24714674
5.  Molecular Typing of CTX-M-Producing Escherichia coli Isolates from Environmental Water, Swine Feces, Specimens from Healthy Humans, and Human Patients 
Applied and Environmental Microbiology  2013;79(19):5988-5996.
CTX-M-producing Escherichia coli is the predominant type of extended-spectrum β-lactamase (ESBL)-producing E. coli worldwide. In this study, molecular typing was conducted for 139 CTX-M-producing E. coli isolates, phenotypically positive for ESBLs, isolated from environmental water, swine, healthy humans, and hospitalized patients in Hangzhou, China. The antibiotic resistance profiles of the isolates for the cephalosporins and fluoroquinolones were determined. The isolates showed 100% resistance to cefotaxime and ceftriaxone while maintaining relatively high susceptibility to cefoxitin, cefepime, and ceftazidime. A total of 61.9% (86/139) of the isolates, regardless of origin, showed high resistance to fluoroquinolones. PCRs and DNA sequencing indicated that blaCTX-M-14 was the most prevalent CTX-M-9 group gene and that blaCTX-M-15 and blaCTX-M-55 were the dominant CTX-M-1 group genes. Isolates from all sources with CTX-M types belonging to the CTX-M-1 or CTX-M-9 group were most frequently associated with epidemics. Molecular homology analysis of the isolates, conducted by phylogenetic grouping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST), demonstrated that the dominant clones belonged to B2-ST131, D-ST648, D-ST38, or A-CC10. These four sequence types (STs) were discovered in E. coli isolates both from humans and from environmental water, suggesting frequent and continuous intercompartment transmission between humans and the aquatic environment. Seven novel sequence types were identified in the current study. In conclusion, this study is the first to report the molecular homology analysis of CTX-M-producing E. coli isolates collected from water, swine, and healthy and hospitalized humans, suggesting that pathogens in the environment might originate both from humans and from animals.
PMCID: PMC3811354  PMID: 23892737
6.  Effect of Naphthalene Acetic Acid on Adventitious Root Development and Associated Physiological Changes in Stem Cutting of Hemarthria compressa 
PLoS ONE  2014;9(3):e90700.
In order to find a way to induce rooting on cuttings of Hemarthria compressa cv. Ya’an under controlled conditions, a project was carried out to study the effect of naphthalene acetic acid (NAA) on rooting in stem cuttings and related physiological changes during the rooting process of Hemarthria compressa. The cuttings were treated with five concentrations of NAA (0, 100, 200 300, 400 mg/l) at three soaking durations (10, 20, 30 minutes), and cuttings without treatment were considered as control. Samples were planted immediately into pots after treatment. IAA-oxidase (IAAO) activity, peroxidase (POD) activity and polyphenol oxidase (PPO) activity were determined after planting. Results showed that NAA had positive effect on rooting at the concentration of 200 mg/l compared to other concentrations at 30 days after planting (DAP). Among the three soaking durations, 20 minutes (min) of 200 mg/l NAA resulted in higher percentages of rooting, larger numbers of adventitious roots and heavier root dry weight per cutting. The lowest IAAO activity was obtained when soaked at 200 mg/l NAA for 20 min soaking duration. This was consistent with the best rooting ability, indicating that the lower IAAO activity, the higher POD activity and PPO activity could be used as an indicator of better rooting ability for whip grass cuttings and might serve as a good marker for rooting ability in cuttings.
PMCID: PMC3942460  PMID: 24595064
7.  Synergistic Effect of Zuo Jin Wan on DDP-Induced Apoptosis in Human Gastric Cancer SGC-7901/DDP Cells 
A traditional Chinese medicine (TCM) formula, Zuo Jin Wan (ZJW), has been found as an anticancer drug in human cancer. In this study, we investigated the synergistic effect of ZJW extracts on DDP-induced apoptosis in human gastric cancer SGC-7901/DDP cells. Our results demonstrated that ZJW extracts could increase the sensitivity of SGC-7901/DDP cells to DDP by increasing the concentration of DDP in cytoplasm and enhance the proapoptosis of DDP by upregulating the JNK and Bax expression, downregulating the Bcl-2 expression, increasing the accumulation of Cytochrome C in cytoplasm, and promoting the activities of caspase-3 and caspase-9. In vivo, ZJW extracts enhanced the inhibiting effect of DDP on tumor growth in SGC-7901/DDP xenograft model and upregulated the expression of p-JNK and Bax but downregulated the Bcl-2 expression in xenograft tumors. In conclusion, in vitro and in vivo, ZJW extracts could enhance the proapoptotic effect of DDP by promoting the activation of JNK and the expression of Bcl-2, inhibiting the Bax expression, followed by increasing the release of Cytochrome C from mitochondria to cytoplasm, and finally activating the caspase cade reaction. Our results implied that ZJW might serve as a synergistic drug with chemotherapeutic drugs DDP in the treatment of gastric cancer.
