Genome-wide mRNA Expression Profiles Research Articles

The potential of baicalin to enhance neuroprotection and mitochondrial function in a human neuronal cell model.

Baicalin is a flavone glycoside derived from flowering plants belonging to the Scutellaria genus. Previous studies have reported baicalin's anti-inflammatory and neuroprotective properties in rodent models, indicating the potential of baicalin in neuropsychiatric disorders where alterations in numerous processes are observed. However, the extent of baicalin's therapeutic effects remains undetermined in a human cell model, more specifically, neuronal cells to mimic the brain environment in vitro. As a proof of concept, we treated C8-B4 cells (murine cell model) with three different doses of baicalin (0.1, 1 and 5 μM) and vehicle control (DMSO) for 24 h after liposaccharide-induced inflammation and measured the levels of TNF-α in the medium by ELISA. NT2-N cells (human neuronal-like cell model) underwent identical baicalin treatment, followed by RNA extraction, genome-wide mRNA expression profiles and gene set enrichment analysis (GSEA). We also performed neurite outgrowth assays and mitochondrial flux bioanalysis (Seahorse) in NT2-N cells. We found that in C8-B4 cells, baicalin at ≥ 1 μM exhibited anti-inflammatory effects, lowering TNF-α levels in the cell culture media. In NT2-N cells, baicalin positively affected neurite outgrowth and transcriptionally up-regulated genes in the tricarboxylic acid cycle and the glycolysis pathway. Similarly, Seahorse analysis showed increased oxygen consumption rate in baicalin-treated NT2-N cells, an indicator of enhanced mitochondrial function. Together, our findings have confirmed the neuroprotective and mitochondria enhancing effects of baicalin in human-neuronal like cells. Given the increased prominence of mitochondrial mechanisms in diverse neuropsychiatric disorders and the paucity of mitochondrial therapeutics, this suggests the potential therapeutic application of baicalin in human neuropsychiatric disorders where these processes are altered.

Transcriptomic profiles reveal differences in gene expression between the testes and epididymis in stallions

Spermatogenesis and sperm maturation take place in the testes and epididymis, respectively. These complex physiological processes are regulated by multiple genes, which have not been studied in the stallion. In this study, Illumina sequencing was used to analyze the transcriptomes of the testes, head, body and tail of the epididymis from three reproductively normal stallions. The mRNA was extracted and the libraries were generated using Next Generation Sequencing (NGS). The expression patterns of differentially expressed genes (DEGs) in the testes and epididymis were determined by bioinformatics analysis. Gene Ontology (GO) enrichment analysis of DEGs was implemented and gene length bias was corrected. Differentially expressed genes were compared between the different segments of the epididymis and the testis (control tissue). GO-terms with adjusted p < 0.05 were considered significantly enriched. Among the four libraries, 18,732 genes were identified. Of those, 6,574 genes (39.1%) were tissue-specific. The distribution of tissue-specific genes was 14.2 % in the testes, 2.2 % in the epididymal head, 1.1 % in the epididymal body, and 1.4 % in the epididymal tail. Compared with testicular tissue, there were 13,349 DEGs (5,595 up-regulated and 7,754 down-regulated) in the epidydimal head, 14,207 DEGs (5,884 up-regulated and 8,323 down-regulated) in the epididymal body, and 14,822 DEGs (5,842 up-regulated and 8,980 down regulated) in the epididymal tail. In the epididymal head,the main downregulated terms were male gamete generation (224 DEGs), spermatogenesis (224 DEGs), organelle fission (264 DEGs), sexual reproduction (343 DEGs) and nuclear division (233 DEGs). The main upregulated terms were associated with the ribosome (322 DEGs), lymphocyte activation (226 DEGs), and cytosolic part (104 DEGs). In the epididymal body, the most significantly downregulated terms were male gamete generation (232 DEGs), spermatogenesis (232 DEGs), sexual reproduction (358 DEGs), cilium morphogenesis (151 DEGs) and cilium (235 DEGs). The most significantly upregulated terms were lysosome (150 DEGs), lytic vacuole (150 DEGs), positive regulation of locomotion (197 DEGs), cytosolic ribosome (71 DEGs), vacuole (182 DEGs). In the epididymal tail, the most significantly downregulated terms were male gamete generation (239 DEGs), spermatogenesis (193 DEGs), cilium (253 DEGs), ciliary part (186 DEGs), cilium morphogenesis (158 DEGs). The most significantly upregulated terms were associated with the ribosome (438 DEGs) and cytosolic part (109 DEGs). In summary, we found decreased expression of genes involved in gamete production, and increased expression of genes involved in protein synthesis, immunity and sperm transport in different segments of the epididymis. These findings provide genome-wide mRNA expression profiles for the horse epididymis and testes, providing a biological basis for future research on stallion fertility.

