Discovery of molecular associations among aging, stem cells, and cancer based on gene expression profiling

The emergence of a huge volume of "omics" data enables a computational approach to the investigation of the biology of cancer. The cancer informatics approach is a useful supplement to the traditional experimental approach. I reviewed several reports that used a bioinformatics approach to analyze the associations among aging, stem cells, and cancer by microarray gene expression profiling. The high expression of aging- or human embryonic stem cell-related molecules in cancer suggests that certain important mechanisms are commonly underlying aging, stem cells, and cancer. These mechanisms are involved in cell cycle regulation, metabolic process, DNA damage response, apoptosis, p53 signaling pathway, immune/inflammatory response, and other processes, suggesting that cancer is a developmental and evolutional disease that is strongly related to aging. Moreover, these mechanisms demonstrate that the initiation, proliferation, and metastasis of cancer are associated with the deregulation of stem cells. These findings provide insights into the biology of cancer. Certainly, the findings that are obtained by the informatics approach should be justified by experimental validation. This review also noted that next-generation sequencing data provide enriched sources for cancer informatics study.

GENE EXPRESSION PROFILING OF HUMAN PROMYELOCYTIC LEUKEMIA HL-60 CELL TREATED BY AJOENE

Objective: Ajoene, a major compound extracted from crashed garlic, has been shown to have antitumor, antimycotic, antimicrobial, antimutagenic functions in vivo or in vitro and treated as a potential antitumor drug. However, the molecular mechanisms underlying the tumor cytotoxicity of ajoene and even garlic substances are poorly defined. In the present study, we aimed to generate gene expression profiles of HL-60 cell treated by ajoene. Methods: A cDNA microarray presenting 2400 of genes amplified from human leukocyte cDNA library was constructed and the gene expression profiles of HL-60 cell induced by ajoene were generated. Results: After data analysis, 28 differentially expressed genes were identified and sequenced. These genes include 21 known genes and 7 ESTs. Most of the known genes are related to cell apoptosis, such as secretory granule (PRG1), beta-2 microglobulin (B2M), 16S ribosomal RNA gene and ribosomal protein S12. Several genes are related to cell differentiation, including the genes similar to H3 histone and ribosomal protein L31. Northern blot analysis was used to verify and quantify the expression of selected genes. Conclusion: Ajoene can induce HL-60 cell apoptosis significantly and may play a role in differentiation. cDNA microarray technology can be a valuable tool to gain insight into molecular events of pharmacological mechanism of herbal medicine.

GENE EXPRESSION PROFILING OF GANGLIOGLIOMA MALIGNANT PROGRESSION BY cDNA ARRAY

Objective: To establish gene expression profiles associated with malignant progression of ganglioglioma. Methods: The primary and two recurrent glioma specimens were collected intraoperatively from the same patient who experienced tumor transformation into anaplastic astrocytoma and glioblastoma multiform for the first and second recurrence respectively. Gene expression was assayed through cDNA array and bioinformatics analysis. Results: A total of 197 differentially expressed genes with differential ratio value more than 3 compared with normal brain tissue were obtained. Among 109 functionally denned genes, those associated with development ranked the first by frequency, followed by genes associated with metabolism, differentiation, signal transduction and so on. As a result of cluster analysis among 368 genes, eleven genes were up regulated with malignant progression, while six genes were down regulated. Conclusion: Gene expression profiles associated with malignant progression of glioma were successfully established, which provides a powerful tool for research on molecular mechanisms of malignant progression of gliomas.