PMCID: PMC3958763  PMID: 24723962
8.  New Integrated Strategy Emphasizing Infection Source Control to Curb Schistosomiasis japonica in a Marshland Area of Hubei Province, China: Findings from an Eight-Year Longitudinal Survey 
PLoS ONE  2014;9(2):e89779.
Schistosomiasis remains a major public health problem in China. The major endemic foci are the lake and marshland regions of southern China, particularly the regions along the middle and lower reach of the Yangtze River in four provinces (Hubei, Hunan, Jiangxi, and Anhui). The purpose of our study is to assess the effect of a new integrated strategy emphasizing infection source control to curb schistosomiasis in marshland regions.
In a longitudinal study, we implemented an integrated control strategy emphasizing infection source control in 16 villages from 2005 through 2012 in marshland regions of Hubei province. The interventions included removing cattle from snail-infested grasslands, providing farmers with mechanized farm equipment, improving sanitation by supplying tap water, building lavatories and latrines, praziquantel chemotherapy, controlling snails, and environmental modification.
Following the integrated control strategy designed to reduce the role of bovines and humans as sources of Schistosoma japonicum infection, the prevalence of human S. japonicum infection declined from 1.7% in 2005 to 0.4% in 2012 (P<0.001). Reductions were also observed in both sexes, across all age groups, and among high risk occupations. Moreover, the prevalence of bovine S. japonicum infection decreased from 11.7% in 2005 to 0.6% in 2012 (P<0.001). In addition, all the 16 villages achieved the national criteria of infection control in 2008.
Our findings indicate that the integrated strategy was likely effective in controlling the transmission of S. japonicum in marshland regions in China.
PMCID: PMC3938508  PMID: 24587030
9.  Luteoloside Suppresses Proliferation and Metastasis of Hepatocellular Carcinoma Cells by Inhibition of NLRP3 Inflammasome 
PLoS ONE  2014;9(2):e89961.
The inflammasome is a multi-protein complex which when activated regulates caspase-1 activation and IL-1β secretion. Inflammasome activation is mediated by NLR proteins that respond to stimuli. Among NLRs, NLRP3 senses the widest array of stimuli. NLRP3 inflammasome plays an important role in the development of many cancer types. However, Whether NLRP3 inflammasome plays an important role in the process of hepatocellular carcinoma (HCC) is still unknown. Here, the anticancer effect of luteoloside, a naturally occurring flavonoid isolated from the medicinal plant Gentiana macrophylla, against HCC cells and the underlying mechanisms were investigated. Luteoloside significantly inhibited the proliferation of HCC cells in vitro and in vivo. Live-cell imaging and transwell assays showed that the migration and invasive capacities of HCC cells, which were treated with luteoloside, were significantly inhibited compared with the control cells. The inhibitory effect of luteoloside on metastasis was also observed in vivo in male BALB/c-nu/nu mouse lung metastasis model. Further studies showed that luteoloside could significantly reduce the intracellular reactive oxygen species (ROS) accumulation. The decreased levels of ROS induced by luteoloside was accompanied by decrease in expression of NLRP3 inflammasome resulting in decrease in proteolytic cleavage of caspase-1. Inactivation of caspase-1 by luteoloside resulted in inhibition of IL-1β. Thus, luteoloside exerts its inhibitory effect on proliferation, invasion and metastasis of HCC cells through inhibition of NLRP3 inflammasome. Our results indicate that luteoloside can be a potential therapeutic agent not only as an adjuvant therapy for HCC, but also, in the control and prevention of metastatic HCC.