Spatially resolved transcriptomic profiling of degraded and challenging fresh frozen samples

Spatially resolved transcriptomics has enabled precise genome-wide mRNA expression profiling within tissue sections. The performance of methods targeting the polyA tails of mRNA relies on the availability of specimens with high RNA quality. Moreover, the high cost of currently available spatial resolved transcriptomics assays requires a careful sample screening process to increase the chance of obtaining high-quality data. Indeed, the upfront analysis of RNA quality can show considerable variability due to sample handling, storage, and/or intrinsic factors. We present RNA-Rescue Spatial Transcriptomics (RRST), a workflow designed to improve mRNA recovery from fresh frozen specimens with moderate to low RNA quality. First, we provide a benchmark of RRST against the standard Visium spatial gene expression protocol on high RNA quality samples represented by mouse brain and prostate cancer samples. Then, we test the RRST protocol on tissue sections collected from five challenging tissue types, including human lung, colon, small intestine, pediatric brain tumor, and mouse bone/cartilage. In total, we analyze 52 tissue sections and demonstrate that RRST is a versatile, powerful, and reproducible protocol for fresh frozen specimens of different qualities and origins.

Identification of the circRNA-miRNA-mRNA Regulatory Network in Pterygium-Associated Conjunctival Epithelium.

To investigate the regulatory mechanism of pterygium formation, we detected differentially expressed messenger RNAs (DE-mRNAs) and differentially expressed circular RNAs (DE-circRNAs) in pterygium-associated conjunctival epithelium (PCE) and normal conjunctival epithelium (NCE). Genome-wide mRNA and circRNA expression profiles of PCE and NCE were determined using high-throughput sequencing. Bioinformatics analyses, including Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, gene set enrichment analysis (GSEA), and protein-protein interaction (PPI) analysis, were conducted. The microRNAs (miRNAs) interacting with the hub DE-mRNAs and DE-circRNAs were predicted and verified using real-time quantitative PCR (RT-qPCR). The data showed that there were 536 DE-mRNAs (280 upregulated and 256 downregulated mRNAs) and 78 DE-circRNAs (20 upregulated and 58 downregulated circRNAs) in PCE. KEGG enrichment analysis indicated that the DE-mRNAs were mainly involved in the following biological processes: IL-17 signalling pathway, viral protein interaction with cytokine and cytokine receptor, cytokine-cytokine receptor interaction, ECM-receptor interaction, and focal adhesion. The GSEA results revealed that the epithelial mesenchymal transition (EMT) process was significantly enriched in upregulated mRNAs. The pterygium-associated circRNA-miRNA-mRNA network was established based on the top 10 DE-circRNAs, 4 validated miRNAs (upregulated miR-376a-5p and miR-208a-5p,downregulated miR-203a-3p and miR-200b-3p), and 31 DE-mRNAs. We found that miR-200b-3p, as a regulator of FN1, SDC2, and MEX3D, could be regulated by 5 upregulated circRNAs. In addition, we screened out EMT-related DE-mRNAs, including 6 upregulated DE-mRNAs and 6 downregulated DE-mRNAs. The EMT-related circRNA-miRNA-mRNA network was established with the top 10 circRNAs, 8 validated miRNAs (upregulated miR-17-5p, miR-181a-5p, and miR-106a-5p, downregulated miR-124-3p, miR-9-5p, miR-130b-5p, miR-1-3p, and miR-26b-5P), and 12 EMT-related DE-mRNAs. We found that hsa_circ_0002406 might upregulate FN1 and ADAM12 by sponging miR-26b-5p and miR-1-3p, respectively, thus promoting EMT in pterygium. Briefly, the study provides a novel viewpoint on the molecular pathological mechanisms in pterygium formation. CircRNA-miRNA-mRNA regulatory networks participate in the pathogenesis of pterygium and might become promising targets for pterygium prevention and treatment.

HOXA1 Is an Antagonist of ERα in Breast Cancer.

Breast cancer is a heterogeneous disease and the leading cause of female cancer mortality worldwide. About 70% of breast cancers express ERα. HOX proteins are master regulators of embryo development which have emerged as being important players in oncogenesis. HOXA1 is one of them. Here, we present bioinformatic analyses of genome-wide mRNA expression profiles available in large public datasets of human breast cancer samples. We reveal an extremely strong opposite correlation between HOXA1 versus ER expression and that of 2,486 genes, thereby supporting a functional antagonism between HOXA1 and ERα. We also demonstrate in vitro that HOXA1 can inhibit ERα activity. This inhibition is at least bimodal, requiring an intact HOXA1 DNA-binding homeodomain and involving the DNA-binding independent capacity of HOXA1 to activate NF-κB. We provide evidence that the HOXA1-PBX interaction known to be critical for the transcriptional activity of HOXA1 is not involved in the ERα inhibition. Finally, we reveal that HOXA1 and ERα can physically interact but that this interaction is not essential for the HOXA1-mediated inhibition of ERα. Like other HOX oncoproteins interacting with ERα, HOXA1 could be involved in endocrine therapy resistance.

