Gene expression is regulated at the transcription and translation levels; thus, both transcription factors (TFs) and microRNAs (miRNA) play roles in regulation of gene expression. This study profiled differentially expressed mRNAs and miRNAs in gastric cancer tissues to construct a TF and miRNA co-regulatory network in order to identify altered genes in gastric cancer progression. A total of 70 cases gastric cancer and paired adjacent normal tissues were subjected to cDNA and miRNA microarray analyses. We obtained 887 up-regulated and 93 down-regulated genes and 41 down-regulated and 4 up-regulated miRNAs in gastric cancer tissues. Using the Transcriptional Regulatory Element Database, we obtained 105 genes that are regulated by the E2F family of genes and using Targetscan, miRanda, miRDB and miRWalk tools, we predicted potential targeting genes of these 45 miRNAs. We then built up the E2F-related TF and miRNA co-regulatory gene network and identified 9 hub-genes. Furthermore, we found that levels of E2F1, 2, 3, 4, 5, and 7 mRNAs associated with gastric cancer cell invasion capacity, and has associated with tumor differentiation. These data showed Overexpression of E2F mRNAs associated with gastric cancer progression.
Dyslexia is a polygenic developmental disorder characterized by difficulties in reading and spelling despite normal intelligence, educational backgrounds and perception. Increasing evidences indicated that dyslexia may share similar genetic mechanisms with other speech and language disorders. We proposed that stuttering candidate genes, DRD2 and SLC6A3, might be associated with dyslexia.
Methods and results
The study was conducted in an unrelated Chinese cohort with 502 dyslexic cases and 522 healthy controls. In total, 23 Tag SNPs covering the two genes were selected for genotyping through Tagger program. Association analysis was performed on each SNP alone and in haplotypes. One SNP markers in DRD2 showed significant association with developmental dyslexia.
These findings indicate that polymorphism of DRD2 gene may be a risk factor of developmental dyslexia in the Chinese population.
Dyslexia; Dopamine D2 receptor (DRD2); Solute carrier family 6, member 3 (SLC6A3); Linkage study
No case of solitary fibrous tumor of the pleura with Doege-Potter syndrome has
been reported in China. This study was to report a rare repeatedly recurrent case
of solitary fibrous tumor of the pleura with Doege-Potter syndrome diagnosed in
China and a three-decade literature review of solitary fibrous tumor of the pleura
with Doege-Potter syndrome worldwide.
A rare case of solitary fibrous tumor of the pleura with Doege-Potter syndrome
was diagnosed in 2005 with follow-up to 2011. All medical records were collected
and literature of solitary fibrous tumor of the pleura with Doege-Potter syndrome
from 1979 to 2011 was obtained through Medline. This typical case, diagnosed and
confirmed by histopathologic results, was a 72-year-old Chinese woman who had a
complaint of night sweat for a month. A localized mass 12 cm × 11 cm × 8 cm in
size was found associated with pleural effusion in her left low chest cavity, and
blood tests showed severe hypoglycemia. Removal of the mass solved the
hypoglycemia. The case was repeatedly recurrent in April, 2010 and March, 2011 and
had no signs of recurrence up to the end of 2011 after surgery. A review of 45
cases of solitary fibrous tumor of the pleura with Doege-Potter syndrome compared
and summarized clinical characteristics, treatments, and outcomes by benign and
malignant tumor nature.
Incidence of solitary fibrous tumor of the pleura with Doege-Potter syndrome
is similar between genders. There are no significant differences in clinical
characteristics between benign and malignant cases. Surgery is the first effective
treatment for solitary fibrous tumor of the pleura with Doege-Potter syndrome and
the completeness of the initial resection is the key to preventing recurrence.
Routine follow-up examinations are recommended for early detection of
Solitary fibrous tumors of pleura; Doege-Potter syndrome; Surgery; Case report review
MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in posttranscriptional gene regulation and function as negative gene regulators. They are an abundant class of RNA, each of which can control hundreds of gene targets and regulate diverse biological processes such as hematopoiesis, organogenesis, apoptosis and cell proliferation. Aberrant miRNA expression contributes to tumorigenesis and cancer progression.