PMCID: PMC3935965  PMID: 24587153
10.  High-Resolution Melting Analysis for accurate detection of BRAF mutations: a systematic review and meta-analysis 
Scientific Reports  2014;4:4168.
The high-resolution melting curve analysis (HRMA) might be a good alternative method for rapid detection of BRAF mutations. However, the accuracy of HRMA in detection of BRAF mutations has not been systematically evaluated. We performed a systematic review and meta-analysis involving 1324 samples from 14 separate studies. The overall sensitivity of HRMA was 0.99 (95% confidence interval (CI) = 0.75–0.82), and the overall specificity was very high at 0.99 (95% CI = 0.94–0.98). The values for the pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 68.01 (95% CI = 25.33–182.64), 0.06 (95% CI = 0.03–0.11), and1263.76 (95% CI = 393.91–4064.39), respectively. The summary receiver operating characteristic curve for the same data shows an area of 1.00 and a Q* value of 0.97. The high sensitivity and specificity, simplicity, low cost, less labor or time and rapid turnaround make HRMA a good alternative method for rapid detection of BRAF mutations in the clinical practice.
PMCID: PMC3933866  PMID: 24566771
11.  Mink S38G Gene Polymorphism and Atrial Fibrillation in the Chinese Population: A Meta-Analysis of 1871 Participants 
The Scientific World Journal  2014;2014:768681.
Mink gene S38G polymorphism in the β-subunit of slow activating component of the delayed rectifier potassium channel current potassium channel has been associated with increased atrial fibrillation (AF) risk. However, the individual studies results were still controversial. To investigate the association of Mink S38G gene polymorphisms with AF, a meta-analysis including 1871 subjects from six individual studies was conducted. Mink S38G gene polymorphism was significantly related to AF under allelic (OR: 1.380, 95% CI: 1.200–1.600, P < 0.00001), recessive (OR: 1.193, 95% CI: 1.033–1.377, P = 0.017), dominant (OR: 1.057, 95% CI: 1.025–1.089, P < 0.00001), additive (OR: 1.105, 95% CI: 1.036–1.178, P = 0.002), homozygous (OR: 1.128, 95% CI: 1.068–1.191, P < 0.00001), and heterozygous genetic models (OR: 1.078, 95% CI: 1.014–1.146, P = 0.016). A significant association between Mink S38G gene polymorphism and AF risk was found. G allele carriers may predispose to AF.
PMCID: PMC3947816
12.  Molecular Evidence of RNA Editing in Bombyx Chemosensory Protein Family 
PLoS ONE  2014;9(2):e86932.
Chemosensory proteins (CSPs) are small scavenger proteins that are mainly known as transporters of pheromone/odor molecules at the periphery of sensory neurons in the insect antennae and in the producing cells from the moth female pheromone gland.
Sequencing cDNAs of RNA encoding CSPs in the antennae, legs, head, pheromone gland and wings from five single individual adult females of the silkworm moth Bombyx mori showed that they differed from genomic sequences by subtle nucleotide replacement (RDD). Both intronless and intronic CSP genes expressed RDDs, although in different rates. Most interestingly, in our study the degree of RDDs in CSP genes were found to be tissue-specific. The proportion of CSP-RDDs was found to be significantly much higher in the pheromone gland. In addition, Western blot analysis of proteins in different tissues showed existence of multiple CSP protein variant chains particularly found in the pheromone gland. Peptide sequencing demonstrated the occurrence of a pleiad of protein variants for most of all BmorCSPs from the pheromone gland. Our findings show that RNA editing is an important feature in the expression of CSPs and that a high variety of RDDs is found to expand drastically thus altering the repertoire of CSP proteins in a tissue-specific manner.