Integrating Transcriptome-Wide Association Study and mRNA Expression Profiling Identifies Novel Genes Associated With Osteonecrosis of the Femoral Head

ObjectiveThis study aims to identify novel candidate genes associated with osteonecrosis of the femoral head (ONFH).MethodsA transcriptome-wide association study (TWAS) was performed by integrating the genome-wide association study dataset of osteonecrosis (ON) in the UK Biobank with pre-computed mRNA expression reference weights of muscle skeleton (MS) and blood. The ON-associated genes identified by TWAS were further subjected to gene ontology (GO) analysis by the DAVID tool. Finally, a trans-omics comparative analysis of TWAS and genome-wide mRNA expression profiling was conducted to identify the common genes and the GO terms shared by both DNA-level TWAS and mRNA-level expression profile for ONFH.ResultsTWAS totally identified 564 genes that were with PTWAS value <0.05 for MS and blood, such as CBX1 (PTWAS = 0.0001 for MS), SRPK2 (PTWAS = 0.0002 for blood), and MYO5A (PTWAS = 0.0005 for blood). After comparing the genes detected by TWAS with the differentially expressed genes identified by mRNA expression profiling, we detected 59 overlapped genes, such as STEAP4 [PTWAS = 0.0270, FC (fold change)mRNA = 7.03], RABEP1 (PTWAS = 0.010, FCmRNA = 2.22), and MORC3 (PTWAS = 0.0053, FCmRNA = 2.92). The GO analysis of TWAS-identified genes discovered 53 GO terms for ON. Further comparing the GO results of TWAS and mRNA expression profiling identified four overlapped GO terms, including cysteine-type endopeptidase activity (PTWAS = 0.0006, PmRNA = 0.0227), extracellular space (PTWAS = 0.0342, PmRNA = 0.0012), protein binding (PTWAS = 0.0112, PmRNA = 0.0106), and ATP binding (PTWAS = 0.0464, PmRNA = 0.0033).ConclusionSeveral ONFH-associated genes and GO terms were identified by integrating TWAS and mRNA expression profiling. It provides novel clues to reveal the pathogenesis of ONFH.

Genome-wide long noncoding RNA and mRNA expression profiles demonstrate associations between exposure to inorganic elements and the risk of developing hepatocellular carcinoma

BackgroundLong noncoding RNAs (lncRNAs) are closely associated with the development of hepatocellular carcinoma (HCC). The present study conducted a genome-wide microarray analysis and qPCR validation to obtain comprehensive insights into this issue.MethodsThirty male HCC patients with chronic HBV infection were included in the present study. Primary HCC tissue and normal tissue were collected. Double-stranded complementary DNA synthesized from 10 pairs of samples was labeled and hybridized to a microarray chip. Further analyses, such as hierarchical clustering, gene ontology (GO) and pathway analyses, were performed. In addition, qPCR validation was performed on tissue samples and additional serum samples.ResultsThe microarray analysis identified 946 upregulated and 571 downregulated lncRNAs and 1720 upregulated and 1106 downregulated mRNAs. Among these RNAs, ENST00000583827.1 (fold change: 21) and uc010isf.1 (fold change: 18) were the most over- and underexpressed lncRNAs in the HCC tissues, respectively. For the mRNAs, KIF20A (fold change: 26) and HEPACAM (fold change: 50) were the most over- and underexpressed in the HCC tissues, respectively. The GO analysis demonstrated that the most differentially expressed mRNAs were related to the response of metal ions. The pathway analysis also suggested that the most enriched pathway was mineral absorption.ConclusionsThe subsequent qPCR validation exhibited high consistency with the microarray analysis, except for three lncRNAs. The qPCR analysis also demonstrated that TCONS_00008984 had a 767-fold overexpression level in HCC tissues when compared with normal tissues, and this finding was confirmed in the serum samples; therefore, TCONS_00008984 has the potential to serve as a diagnostic marker or prognostic indicator. The GO and pathway analyses indicated that exposure to inorganic elements may be involved in HCC risk.

MiR-146b-3p regulates proliferation of pancreatic cancer cells with stem cell-like properties by targeting MAP3K10.