In this study we provided a summarized review of the most important new data available on hepatocellular carcinoma (HCC)-associated miRNAs. The data were collected through searching the related keywords and were categorized and summarized in different sections.
Researchers have reported that miRNAs can repress the expression of important cancer-related genes and might be helpful in the diagnosis and treatment of cancer. During the past two decades, numerous studies have shown that miRNAs play an essential role in inhibiting HCC via several different pathways. Deregulated miRNAs may contribute to carcinogenesis, indicating that miRNAs can act as tumor suppressors and oncogenes.
In this mini review, we highlight current findings and discuss recent work to determine the contribution of miRNA expression to the maintenance and growth of HCC, thereby providing a significant source of hope that miRNAs could serve as therapeutic targets.
Hepatocellular Carcinoma; MicroRNAs; Regulation; Therapeutic Targets
We have compared mutation analysis by Amplification Refractory Mutation System (ARMS) and epidermal growth factor receptor (EGFR) mutant-specific antibodies for their ability to detect two common activating EGFR mutations in a cohort of 115 advanced non-small cell lung cancer (NSCLC), including cytology material, core biopsy, and bronchoscopic biopsies. Assessment of EGFR mutation status was performed by using antibodies and ARMS assay specific to the two major forms of mutant EGFR, exon 19 deletion E746-A750 (c.2235_2249del15 or c.2236_2250del15, p. Glu746_Ala750 del) and exon 21 L858R point mutation (c.2573T>G, p.Leu858Arg). In this study the optimal buffer for antigen retrieval was sodium citrate (pH 6.0). Q score was used to evaluate the specific mutant EGFR proteins expression. Validation using clinical material showed deletions in exon 19 were detected in 19.1% and L858R mutation in 20% of all cases by ARMS assay. A cutoff value of score 1 was used as positive by IHC. No wild type cases were immuno-reactive. The antibodies performed well in cytology, core biopsies and bronchoscopic biopsies. There were only one false positive case using L858R IHC (sensitivity 100%, specificity 98.5%, positive predictive value 96%, negative predictive value 100%). All 23 E746-A750 exon 19 deletions identified by mutation analysis were positive by IHC. The sensitivity of exon 19 IHC for E746-A750 was 100%, specificity 100%, positive predictive value 100% and negative predictive value 100%. The result of the IHC stains was finely correlated with mutations status determined by ARMS assay. Although inferior to molecular genetic analysis of the EGFR gene, IHC is highly specific and sensitive for the targeted EGFR mutations. The antibodies are likely to be of clinical value in cases especially where limited tumor material is available, or in situations where molecular genetic analysis is not readily available.
NSCLC; cytology; EGFR mutation; immunohistochemistry
Tissue hypoxia induces reprogramming of cell metabolism and may result in normal cell transformation and cancer progression. Hypoxia-inducible factor 1-alpha (HIF-1α), the key transcription factor, plays an important role in gastric cancer development and progression. This study aimed to investigate the underlying regulatory signaling pathway in gastric cancer using gastric cancer tissue specimens. The integration of gene expression profile and transcriptional regulatory element database (TRED) was pursued to identify HIF-1α ↔ NFκB1 → BRCA1 → STAT3 ← STAT1 gene pathways and their regulated genes. The data showed that there were 82 differentially expressed genes that could be regulated by these five transcription factors in gastric cancer tissues and these genes formed 95 regulation modes, among which seven genes (MMP1, TIMP1, TLR2, FCGR3A, IRF1, FAS, and TFF3) were hub molecules that are regulated at least by two of these five transcription factors simultaneously and were associated with hypoxia, inflammation, and immune disorder. Real-Time PCR and western blot showed increasing of HIF-1α in mRNA and protein levels as well as TIMP1, TFF3 in mRNA levels in gastric cancer tissues. The data are the first study to demonstrate HIF-1α-regulated transcription factors and their corresponding network genes in gastric cancer. Further study with a larger sample size and more functional experiments is needed to confirm these data and then translate into clinical biomarker discovery and treatment strategy for gastric cancer.