PMCID: PMC3923736  PMID: 24551045
13.  Production of shikimic acid from Escherichia coli through chemically inducible chromosomal evolution and cofactor metabolic engineering 
Shikimic acid (SA) produced from the seeds of Chinese star anise (Illicium verum) is a key intermediate for the synthesis of neuraminidase inhibitors such as oseltamivir (Tamiflu®), an anti-influenza drug. However, plants cannot deliver a stable supply of SA. To avoid the resulting shortages and price fluctuations, a stable source of affordable SA is required. Although recent achievements in metabolic engineering of Escherichia coli strains have significantly increased SA productivity, commonly-used plasmid-based expression systems are prone to genetic instability and require constant selective pressure to ensure plasmid maintenance. Cofactors also play an important role in the biosynthesis of different fermentation products. In this study, we first constructed an E. coli SA production strain that carries no plasmid or antibiotic marker. We then investigated the effect of endogenous NADPH availability on SA production.
The pps and csrB genes were first overexpressed by replacing their native promoter and integrating an additional copy of the genes in a double gene knockout (aroK and aroL) of E. coli. The aroG fbr , aroB, aroE and tktA gene cluster was integrated into the above E. coli chromosome by direct transformation. The gene copy number was then evolved to the desired value by triclosan induction. The resulting strain, E. coli SA110, produced 8.9-fold more SA than did the parental strain E. coli (ΔaroKΔaroL). Following qRT-PCR analysis, another copy of the tktA gene under the control of the 5Ptac promoter was inserted into the chromosome of E. coli SA110 to obtain the more productive strain E. coli SA110. Next, the NADPH availability was increased by overexpressing the pntAB or nadK genes, which further enhanced SA production. The final strain, E. coli SA116, produced 3.12 g/L of SA with a yield on glucose substrate of 0.33 mol/mol.
An SA-producing E. coli strain that carries neither a plasmid nor an antibiotic marker was constructed by triclosan-induced chromosomal evolution. We present the first demonstration that increasing NADPH availability by overexpressing the pntAB or nadK genes significantly enhances SA production.
PMCID: PMC3923554  PMID: 24512078
Shikimic acid; Escherichia coli; Chemically induced chromosomal evolution; NADPH; Transhydrogenase; NAD kinase
14.  Epidemiological characteristics of acute disseminated encephalomyelitis in Nanchang, China: a retrospective study 
BMC Public Health  2014;14:111.
Acute disseminated encephalomyelitis (ADEM) is an autoimmune disease that typically follows a monophasic course and may affect any age group. The precise population-based incidence of ADEM is still unknown in most countries. In China, there is no ADEM surveillance system. The exact incidence of ADEM is difficult to estimate, and other epidemiological characteristics of ADEM are unknown. The purpose of this study is to investigate the epidemiological characteristics of ADEM in Nanchang, China.
A retrospective investigation was conducted with ADEM patients admitted to second-level and third-level hospitals in Nanchang from 2008 to 2010, aiming to analyse the epidemiologic characteristics of ADEM in the population in Nanchang. ADEM patients, defined as patients who were diagnosed according to the consensus definition of ADEM provided by the International Pediatric MS Study Group, were enrolled in the study. The data were extracted from the ADEM patients’ medical records.
Forty-seven ADEM patients were investigated. The average annual incidence was 0.31/100,000; the incidence among males (0.31/100,000) was nearly equal to that among females (0.31/100,000). The median age of onset was 25.97 years old, and the peak incidence was observed in the 5- to 9-year-old age group (0.75/100,000), followed by the over-60 age group (0.55/100,000). ADEM occurs throughout the year, but it occurs most frequently in March (n = 7) and least frequently in April and July (both n = 2). The patient numbers are roughly even in the other months. In the 2 months before the onset of ADEM, 15 patients presented with a preceding infection, but none of the patients received a vaccination. An increased number of vaccination was not accompanied by a corresponding increased number of cases of ADEM.
The average annual incidence of ADEM was 0.31/100,000 in Nanchang. The incidence among males was nearly equal to that among females. The peak age of onset was 5–9 years old. The peak season of onset was not apparent. There was no evidence of an association between increased number of vaccines administered and number of cases of ADEM in Nanchang, China.