Purpose: Cancer stem cells (CSCs) initiate and maintain tumorigenesis due to their unique pluripotency. However, pancreatic stem cell gene signatures are not completely revealed yet. Here, we isolated pancreatic cancer stem cells (P-CSCs) and exploited their distinct genome-wide mRNA and miRNA expression profiles using microarrays.Methods: CD24+ CD44+ ESA+ cells were isolated from two pancreatic xenograft cells by the flow cytometry and identified the stem cell-like properties by the tumor formation, self-renew and chemoresistance. Microarrays and qRT-PCR were used to exploit their distinct Genome-wide mRNA and miRNA expression profiles. The function and candidate target genes of key microRNA were detected after Ectopic restoration in the pancreatic cancer cell lines MIA Paca-2 (CSChigh) and BxPC-3 (CSClow).Results: In this study, we isolated P-CSCs from two xenografts cells. Genome-wide profiling experiments showed 479 genes and 15 microRNAs specifically expressed in the P-CSCs, including genes involved in TGF-β and p53 signaling pathways and particularly miR-146b-3p as the most significantly downregulated miRNA. We confirmed miR-146b-3p as a downregulated signature in pancreatic cancer tissues and cell line MIA Paca-2 (CSChigh) cells. Ectopic restoration of miR-146b-3p expression with pre-miR reduced cell proliferation, induced apoptosis, increased G1 phase and reduced S phase in cell cycle in MIA Paca-2 (CSChigh), but not in BxPC-3 (CSClow). Re-expression of miR-146b-3p with lentivirus significantly inhibited tumorigenicity in vivo in MIA Paca-2, but slightly in BxPC-3. Furthermore, we demonstrated that miR-146b-3p directly targeted MAP3K10 and might activate Hedgehog pathway as well through DYRK2 and GLI2.Conclusions: These results suggest that P-CSCs have distinct gene expression profiles. MiR-146b-3p inhibits proliferation and induced apoptosis in P-CSCs high cells lines by targeting MAP3K10. Targeting P-CSCs specific genes may provide novel strategies for therapeutic purposes.

Integrative Analysis of Transcriptome-Wide Association Study and mRNA Expression Profiles Identifies Candidate Genes Associated With Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a type of scarring lung disease characterized by a chronic, progressive, and irreversible decline in lung function. The genetic basis of IPF remains elusive. A transcriptome-wide association study (TWAS) of IPF was performed by FUSION using gene expression weights of three tissues combined with a large-scale genome-wide association study (GWAS) dataset, totally involving 2,668 IPF cases and 8,591 controls. Significant genes identified by TWAS were then subjected to gene ontology (GO) and pathway enrichment analysis. The overlapped GO terms and pathways between enrichment analysis of TWAS significant genes and differentially expressed genes (DEGs) from the genome-wide mRNA expression profiling of IPF were also identified. For TWAS significant genes, protein–protein interaction (PPI) network and clustering modules analyses were further conducted using STRING and Cytoscape. Overall, TWAS identified a group of candidate genes for IPF under the Bonferroni corrected P value threshold (0.05/14929 = 3.35 × 10–6), such as DSP (PTWAS = 1.35 × 10–29 for lung tissue), MUC5B (PTWAS = 1.09 × 10–28 for lung tissue), and TOLLIP (PTWAS = 1.41 × 10–15 for whole blood). Pathway enrichment analysis identified multiple candidate pathways, such as herpes simplex infection (P value = 7.93 × 10–5) and antigen processing and presentation (P value = 6.55 × 10–5). 38 common GO terms and 8 KEGG pathways shared by enrichment analysis of TWAS significant genes and DEGs were identified. In the PPI network, 14 genes (DYNLL1, DYNC1LI1, DYNLL2, HLA-DRB5, HLA-DPB1, HLA-DQB2, HLA-DQA2, HLA-DQB1, HLA-DRB1, POLR2L, CENPP, CENPK, NUP133, and NUP107) were simultaneously detected by hub gene and module analysis. In conclusion, through integrative analysis of TWAS and mRNA expression profiles, we identified multiple novel candidate genes, GO terms and pathways for IPF, which contributes to the understanding of the genetic mechanism of IPF.

Survival Following Traumatic Brain Injury in Drosophila Is Increased by Heterozygosity for a Mutation of the NF-κB Innate Immune Response Transcription Factor Relish.