Gene Expression Profiling of the Mouse Pancreas during the Secondary Transition in the Organogenesis of the Pancreatic Gland*

Diabetes mellitus is a chronic disease that impacts the homeostasis of blood sugar levels caused by loss or defect of insulin-producing β-cells in the Islets of Langerhans. Type 1 diabetes (T1D) is caused by auto-immune mediated destruction of β-cells, whereas in T2D, insulin is produced but used inefficiently. T2D accounts for 90% of people with diabetes worldwide (WHO 1999) and is the fastest increasing disease worldwide (https://diabetesatlas.org/en/). For an improved understanding of the pathomechanism of diabetes, profound knowledge of pancreas organogenesis and the associated gene regulatory networks is required. Therefore, we dissected and profiled the pancreatic endodermal and non-endodermal compartment between the embryonic stages (E) 12.5 and E 15.5 when progenitor cells commit to their different pancreatic lineages. Our associated study mined the global mRNA expression profile to increase the understanding of the secondary transition, endodermal-non-endodermal tissue interaction, and diabetic-related gene regulation. Furthermore, we validated 635 regulated pancreatic genes using the publicly available GenePaint.org, respective gp3.mpg.de to evaluate genes associated with genetic variants in Single-nucleotide polymorphism (SNP) related to T2D.

Effect of Chuanzhifang component (ZGC) on macrophage inflammatory injury based on whole gene expression profile

Objective: The effect of Chuanzhi Fang (ZGC) on the whole genome expression profile of RAW264.7 cells activated by lipopolysaccharide (LPS) was analyzed, and to explore the possible mechanism of action and core target of this formula on macrophage inflammatory injury at the overall level. Methods: A model of LPS-induced inflammation in RAW264.7 cells was constructed, and the effect of ZGC intervention on the genome-wide expression of inflammatory macrophages 3was examined by gene microarray technology, GO/KEGG enrichment analysis was performed for significantly differentially expressed genes among each group. Results: The results of genome-wide expression profiling microarray analysis showed that the ZGC intervention group upregulated the expression of 5 genes including C4bp and inhibited the expression of 22 genes including Mgat3, Psma6, and Siglecg relative to the LPS model group. KEGG signaling pathway analysis results showed that ZGC mainly acted through cytokine receptor interaction and the C-type lectin receptor signaling pathway. Conclusion: ZGC can interfere with the abnormal expression of 27 genes in inflammatory macrophages, and the related genes may exert corresponding anti-inflammatory effects by affecting cytokine receptor interactions, C-type lectin receptor signaling pathway, and TLR4/ NF-κB signaling pathway.

Molecular subtypes identified by gene expression profiling in early stage endometrioid endometrial adenocarcinoma

Background Early stage （FIGO stage Ⅰ-Ⅱ） endometrioid endometrial adenocarcinoma （EEA） is very common in clinical practice.However,patients with the early stage EEA show various clinical behaviors due to biological heterogeneity.Hence,we aimed to discover distinct classes of tumors based on gene expression profiling,and analyze whether the molecular classification correlated with the histopathological stages or other clinical parameters.Methods Hierarchical clustering was performed for class discovery in 28 eady stage EEA samples using a special cDNA microarray chip containing 492 genes designed for endometrial cancer.Correlations between clinicopathologic parameters and our classification were analyzed.And the significance analysis of microarrays （SAM） array was used to identify the signature genes according to the tumor grade and myometrial invasion.Results Three tumor subtypes （subtypes Ⅰ,Ⅱ and Ⅲ） were identified by hierarchical clustering,each subtype had different clinicopathological factors,such as tumor grade,myometrial invasion status,and FIGO stage.Moreover,SAM analysis showed 34 up-regulated genes in high grade tumors,and 38 up-regulated genes and 1 down-regulated in deep myometrial invasive tumors.The overlap genes between these two high-risk factors were markedly up-regulated in subtype Ⅰ,but down-regulated in subtype Ⅲ.Conclusion We have identified novel molecular subtypes in early stage EEA.Differential gene signatures characterize each tumor subtype,which could be used for recognizing the tumor risk and providing a basis for further treatment stratification.