PMCID: PMC3922734  PMID: 24495742
Acute disseminated encephalomyelitis; Incidence; Epidemiology
15.  Cytotoxicity and enhancement activity of essential oil from Zanthoxylum bungeanum Maxim. as a natural transdermal penetration enhancer*  
The aim of this present study is to investigate the effect of Zanthoxylum bungeanum oil (essential oil from Z. bungeanum Maxim.) on cytotoxicity and the transdermal permeation of 5-fluorouracil and indomethacin. The cytotoxicity of Z. bungeanum oil on dermal fibroblasts and epidermal keratinocytes was studied using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The rat skin was employed to determine the percutaneous penetration enhancement effect of Z. bungeanum oil on hydrophilic and lipophilic model drugs, i.e., 5-fluorouracil and indomethacin. The secondary structure changes of the rat stratum corneum (SC) were determined using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and saturated solubilities and SC/vehicle partition coefficients of two model drugs with and without Z. bungeanum oil were also measured to understand its related mechanisms of action. It was found that the half maximal inhibitory concentration (IC50) values of Z. bungeanum oil were significantly lower in HaCaT and CCC-ESF-1 cell lines compared to the well-established and standard penetration enhancer Azone. The Z. bungeanum oil at various concentrations effectively facilitated the percutaneous penetration of two model drugs across the rat skin. In addition, the mechanisms of permeation enhancement by Z. bungeanum oil could be explained with saturated solubility, SC/vehicle partition coefficient, and secondary structure changes of SC.
PMCID: PMC3924391  PMID: 24510708
Zanthoxylum bungeanum Maxim.; Essential oil; Transdermal delivery; Penetration enhancer; HaCaT; Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR)
16.  An Unconventional Antigen Translated by a Novel Internal Ribosome Entry Site Elicits Antitumor Humoral Immune Reactions1 
Self-tumor Ags that elicit antitumor immune responses in responses to IFN-α stimulation remain poorly defined. We screened a human testis cDNA library with sera from three polycythemia vera patients who responded to IFN-α and identified a novel Ag, MPD6. MPD6 belongs to the group of cryptic Ags without conventional genomic structure and is encoded by a cryptic open reading frame located in the 3′-untranslated region of myotrophin mRNA. MPD6 elicits IgG Ab responses in a subset of polycythemia vera patients, as well as patients with chronic myelogenous leukemia and prostate cancer, suggesting that it is broadly immunogenic. The expression of myotrophin-MPD6 transcripts was upregulated in some tumor cells, but only slightly increased in K562 cells in response to IFN-α treatment. By using bicistronic reporter constructs, we showed that the translation of MPD6 was mediated by a novel internal ribosome entry site (IRES) upstream of the MPD6 reading frame. Furthermore, the MPD6-IRES-mediated translation, but not myotrophin-MPD6 transcription, was significantly upregulated in response to IFN-α stimulation. These findings demonstrate that a novel IRES-mediated mechanism may be responsible for the translation of unconventional self-Ag MPD6 in responsive to IFN-α stimulation. The eliciting antitumor immune response against unconventional Ag MPD6 in patients with myeloproliferative diseases suggests MPD6 as a potential target of novel immunotherapy.
PMCID: PMC3902139  PMID: 16982933
17.  An N-terminal region of translationally controlled tumor protein is required for its antiapoptotic activity 
Oncogene  2005;24(30):4778-4788.
Bcl-xL plays a critical role in maintaining cell survival. However, the relationship between the potential interaction of Bcl-xL with other cytosolic proteins and the regulation of cell survival remains incompletely defined. We have identified translationally controlled tumor protein (TCTP), a multifunctional protein, as a novel antiapoptotic Bcl-xL-interacting protein. TCTP interacted in vivo and in vitro with Bcl-xL, and their sites have been mapped to an N-terminal region of TCTP and the Bcl-2 homology domain 3 of Bcl-xL. Consistent with a role in maintaining T-cell survival during activation, TCTP was significantly upregulated in murine T cells activated by T-cell antigen receptor (TCR) ligation and CD28 costimulation, which was correlated with the upregulation of Bcl-xL in activated T cells. Moreover, downregulation of TCTP expression by antisense technology in T cells results in the increase of T-cell apoptosis. Furthermore, the N-terminal region of TCTP was required for its ability to inhibit apoptosis. In conclusion, this study has demonstrated that an N-terminal region of a cytosolic protein, TCTP, is required for its binding to Bcl-xL and for its antiapoptotic activity.
