Bioinformatics analyses of differentially expressed genes associated with spinal cord injury:a microarray-based analysis in a mouse model

Gene spectrum analysis has shown that gene expression and signaling pathways change dramatically after spinal cord injury,which may affect the microenvironment of the damaged site.Microarray analysis provides a new opportunity for investigating diagnosis,treatment,and prognosis of spinal cord injury.However,differentially expressed genes are not consistent among studies,and many key genes and signaling pathways have not yet been accurately studied.GSE5296 was retrieved from the Gene Expression Omnibus DataSet.Differentially expressed genes were obtained using R/Bioconductor software(expression changed at least two-fold;P < 0.05).Database for Annotation,Visualization and Integrated Discovery was used for functional annotation of differentially expressed genes and Animal Transcription Factor Database for predicting potential transcription factors.The resulting transcription regulatory protein interaction network was mapped to screen representative genes and investigate their diagnostic and therapeutic value for disease.In total,this study identified 109 genes that were upregulated and 30 that were downregulated at 0.5,4,and 24 hours,and 3,7,and 28 days after spinal cord injury.The number of downregulated genes was smaller than the number of upregulated genes at each time point.Database for Annotation,Visualization and Integrated Discovery analysis found that many inflammation-related pathways were upregulated in injured spinal cord.Additionally,expression levels of these inflammation-related genes were maintained for at least 28 days.Moreover,399 regulation modes and 77 nodes were shown in the protein-protein interaction network of upregulated differentially expressed genes.Among the 10 upregulated differentially expressed genes with the highest degrees of distribution,six genes were transcription factors.Among these transcription factors,ATF3 showed the greatest change.ATF3 was upregulated within 30 minutes,and its expression levels remained high at28 days after spinal cord injury.These key genes screened by bioinformatics tools can be used as biological markers to diagnose diseases and provide a reference for identifying therapeutic targets.

Genome Array on Differentially Expressed Genes of Skin Tissue in Cashmere Goat at Early Anagen of Cashmere Growth Cycle Using DNA Microarray

In order to study the molecular mechanism involved in cashmere regeneration, this study investigated the gene expression profile of skin tissue at various stages of the cashmere growth cycle and screen differentially expressed genes at proangen in 10 cashmere goats at 2 years of age using agilent sheep oligo microarray. Significance analysis of microarray （SAM） methods was used to identify the differentially expressed genes, Hierarchical clustering was performed to clarify these genes in association with different cashmere growth stages, and GO （Gene ontology） and the pathway analyses were con-ducted by a free web-based Molecular Annotation System3.0 （MAS 3.0）. Approximately 10200 probe sets were detected in skin tissue of 2-yr-old cashmere goat. After SAM analysis of the microarray data, totally 417 genes were shown to be differentially expressed at different cashmere growth stages, and 24 genes are significantly up-regulated （21） or down-regulated （3） at proangen concurrently compared to angen and telogen. Hierarchical clustering analysis clearly distinguished the differentially expressed genes of each stage. GO analysis indicated that these altered genes at proangen were predominantly involved in collagen fibril organization, integrin-mediated signaling pathway, cell-matrix adhesion, cell adhesion, transforming growth factor-β （TGF-β） receptor signaling pathway, regulation of cell growth. Kyoto encyclopedia of genes and genomes （KEGG） analysis showed that the significant pathways involved mainly included focal adhesion and extracellular matrixc （ECM）-receptor interaction. Some important genes involved in these biological processes, such as COL1A1, COL1A2, COL3A1, SPARC, CYR61 and CTGF, were related to tissue remolding and repairing and detected by more than one probe with similar expression trends at different stages of cashmere growth cycle. The different expression of these genes may contribute to understanding the molecular mechanism of cashmere regeneration.

Microarray analysis of genes differentially expressed in placentas of pregnancy-induced hypertension patients

Objective: To uncover new clue for the research of the etiology of pregnancy-induced hypertension (PIH) by testing the gene expression difference between preeclamptic placentas and normal ones. Methods: mRNA level of 4 PIH placentas were examined using 4000 feature cDNA microarray in comparison with the pooled control consisting of total RNA from 4 cases of PIH placentas after the control cDNA and experimental cDNA were labeled by cy3 and cy5 respectively. Results: Fifty-eight to 131 genes were found down or up-regulated in 4 runs of hybridization. Among the differentially expressed genes, 22 genes, including genes encoding secreted protein ADRP, CYR61, EPI and HIF2, had the concordance in at least 2 cases were up-regulated or down-regulated. Conclusion: cDNA microarray is a high throughput and time-saving method to monitor the altered gene expression and the result could provide interesting clue and strategy for the etiological research of PIH.