Comprehensive genomic analysis and expression profiling of cysteine-rich polycomb-like transcription factor gene family in tea tree

Cysteine-rich polycomb-like(CPP)is a small gene family in plants,which plays key role in plant development and stress response.Although CPP transcription factors have been characterized in several other plant species,a genome-wide characterization of the CPP gene family has been absent in Camellia sinensis.In this study,we totally identified 7,8,and 8 non-redundant CsCPP genes in three published genomes,including Camellia sinensis var.assamica cv.Yunkang-10(CSA-YK10),Camellia sinensis var.sinensis cv.Biyun(CSS-BY)and Camellia sinensis var.sinensis cv.Shuchazao(CSS-SCZ).CPP proteins from tea tree and other plant species were classified into three groups,which were further divided into four subgroups based on phylogenetic relationships.Most CPP genes in the same subgroup had similar gene structures and conserved motifs.The cis-acting elements analysis indicated that CPP genes might be involved in plant growth,development and stress responses.Analysis of gene expression using qRT-PCR experiments validated that CPP genes exhibited different expression patterns across the examined tissues.All the genes were expressed differentially in a range of tissues,indicating that CPPs were involved in a range of developmental and physiological processes.This study has obtained new insights into the evolution and function of the CPP gene family in the growth and development of tea plants,and also provide candidate genes for further functional characterization in tea tree.

MP3RNA-seq:Massively parallel 3’end RNA sequencing for high-throughput gene expression profiling and genotyping

Transcriptome deep sequencing(RNA‐seq)hasbecome a routine method for global geneexpression profiling.However,its application tolarge‐scale experiments remains limited by costand labor constraints.Here we describe amassively parallel 3′end RNA‐seq(MP3RNA‐seq)method that introduces unique samplebarcodes during reverse transcription to permitsample pooling immediately following this initialstep.MP3RNA‐seq allows for handling of hun-dreds of samples in a single experiment,at acost of about$6 per sample for libraryconstruction and sequencing.MP3RNA‐seq iseffective for not only high‐throughput geneexpression profiling,but also genotyping.Todemonstrate its utility,we applied MP3RNA‐seqto 477 double haploid lines of maize.We iden-tified 19,429 genes expressed in at least 50%ofthe lines and 35,836 high‐quality singlenucleotide polymorphisms for genotypinganalysis.Armed with these data,we performedexpression and agronomic trait quantitativetrait locus(QTL)mapping and identified 25,797expression QTLs for 15,335 genes and 21 QTLsfor plant height,ear height,and relative earheight.We conclude that MP3RNA‐seq is highlyreproducible,accurate,and sensitive forhigh‐throughput gene expression profiling andgenotyping,and should be generally applicableto most eukaryotic species.

Gene expression profiling as a prognostic tool in multiple myeloma

Multiple myeloma(MM)is an aggressive plasma cell malignancy with high degrees of variability in outcome,some patients experience long remissions,whilst others survive less than two years from diagnosis.Therapy refractoriness and relapse remain challenges in MM management,and there is a need for improved prognostication and targeted therapies to improve overall survival(OS).The past decade has seen a surge in gene expression profiling(GEP)studies which have elucidated the molecular landscape of MM and led to the identification of novel gene signatures that predict OS and outperform current clinical predictors.In this review,we discuss the limitations of current prognostic tools and the emerging role of GEP in diagnostics and in the development of personalised medicine approaches to combat drug resistance.

Gene signatures to therapeutics:Assessing the potential of ivermectin against t(4;14)multiple myeloma