In recent years, the reported infection cases by coxsackievirus (CV) have been on the rise. In order to reveal the relationship between the nucleotide and amino acid sequences and the viral virulence of the CVB3/MKP strain causing myocarditis, we initially confirmed the virulence of the strain in myocardial tissue and then carried out the whole genome sequencing of CVB3/MKP strain and performed a phylogenetic analysis among different CVB3 strains.
CVB3/MKP infected mouse model was established to check lesions of myocardial tissue in mice using immunohistochemical detection at different periods. RT-PCR analysis was used to amplify seven fragments covering the whole viral sequence and comparable analysis was performed.
The immunohistochemical results showed that particles of CVB3/MKP virus persisted in the cardiac tissue and caused severe pathology. The length of whole genome sequence of CVB3/MKP strain was 7400 bp. CVB3/MKP had 99.7% and 99.6% homology in nucleotide sequence with CVB3/28 and non-virulent CVB3/0, respectively. The former can induce pancreatitis and myocarditis. The nucleotide sequence in the 5′untranslated region of CVB3/MKP strain shared 99.6% and 99.5% homology with CVB3/20 and CVB3/Nancy, respectively.
We confirmed in our animal experiments that CVB3/MKP had cardiotoxicity. CVB3/MKP, CVB3/28, and CVB3/0 may share evolutionary convergence and the 5′untranslated region (5′UTR) may be associated with virulence phenotype. Our findings will provide a basis for identifying the genomic determinant of viral virulence of CVB3/MKP strain and phylogenetic relationship among different CVB3 strains.
Coxsackievirus B3/MKP; Myocarditis; Phylogenetic analysis; Functional genomics
Different subtypes of Mycobacterium tuberculosis (MTB) may induce diverse severe human infections, and some of their symptoms are similar to other pathogenes, e.g. Nontuberculosis mycobacteria (NTM). So determination of mycobacterium subtypes facilitates the effective control of MTB infection and proliferation. This study exploits a novel DNA barcoding visualization method for molecular typing of 17 mycobacteria genomes published in the NCBI prokaryotic genome database. Three mycobacterium genes (Rv0279c, Rv3508 and Rv3514) from the PE/PPE family of MT Band were detected to best represent the inter-strain pathogenetic variations. An accurate and fast MTB substrain typing method was proposed based on the combination of the aforementioned three biomarker genes and the 16S rRNA gene. The protocol of establishing a bacterial substrain typing system used in this study may also be applied to the other pathogenes.
Mycobacterium; Molecular typing; Typing biomarker; Bioinformatics; Differential diagnosis of mycobacteria
The laboratory of genetics and physiology 2 (LGP2) is a key component of the RNA helicase family of retinoic acid-inducible gene 1- (RIG-I-) like receptors (RLRs) and is widely involved in viral RNA recognition and regulation during innate immune responses. Unlike RIG-I and melanoma differentiation-associated 5, both RLR members, LGP2 lacks the caspase-recruitment domain (CARD), which is required for recruiting and interacting with downstream signaling proteins to activate a cascade of downstream signaling events. The absence of the CARD results in divergent functional performance for LGP2 compared to these other RLR members. Both negative and positive regulatory roles have been reported for LGP2 in antiviral immune responses. It is currently unclear how the unusual properties of LGP2 mediate opposing roles. Future studies should elucidate the molecular mechanism(s) of LGP2 action. This minireview provides a brief overview of LGP2 structure and functions, with an expanded discussion on the regulation mechanisms in response to viral infection, hopefully stimulating insight into the divergent roles of LGP2 in the regulation of antiviral immune responses.
The aim of this study is to assess related risk factors and predict early- and late-onset seizure after first-ever stroke. A total of 2474 consecutive patients with initial stroke in China from 1997 to 2007 were retrospectively investigated, in which, 24 clinical and radiological indexes were used for evaluation. Odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression. A total of 232 (11.1%) of patients developed seizures during a mean follow-up period of 18 months, with 123 experiencing early-onset and 109 late-onset seizure. The independent risk factors for early-onset seizure were large lesion (OR = 9.36), subarachnoid hemorrhage (OR = 5.28), initial hyponatremia (OR = 2.10), and cortical involvement (OR = 1.33). The independent risk factors for late-onset seizure were cortical involvement (OR = 11.84) and large lesion (OR = 1.87). These results demonstrated that the risk factors for early seizure after stroke are large lesion, subarachnoid hemorrhage, and cortical involvement. Surprisingly, hyponatremia also predicts seizure in stroke patients. Cortical involvement is a major risk factor for late-onset seizure after stroke.
