Cis-regulatory Factors Research Articles

SUMO Sites Prediction in Human Transcription Factors Involved in Hypoxia induced Cardiac Illnesses

Protein SUMOylation is a reversible and well knownpost-translational modificationprocess of the cells. It may change a protein's cellular location, interactions, and possible structural shape before it develops to carry out its basic functions.Also, it decides the binding of transcription factors and DNA binding proteins tochromatin in addition to various cis and trans regulatory factors. Alterations in protein SUMOylation have been linked with a variety of disorders and developmental anomalies.Tentative approaches to identify SUMO binding sites are challenging due todynamic nature of the SUMOylation processand various critical lab experimentswhich are involved very high cost.Therefore, the computational methodologies may guide the experimental identification of SUMOylation sites and provide insights for improving comprehensionofSUMOylation mechanism in the cells.In this study, we identify the SUMO binding sites in transcription factors that are actively involved and have crucial roles in cardiac development andpathophysiology of the heart.A list of important transcription factors was preparedfrom thehuman transcription factor database.The GPS-SUMO, SUMO plot, and JASSA web serverswere used for the prediction of SUMO binding sites in cardiac transcription factors.We identified the SUMOylation of several novel, previously uncharacterized SUMO targetsthat are actively involved in thecardiovascular system.Thus, the present study may help to uncoverthe significance ofSUMO modificationin cardiac development and illnesses which creates a fresh avenue for future studies ontarget-specific SUMOylation for identification of novel therapeutic targets andmanagement strategies forhypoxia-induced cardiovascular disorders.

Exploring the genetic landscape of nitrogen uptake in durum wheat: genome-wide characterization and expression profiling of NPF and NRT2 gene families.

Nitrate uptake by plants primarily relies on two gene families: Nitrate transporter 1/peptide transporter (NPF) and Nitrate transporter 2 (NRT2). Here, we extensively characterized the NPF and NRT2 families in the durum wheat genome, revealing 211 NPF and 20 NRT2 genes. The two families share many Cis Regulatory Elements (CREs) and Transcription Factor binding sites, highlighting a partially overlapping regulatory system and suggesting a coordinated response for nitrate transport and utilization. Analyzing RNA-seq data from 9 tissues and 20 cultivars, we explored expression profiles and co-expression relationships of both gene families. We observed a strong correlation between nucleotide variation and gene expression within the NRT2 gene family, implicating a shared selection mechanism operating on both coding and regulatory regions. Furthermore, NPF genes showed highly tissue-specific expression profiles, while NRT2s were mainly divided in two co-expression modules, one expressed in roots (NAR2/NRT3 dependent) and the other induced in anthers and/ovaries during maturation. Our evidences confirmed that the majority of these genes were retained after small-scale duplication events, suggesting a neo- or sub-functionalization of many NPFs and NRT2s. Altogether, these findings indicate that the expansion of these gene families in durum wheat could provide valuable genetic variability useful to identify NUE-related and candidate genes for future breeding programs in the context of low-impact and sustainable agriculture.

Deep learning for detecting and elucidating human T-cell leukemia virus type 1 integration in the human genome.

Human T-cell leukemia virus type 1 (HTLV-1), a retrovirus, is the causative agent for adult Tcell leukemia/lymphoma and many other human diseases. Accurate and high throughput detection of HTLV-1 virus integration sites (VISs) across the host genomes plays a crucial role in the prevention and treatment of HTLV-1-associated diseases. Here, we developed DeepHTLV, the first deep learning framework for VIS prediction de novo from genome sequence, motif discovery, and cis-regulatory factor identification. We demonstrated the high accuracy of DeepHTLV with more efficient and interpretive feature representations. Decoding the informative features captured by DeepHTLV resulted in eight representative clusters with consensus motifs for potential HTLV-1 integration. Furthermore, DeepHTLV revealed interesting cis-regulatory elements in regulation of VISs that have significant association with the detected motifs. Literature evidence demonstrated nearly half (34) of the predicted transcription factors enriched with VISs were involved in HTLV-1-associated diseases. DeepHTLV is freely available at https://github.com/bsml320/DeepHTLV.

Investigating chromatin accessibility during development and differentiation by ATAC-sequencing to guide the identification of cis-regulatory elements.