PMCID: PMC3901995  PMID: 15870695
Bcl-xL; TCTP; apoptosis; protein interaction
18.  A Novel Mechanism of Alternative Promoter and Splicing Regulates the Epitope Generation of Tumor Antigen CML66-L1 
This report describes the difference in the epitope generation of two isoforms of self-tumor Ag CML66 and the regulation mechanism. We identified a new CML66 short isoform, termed CML66-S. The previously identified long CML66 is referred to as CML66-L. CML66-S shares the C terminus with CML66-L but has its unique N terminus. CML66-S is predominantly expressed in testis, but is also expressed in very low levels in tumor cells, whereas CML66-L is expressed in tumor cells and testis. Differential expression of CML66-L and CML66-S in tumor cells resulted from regulation at transcription, although alternative splicing also participated in the generation of the isoforms. In addition, Ab titers to a CML66-L peptide were significantly higher than that to CML66-S peptide in the sera from patients with tumors. Finally, the Abs to full-length CML66-L in the sera from patients with tumors were correlated with the Abs in the sera from these patients to CML66-L-38, which is a fusion protein with a CML66-L-specific N terminus. This suggests that the CML66-L isoform is mainly responsible for the epitope generation. Our studies have identified the alternative promoter in combination with alternative splicing as a novel mechanism for regulation of the epitope generation of a self-tumor Ag.
PMCID: PMC3901998  PMID: 14688378
19.  Increased noncanonical splicing of autoantigen transcripts provides the structural basis for expression of untolerized epitopes 
Alternative splicing is important for increasing the complexity of the human proteome from a limited genome. Previous studies have shown that for some autoantigens, there is differential immunogenicity among alternatively spliced isoforms.
Herein, we tested the hypothesis that alternative splicing is a common feature for transcripts of autologous proteins that are autoantigens. The corollary hypothesis tested was that nonautoantigen transcripts have a lower frequency of alternative splicing.
The extent of alternative splicing within 45 randomly selected self-proteins associated with autoimmune diseases was compared with 9554 randomly selected proteins in the human genome by using bioinformatics analyses. Isoform-specific regions that resulted from alternative splicing were studied for their potential to be epitopes for antibodies or T-cell receptors.
Alternative splicing occurred in 100% of the autoantigen transcripts. This was significantly higher than the approximately 42% rate of alternative splicing observed in the 9554 randomly selected human gene transcripts (P < .001). Within the isoform-specific regions of the autoantigens, 92% and 88% encoded MHC class I and class II–restricted T-cell antigen epitopes, respectively, and 70% encoded antibody binding domains. Furthermore, 80% of the autoantigen transcripts underwent noncanonical alternative splicing, which is also significantly higher than the less than 1% rate in randomly selected gene transcripts (P < .001).
These studies suggest that noncanonical alternative splicing may be an important mechanism for the generation of untolerized epitopes that may lead to autoimmunity.
Furthermore, the product of a transcript that does not undergo alternative splicing is unlikely to be a target antigen in autoimmunity.
PMCID: PMC3902068  PMID: 15577853
Autoantigens; alternative splicing; exons; isoforms; antigen epitopes; immunogenicity; immune tolerance; autoimmune diseases
20.  Phylogeography of Pinus armandii and Its Relatives: Heterogeneous Contributions of Geography and Climate Changes to the Genetic Differentiation and Diversification of Chinese White Pines 
PLoS ONE  2014;9(1):e85920.
