While lung cancer is the leading cause of cancer death in the US, we have a limited understanding of the earliest molecular events preceding the onset of disease. Prior work has demonstrated that cigarette smoke creates a molecular “field of injury” throughout the airway epithelium and that there are distinct alterations in the airway transcriptome among smokers who have lung cancer. Molecular characterization of this airway “field of injury” in current and former smokers with premalignant lesions (PMLs) could provide novel insights into the earliest molecular events associated with lung carcinogenesis and identify relatively accessible biomarkers to guide lung cancer detection and early intervention. Using mRNA sequencing (mRNA-Seq), we profiled 82 cytologically normal bronchial airway epithelial cells collected during autofluorescence bronchoscopy from high-risk smokers with and without bronchial PMLs, 75 of which were used in downstream analyses. We identified 280 genes differentially expressed in the “field of injury” between subjects with (n=50) and without (n=25) PMLs (FDR<0.002), 81 of which were up-regulated in subjects with PMLs. Oxidative phosphorylation (OXPHOS), the electron transport chain (ETC), and mitochondrial protein transport pathways were strongly enriched among these up-regulated genes (FDR<0.05). We next demonstrated that OXPHOS activation is shared between the “field” and the PMLs with increased oxygen consumption and increased staining for mitochondrial markers in biopsies of PMLs from patients as well as an animal model of lung squamous cell carcinoma (SCC) premalignancy. The 280-gene signature also has a significant concordant relationship to gene expression changes identified in PMLs adjacent to lung SCC tumors, in lung SCC tumors, and in the cytologically normal airway of individuals with lung cancer (FDR<0.05). These findings suggest that these expression changes are reflective of early cancer-associated changes occurring throughout the respiratory tract, and that pathways such as OXPHOS may be targets for chemoprevention. We subsequently developed an airway gene expression biomarker that predicts the presence of PMLs (AUC=0.92, n=17 samples in test set) and show that changes in the biomarker score are associated with progression and regression of PMLs in an independent cohort (AUC=0.75, n=51 samples). The biomarker results indicate that molecular alterations in the field of injury are dynamic with progression or regression of PMLs, suggesting that these changes may be leveraged to stratify high-risk smokers with progressive disease into early intervention trials and monitor disease progression or recurrence. Overall design: 82 mRNA-Seq samples from 25 smokers without PMLs, 50 smokers with PMLs, and 7 smokers with metaplasia.
Detecting the Presence and Progression of Premalignant Lung Lesions via Airway Gene Expression.
No sample metadata fields
View SamplesWhile lung cancer is the leading cause of cancer death in the US, we have a limited understanding of the earliest molecular events preceding the onset of disease. Prior work has demonstrated that cigarette smoke creates a molecular “field of injury” throughout the airway epithelium and that there are distinct alterations in the airway transcriptome among smokers who have lung cancer. Molecular characterization of this airway “field of injury” in current and former smokers with premalignant lesions (PMLs) could provide novel insights into the earliest molecular events associated with lung carcinogenesis and identify relatively accessible biomarkers to guide lung cancer detection and early intervention. Using mRNA sequencing (mRNA-Seq), we profiled cytologically normal bronchial airway epithelial cells collected during autofluorescence bronchoscopy from high-risk smokers (n=75) with and without bronchial PMLs. We identified 280 genes differentially expressed in the “field of injury” between subjects with (n=50) and without (n=25) PMLs (FDR<0.002), 81 of which were up-regulated in subjects with PMLs. Oxidative phosphorylation (OXPHOS), the electron transport chain (ETC), and mitochondrial protein transport pathways were strongly enriched among these up-regulated genes (FDR<0.05). We next demonstrated that OXPHOS activation is shared between the “field” and the PMLs with increased oxygen consumption and increased staining for mitochondrial markers in biopsies of PMLs from patients as well as an animal model of lung squamous cell carcinoma (SCC) premalignancy. The 280-gene signature also has a significant concordant relationship to gene expression changes identified in PMLs adjacent to lung SCC tumors, in lung SCC tumors, and in the cytologically normal airway of individuals with lung cancer (FDR<0.05). These findings suggest that these expression changes are reflective of early cancer-associated changes occurring throughout the respiratory tract, and that pathways such as OXPHOS may be targets for chemoprevention. We subsequently developed an airway gene expression biomarker that predicts the presence of PMLs (AUC=0.92, n=17 samples in test set) and show that changes in the biomarker score are associated with progression and regression of PMLs in an independent cohort (AUC=0.75, n=51 samples). The biomarker results indicate that molecular alterations in the field of injury are dynamic with progression or regression of PMLs, suggesting that these changes may be leveraged to stratify high-risk smokers with progressive disease into early intervention trials and monitor disease progression or recurrence. Overall design: 51 mRNA-Seq samples from 23 subjects obtained via bronchscopy (18 subjects with 2 procedures, 5 subjects with 3 procedures).