Traumatic brain injury (TBI) pathologies are caused by primary and secondary injuries. Primary injuries result from physical damage to the brain, and secondary injuries arise from cellular responses to primary injuries. A characteristic cellular response is sustained activation of inflammatory pathways commonly mediated by nuclear factor-κB (NF-κB) transcription factors. Using a Drosophila melanogaster TBI model, we previously found that the main proximal transcriptional response to primary injuries is triggered by activation of Toll and Imd innate immune response pathways that engage NF-κB factors Dif and Relish (Rel), respectively. Here, we found by mass spectrometry that Rel protein level increased in fly heads at 4-8 hr after TBI. To investigate the necessity of Rel for secondary injuries, we generated a null allele, Reldel , by CRISPR/Cas9 editing. When heterozygous but not homozygous, the Reldel mutation reduced mortality at 24 hr after TBI and increased the lifespan of injured flies. Additionally, the effect of heterozygosity for Reldel on mortality was modulated by genetic background and diet. To identify genes that facilitate effects of Reldel on TBI outcomes, we compared genome-wide mRNA expression profiles of uninjured and injured +/+, +/Reldel , and Reldel /Reldel flies at 4 hr following TBI. Only a few genes changed expression more than twofold in +/Reldel flies relative to +/+ and Reldel /Reldel flies, and they were not canonical innate immune response genes. Therefore, Rel is necessary for TBI-induced secondary injuries but in complex ways involving Rel gene dose, genetic background, diet, and possibly small changes in expression of innate immune response genes.

Identification of transcriptome differences in goat ovaries at the follicular phase and the luteal phase using an RNA-Seq method

The ovaries, the main female reproductive organs, directly mediate ovulation and reproductive hormone secretion. These complex physiological processes are regulated by multiple genes and pathways. However, there is a lack of research on goat ovaries, and the molecular mechanisms underlying the signaling pathways remain unclear. In this study, Illumina HiSeq 4000 sequencing was used to sequence the transcriptomes of goat ovaries. The expression patterns of differentially expressed mRNAs in goat ovaries at both the follicular and luteal phases were determined by bioinformatics analysis. A total of 1,122, 014, 112 clean reads were obtained, and 3770 differentially expressed mRNAs were identified for further analysis. There were 1727 and 2043 upregulated mRNAs in the luteal phase and follicular phase, respectively. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, some mRNAs that were highly expressed in ovaries during the luteal phase, such as HSD17B7, 3BHSD, and SRD5A2, may be related to the synthesis of progesterone. In addition, some mRNAs that were highly expressed in ovaries during the follicular phase, such as RPL12, RPS13 and RPL10, are related to the growth and maturation of oocytes. Taken together, the findings of this study provide genome-wide mRNA expression profiles for goat ovaries at the follicular and luteal phases and identify mRNAs associated with goat hormone secretion and follicular development. In addition, this study provides a theoretical basis for further investigation of goat reproductive regulation.

The integrative analysis of DNA methylation and mRNA expression profiles confirmed the role of selenocompound metabolism pathway in Kashin-Beck disease

ABSTRACT Kashin-Beck disease (KBD) is an endemic chronic osteochondropathy. The etiology of KBD remains unknown. In this study, we conducted an integrative analysis of genome-wide DNA methylation and mRNA expression profiles between KBD and normal controls to identify novel candidate genes and pathways for KBD. Articular cartilage samples from 17 grade III KBD patients and 17 healthy controls were used in this study. DNA methylation profiling of knee cartilage and mRNA expression profile data were obtained from our previous studies. InCroMAP was performed to integrative analysis of genome-wide DNA methylation profiles and mRNA expression profiles. Gene ontology (GO) enrichment analysis was conducted by online DAVID 6.7. The quantitative real-time polymerase chain reaction (qPCR), Western blot, immunohistochemistry (IHC), and lentiviral vector transfection were used to validate one of the identified pathways. We identified 298 common genes (such as COL4A1, HOXA13, TNFAIP6 and TGFBI), 36 GO terms (including collagen function, skeletal system development, growth factor), and 32 KEGG pathways associated with KBD (including Selenocompound metabolism pathway, PI3K-Akt signaling pathway, and TGF-beta signaling pathway). Our results suggest the dysfunction of many genes and pathways implicated in the pathogenesis of KBD, most importantly, both the integrative analysis and in vitro study in KBD cartilage highlighted the importance of selenocompound metabolism pathway in the pathogenesis of KBD for the first time.