Identifi cation of the differential expressive tumor associated genes in rectal cancers by cDNA microarray

AIM： To identify tumor associated genes of rectal cancer and to probe the application possibility of gene expression profiles for the classification of tumors.METHODS： Rectal cancer tissues and their paired normal mucosa were obtained from patients undergoing surgical resection of rectal cancer. Total RNA was extracted using Trizol reagents. First strand cDNA synthesis was indirectly labeled with aminoallyl-dUTP and coupled with Cy3 or Cy5 dye NHS mono-functional ester. After normalization to total spots, the genes which background subtracted intensity did not exceed 2 SD above the mean blank were excluded. The data were then sorted to obtain genes differentially expressed by ≥ 2 fold up or down in at least 5 of the 21 patients.RESULTS： In the 21 rectal cancer patients, 23 genes were up-regulated in at least 5 samples and 15 genes were down-regulated in at least 5 patients. Hierachical cluster analysis classified the patients into two groups according to the clinicopathological stage, with one group being all above stage Ⅱ and one group all below stage Ⅱ.CONCLUSION： The up-regulated genes and downregulated genes may be molecular markers of rectal cancer. The expression profiles can be used for classification of rectal cancer.

Study with microarrays of the differential gene expression profiles of glioblastoma

Objective:Thisstudyaimsto screenthedifferentiallyexpressedgenesof glioblastomausingmicroarraytech-nique.Methods:Specimensof glioblastomaandnormalbraintissuewereobtainedfrompathologicallyconfirmedpatients.A cDNAmicroarraycomprising14000clonescoveringthewholesetsof theretro-transcriptionalproductsof themRNAs of variousgliomasandthoseof normalbraintissueswas established,withwhichthedifferencesin geneexpressionbe-tweenglioblastomaandnormalbraintissueswereinvestigated.Results:Itwas foundthat94genesweremorethan3-fold differentiallyexpressedwith298morethandoubledintheglioblastomaincomparisonwiththenormalbraintissue.Some over-expressedgenesintheglioblastomawerescarcelyexpressedinnormalbraintissues,andseveralnovelgenesthatmay havebiologicalrelevanceintheprocessof gliomagenesiswereidentified.Conclusion:Microarraytechniquecombined withrelevantcDNArepositorycanfacilitaterapidlarge-scaleidentificationof potentialtargetgenesfordiagnosisandther-apy of glioma.

Microarray-Based Differential Expression Monitoring of 79 Novel Genes in Human Fetal Tissues

ESTs fragments which represents corresponding novel genes were obtained by sequencing and bioinformatics analysis of human fet al kidney cDNA library. Microarray was prepared by using these novel EST fragmen ts by automatic spotting. Expression patters of 79 ESTs of novel genes from huma n fetal kidney were analyzed in fetal brain and fetal heart tissues of 20\|week\ | and 26\|week\|age fetus by performing of cDNA chip hybridization. This provide s clues for studying exact functions of the novel genes. 8 genes were obtained w hich were expressed differentially in the fetal brain and heart of 20\|week\| an d 26\|week\|age respectively. Then differentially expressed genes were identifie d by Northern analysis. The more exact function of the novel genes is under stud y.

Effect of Menopause on Gene Expression Profiles of Circu-lating Monocytes: A Pilot in vivo Microarray Study

Menopause is one of the key physiological events in the female life and can increase the risk for a number of complex autoimmune, neurodegenerative, metabolic, and cardiovascular disorders. Circulating monocytes can differentiate into various cell types and play an important role in tissue morphogenesis and immune response. We studied gene expression profiles of peripheral blood monocytes in healthy pre- and postmenopausal women using Affymetrix Human U133A GeneChip array that contains probes for -14,500 genes. Comparative analyses between the samples showed that 20 genes were up- and 20 were down-regulated. Of these genes, 28 were classified into six major GO categories relevant to such biological processes as the cell proliferation, immune response, cellular metabolism, and the others. The remaining 12 genes have yet unidentified biological functions. Our results support the hypothesis that functional state of circulating monocytes is indeed affected by menopause, and resulting changes may be determined through the genomewide gene expression profiling. Several differentially expressed genes identified in this study may be candidates for further studies of menopause-associated systemic autoimmune, neurodegenerative, and cardiovascular disorders. Our study is only the first attempt in this direction, but it lays a basis for further research.