Mapping accessible chromatin across time scales can give insights into its dynamic nature, for example during cellular differentiation and tissue or organism development. Analysis of such data can be utilised to identify functional cis-regulatory elements (CRE) and transcription factor binding sites and, when combined with transcriptomics, can reveal gene regulatory networks (GRNs) of expressed genes. Chromatin accessibility mapping is a powerful approach and can be performed using ATAC-sequencing (ATAC-seq), whereby Tn5 transposase inserts sequencing adaptors into genomic DNA to identify differentially accessible regions of chromatin in different cell populations. It requires low sample input and can be performed and analysed relatively quickly compared with other methods. The data generated from ATAC-seq, along with other genomic approaches, can help uncover chromatin packaging and potential cis-regulatory elements that may be responsible for gene expression. Here, we describe the ATAC-seq approach and give examples from mainly vertebrate embryonic development, where such datasets have identified the highly dynamic nature of chromatin, with differing landscapes between cellular precursors for different lineages.

Epigenetic fluctuations underlie gene expression timescales and variability.

Isogenic populations of mammalian cells exhibit significant gene expression variability. This variability can be separated into two components. Variance arises from events specific to the transcribed gene (i.e., cis or allele-specific sources) and variance from events that impact many genes at once (i.e., trans and global processes). Furthermore, the activity of the different regulatory factors that influence gene expression fluctuates at different timescales. Fast timescales will result in rapid fluctuation of gene expression, whereas slow timescales will result in longer persistence of gene expression levels over time. Here, we investigated sources of gene expression that are intrinsic, i.e., coming from cis-regulatory factors and follow slow timescales. To do so, we developed a reporter system that isolates allele-specific variability and measures its persistence in imaging and long-term fluctuation analysis experiments. Our results identify a new source of gene expression variability that is allele-specific but that fluctuates on timescales of days. We hypothesized that allele-specific fluctuations of epigenetic regulatory factors are responsible for the newly discovered allele-specific and slow source of gene expression variability. Using mathematical modeling, we showed that adding this effect to the two-state model is sufficient to account for all empirical observations. Furthermore, using direct assays of chromatin markers, we find fluctuation in H3K4me3 levels that match the observed changes in gene expression levels providing direct experimental support of our model. Collectively, our work shows that slow fluctuations of regulatory chromatin modifications contribute to the variability in gene expression.

CharID: a two-step model for universal prediction of interactions between chromatin accessible regions.

Open chromatin regions (OCRs) allow direct interaction between cis-regulatory elements and trans-acting factors. Therefore, predicting all potential OCR-mediated loops is essential for deciphering the regulation mechanism of gene expression. However, existing loop prediction tools are restricted to specific anchor types. Here, we present CharID (Chromatin Accessible Region Interaction Detector), a two-step model that combines neural network and ensemble learning to predict OCR-mediated loops. In the first step, CharID-Anchor, an attention-based hybrid CNN-BiGRU network is constructed to discriminate between the anchor and nonanchor OCRs. In the second step, CharID-Loop uses gradient boosting decision tree with chromosome-split strategy to predict the interactions between anchor OCRs. The performance was assessed in three human cell lines, and CharID showed superior prediction performance compared with other algorithms. In contrast to the methods designed to predict a particular type of loops, CharID can detect varieties of chromatin loops not limited to enhancer-promoter loops or architectural protein-mediated loops. We constructed the OCR-mediated interaction network using the predicted loops and identified hub anchors, which are highlighted by their proximity to housekeeping genes. By analyzing loops containing SNPs associated with cardiovascular disease, we identified an SNP-gene loop indicating the regulation mechanism of the GFOD1. Taken together, CharID universally predicts diverse chromatin loops beyond other state-of-the-art methods, which are limited by anchor types, and experimental techniques, which are limited by sensitivities drastically decaying with the genomic distance of anchors. Finally, we hosted Peaksniffer, a user-friendly web server that provides online prediction, query and visualization of OCRs and associated loops.

Analysis of gene network bifurcation during optic cup morphogenesis in zebrafish

Sight depends on the tight cooperation between photoreceptors and pigmented cells, which derive from common progenitors through the bifurcation of a single gene regulatory network into the neural retina (NR) and retinal-pigmented epithelium (RPE) programs. Although genetic studies have identified upstream nodes controlling these networks, their regulatory logic remains poorly investigated. Here, we characterize transcriptome dynamics and chromatin accessibility in segregating NR/RPE populations in zebrafish. We analyze cis-regulatory modules and enriched transcription factor motives to show extensive network redundancy and context-dependent activity. We identify downstream targets, highlighting an early recruitment of desmosomal genes in the flattening RPE and revealing Tead factors as upstream regulators. We investigate the RPE specification network dynamics to uncover an unexpected sequence of transcription factors recruitment, which is conserved in humans. This systematic interrogation of the NR/RPE bifurcation should improve both genetic counseling for eye disorders and hiPSCs-to-RPE differentiation protocols for cell-replacement therapies in degenerative diseases.