The detection of serum tumor markers is valuable for the early diagnosis of lung cancer. Tumor markers are frequently used for the management of cancer patients. However, single markers are less efficient but marker combinations increase the cost, which is troublesome for clinics. To find an optimal serum marker combination panel that benefits the patients and the medical management system as well, four routine lung cancer serum markers (SCCA, NSE, CEA, and CYFRA21-1) were evaluated individually and in combination. Meanwhile, the costs and effects of these markers in clinical practice in China were assessed by cost-effectiveness analysis. As expected, combinations of these tumor markers improved their sensitivity for lung cancer and different combination panels had their own usefulness. NSE + CEA + CYFRA21-1 was the optimal combination panel with highest Youden's index (0.64), higher sensitivity (75.76%), and specificity (88.57%), which can aid the clinical diagnosis of lung cancer. Nevertheless, the most cost-effective combination was SCCA + CEA, which can be used to screen the high-risk group.
The toll-like receptors (TLRs) are important components of the respiratory epithelium host innate defense, enabling the airway surface to recognize and respond to a variety of insults in inhaled air. Based on the knowledge that smokers are more susceptible to pulmonary infection and that the airway epithelium of smokers with chronic obstructive pulmonary disease (COPD) is characterized by bacterial colonization and acute exacerbation of airway infections, we assessed whether smoking alters expression of TLRs in human small airway epithelium, the primary site of smoking-induced disease. Microarrays were used to survey the TLR family gene expression in small airway (10th–12th order) epithelium from healthy nonsmokers (n=60), healthy smokers (n=73) and smokers with COPD (n=36). Using the criteria of detection call of present in ≥50%, 6 of 10 TLRs (1, 2, 3, 4, 5 and 8) were expressed. Compared to nonsmokers, the most striking change was for TLR5, which was down-regulated in healthy smokers (1.4-fold, p<10−10) and smokers with COPD (1.6-fold, p<10−11). TaqMan RT-PCR confirmed these observations. Bronchial biopsy immunofluorescence studies showed that TLR5 was expressed mainly on the apical side of the epithelium and was decreased in healthy smokers and smokers with COPD. In vitro, the level of TLR5 downstream genes, IL-6 and IL-8, were highly induced by flagellin in TLR5 high-expressing cells compared to TLR5 low-expressing cells. In the context that TLR5 functions to recognize pathogens and activate innate immune responses, the smoking-induced down-regulation of TLR5 may contribute to smoking-related susceptibility to airway infection, at least for flagellated bacteria.
Although electrocardiogram (ECG) fluctuates over time and physical activity, some of its intrinsic measurements serve well as biometric features. Considering its constant availability and difficulty in being faked, the ECG signal is becoming a promising factor for biometric authentication. The majority of the currently available algorithms only work well on healthy participants. A novel normalization and interpolation algorithm is proposed to convert an ECG signal into multiple template cycles, which are comparable between any two ECGs, no matter the sampling rates or health status. The overall accuracies reach 100% and 90.11% for healthy participants and cardiovascular disease (CVD) patients, respectively.
Hepatitis B virus (HBV) infection is a major global health problem. The infectious virion contains an inner “core particle”, which is made of 180 or 240 copies of core protein, alternatively known as hepatitis B core antigen, or HBcAg which encloses the viral genome.
In this study, we characterized HBV genotypes and used Bayesian analyses to estimate date of emergence of the most recent common ancestor (TMRCA) of three HBV genotypes, A, B, and D.
We estimated that the rate of evolution of HBV core protein gene to be 1.127 (0.925–1.329, 95% HPD) substitutions per site per year. The TMRCA of HBV for genotypes A, B, D were 118 (54–194, 95% HPD) year, 184 (78–323, 95% HPD) year and 133 (65–230, 95% HPD) year, respectively. Demographic histories of the HBcAg gene showed that the relative genetic diversity had a sharp increase within the first 10 years of its emergence.