The integration of transcriptome-wide association study and mRNA expression profiling data to identify candidate genes and gene sets associated with dental caries

ObjectiveThe aim of this study was to identify candidate genes and gene sets associated with dental caries by an integrative analysis of transcriptome-wide association study (TWAS) and messenger RNA (mRNA) expression profiling of dental caries. MethodsA genome-wide association study (GWAS) dataset of dental caries was obtained from the UK Biobank. A TWAS of dental caries was conducted with the FUSION tool using the gene expression reference weights of musculoskeletal, whole blood, and peripheral blood genes. The dental caries-associated genes identified by the TWAS were further subjected to gene ontology (GO) and pathway enrichment analyses to explore dental caries-related gene sets. Finally, the TWAS results of dental caries were compared with genome-wide mRNA expression profiling of dental caries to detect common genes and gene sets. ResultsThe TWAS identified 165 musculoskeletal genes, 110 whole blood genes, and 228 peripheral blood genes. GO analysis of the genes identified by the TWAS detected 57 GO terms. For pathway enrichment analysis, we detected 12 candidate pathways. After comparing the TWAS-identified genes with the mRNA expression profiling data, we detected 6 common genes. Further comparing the GO results of the TWAS and mRNA expression profiling identified 5 common GO terms. ConclusionWe identified a group of dental caries-associated genes and GO terms, providing novel clues for understanding the genetic mechanisms of dental caries.

Identifying a ten-microRNA signature as a superior prognosis biomarker in colon adenocarcinoma

BackgroundIncreasing studies have suggested that aberrant expression of microRNAs might play essential roles in the progression of cancers. In this study, we sought to construct a high-specific and superior microRNAs signature to improve the survival prediction of colon adenocarcinoma (COAD) patients.MethodsThe genome-wide miRNAs, mRNA and lncRNA expression profiles and corresponding clinical information of COAD were collected from the TCGA database. Differential expression analysis, Kaplan–Meier curve and time-dependent ROC curve were calculated and performed using R software and GraphPad Prism7. Univariate and multivariate Cox analysis was performed to evaluate the prognostic ability of signature. Functional enrichment analysis was analyzed using STRING database.ResultsWe identified ten prognosis-related microRNAs, including seven risky factors (hsa-miR-197, hsa-miR-32, hsa-miR-887, hsa-miR-3199-2, hsa-miR-4999, hsa-miR-561, hsa-miR-210) and three protective factors (hsa-miR-3917, hsa-miR-3189, hsa-miR-6854). The Kaplan–Meier survival analysis showed that the patients with high risk score had shorter overall survival (OS) in test series. And the similar results were observed in both validation and entire series. The time-dependent ROC curve suggested this signature have high accuracy of OS for COAD. The Multivariate Cox regression analysis and stratification analysis suggested that the ten-microRNA signature was an independent factor after being adjusted with other clinical characteristics. In addition, we also found microRNA signature have higher AUC than other signature. Furthermore, we identified some miRNA-target genes that affect lymphatic metastasis and invasion of COAD patients.ConclusionIn this study, we established a ten-microRNA signature as a potentially reliable and independent biomarker for survival prediction of COAD patients.

Integrating transcriptome-wide association study and mRNA expression profiling identified candidate genes and pathways associated with osteomyelitis

Objective: Osteomyelitis (OM) is an acute or chronic inflammatory process, characterized by severe inflammation and progressive bone destruction. Limited efforts have been made to explore the genetic basis of OM.Method: The genome-wide association study data set of OM was obtained from the UK Biobank. A transcriptome-wide association study (TWAS) of OM was conducted by the FUSION tool using the gene expression reference weights of lymphocytes and blood. The OM-associated genes identified by TWAS were subjected to gene ontology (GO) enrichment analysis to explore OM-related gene sets. The TWAS results of OM were finally compared with a genome-wide mRNA expression profiling of OM to detect common genes and gene sets.Results: TWAS of OM detected 86 genes for lymphocytes and 387 genes for blood. Comparing the genes identified by TWAS and mRNA expression profiling detected eight common genes for OM, including VWF (pTWAS = 0.0030, pmRNA = 3.44 × 10−9), CCDC50 (pTWAS = 0.0130, pmRNA = 0.0003), and TPD52 (pTWAS = 0.0180, pmRNA = 1 × 10−6). GO analysis of the genes identified by TWAS detected multiple OM-associated GO terms, e.g. peroxisomal matrix (pTWAS = 0.0082), extracellular exosome (pTWAS = 0.0248), and monooxygenase activity (pTWAS = 0.0040). Further comparing the GO results of TWAS and mRNA expression profiling detected one common GO term, named extracellular exosome (pTWAS = 0.0248, pmRNA = 0.0027).Conclusion: This integrative study of TWAS and mRNA expression profiling detected multiple candidate genes and GO terms for OM. Our results provide novel clues for understanding the pathogenesis of OM.