Modeling transcriptional regulation using gene regulatory networks based on multi-omics data sources

BackgroundTranscriptional regulation is complex, requiring multiple cis (local) and trans acting mechanisms working in concert to drive gene expression, with disruption of these processes linked to multiple diseases. Previous computational attempts to understand the influence of regulatory mechanisms on gene expression have used prediction models containing input features derived from cis regulatory factors. However, local chromatin looping and trans-acting mechanisms are known to also influence transcriptional regulation, and their inclusion may improve model accuracy and interpretation. In this study, we create a general model of transcription factor influence on gene expression by incorporating both cis and trans gene regulatory features.ResultsWe describe a computational framework to model gene expression for GM12878 and K562 cell lines. This framework weights the impact of transcription factor-based regulatory data using multi-omics gene regulatory networks to account for both cis and trans acting mechanisms, and measures of the local chromatin context. These prediction models perform significantly better compared to models containing cis-regulatory features alone. Models that additionally integrate long distance chromatin interactions (or chromatin looping) between distal transcription factor binding regions and gene promoters also show improved accuracy. As a demonstration of their utility, effect estimates from these models were used to weight cis-regulatory rare variants for sequence kernel association test analyses of gene expression.ConclusionsOur models generate refined effect estimates for the influence of individual transcription factors on gene expression, allowing characterization of their roles across the genome. This work also provides a framework for integrating multiple data types into a single model of transcriptional regulation.

Comparative Transcriptomic Analysis of Gene Expression Inheritance Patterns Associated with Cabbage Head Heterosis

The molecular mechanism of heterosis or hybrid vigor, where F1 hybrids of genetically diverse parents show superior traits compared to their parents, is not well understood. Here, we studied the molecular regulation of heterosis in four F1 cabbage hybrids that showed heterosis for several horticultural traits, including head size and weight. To examine the molecular mechanisms, we performed a global transcriptome profiling in the hybrids and their parents by RNA sequencing. The proportion of genetic variations detected as single nucleotide polymorphisms and small insertion–deletions as well as the numbers of differentially expressed genes indicated a larger role of the female parent than the male parent in the genetic divergence of the hybrids. More than 86% of hybrid gene expressions were non-additive. More than 81% of the genes showing divergent expressions showed dominant inheritance, and more than 56% of these exhibited maternal expression dominance. Gene expression regulation by cis-regulatory mechanisms appears to mediate most of the gene expression divergence in the hybrids; however, trans-regulatory factors appear to have a higher effect compared to cis-regulatory factors on parental expression divergence. These observations bring new insights into the molecular mechanisms of heterosis during the cabbage head development.

NEUROD1 Intrinsically Initiates Differentiation of Induced Pluripotent Stem Cells into Neural Progenitor Cells.

Cell type specification is a delicate biological event in which every step is under tight regulation. From a molecular point of view, cell fate commitment begins with chromatin alteration, which kickstarts lineage-determining factors to initiate a series of genes required for cell specification. Several important neuronal differentiation factors have been identified from ectopic over-expression studies. However, there is scarce information on which DNA regions are modified during induced pluripotent stem cell (iPSC) to neuronal progenitor cell (NPC) differentiation, the cis regulatory factors that attach to these accessible regions, or the genes that are initially expressed. In this study, we identified the DNA accessible regions of iPSCs and NPCs via the Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq). We identified which chromatin regions were modified after neuronal differentiation and found that the enhancer regions had more active histone modification changes than the promoters. Through motif enrichment analysis, we found that NEUROD1 controls iPSC differentiation to NPC by binding to the accessible regions of enhancers in cooperation with other factors such as the Hox proteins. Finally, by using Hi-C data, we categorized the genes that directly interacted with the enhancers under the control of NEUROD1 during iPSC to NPC differentiation.

DNMTs and Impact of CpG Content, Transcription Factors, Consensus Motifs, lncRNAs, and Histone Marks on DNA Methylation.