Using a bayesian evolutionary method to predict the outbreak trends of HBV through evolutionary trees of HBV, and provide theoretical foundations for clinical prevention and treatment of HBV.
HBV; Genotypes; Bayesian analyses; TMRCA
The discovery of microRNAs (miRNAs) provides a new and powerful tool for studying the mechanisms, diagnosis and treatments of cancer. In this study, we employed AFFX miRNA expression chips to search for miRNAs that may be aberrantly expressed in gastric cancer tissues and to investigate the potential roles that miRNAs may play in the development and progression of gastric cancer. 14 miRNAs were found to be down-regulated and 2 miRNAs up-regulated in gastric cancer tissues compared to the normal gastric tissues. Among the aberrantly expressed miRNAs, miR-574-3p was selected to further study its expression features and functional roles. Interestingly, the reduced expression of miR-574-3p occurred mainly in the early stages of gastric cancer or in cancers with high level of differentiation, suggesting that it can be used as a marker for a mild case of gastric cancer. Functional study revealed that cell proliferation, migration and invasion were significantly inhibited in miR-574-3p-transfected gastric cancer SGC7901 cells. Computational prediction and experimental validation suggest that Cullin2 may be one of the targets of miR-574-3p. Overall our study suggests that the aberrantly expressed miRNAs may play regulatory and functional roles in the development and progression of gastric cancer.
microRNA; gastric cancer; target gene; proliferation; invasion
Motivation: Computational inference methods that make use of graphical models to extract regulatory networks from gene expression data can have difficulty reconstructing dense regions of a network, a consequence of both computational complexity and unreliable parameter estimation when sample size is small. As a result, identification of hub genes is of special difficulty for these methods.
Methods: We present a new algorithm, Empirical Light Mutual Min (ELMM), for large network reconstruction that has properties well suited for recovery of graphs with high-degree nodes. ELMM reconstructs the undirected graph of a regulatory network using empirical Bayes conditional independence testing with a heuristic relaxation of independence constraints in dense areas of the graph. This relaxation allows only one gene of a pair with a putative relation to be aware of the network connection, an approach that is aimed at easing multiple testing problems associated with recovering densely connected structures.
Results: Using in silico data, we show that ELMM has better performance than commonly used network inference algorithms including GeneNet, ARACNE, FOCI, GENIE3 and GLASSO. We also apply ELMM to reconstruct a network among 5492 genes expressed in human lung airway epithelium of healthy non-smokers, healthy smokers and individuals with chronic obstructive pulmonary disease assayed using microarrays. The analysis identifies dense sub-networks that are consistent with known regulatory relationships in the lung airway and also suggests novel hub regulatory relationships among a number of genes that play roles in oxidative stress and secretion.
Availability and implementation: Software for running ELMM is made available at http://mezeylab.cb.bscb.cornell.edu/Software.aspx.
Contact: email@example.com or firstname.lastname@example.org
Supplementary data are available at Bioinformatics online.
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). The annotation of functional genome and signaling network in M. tuberculosis are still not systematic. Essential gene modules are a collection of functionally related essential genes in the same signaling or metabolic pathway. The determination of essential genes and essential gene modules at genomic level may be important for better understanding of the physiology and pathology of M. tuberculosis, and also helpful for the development of drugs against this pathogen. The establishment of genomic operon database (DOOR) and the annotation of gene pathways have felicitated the genomic analysis of the essential gene modules of M. tuberculosis.
Bibliometric approach has been used to perform a High-throughput screen for essential genes of M. tuberculosis strain H37Rv. Ant colony algorithm were used to identify the essential genes in other M. tuberculosis reference strains. Essential gene modules were analyzed by operon database DOOR. The pathways of essential genes were assessed by Biocarta, KEGG, NCI-PID, HumanCyc and Reactome. The function prediction of essential genes was analyzed by Pfam.
A total approximately 700 essential genes were identified in M. tuberculosis genome. 40% of operons are consisted of two or more essential genes. The essential genes were distributed in 92 pathways in M. tuberculosis. In function prediction, 61.79% of essential genes were categorized into virulence, intermediary metabolism/respiration,cell wall related and lipid metabolism, which are fundamental functions that exist in most bacteria species.