Geographic barriers and Quaternary climate changes are two major forces driving the evolution, speciation, and genetic structuring of extant organisms. In this study, we used Pinus armandii and eleven other Asian white pines (subsection Strobus, subgenus Pinus) to explore the influences of geographic factors and Pleistocene climatic oscillations on species in South China, a region known to be centers of plant endemism and biodiversity hotspots. Range-wide patterns of genetic variation were investigated using chloroplast and mitochondrial DNA markers, with extensive sampling throughout the entire range of P. armandii. Both cpDNA and mtDNA revealed that P. armandii exhibits high levels of genetic diversity and significant population differentiation. Three geographically distinct subdivisions corresponding to the Qinling-Daba Mountains (QDM), Himalaya-Hengduan Mountains (HHM) and Yungui Plateau (YGP) were revealed in mainland China by cpDNA. Their break zone was located in the southeastern margin of the Qinghai-Tibetan Plateau (QTP). A series of massive mountains, induced by the QTP uplift, imposed significant geographic barriers to genetic exchange. The disjunct distribution patterns of ancestral haplotypes suggest that a large continuous population of the white pines may have existed from southwest to subtropical China. Repeated range shifts in response to the Pleistocene glaciations led to the isolation and diversification of the subtropical species. The two Taiwanese white pines share a common ancestor with the species in mainland China and obtain their chloroplasts via long-distance pollen dispersal from North Asian pines. Distinct genetic patterns were detected in populations from the Qinling-Daba Mountains, Yungui Plateau, Himalaya-Hengduan Mountains, and subtropical China, indicating significant contributions of geographic factors to the genetic differentiation in white pines. Our study depicts a clear picture of the evolutionary history of Chinese white pines and highlights the heterogeneous contributions of geography and Pleistocene climatic fluctuations to the extremely high plant species diversity and endemism in South China.
PMCID: PMC3897548  PMID: 24465789
21.  Genome characteristics reveal the impact of lichenization on lichen-forming fungus Endocarpon pusillum Hedwig (Verrucariales, Ascomycota) 
BMC Genomics  2014;15:34.
Lichen is a classic mutualistic organism and the lichenization is one of the fungal symbioses. The lichen-forming fungus Endocarpon pusillum is living in symbiosis with the green alga Diplosphaera chodatii Bialsuknia as a lichen in the arid regions.
454 and Illumina technologies were used to sequence the genome of E. pusillum. A total of 9,285 genes were annotated in the 37.5 Mb genome of E. pusillum. Analyses of the genes provided direct molecular evidence for certain natural characteristics, such as homothallic reproduction and drought-tolerance. Comparative genomics analysis indicated that the expansion and contraction of some protein families in the E. pusillum genome reflect the specific relationship with its photosynthetic partner (D. chodatii). Co-culture experiments using the lichen-forming fungus E. pusillum and its algal partner allowed the functional identification of genes involved in the nitrogen and carbon transfer between both symbionts, and three lectins without signal peptide domains were found to be essential for the symbiotic recognition in the lichen; interestingly, the ratio of the biomass of both lichen-forming fungus and its photosynthetic partner and their contact time were found to be important for the interaction between these two symbionts.
The present study lays a genomic analysis of the lichen-forming fungus E. pusillum for demonstrating its general biological features and the traits of the interaction between this fungus and its photosynthetic partner D. chodatii, and will provide research basis for investigating the nature of its drought resistance and symbiosis.
PMCID: PMC3897900  PMID: 24438332
Mycobiont; Phycobiont; Lichenization; Symbiosis; Symbiosis-related gene; Photosynthetic products
22.  Effects of pentoxifylline on nonalcoholic fatty liver disease: A meta-analysis 
AIM: To evaluate the effects of pentoxifylline therapy in patients with nonalcoholic fatty liver disease (NAFLD).
METHODS: We searched PubMed, Medline, Google Scholar, Embase, Web of Science, the Cochrane Library and the Chinese Biomedicine Database for all relevant controlled trials of pentoxifylline in patients with NAFLD from 1997 to July 2013. Five studies (3 randomized, double-blind, placebo-controlled trials and 2 prospective cohort studies with concurrent controls) were included in this meta-analysis. Statistical analysis was performed using RevMan 5.0 software.
RESULTS: Five randomized trials of 147 patients with NAFLD/nonalcoholic steatohepatitis (NASH) were included. The results showed that compared to placebo, pentoxifylline therapy resulted in a significant decrease in body weight (P = 0.04), alanine aminotransferase (P < 0.00001), aspartate transaminase (P = 0.0006), glucose (P = 0.0008) and tumor necrosis factor-α (P = 0.007), but did not significantly affect body mass index (P = 0.28), total cholesterol (P = 0.80), triglyceride (P = 0.98), alkaline phosphatase (P = 0.29), γ-glutamyl transferase (P = 0.39) and interleukin-6 (P = 0.38). With regard to histological changes, pentoxifylline only reduced the NAFLD activity score (P < 0.00001) and improved lobular inflammation (P < 0.0001). Improvements in steatosis grade (P = 0.11), ballooning (P = 0.10) and fibrosis (P = 0.50) were not obvious.