Detecting the Presence and Progression of Premalignant Lung Lesions via Airway Gene Expression.
No sample metadata fields
View SamplesMelanoma cell lines were assessed for differences in gene expression patterns between the lines sensitive and resistant to BRAF and MEK inhibitor drugs.
The transcription cofactor c-JUN mediates phenotype switching and BRAF inhibitor resistance in melanoma.
Specimen part, Cell line
View SamplesUBF is an essential RNA Polymerase I (Pol I)-transcription factor. Our research investigates extra roles for UBF in regulation of Pol II gene expression. Our gene expression data identifies genes that are differentially regulated following UBF knockdown by siRNA.
A novel role for the Pol I transcription factor UBTF in maintaining genome stability through the regulation of highly transcribed Pol II genes.
Specimen part, Cell line
View SamplesMicroRNA (miRNA) play a major role in the post-transcriptional regulation of gene expression. In mammals most miRNA derive from the introns of protein coding genes where they exist as hairpin structures in the primary gene transcript, synthesized by RNA polymerase II (Pol II). These are cleaved co-transcriptionally by the Microprocessor complex, comprising DGCR8 and the RNase III endonuclease Drosha, to release the precursor (pre-)miRNA hairpin, so generating both miRNA and spliced messenger RNA1-4. However, a substantial minority of miRNA originate from Pol II-synthesized long non coding (lnc) RNA where transcript processing is largely uncharacterized5. Here, we show that most lnc-pri-miRNA do not use the canonical cleavage and polyadenylation (CPA) transcription termination pathway6, but instead use Microprocessor cleavage both to release pre-miRNA and terminate transcription. We present a detailed characterization of one such lnc-pri-miRNA that generates the highly expressed liver-specific miR-1227. Genome-wide analysis then reveals that Microprocessor-mediated transcription termination is commonly used by lnc-pri-miRNA but not by protein coding miRNA genes. This identifies a fundamental difference between lncRNA and pre-mRNA processing. Remarkably, inactivation of the Microprocessor can lead to extensive transcriptional readthrough of lnc-pri-miRNA, resulting in inhibition of downstream genes by transcriptional interference. Consequently we define a novel RNase III-mediated, polyadenylation-independent mechanism of Pol II transcription termination in mammalian cells. Overall design: Chromatin associated RNA-seq from sicntrl,siDrosha,siDGCR8 treated Hela cells. Same for sicntrl and siDGCR8 from Huh7 cells. Nuclear polyA + and polyA- RNA-seq from sicntrl and siDGCR8 in HeLa cells. Chromatin associated RNA-seq from siDicer treated Hela cells.
Microprocessor mediates transcriptional termination of long noncoding RNA transcripts hosting microRNAs.
No sample metadata fields
View SamplesNumerous long intervening non-coding RNA (lincRNA) are generated from the mammalian genome by RNA polymerase II (Pol II) transcription. Although multiple functions have been ascribed to lincRNA, their synthesis and turnover remain poorly characterised. Here we define systematic differences in transcription and RNA processing between protein-coding and lincRNA genes in human HeLa cells. This is based on a range of nascent transcriptomic approaches applied to different nuclear fractions, including mammalian native elongating transcript sequencing (mNET-seq). Notably mNET-seq patterns specific for different Pol II CTD phosphorylation states reveal weak co-transcriptional splicing and poly(A) signal independent Pol II termination on lincRNA as compared to pre-mRNA. In addition, lincRNA are mostly restricted to chromatin where they are co-transcriptionally degraded by the RNA exosome. We also show that a lincRNA specific co-transcriptional RNA cleavage mechanism acts to induce premature termination. In effect functional lincRNA must escape from this targeted nuclear surveillance process. Overall design: We employed CTD phospho specific mNET-Seq with pla-B splicing inhibitor and RNA processing factors knockdown (DGCR8, Dicer1, EXOSC3 and CPSF73 proteins). mNET-seq experiments with 1% Empigen detergent treatment were performed to separate Pol II-associated complex from Pol II. We also analyzed subcellur RNA and pA+ and pA- nucleoplasm RNA libraries for RNA processing efficiency and the turnover. There are 4 raw files come from an illumina experiment (per sample), produced in 2 lanes. They were all mapped together.