We have identified the essential genes of M. tuberculosis using bibliometric approach at genomic level. The essential gene modules were further identified and analyzed.
Mycobacterium tuberculosis; Essential gene modules; Operon; Pathway
Gastric cancer is one of the most common malignant tumors in the world. Finding effective diagnostic biomarkers in urine or serum would represent the most ideal solution to detecting gastric cancer during annual physical examination. This study was to evaluate the potential of endothelial lipase (EL) as a urinary biomarker for diagnosis of gastric cancer.
The expression levels of EL was measured using Western blotting and immunohistochemical staining experiments on (tissue, serum, and urine) samples of gastric cancer patients versus healthy people. We also checked the EL levels in the urine samples of other cancer types (lung, colon and rectum cancers) and benign lesions (gastritis and gastric leiomyoma) to check if EL was specific to gastric cancer.
We observed a clear separation between the EL expression levels in the urine samples of 90 gastric cancer patients and of 57 healthy volunteers. It was approximately 9.9 fold average decrease of the EL expression levels in the urine samples of gastric cancer compared to the healthy controls (P <0.0001), achieving a 0.967 AUC value for the ROC (receiver operating characteristic) curve, demonstrating it’s highly accurate as a diagnostic marker for gastric cancer. Interestingly, the expression levels of EL in tissue and serum samples were not nearly as discriminative as in urine samples (P = 0.90 and P = 0.79). In immunohistochemical experiments, positive expression of the EL protein was found in 67% (8/12) of gastric adjacent noncancerous and in 58% (7/12) of gastric cancer samples. There was no significant statistical in the expression levels of this protein between the gastric cancer and the matching noncancerous tissues (P =0.67).
The urinary EL as a highly accurate gastric cancer biomarker that is potentially applicable to the general screening with high sensitivity and specificity.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4527331618757552
Endothelial lipase; Biomarker; Gastric cancer; Diagnosis
Measles remains a severe global health threat, and nearly 30 million new cases are reported annually. Although many studies have analyzed measles viruses (MV) at the epidemiologic and phylogenetic levels, no study has yet to integrate these two types of data. To this end, we isolated 16 wild-type MV strains China's Jilin province. The MV genotype H1 was the most prevalent strain. After sequencing the nucleoprotein (N) genes of these strains, a maximum clade credibility tree was constructed by the Bayesian Markov Chain Monte Carlo method using 450 MV strains from GenBank with epidemiological information. The MV N gene evolution rate was 1.127E-3. Analysis of the time of the most recent common ancestor (TMRCA) for genotypes A/B/C/G/H revealed that genotypes D and B had the largest and smallest TMRCA (45.86 and 26.63, respectively). The highest level of genetic diversity for the MV N gene occurred around the year 2000. Here in this study, we uncovered the MV genotypes circulating in China's Jilin Province and estimated the epidemiologic and phylogenetic relationship for the six different genotypes of MV.
Etiologic diagnoses of lower respiratory tract infections (LRTI) have been relying primarily on bacterial cultures that often fail to return useful results in time. Although DNA-based assays are more sensitive than bacterial cultures in detecting pathogens, the molecular results are often inconsistent and challenged by doubts on false positives, such as those due to system- and environment-derived contaminations. Here we report a nationwide cohort study on 2986 suspected LRTI patients across P. R. China. We compared the performance of a DNA-based assay qLAMP (quantitative Loop-mediated isothermal AMPlification) with that of standard bacterial cultures in detecting a panel of eight common respiratory bacterial pathogens from sputum samples. Our qLAMP assay detects the panel of pathogens in 1047(69.28%) patients from 1533 qualified patients at the end. We found that the bacterial titer quantified based on qLAMP is a predictor of probability that the bacterium in the sample can be detected in culture assay. The relatedness of the two assays fits a logistic regression curve. We used a piecewise linear function to define breakpoints where latent pathogen abruptly change its competitive relationship with others in the panel. These breakpoints, where pathogens start to propagate abnormally, are used as cutoffs to eliminate the influence of contaminations from normal flora. With help of the cutoffs derived from statistical analysis, we are able to identify causative pathogens in 750 (48.92%) patients from qualified patients. In conclusion, qLAMP is a reliable method in quantifying bacterial titer. Despite the fact that there are always latent bacteria contaminated in sputum samples, we can identify causative pathogens based on cutoffs derived from statistical analysis of competitive relationship.