BACKGROUND Multiple myeloma(MM)is a terminal differentiated B-cell tumor disease characterized by clonal proliferation of malignant plasma cells and excessive levels of monoclonal immunoglobulins in the bone marrow.The translocation,(t)(4;14),results in high-risk MM with limited treatment alternatives.Thus,there is an urgent need for identification and validation of potential treatments for this MM subtype.Microarray data and sequencing information from public databases could offer opportunities for the discovery of new diagnostic or therapeutic targets.AIM To elucidate the molecular basis and search for potential effective drugs of t(4;14)MM subtype by employing a comprehensive approach.METHODS The transcriptional signature of t(4;14)MM was sourced from the Gene Expression Omnibus.Two datasets,GSE16558 and GSE116294,which included 17 and 15 t(4;14)MM bone marrow samples,and five and four normal bone marrow samples,respectively.After the differentially expressed genes were identified,the Cytohubba tool was used to screen for hub genes.Then,the hub genes were analyzed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis.Using the STRING database and Cytoscape,protein–protein interaction networks and core targets were identified.Potential small-molecule drugs were identified and validated using the Connectivity Map database and molecular docking analysis,respectively.RESULTS In this study,a total of 258 differentially expressed genes with enriched functions in cancer pathways,namely cytokine receptor interactions,nuclear factor(NF)-κB signaling pathway,lipid metabolism,atherosclerosis,and Hippo signaling pathway,were identified.Ten hub genes(cd45,vcam1,ccl3,cd56,app,cd48,btk,ccr2,cybb,and cxcl12)were identified.Nine drugs,including ivermectin,deforolimus,and isoliquiritigenin,were predicted by the Connectivity Map database to have potential therapeutic effects on t(4;14)MM.In molecular docking,ivermectin showed strong binding affinity to all 10 identified targets,especially cd45 and cybb.Ivermectin inhibited t(4;14)MM cell growth via the NF-κB pathway and induced MM cell apoptosis in vitro.Furthermore,ivermectin increased reactive oxygen species accumulation and altered the mitochondrial membrane potential in t(4;14)MM cells.CONCLUSION Collectively,the findings offer valuable molecular insights for biomarker validation and potential drug development in t(4;14)MM diagnosis and treatment,with ivermectin emerging as a potential therapeutic alternative.

Analysis of Pathway Activity in Primary Tumors and NCI60 Cell Lines Using Gene Expression Profiling Data

To determine cancer pathway activities in nine types of primary tumors and NCI60 cell lines, we applied an in silico approach by examining gene signatures reflective of consequent pathway activation using gene expression data. Supervised learning approaches predicted that the Ras pathway is active in -70% of lung adenocarcinomas but inactive in most squamous cell carcinomas, pulmonary carcinoids, and small cell lung carcinomas. In contrast, the TGF-β, TNF-α, Src, Myc, E2F3, and β-catenin pathways are inactive in lung adenocarcinomas. We predicted an active Ras, Myc, Src, and/or E2F3 pathway in significant percentages of breast cancer, colorectal carcinoma, and gliomas. Our results also suggest that Ras may be the most prevailing oncogenic pathway. Additionally, many NCI60 cell lines exhibited a gene signature indicative of an active Ras, Myc, and/or Src, but not E2F3, β-catenin, TNF-α, or TGF-β pathway. To our knowledge, this is the first comprehensive survey of cancer pathway activities in nine major tumor types and the most widely used NCI60 cell lines. The ＂gene expression pathway signatures＂ we have defined could facilitate the understanding of molecular mechanisms in cancer development and provide guidance to the selection of appropriate cell lines for cancer research and pharmaceutical compound screening.

A Gene Expression Profiling of Early Rice Stamen Development that Reveals Inhibition of Photosynthetic Genes by OsMADS58

Stamen is a unique plant organ wherein germ cells or microsporocytes that commit to meiosis are initiated from somatic cells during its early developmental process. While genes determining stamen identity are known according to the ABC model of floral development, little information is available on how these genes affect germ cell initiation. By using the Affymetrix GeneChip Rice Genome Array to assess 51 279 tran- scripts, we established a dynamic gene expression profile （GEP） of the early developmental process of rice （Oryza sativa） stamen. Systematic analysis of the GEP data revealed novel expression patterns of some developmentally important genes including meiosis-, tapetum-, and phytohormone-related genes. Following the finding that a substantial amount of nuclear genes encoding photosynthetic proteins are ex- pressed at the low levels in early rice stamen, through the ChlP-seq analysis we found that a C-class MADS box protein, OsMADS58, binds many nuclear-encoded genes participated in photosystem and light reac- tions and the expression levels of most of them are increased when expression of OsMADS58 is downre- gulated in the osmads58 mutant. Furthermore, more pro-chloroplasts are observed and increased signals of reactive oxygen species are detected in the osmads58 mutant anthers. These findings implicate a novel link between stamen identity determination and hypoxia status establishment.