Analysis of gene expression profiles in pancreatic carcinoma by using cDNA microarray

OBJECTIVES: To survey the gene expression profiles in pancreatic carcinoma by using cDNA microarray and detect target genes for further study. METHODS: Three mixed samples from 2 cases of normal pancreatic tissue and 4 cases of moderate-differentiated pancreatic carcinoma were studied by means of cDNA microarray consisting of 18 000 genes. RESULTS: 1484 and 1353 different expressed genes were observed in two cancer samples respectively. We identified 455 genes altered with the same tendency in both samples, including 102 up-regulated and 353 down-regulated genes. There were 274 known genes and 181 unknown genes; 27.8% and 52.0% genes respectively had an expression level in cancer that was 2-fold higher or lower than that in normal samples. Tumor suppressor genes, growth factors and receptor genes, signal conduction genes, transcription factor genes were identified. CONCLUSIONS: cDNA microarray is an efficient and high-throughout method to investigate gene expression profiles in pancreatic carcinoma. MBD1, EDG1 and gene hypermethylation mechanism would play an important role in the pathogenesis of pancreatic carcinoma.

GENE EXPRESSION PROFILING IN MULTIDRUG RESISTANT KB CELLS USING cDNA MICROARRAYS

Objective: A single mechanistic pathway cannot explain the genesis of drug resistance in cancer. Drug resistance in cancer is a major obstacle to successful chemotherapy. KB cells provide a useful starting point for selection of the multidrug resistant (MDR) cell lines. Methods: We used cDNA microarrays containing 12,720 sequences of known genes, expressed sequence tags and unknown clones to monitor gene expression profiles in MDR KB cells. Results: Preliminary data analysis showed that 18 genes were up-regulated and 18 genes were down-regulated by comparison of expression patterns between KB 3-1 and MDR KB-V1 cells. Furthermore, the highly over-expressed CGA, CLU genes in MDR KB-V1 cell were verified with conventional Northern blot analysis. These genes contain information predictive of drug resistance of cancer cells. Conclusion: Our study demonstrates that genome-wide gene expression profiling by using cDNA microarray technique is a valuable approach in obtaining molecular mechanism of drug resistance in cancer cells.

Monitoring microarray-based gene expression profile changes in hepatocellular carcinoma

AIM: To find out key genes responsible for hepatocarc inogenesis and to further understand the underlying molecular mechanism through investigating the differential gene expression between human normal liver tissue and hepatocellular carcinoma (HCC).METHODS: DNA microarray was prepared by spotting PCR products of 1 000 human genes including 445 novel genes, 540 known genes as well as 12 positive (housekeeping) and 3 negative controls (plant gene) onto treated glass slides. cDNA probes were prepared by labeling normal liver tissue mRNA and cancer liver tissue mRNA with Cy3-dUTP and Cy5-dUTP separately through reverse transcription. The arrays were hybridized against the cDNA probe and the fluorescent signals were scanned. The dataobtained from repeated experiments were analyzed. RESULTS: Among the 20 couple samples investigated (from cancerous liver tissue and normal liver tissue), 38 genes including 21 novel genes and 17 known genes exhibited different expressions. CONCLUSION: cDNA microarray technique is powerful to identify candidate target genes that may play important roles in human carcinogenesis. Further analysis of the obtained genes is helpful to understand the molecular changes in HCC progression and ultimately may lead to the identification of new targets for HCC diagnosis and intervention.

DNA Microarray Analysis of Gene Expression in Eutopic Endometrium from Patients with Endometriosis

Pathogenesis of the endometriosis is complex and the etiology is still unclear. The objective of this study was to examine that endometrial gene expression in late secretory phase endometrium differs between patients with and without endometriosis. Five patients with proven advanced-stage endometriosis and 5 controls underwent endometrial biopsy in the late secretory phase. Analysis of eutopic endometrial gene expression was performed using Affymetrix gene arrays and differentially expressed genes were assigned to gene ontology groups based on overrepresented analysis using Database for Annotation, Visualization, and Integrated Discovery software. Four hundred sixty two genes were identified as up-regulated such as matrix metalloproteinase 10, cytochrome P450 family 24 subfamily A polypeptide 1, matrix metalloproteinase 3, chemokine (C-C motif) ligand 20, Rho family GTPase 1, interleukin 1-beta, and insulin-like growth factor binding protein 1. Six hundred forty three genes were down-regulated in all endometriotic samples. A lot of genes related with metabolic process, cellular ketone metabolic process and ncRNA metabolic processing were included. Expression patterns of selected five genes were validated by quantitative real time PCR. The results of this analysis support that the eutopic endometrium from patients with advanced-stage endometriosis has distinct gene expression profile from eutopic endometrium of control without endometriosis.