DNA methyltransferases (DNMTs) play an essential role in DNA methylation and transcriptional regulation in the genome. DNMTs, along with other poorly studied elements, modulate the dynamic DNA methylation patterns of embryonic and adult cells. We summarize the current knowledge on the molecular mechanism of DNMTs’ functional targeting to maintain genome-wide DNA methylation patterns. We focus on DNMTs’ intrinsic characteristics, transcriptional regulation, and post-transcriptional modifications. Furthermore, we focus special attention on the DNMTs’ specificity for target sites, including key cis-regulatory factors such as CpG content, common motifs, transcription factors (TF) binding sites, lncRNAs, and histone marks to regulate DNA methylation. We also review how complexes of DNMTs/TFs or DNMTs/lncRNAs are involved in DNA methylation in specific genome regions. Understanding these processes is essential because the spatiotemporal regulation of DNA methylation modulates gene expression in health and disease.

Differential gene regulatory pattern in the human brain from schizophrenia using transcriptomic-causal network

BackgroundCommon and complex traits are the consequence of the interaction and regulation of multiple genes simultaneously, therefore characterizing the interconnectivity of genes is essential to unravel the underlying biological networks. However, the focus of many studies is on the differential expression of individual genes or on co-expression analysis.MethodsGoing beyond analysis of one gene at a time, we systematically integrated transcriptomics, genotypes and Hi-C data to identify interconnectivities among individual genes as a causal network. We utilized different machine learning techniques to extract information from the network and identify differential regulatory pattern between cases and controls. We used data from the Allen Brain Atlas for replication.ResultsEmploying the integrative systems approach on the data from CommonMind Consortium showed that gene transcription is controlled by genetic variants proximal to the gene (cis-regulatory factors), and transcribed distal genes (trans-regulatory factors). We identified differential gene regulatory patterns in SCZ-cases versus controls and novel SCZ-associated genes that may play roles in the disorder since some of them are primary expressed in human brain. In addition, we observed genes known associated with SCZ are not likely (OR = 0.59) to have high impacts (degree > 3) on the network.ConclusionsCausal networks could reveal underlying patterns and the role of genes individually and as a group. Establishing principles that govern relationships between genes provides a mechanistic understanding of the dysregulated gene transcription patterns in SCZ and creates more efficient experimental designs for further studies. This information cannot be obtained by studying a single gene at the time.

Neonatal genetics of gene expression reveal potential origins of autoimmune and allergic disease risk

Chronic immune-mediated diseases of adulthood often originate in early childhood. To investigate genetic associations between neonatal immunity and disease, we map expression quantitative trait loci (eQTLs) in resting myeloid cells and CD4+ T cells from cord blood samples, as well as in response to lipopolysaccharide (LPS) or phytohemagglutinin (PHA) stimulation, respectively. Cis-eQTLs are largely specific to cell type or stimulation, and 31% and 52% of genes with cis-eQTLs have response eQTLs (reQTLs) in myeloid cells and T cells, respectively. We identified cis regulatory factors acting as mediators of trans effects. There is extensive colocalisation between condition-specific neonatal cis-eQTLs and variants associated with immune-mediated diseases, in particular CTSH had widespread colocalisation across diseases. Mendelian randomisation shows causal neonatal gene expression effects on disease risk for BTN3A2, HLA-C and others. Our study elucidates the genetics of gene expression in neonatal immune cells, and aetiological origins of autoimmune and allergic diseases.

Genome-wide localization of the polyphenol quercetin in human monocytes

BackgroundQuercetin is a polyphenol of great interest given its antioxidant activity and involvement in the immune response. Although quercetin has been well studied at the molecular level as a gene regulator and an activator of specific cellular pathways, not much attention has been given to its mechanism of action at the genome-wide level. The present study aims to characterize quercetin’s interaction with cellular DNA and to show its subsequent effect on downstream transcription.ResultsTwo massive parallel DNA-sequencing technologies were used: Chem-seq and RNA-seq. We demonstrate that upon binding to DNA or genome-associated proteins, quercetin acts as a cis-regulatory transcription factor for the expression of genes that are involved in the cell cycle, differentiation and development.ConclusionsSuch findings could provide new and important insights into the mechanisms by which the dietary polyphenol quercetin influences cellular functions.