Characterization of the 19 Novel Cotton FLA Genes and Their Expression Profiling in Fiber Development and in Response to Phytohormones and Salt Stress

Fasciclin-like arabinogalactan proteins(FLAs),a subclass of arabinogalactan proteins(AGPs),are usually involved in cell development in plants.To investigate the expression profiling as well

Expression Profiling Identifies Candidate Genes for Fiber Yield and Quality

Gene expression profiling at early stages(0～2 DPA) of fiber development in Gossypium hirsutum identified a number of transcription factors which were down regulated in fiberless mutants relative to wild type controls and which could play a role in controlling early fiber development.Chief among these was GhMYB25,a Mixta-like MYB gene.Transgenic GhMYB25-silenced cotton

Identifying genetic susceptibility to Aspergillus fumigatus infection using collaborative cross mice and RNA-Seq approach

Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidate genes associated with host susceptibility to Aspergillus fumigatus(Af)using an RNAseq approach in CC lines and hepatic gene expression.Methods:We studied 31 male mice from 25 CC lines at 8 weeks old;the mice were infected with Af.Liver tissues were extracted from these mice 5 days post-infection,and next-generation RNA-sequencing(RNAseq)was performed.The GENE-E analysis platform was used to generate a clustered heat map matrix.Results:Significant variation in body weight changes between CC lines was ob-served.Hepatic gene expression revealed 12 top prioritized candidate genes differ-entially expressed in resistant versus susceptible mice based on body weight changes.Interestingly,three candidate genes are located within genomic intervals of the previ-ously mapped quantitative trait loci(QTL),including Gm16270 and Stox1 on chromo-some 10 and Gm11033 on chromosome 8.Conclusions:Our findings emphasize the CC mouse model's power in fine mapping the genetic components underlying susceptibility towards Af.As a next step,eQTL analysis will be performed for our RNA-Seq data.Suggested candidate genes from our study will be further assessed with a human cohort with aspergillosis.

Identification of potential immune-related prognostic biomarkers of lung cancer using gene co-expression network analysis

Objective The objective of this study was to identify new carcinogenetic hub genes and develop the integration of differentially expressed genes to predict the prognosis of lung cancer.Methods GSE139032 microarray data packages were downloaded from the Gene Expression Omnibus for planning,testing,and review of data.We identified KRT6C,LAMC2,LAMB3,KRT6A,and MYEOV from a key module for validation.Results We found that the five genes were related to a poor prognosis,and the expression levels of these genes were associated with tumor stage.Furthermore,Kaplan-Meier plotter showed that the five hub genes had better prognostic values.The mean levels of methylation in lung adenocarcinoma(LUAD)were significantly lower than those in healthy lung tissues for the hub genes.However,gene set enrichment analysis(GSEA)for single hub genes showed that all of them were immune-related.Conclusion Our findings demonstrated that KRT6C,LAMC2,LAMB3,KRT6A,and MYEOV are all candidate diagnostic and prognostic biomarkers for LUAD.They may have clinical implications in LUAD patients not only for the improvement of risk stratification but also for therapeutic decisions and prognosis prediction.