CONCLUSION: Pentoxifylline therapy results in weight loss, improved liver function and histological changes in patients with NAFLD/NASH. Therefore, pentoxifylline may be a new treatment option for NAFLD.
PMCID: PMC3923033  PMID: 24574727
Pentoxifylline; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis; Meta-analysis
23.  Triazole-dithiocarbamate based, selective LSD1 inactivators inhibit gastric cancer cell growth, invasion and migration 
Journal of medicinal chemistry  2013;56(21):10.1021/jm401002r.
Lysine specific demethylase 1 (LSD1), the first identified histone demethylase, plays an important role in epigenetic regulation of gene activation and repression. The up-regulated LSD1's expression has been reported in several malignant tumors. In the current study, we designed and synthesized five series of 1, 2, 3-triazole-dithiocarbamate hybrids and screened their inhibitory activity toward LSD1. We found that some of these compounds, especially compound 26, exhibited the most specific and robust inhibition of LSD1. Interestingly, compound 26 also showed potent and selective cytotoxicity against LSD1 overexpressing gastric cancer cell lines MGC-803 and HGC-27, as well as marked inhibition of cell migration and invasion, compared to 2-PCPA. Furthermore, compound 26 effectively reduced the tumor growth bared by human gastric cancer cells in vivo with no signs of adverse side effects. These findings suggested that compound 26 deserves further investigation as a lead compound in the treatment of LSD1 overexpressing gastric cancer.
PMCID: PMC3881423  PMID: 24131029
24.  Correction: PTCH1 Gene Mutations in Keratocystic Odontogenic Tumors: A Study of 43 Chinese Patients and a Systematic Review 
PLoS ONE  2014;9(1):10.1371/annotation/6f3dfecd-6a37-44d3-9ee4-472d1eacc9a5.
PMCID: PMC3879385
25.  Use and Accuracy of Diagnostic Imaging by Hospital Type in Pediatric Appendicitis 
Pediatrics  2013;131(1):e37-e44.
Accurate, timely diagnosis of pediatric appendicitis minimizes unnecessary operations and treatment delays. Preoperative abdominal-pelvic computed tomography (CT) scan is sensitive and specific for appendicitis; however, concerns regarding radiation exposure in children obligate scrutiny of CT use. Here, we characterize recent preoperative imaging use and accuracy among pediatric appendectomy subjects.
We retrospectively reviewed children who underwent operations for presumed appendicitis at a single tertiary-care children’s hospital and examined preoperative CT and ultrasound use with subject characteristics. Preoperative imaging accuracy was compared with postoperative and histologic diagnosis as the reference standard.
Most children (395/423, 93.4%) who underwent an operation for appendicitis during 2009–2010 had preoperative imaging. Final diagnoses included normal appendix (7.3%) and perforated appendicitis (23.6%). In multivariable analysis, initial evaluation at a community hospital versus the children’s hospital was associated with 4.4-fold higher odds of obtaining a preoperative CT scan (P = .002), whereas preoperative ultrasound was less likely (odds ratio 0.20; P = .003). Ultrasound and CT sensitivities for appendicitis were diminished for studies performed at community hospitals compared with the children’s hospital. Girls were 4.5-fold more likely to undergo both ultrasound and CT scans and were associated with lower ultrasound sensitivity for appendicitis.
Widespread preoperative imaging did not eliminate unnecessary pediatric appendectomies. Controlling for factors potentially associated with referral bias, a CT scan was more likely to be performed in children initially evaluated at community hospitals compared with the children’s hospital. Broadly-applicable strategies to systematically maximize diagnostic accuracy for childhood appendicitis, while minimizing ionizing radiation exposure, are urgently needed.
PMCID: PMC3529953  PMID: 23266930
appendicitis; pediatrics; diagnostic imaging; computed tomography; ultrasound

Results 1-25 (241)