Transcriptome analysis of Plasmodium berghei during exo-erythrocytic development

BackgroundThe complex life cycle of malaria parasites requires well-orchestrated stage specific gene expression. In the vertebrate host the parasites grow and multiply by schizogony in two different environments: within erythrocytes and within hepatocytes. Whereas erythrocytic parasites are well-studied in this respect, relatively little is known about the exo-erythrocytic stages.MethodsIn an attempt to fill this gap, genome wide RNA-seq analyses of various exo-erythrocytic stages of Plasmodium berghei including sporozoites, samples from a time-course of liver stage development and detached cells were performed. These latter contain infectious merozoites and represent the final step in exo-erythrocytic development.ResultsThe analysis represents the complete transcriptome of the entire life cycle of P. berghei parasites with temporal detailed analysis of the liver stage allowing comparison of gene expression across the progression of the life cycle. These RNA-seq data from different developmental stages were used to cluster genes with similar expression profiles, in order to infer their functions. A comparison with published data from other parasite stages confirmed stage-specific gene expression and revealed numerous genes that are expressed differentially in blood and exo-erythrocytic stages. One of the most exo-erythrocytic stage-specific genes was PBANKA_1003900, which has previously been annotated as a “gametocyte specific protein”. The promoter of this gene drove high GFP expression in exo-erythrocytic stages, confirming its expression profile seen by RNA-seq.ConclusionsThe comparative analysis of the genome wide mRNA expression profiles of erythrocytic and different exo-erythrocytic stages could be used to improve the understanding of gene regulation in Plasmodium parasites and can be used to model exo-erythrocytic stage metabolic networks toward the identification of differences in metabolic processes during schizogony in erythrocytes and hepatocytes.

High expression of APC is an unfavorable prognostic biomarker in T4 gastric cancer patients.

BACKGROUNDAdenoma polyposis coli (APC) mutation is associated with tumorigenesis via the Wnt signaling pathway.AIMTo investigate the clinical features and mechanism of APC expression in gastric cancer (GC).METHODSBased on APC expression profile, the related genome-wide mRNA expression, microRNA (miRNA) expression, and methylation profile in GC, the relationship between APC and GC, as well as the prognostic significance of APC were systematically analyzed by multi-dimensional methods.RESULTSWe found that high expression of APC (APChigh) was significantly associated with adverse outcomes of T4 GC patients. Genome-wide gene expression analysis revealed that varying APC expression levels in GC were associated with some important oncogenes, and corresponding cellular functional pathways. Genome-wide miRNA expression analysis indicated that most of miRNAs associated with high APC expression were downregulated. The mRNA-miRNA regulatory network analysis revealed that down-regulated miRNAs affected their inhibitory effect on tumor genes. Genome-wide methylation profiles associated with APC expression showed that there was differential methylation between the APChigh and APClow groups. The number of hypermethylation sites was larger than that of hypomethylation sites, and most of hypermethylation sites were enriched in CpG islands.CONCLUSIONOur research demonstrated that high APC expression is an unfavorable prognostic factor for T4 GC patients and may be used as a novel biomarker for pathogenesis research, diagnosis, and treatment of GC.

Identification of alternative splicing and lncRNA genes in pathogenesis of small cell lung cancer based on their RNA sequencing

The molecular mechanisms involved in small-cell lung cancer (SCLC) are largely unknown. Recent studies have suggested that long non-coding RNAs (lncRNAs) are likely to play a critical role. There is an urgent need for suitable molecular biomarkers for SCLC diagnosis and for assessing patient prognosis. In this study, we used public databases to identify mRNA-like candidate lncRNAs. A multi-step computational approach was used to construct a functional SCLC lncRNAs-mediated competing with endogenous RNA (ceRNA) network (LMCN) by integrating genome-wide lncRNAs and mRNA expression profiles, miRNA-target interactions, functional analyses, and clinical survival analyses. The results revealed the significance of lncRNAs interactions with ceRNAs in SCLC, indicating that integration of expression profiles and alternative splicing could be used to identify biomarkers and the underlying pathological changes. The following genes: EPB41L4A-AS1, HOXA-AS2, XIST, DLEU2, FGD5-AS1, ALMS1-IT1, SNHG12, MIR17HG, MIR4720, and SCARNA10 in cluster, as well as shared alternative splicing events, were considered to be critical genes. Olfactory transduction and endocytosis were the top-enriched pathways in SCLC. The selected cluster, including critical genes, might also be a potential pathway of SCLC pathogenesis. As a result, this research provides the perspective information to explore the potential critical genes and its pathways in SCLC therapy.

Co-expression analysis reveals dysregulated miRNAs and miRNA-mRNA interactions in the development of contrast-induced acute kidney injury.