Methotrexate combined with methylprednisolone for the recovery of motor function and differential gene expression in rats with spinal cord injury

Methylprednisolone is a commonly used drug for the treatment of spinal cord injury, but high doses of methylprednisolone can increase the incidence of infectious diseases. Methotrexate has anti-inflammatory activity and immunosuppressive effects, and can reduce in- flammation after spinal cord injury. To analyze gene expression changes and the molecular mechanism of methotrexate combined with methylprednisolone in the treatment of spinal cord injury, a rat model of spinal cord contusion was prepared using the PinPointTM preci- sion cortical impactor technique. Rats were injected with methylprednisolone 30 mg/kg 30 minutes after injury, and then subcutaneously injected with 0.3 mg/kg methotrexate 1 day after injury, once a day, for 2 weeks. TreadScan gait analysis found that at 4 and 8 weeks after injury, methotrexate combined with methylprednisolone significantly improved hind limb swing time, stride time, minimum longitudinal deviation, instant speed, footprint area and regularity index. Solexa high-throughput sequencing was used to analyze differential gene ex- pression. Compared with methylprednisolone alone, differential expression of 316 genes was detected in injured spinal cord treated with methotrexate and methylprednisolone. The 275 up-regulated genes were mainly related to nerve recovery, anti-oxidative, anti-inflammatory and anti-apoptotic functions, while 41 down-regulated genes were mainly related to proinflammatory and pro-apoptotic functions. These results indicate that methotrexate combined with methylprednisolone exhibited better effects on inhibiting the activity of inflammatory cytokines and enhancing antioxidant and anti-apoptotic effects and thereby produced stronger neuroprotective effects than methotrexate alone. The 316 differentially expressed genes play an important role in the above processes.

Genome-wide identification,phylogeny and expression analysis of the SBP-box gene family in maize(Zea mays)

The SQUAMOSA promoter binding protein （SBP）-box genes encode a kind of plant-specific transcription factors （TFs） and play important roles in the regulation of plant development. In this study, a genome-wide characterization of this family was conducted in maize （Zea mays）. Thirty-one SBP-box genes were identified to be distributed in nine chromosomes and 16 of them were complementary to the mature ZmmiR156 sequences. All the Z. mays SBP （ZmSBP） genes were classified into two clusters with eight subgroups according to the phylogenetic analysis of proteins, which were consistent with the pattern of exon-intron structures. The phylogenetic tree of the ZmSBP, Oryza sativa SBP-like （OsSPL） and Arabidopsis thaliana SBP-like （AtSPL） genes were constructed and all the SBP-box genes were divided into eight groups, which was the same as the classification of ZmSBP genes. The comparision of the expression profiles of all SBP-box genes in these three species indicated that most orthologous genes had similar expression patterns. The results from this study provided a basic understanding of the ZmSBP genes and might facilitate future researches for elucidating the SBP-box genes function in maize.

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.

Differential Gene Expression Profiles in Acute Hepatic Failure Model in Mice Infected with MHV-3 Virus Intervened by Anti-hepatic Failure Compound

Differential gene expression profiles in Balb/cJ mouse model of acute hepatic failure infected with MHV-3 virus intervened by anti-hepatic failure compound （AHFC） and the changes of cytokines regulated by genes were investigated. The Balb/cj mice were divided into AHFC-intervened group and control group randomly. Acute hepatic failure model of Balb/cJ mice infected with MHV-3 virus was established. The survival rate in the two groups was observed. It was found that the survival rate in the AHFC-intervened group and control group was 90% and 50% respectively 48 h after intraperitoneal injection of MHV-3 （P〈0.05）. Before and after the experiment, the cytokines in peripheral blood of the survival mice were determined, and RNA was extracted from survival mouse liver tissue for the analysis of the differential gene expression by a 36 kb mouse oligonuleotide DNA array. In all the genes of microarray there were 332 genes expressed differently in the two groups, in which 234 genes were up-regulated and 78 genes down-regulated. Through clustering analysis, the differential expression of immune related genes, including TNF receptor superfamily, Kctd9, Bcl-2, Fgl2, IL-8, IL-6, IFN-7, TNF-α etc. might be related with the curative effectiveness of AHFC. It was suggested that AHFC can balance the immune state of mouse model of acute hepatic failure infected with MHV-3 virus mainly through regulating the expression of immune related genes, decrease the immune damage and inhibit liver cell apoptosis of mouse acute hepatic failure model obviously so as to increase the survival rate of mouse models of acute hepatic failure.