Differential contribution of cis and trans gene transcription regulatory mechanisms in amygdala and prefrontal cortex and modulation by social stress

While both individual transcription factors and cis-acting sites have been studied in relation to psychiatric disorders, there is little knowledge of the relative contribution of trans-acting and cis-acting factors to gene transcription in the brain. Using an RNA-seq approach in mice bred from two evolutionary-distinct mice strains, we determined the contribution of cis and trans factors to gene expression in the prefrontal cortex and amygdala, two regions of the brain relevant to the stress response, and the contribution of cis and trans factors in the prefrontal cortex after Chronic Social Defeat (CSD) in mice. More genes were regulated by cis-regulatory factors in both brain regions, underlying the importance of cis-acting gene regulation in the brain. However, there was an increase in genes regulated by trans-regulatory mechanisms in the amygdala, compared to the prefrontal cortex. These genes were involved in synaptic functions, and were enriched for binding sites for transcription factors, including Egr1. CSD induced an increase in genes regulated by trans-regulatory mechanisms in the prefrontal cortex, and induced a pattern similar to the unstressed amygdala. Overall, we show brain site-specific patterns in cis and trans regulatory mechanisms, and show that these patterns can be modified by a psychological trigger.

English

Hybrid promoters are created by shuffling of DNA fragments while keeping intact regulatory regions crucial of promoter activity. Two fragments of alcohol dehydrogenase (Adh) promoter from Zea mays were selected to generate hybrid promoter. Sequence analysis of both alcohol dehydrogenase promoter fragments through bioinformatics tools identified several crucial cis regulatory elements and transcription factors binding sites. Both fragments were separately cloned in the TA vector (pTZ57R/T) and fused to get the complete hybrid promoter (Adh-H). Alcohol dehydrogenase hybrid promoter was further cloned in expression vector pGR1 through adaptor ligation. Transient β-glucuronidase (GUS) assay revealed that hybrid promoter exhibited high expression under anaerobic conditions in wheat tissues. From the study it is concluded that hybrid promoter (Adh-H) may be used to derive gene expression in monocots during anaerobic conditions. The present work also provides an important insight in the designing of hybrid monocot promoters to improve multiple traits in crops without facing intellectual property rights (IPRs) issues.   Key words: Hybrid promoter, histochemical β-glucuronidase (GUS) assay staining, cis regulatory elements, alcohol dehydrogenase, Zea mays.

Cloning, characterization and analysis of the 5' regulatory region of zebrafish xpd gene.

The gene XPD/ERCC2 encodes an ATP-dependent 5'-3' helicase of 760 amino acids. There are few transcription factors known to be involved in the regulation of XPD, and these include the hypoxia-inducible factor-1α (HIF-1α), p53, hepatitis B virus x protein (HBx) and specificity protein 1 (Sp1). To identify functional elements of xpd gene in fish we employed a comparative genomic approach. In our in silico attempt to identify cis-regulatory transcription factor binding sites (TFBSs) conserved among the xpd promoter sequences from five available fish species, we verified that in some cases the spatial disposition of the putative TFBSs was not maintained, but they were present in all the sequences, allowing the prediction of conserved regulatory elements within the promoter sequences analysed. We also investigated the transcriptional regulation of the zebrafish xpd gene. Our in vitro transient transfection-reporter analysis identified a region in the zebrafish xpd gene responsible for xpd regulation, along with regulatory regions that inhibit the activity of this promoter in somatic cells. Moreover, we found two p53 binding sites in the xpd promoter and upon co-transfection assays we observed a repression due to p53. This provides the first identification and characterization of promoter regions that regulate the transcription of the zebrafish xpd gene, and offers insights into the regulation of this gene by p53. Together, these studies further support the utility of comparative genomics to uncover gene regulatory sequences based on evolutionary conservation and provide the basic information to explore and better understand the regulation and expression of XPD.

Potential impact of gene regulatory mechanisms on the evolution of multicellularity in the volvocine algae

A fundamental question in biology is how multicellular organisms can arise from their single-celled precursors. The evolution of multicellularity requires the adoption of new traits in unicellular ancestors that allows the generation of form by, for example, increasing the size and developing new cell types. But what are the genetic, cellular and biochemical bases underlying the evolution of multicellularity? Recent advances in evolutionary developmental biology suggest that the regulation of gene expression by cis-regulatory factors, gene duplication and alternative splicing contribute to phenotypic evolution. These mechanisms enable different degrees of phenotypic divergence and complexity with variation in traits from genomes with similar gene contents. In addition, signaling pathways specific to cell types are developed to guarantee the modulation of cellular and developmental processes matched to the cell types as well as the maintenance of multicellularity.