The pathogenesis of contrast-induced acute kidney injury (CI-AKI) is incompletely understood. MicroRNAs (miRNAs) are important mediators that normally function via post-transcriptional degradation of target mRNAs. Emerging evidence indicates the appearance of differentially expressed (DE) miRNAs in CI-AKI following the injection of intravenous contrast medium. However, there are differences in the pathological mechanism and incidence of CI-AKI between intravenous and intra-arterial contrast administration. The present study aimed to investigate the critical roles of dysregulated miRNAs and their associated mRNAs in kidney injury following intra-arterial contrast medium exposure. Based on a reliable CI-AKI rat model, we conducted genome-wide miRNA and mRNA expression profiling analysis using deep sequencing. In the study, 36 DE mature miRNAs were identified (fold change > 1.5 and p value < 0.05) in the kidneys of CI-AKI rats (n = 3) compared with that in the controls (n = 3), consisting of 23 up-regulated and 13 down-regulated DE miRNAs. Bioinformatic analysis revealed that wingnut (Wnt), transforming growth factor beta (TGF-β), and 5'-AMP-activated protein kinase (AMPK) signaling pathways were most likely to be modulated by these dysregulated miRNAs. Around 453 dysregulated genes (fold change > 2.0 and p value < 0.05) were identified. Integrated analysis revealed 2037 putative miRNA-mRNA pairs with negative correlations. Among them, 6 DE miRNAs and 13 genes were selected for further quantitative real-time reverse transcription polymerase chain reaction validation (n = 6 for each group), and a good correspondence between the two techniques was observed. In conclusion, the present study provided evidence of miRNA-mRNA interactions in the development of kidney injury following an intra-arterial contrast injection. These findings provide insights into the underlying mechanisms of CI-AKI.

Abstract 4907: Transcriptomic profiling identifies a novel mitochondrial gene expression signature that predicts recurrence in microsatellite stable stage II and III colorectal cancer

Abstract Purpose: Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States. Current TNM (Tumor, Node, and Metastasis) classification approach is suboptimal in determining the prognosis of CRC patients. While there is a general consensus that stage II and III CRC patients with microsatellite instability (MSI) exhibit better outcomes, there is a lack of availability of biomarkers that can predict prognosis in microsatellite stable (MSS) patients. Given the emerging evidence that mitochondrial (mt) genomic instability is one of the hallmark features of cancer progression, herein, we systematically explored and established a novel mt-gene panel as a prognostic signature in CRC. Experimental design: Three genome wide mRNA expression profiling datasets were analyzed for the biomarker discovery (GSE33113, n=65) and validation (GSE14333, n=196; TCGA, n=62) of a mt-gene expression signature that predicts recurrence in stage II/III MSS CRC patients. Subsequently, a 14-gene signature was established, and independently tested (n=257) and validated (n=212) in two clinical cohorts, using qRT-PCR assays. The uni- and multi-variate Cox proportional hazard (CoxPH) regression analyses were performed to evaluate the performance of the mt-gene signature individually, and in combination with various clinicopathological factors (e.g. TNM staging, lymphatic invasion, and tumor infiltration) for predicting recurrence free survival (RFS). Results: The expression analysis of 568 mt-genes in CRC patients with and without recurrence, resulted in the identification of 32 significantly dysregulated genes (p&amp;lt;0.05). The univariate CoxPH analysis yielded a 14-gene signature that accurately predicted recurrence in the discovery (AUC = 0.89), and two independent validation cohorts (AUC = 0.75 and 0.79, respectively). This 14-gene signature demonstrated significant associations with poor RFS in independent testing and clinical validation cohorts of CRC patients (AUC = 0.87 and 0.73, respectively). Univariate analysis revealed that in addition to the mt-gene signature, TNM-stage (p = 0.007) and lymphatic invasion (p = 0.0004) were significant predictors of RFS; while multivariate analyses demonstrated that our mt-gene signature was an independent predictor (HR = 2.71; P&amp;lt;0.001) of tumor recurrence in stage II/III CRC patients. Intriguingly, a risk-stratification model comprising of the 14-gene signature together with TNM-stage and lymphatic invasion status achieved an even superior AUC of 0.89 and 0.78 in both clinical cohorts. Conclusions: We have identified a novel, 14-gene signature as an independent predictor of tumor recurrence; which in combination with TNM-stage and lymphatic invasion, offers an easy-to-translate and facile assay for the personalized risk-assessment in stage II/III MSS-CRC patients. Citation Format: SOUVIK GHATAK, Raju Kandimalla, Jasjit K. Banwait, Hiroyuki Uetake, Francesc Balaguer, Luis Bujanda, Ajay Goel. Transcriptomic profiling identifies a novel mitochondrial gene expression signature that predicts recurrence in microsatellite stable stage II and III colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4907.