Mucus hypersecretion contributes to the morbidity and mortality of smoking-related lung diseases, especially chronic obstructive pulmonary disease (COPD), which starts in the small airways. Despite progress in animal studies, the genes and their expression pattern involved in mucus production and secretion in human airway epithelium are not well understood. We hypothesized that comparison of the transcriptomes of the small airway epithelium of individuals that express high vs low levels of MUC5AC, the major macromolecular component of airway mucus, could be used as a probe to identify the genes related to human small airway mucus production/secretion.
Flexible bronchoscopy and brushing were used to obtain small airway epithelium (10th to 12th order bronchi) from healthy nonsmokers (n=60) and healthy smokers (n=72). Affymetrix HG-U133 plus 2.0 microarrays were used to assess gene expression. Massive parallel sequencing (RNA-Seq) was used to verify gene expression of small airway epithelium from 5 nonsmokers and 6 smokers.
MUC5AC expression varied 31-fold among the healthy nonsmokers. Genome-wide comparison between healthy nonsmokers (n = 60) grouped as “high MUC5AC expressors” vs “low MUC5AC expressors” identified 528 genes significantly up-regulated and 15 genes significantly down-regulated in the high vs low expressors. This strategy identified both mucus production and secretion related genes under control of a network composed of multiple transcription factors. Based on the literature, genes in the up-regulated list were used to identify a 73 “MUC5AC-associated core gene” list with 9 categories: mucus component; mucus-producing cell differentiation-related transcription factor; mucus-producing cell differentiation-related pathway or mediator; post-translational modification of mucin; vesicle transport; endoplasmic reticulum stress-related; secretory granule-associated; mucus secretion-related regulator and mucus hypersecretory-related ion channel. As a validation cohort, we assessed the MUC5AC-associated core gene list in the small airway epithelium of an independent set of healthy smokers (n = 72). There was up-regulation of MUC5AC in the small airway epithelium of smokers (2.3-fold, p < 10-8) associated with a coordinated up-regulation of MUC5AC-associated core gene expression pattern in the small airway epithelium of smokers (p < 0.01). Deep sequencing confirmed these observations.
The identification of the genes associated with increased airway mucin production in humans should be useful in understanding the pathogenesis of airway mucus hypersecretion and identifying therapeutic targets.
Mucus hypersecretion contributes to the morbidity and mortality of smoking-related lung diseases, especially chronic obstructive pulmonary disease (COPD), which starts in the small airways. Little is known about the gene networks associated with the synthesis and secretion of mucins in the human small airway epithelium. Taking advantage of the knowledge that MUC5AC is a major mucin secreted by the small airway epithelium, the expression of MUC5AC in small airway epithelium is highly regulated at the transcriptional level and our observation that healthy nonsmokers have variable numbers of MUC5AC+ secretory cells in the human small airway epithelium, we compared genome-wide gene expression of the small airway epithelium of high vs low MUC5AC expressors from 60 nonsmokers to identify the genes associated with MUC5AC expression. This novel strategy enabled identification of a 73 “MUC5AC-associated core gene” list with 9 categories, which control a series of processes from mucin biosynthesis to mucus secretion. The coordinated gene expression pattern of MUC5AC-associated core genes were corroborated in an independent cohort of 72 healthy smokers. Deep sequencing of small airway epithelium RNA confirmed these observations. This finding will be useful in identifying therapeutic targets to treat small airway mucus hypersecretion.
The small airway epithelium (SAE), the cell population that covers the human airway surface from the 6th generation of airway branching to the alveoli, is the major site of lung disease caused by smoking. The focus of this study is to provide quantitative assessment of the SAE transcriptome in the resting state and in response to chronic cigarette smoking using massive parallel mRNA sequencing (RNA-Seq).