SNP rs1049430 in the 3′-UTR of SH3GL2 regulates its expression: Clinical and prognostic implications in head and neck squamous cell carcinoma

Single nucleotide polymorphisms (SNPs) in the 3′-UTR region are emerging cis-regulatory factors associated with the occurrences of several human diseases. SH3GL2, which is located at chromosome 9p21-22, is associated with hyperplastic/mildly dysplastic lesions of the head and neck and has a long 3′-UTR with multiple SNPs. The aim of the present study was to determine the susceptible allele(s) in the 3′-UTR SNPs of SH3GL2 in head and neck squamous cell carcinoma (HNSCC). First, we screened the genotypes of all SNPs located in the 3′-UTR of SH3GL2 in 110 controls and 147 cases in Indian populations by sequencing. A SNP (rs1049430:>G/T) that showed only heterozygosity was further confirmed by genotyping with an Illumina GoldenGate platform in 530 controls and 764 cases. Genotype-specific survival analysis of the HNSCC patients was performed. In addition, genotype-specific mRNA stability, isoform expression and protein expression were analyzed. SNP rs1049430 was not associated with disease occurrence, but it was associated with poor patient outcome. The G allele was associated with decreased SH3GL2 mRNA stability, differential splicing and low protein expression. Thus, our data demonstrate that the presence of the susceptible G allele in SNP rs1049430 is associated with the inactivation of SH3GL2 and could be used as a prognostic marker of HNSCC.

Abstract 3401: Inter-individual variation in MUC5B allele specific expression in normal bronchial epithelial cells and relationship to lung cancer

Abstract Background: Familial interstitial pneumonia and idiopathic pulmonary fibrosis are associated with increased risk of lung cancer. Seibold et al (NEJM, 2011) recently identified a common variant in the putative promoter of MUC5B (rs35705950) associated with level of MUC5B expression in lung tissue and also with development of these diseases. The goal of this study was to determine whether the MUC5B rs35705950 variant is associated with a) MUC5B allele-specific expression (ASE) or total expression in normal bronchial epithelial cells (NBEC) or b) lung cancer risk. Through funding in part from RC2 CA148572 and HL108016 we collected NBEC samples from over 500 subjects with lung cancer or at risk for lung cancer. Methods: This was a pilot study of 85 subjects (26 cancer cases and 59 non-cancer controls). RNA was extracted from normal bronchial airway brush NBEC specimens of 85 subjects and reverse transcribed. Using next generation sequencing (NGS), allele-specific expression (ASE) was measured as allelic imbalance in each cDNA at three marker SNPs in MUC5B coding region (rs2075859, rs2943510, and rs4963059) selected for common (>0.05) minor allele frequency, using matched peripheral blood cell gDNA as a control. Specifically, each cDNA and matched gDNA sample was subjected to targeted competitive template multiplex PCR amplicon library generation followed by NGS (Blomquist et al, PLOS one, 2013) on Illumina Hiseq platform. This NGS method controlled for inter-target variation in PCR amplification during library preparation by measuring each transcript native template relative to a known number of synthetic competitive template internal standard copies. The genotype at putative cis-regulatory SNP rs35705950 was assessed in gDNA from 95 subjects (31 cancer cases and 64 non-cancer controls) including those assessed for ASE using a TaqMan® SNP assay. Results: There was significant (p<0.001) inter-individual variation in MUB5B allelic imbalance among heterozygotes at all three marker SNP loci and the level of imbalance measured at rs2075859 was greater in NBEC from cancer cases compared with non-cancer controls (P=0.0264). The genotype (i.e., heterozygote vs homozygote) at putative cis-regulatory SNP rs35705950 was not associated with MUC5B allelic imbalance or with lung cancer status. Inter-individual variation in MUC5B total expression was large (>3 log) but not associated with lung cancer. Conclusions: These results support previous observations that there is significant inter-individual variation in cis-regulation of MUC5B in NBEC and suggest that this variation also may contribute to inherited lung cancer risk. Lack of association between rs35705950 genotype and MUC5B ASE may have been due to role of other cis-regulatory factors, and/or environmentally associated transfactors that contributed to large inter-individual variation in total MUC5B expression. Citation Format: Xiaolu Zhang, Jiyoun Yeo, Erin L. Crawford, Thomas M. Blomquist, James C. Willey. Inter-individual variation in MUC5B allele specific expression in normal bronchial epithelial cells and relationship to lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3401. doi:10.1158/1538-7445.AM2014-3401