Distinctive Patterns of Transcription and RNA Processing for Human lincRNAs.
Cell line, Subject
View SamplesNutritional and genetic risk factors for intestinal tumors are additive on mouse tumor phenotypes, demonstrating that diet and genetic factors impact risk by distinct combinatorial mechanisms. We analyzed expression profiles of small intestine crypts and villi from mice with nutritional and genetic risk factors. The results advanced our understanding of the mechanistic roles played by major risk factors in the pathogenesis of intestinal tumors.
Paneth cell marker expression in intestinal villi and colon crypts characterizes dietary induced risk for mouse sporadic intestinal cancer.
Age, Specimen part
View SamplesMultiple Sclerosis (MS) is an immune-mediated chronic inflammatory disease affecting the central nervous system. The cause of MS is not known and the mechanism of IFN-beta, a disease-modifying treatment (DMT) approved for MS, is not well-understood. Oligonucleotide microarrays were used to study gene expression in plasmacytoid denditic cells (pDCs) which are antigen-presenting cells implicated in MS pathogenesis.
Multiple sclerosis-linked and interferon-beta-regulated gene expression in plasmacytoid dendritic cells.
Sex, Age, Specimen part, Disease, Disease stage, Subject
View SamplesRecent studies have identified intracellular metabolism as a fundamental determinant of macrophage function. In obesity, proinflammatory macrophages accumulate in adipose tissue and trigger chronic low-grade inflammation, that promotes the development of systemic insulin resistance, yet changes in their intracellular energy metabolism are currently unknown. We therefore set out to study metabolic signatures of adipose tissue macrophages (ATMs) in lean and obese conditions. F4/80-positive ATMs were isolated from obese vs lean mice. High-fat feeding of wild-type mice and myeloid-specific Hif1-/- mice was used to examine the role of hypoxia-inducible factor-1 (HIF-1) in ATMs part of obese adipose tissue. In vitro, bone marrow-derived macrophages were co-cultured with adipose tissue explants to examine adipose tissue-induced changes in macrophage phenotypes. Transcriptome analysis, real-time flux measurements, ELISA and several other approaches were used to determine the metabolic signatures and inflammatory status of macrophages. In addition, various metabolic routes were inhibited to determine their relevance for cytokine production. Transcriptome analysis and extracellular flux measurements of mouse ATMs revealed unique metabolic rewiring in obesity characterised by both increased glycolysis and oxidative phosphorylation. Similar metabolic activation of CD14+ cells in obese individuals was associated with diabetes outcome. These changes were not observed in peritoneal macrophages from obese vs lean mice and did not resemble metabolic rewiring in M1-primed macrophages. Instead, metabolic activation of macrophages was dose-dependently induced by a set of adipose tissue-derived factors that could not be reduced to leptin or lactate. Using metabolic inhibitors, we identified various metabolic routes, including fatty acid oxidation, glycolysis and glutaminolysis, that contributed to cytokine release by ATMs in lean adipose tissue. Glycolysis appeared to be the main contributor to the proinflammatory trait of macrophages in obese adipose tissue. HIF-1, a key regulator of glycolysis, nonetheless appeared to play no critical role in proinflammatory activation of ATMs during early stages of obesity. Our results reveal unique metabolic activation of ATMs in obesity that promotes inflammatory cytokine release. Further understanding of metabolic programming in ATMs will most likely lead to novel therapeutic targets to curtail inflammatory responses in obesity.
Unique metabolic activation of adipose tissue macrophages in obesity promotes inflammatory responses.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene expression profiles of prostate cancer reveal involvement of multiple molecular pathways in the metastatic process.
Age, Specimen part, Race
View Samples