The data demonstrate that 48% of SAE expressed genes are ubiquitous, shared with many tissues, with 52% enriched in this cell population. The most highly expressed gene, SCGB1A1, is characteristic of Clara cells, the cell type unique to the human SAE. Among other genes expressed by the SAE are those related to Clara cell differentiation, secretory mucosal defense, and mucociliary differentiation. The high sensitivity of RNA-Seq permitted quantification of gene expression related to infrequent cell populations such as neuroendocrine cells and epithelial stem/progenitor cells. Quantification of the absolute smoking-induced changes in SAE gene expression revealed that, compared to ubiquitous genes, more SAE-enriched genes responded to smoking with up-regulation, and those with the highest basal expression levels showed most dramatic changes. Smoking had no effect on SAE gene splicing, but was associated with a shift in molecular pattern from Clara cell-associated towards the mucus-secreting cell differentiation pathway with multiple features of cancer-associated molecular phenotype.
These observations provide insights into the unique biology of human SAE by providing quantit-ative assessment of the global transcriptome under physiological conditions and in response to the stress of chronic cigarette smoking.
Identification and typing of human enterovirus (HEVs) are important to pathogen detection and therapy. Previous phylogeny-based typing methods are mainly based on multiple sequence alignments of specific genes in the HEVs, but the results are not stable with respect to different choices of genes. Here we report a novel method for identification and typing of HEVs based on information derived from their whole genomes. Specifically, we calculate the k-mer based barcode image for each genome, HEV or other human viruses, for a fixed k, 1
The purpose of the present study was to investigate the therapeutic effect of magnetic fluid hyperthermia (MFH) induced by an alternating magnetic field (AMF) on human carcinoma A549 xenograft in nude mice. An animal model of human lung cancer was established by subcutaneous injection of human lung cancer A549 cells in BALB/c nude mice. The xenograft mice were randomly divided into four groups and each group was treated with an injection of a different concentration of magnetic fluid: control, low-dose (67.5 mg/ml), medium-dose (90.0 mg/ml) and high-dose group (112.5 mg/ml), respectively. Following the injection (24 h), the tumor was heated in an AMF for 30 min. Tumor volumes were then measured every week. The therapeutic effect was assessed by measuring the tumor volume and weight. Pathological examination was performed with a light and electronic microscope following treatment. The temperature at the surface of the tumor in the low-, medium- and high-dose groups increased to 41.3, 44.5 and 46.8°C, respectively. The tumor grew significantly slower in the medium- and high-dose groups (both p<0.05) compared to the control group. Cytoclasis and apoptosis were detected under light and electron microscopy. In conclusion, MFH induced by AMF inhibited tumor growth and promoted apoptosis of human carcinoma A549 cells in a xenograft mice model.
magnetic fluid; hyperthermia; lung cancer
The Wnt pathway mediates differentiation of epithelial tissues; depending on the tissue types, Wnt can either drive or inhibit the differentiation process. We hypothesized that key genes in the Wnt pathway are suppressed in the human airway epithelium under the stress of cigarette smoking, a stress associated with dysregulation of the epithelial differentiated state.
Microarrays were used to assess the expression of Wnt-related genes in the small airway epithelium (SAE) obtained via bronchoscopy and brushing of healthy nonsmokers, healthy smokers, and smokers with COPD. Thirty-three of 56 known Wnt-related genes were expressed in the SAE. Wnt pathway downstream mediators β-catenin and the transcription factor 7-like 1 were down-regulated in healthy smokers and smokers with COPD, as were many Wnt target genes. Among the extracellular regulators that suppress the Wnt pathway, secreted frizzled-related protein 2 (SFRP2), was up-regulated 4.3-fold in healthy smokers and 4.9-fold in COPD smokers, an observation confirmed by TaqMan Real-time PCR, Western analysis and immunohistochemistry. Finally, cigarette smoke extract mediated up-regulation of SFRP2 and down-regulation of Wnt target genes in airway epithelial cells in vitro.
Smoking down-regulates the Wnt pathway in the human airway epithelium. In the context that Wnt pathway plays an important role in differentiation of epithelial tissues, the down-regulation of Wnt pathway may contribute to the dysregulation of airway epithelium differentiation observed in smoking-related airway disorders.
Results 1-25 (30)
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