Gene Expression Patterns in Different Wool Densities of Rex Rabbit Using cDNA Microarray

This study was carried out to identify gene expression patterns in different wool densities of rex rabbit. The mid-dorsal skin samples from 8 rex rabbits were studied. They were divided into two groups according to different wool densities. Total RNA was isolated and labeled by reverse transcription reaction with Cy5-dCTP and Cy3-dCTP for cDNA probe. The cDNA probe was hybridized with cDNA microarrays containing 14 601 rabbit’s genes. The differently expressed genes were analysed with the Gene Ontology （GO） classification and the pathway analysis. Hierarchical clustering was performed to clarify genes in association with different wool densities. The 2 657 differentially expressed genes were identified. Among them, 1 103 genes were functionally known genes, 687 genes were up-regulated and 419 were down-regulated. GO analysis indicated that these altered genes were associated with metabolism, signal transduction, cell cycle, cell adhesion, cell proliferation, cell division, apoptosis, and other processes. KEGG analysis showed that 95 signal pathways associated with up-regulated genes and 87 signal pathways associated with down-regulated genes had changed significantly （P0.05）. Some important differentially expressed genes in different wool densities of rex rabbit were identified, such as MMP2, TGF-β1, TGF-β2, IGF-1, ITGB1, RPS6KB1, BMP2, ActRIIB, CDK2, and CCNA2. Hierarchical clustering analysis separated the differentially expressed genes into 5 main characteristic groups. Data from cDNA microarray experiments clearly distinguished between group A and group B. Some important genes were identified, which might be useful in further study on wool density markers of rex rabbit.

Analysis of Gene Expression Profile in Lung Adenosquamous Carcinoma Using cDNA Microarray

Gene expression profile of the lung adenosquamous carcinoma was characterized by using cDNA microarray chip containing 4 096 human genes. Among target genes, 508 differentially expressed genes were identified in adenosquamous carcinoma of the lung, 232 genes were overexpressed and 276 genes were underexpressed. Among them, 92 genes are cell signals transduction genes, 34 genes are proto-oncogenes and tumor suppressor genes or cell cycle related genes or cell apoptosis related genes, 29 genes are cell skeleton genes, 28 genes are DNA synthesis, repair and recombination genes, 12 genes are DNA binding and transcription genes. These genes may be associated with the occurence and development of adenosquamous carinome of the lung. Key words lung carcinoma - adenosquamous carcinoma - microarray - gene expression profile CLC number R 734.2 Foundation item: Supported by the National Natural Science Foundation of China (39870305)Biography: YANG Fei(1972-), female, Ph. D candidate, research direction: etiology and pathogenesis of lung cancer.

Verification of gene expression profiles for colorectal cancer using 12 internet public microarray datasets

AIM: To verify gene expression profiles for colorectal cancer using 12 internet public microarray datasets.

Deep Learning Enabled Microarray Gene Expression Classification for Data Science Applications

In bioinformatics applications,examination of microarray data has received significant interest to diagnose diseases.Microarray gene expression data can be defined by a massive searching space that poses a primary challenge in the appropriate selection of genes.Microarray data classification incorporates multiple disciplines such as bioinformatics,machine learning(ML),data science,and pattern classification.This paper designs an optimal deep neural network based microarray gene expression classification(ODNN-MGEC)model for bioinformatics applications.The proposed ODNN-MGEC technique performs data normalization process to normalize the data into a uniform scale.Besides,improved fruit fly optimization(IFFO)based feature selection technique is used to reduce the high dimensionality in the biomedical data.Moreover,deep neural network(DNN)model is applied for the classification of microarray gene expression data and the hyperparameter tuning of the DNN model is carried out using the Symbiotic Organisms Search(SOS)algorithm.The utilization of IFFO and SOS algorithms pave the way for accomplishing maximum gene expression classification outcomes.For examining the improved outcomes of the ODNN-MGEC technique,a wide ranging experimental analysis is made against benchmark datasets.The extensive comparison study with recent approaches demonstrates the enhanced outcomes of the ODNN-MGEC technique in terms of different measures.

Oligomicroarray-based primary study of gene expression profile changes in Barrett’s esophagus

Objective: To analyze the differential expression genes (DEGs) between Barrett’s esophagus (BE) and normal esophagus mucosa and explore the target genes related to the development and progression of BE. Methods: The total RNAs of matched BE and normal esophagus mucosa of BE patients were isolated using one step Trizol method. Matched RNAs were qualified using 10 g/L agarose gel electrophoresis. cRNAs were synthesized, fluorescence labeled and purified after total RNAs were purified. The RNAs of BE and normal esophagus mucosa were hybridized with Agilent oligomicroarray (30 968 probes). The fluorescence intensity features were detected by Agilent scanner and quantified by feature extraction software. Results: (1) The total RNA, reverse transcription product and fluorescence labeled cRNA were all of high quality; (2) There were 142 up-regulated genes and 284 down-regulated genes among 2-fold DEGs. Conclusion: Microarray-based studies are feasible in endoscopically obtained tissues. Many BE-associated genes are screened by the high-throughput gene chip. The development and progression of BE is a complicated process involving multiple genes and multiple procedures, and functional study of these genes may help to identify the key genes or pathways involved in the pathogenesis and development of BE.

cDNA Microarray Analysis of Insulin Resistance-associated Genes in Fructose-fed Rats

This study was conducted to investigate the gene expression in fructose-fed rat skeletal muscle by cDNA chip which could provide support to elucidate the molecular mechanisms underlying insulin resistance. The rats were divided into two groups, one of which was normal control and the other was fed with fructose-rich diet. The mRNA was isolated and purified from the skeletal muscle of two groups. The mRNA from two kinds of tissue was reverse transcribed to cDNA with Cy3-dUTP and Cy5-dUTP separately to prepare hybridization probes. The mixed probes were hybridized to cDNA microarray. The microarray was scanned, analyzed and repeated for two times. Among the total 4 096 tested genes, 140 genes were differently expressed, 62 up-regulated,78 down-regulated, the expression of Ptprd and Gilz and multiple genes of oxidative metabolism is associated in insulin resistance. The differential expression of gene may be related to the pathogenesis of insulin resistance.

Study on Wusan Granule Anti-tumor Related Target Gene Screened by cDNA Microarray

To screen Wusan Granule anti-tumor related target gene using cDNA microarray technique, both mRNA from Lewis lung carcinoma tissues treated by Wusan Granule and untreated control are reversibly transcribed to prepare cDNA probes which are labeled by Cy5 and Cy3. Then, the probes are hybridized to the mice cDNA microarray type MGEC-20S. After hybridization, the cDNA microarray is scanned by ScanArray 3 000 scanner and the data is analyzed by ImaGene 3 software to screen the differentially expressed genes. There are 45 differentially expressed genes including 18 known genes and 27 unknown genes between the two groups, and among them, 20 elevated genes and 25 reduced genes are identified. Additionally, the genes related to invasion and metastasis of malignant carcinomas are down-regulated and the genes related to apoptosis are up-regulated. The cDNA microarray technique is a high-throughput approach to screen the Wusan Granule anti-tumor related target genes, which allow us to explore the molecular biological mechanism on a genomic scale.

AnalysisofdifferencesofgeneexpressionsinkeloidandnormalskinwiththeaidofcDNAmicroarray

Background:Microarray analysis is a popular tool to investigate the function of genes that are responsi-ble for the phenotype of the disease.Keloid is a intricate lesion which is probably modulated by interplay of manygenes.We ventured to study the differences of gene expressions between keloids and normal skins with the aid ofcDNA microarray in order to explore the molecular mechanism underlying keloid formation.Methods:The PCRproducts of 8400 human genes were spotted on a chip in array.The DNAs were t...

Bioinformatics analysis of microarray data to explore the key genes involved in HSF4 mutation-induced cataract

AIM： To reveal the mechanisms of heat-shock transcription factor 4 （HSF4） mutation-induced cataract.METHODS： GSE22362, including 3 HSF4-null lens and 3 wild-type lens, was obtained from Gene Expression Omnibus database. After data preprocessing, the differentially expressed genes （DEGs） were identified using the limma package. Based on Database for Annotation, Visualization and Integrated Discovery （DAVID） tool, functional and pathway enrichment analyses were performed for the DEGs. Followed by protein-protein interaction （PPI） network was constructed using STRING database and Cytoscape software. Furthermore, the validated microRNA （miRNA）-DEG pairs were obtained from miRWalk2.0 database, and then miRNA-DEG regulatory network was visualized by Cytoscape software. RESULTS： A total of 176 DEGs were identified in HSF4-null lens compared with wild-type lens. In the PPI network, FBJ osteosarcoma oncogene （FOS）, early growth response 1 （EGR1） and heme oxygenase （decycling） 1 （HMOX1） had higher degrees and could interact with each other. Besides, mmu-miR-15a-5p and mmu-miR-26a-5p were among the top 10 miRNAs in the miRNA-DEG regulatory network. Additionally, mmu-miR-26a-5p could target EGR1 in the regulatory network. CONCLUSION： FOS, EGR1, HMOX1, mmu-miR-26a-5p and mmu-miR-15a-5p might function in the pathogenesis of HSF4 mutation-induced cataract.