Dataset Information

ScATAC-seq analysis using gastric mucosa with intestinal metaplasia

ABSTRACT: Nucleosome positionings of gastric mucosa with intestinal metaplasia at single cell resolution

ORGANISM(S): Homo sapiens

PROVIDER: GSE221292 | GEO | 2023/10/01

REPOSITORIES: GEO

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Project description:Background: Intestinal metaplasia (IM) is a gastric precancerous lesion that precedes the development of gastric cancer in up to 3.77 cases/1000 person-years. It consists in a trans-differentiation process of gastric to intestinal tissue. Two histological subtypes exist, complete (CIM) and incomplete (IIM), the latter having higher progression rates to gastric cancer . Our objective was to identify molecular processes responsible for the tumoral transition from intestinal metaplasia to GC and the initial steps of this lesion Methods: We used expression microarray to compare the transcriptome of intestinal metaplasia subtypes that progress to gastric cancer (IIM-GC and CIM-GC) after a follow-up period with respect to those that do not progress (IIM control and CIM control). Also, IM-NoGC (IM control, comprising both IIM and CIM Control) was compared with healthy gastric mucosa. Differentially expressed genes were obtained and functional analyses (GSEA and IPA softwares) were performed. Some deregulated genes were validated by qPCR. Results: Histological subtypes of intestinal metaplasia that progress or not to GC differ less among them than to healthy mucosa. Incomplete intestinal metaplasia has a higher number of over-expressed carcinogenic genes and molecular processes than the complete subtype. Most relevant molecular processes and genes in this group include antigenic processing, inflammation, activation of cell cycle and cell proliferation, oncogenes and tumor suppressors. When IM-NoGC is compared with healthy gastric mucosa new identified transcripts include TRIM, TMEM, homeobox, transporters and nucleolar RNAs SNORDs116. We confirm previously reported processes such us intestinal differentiation, metabolism of lipids and of xenobiotics and identify new ones such as non tumoral Warburg effect and melatonin degradation. Conclusions: Differentially expressed genes and molecular processes have been identified for the first time in intestinal metaplasia that progress to gastric cancer. New genes and molecular processes have also been identified in intestinal metaplasia in comparison with healthy gastric mucosa.

Project description:Background & Aims: Tissue metaplasia is uncommon in adults because established cis-element programs resist rewiring. In Barrett’s esophagus, the distal esophageal mucosa acquires predominantly intestinal character, with notable gastric features, and is predisposed to develop invasive cancers. We sought to understand the chromatin underpinnings of Barrett’s metaplasia and why it commonly displays simultaneous gastric and intestinal properties. Methods: We profiled cis-regulatory elements with active histone modifications in primary human biopsy materials using chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq). Mutations in Barrett’s esophagus were examined in relation to tissue-specific enhancer landscapes using a random-forest machine learning algorithm. We also profiled open chromatin at single-cell resolution in primary Barrett’s biopsy specimens using the assay for transposase-accessible chromatin (ATAC-seq). We used one- and two-color immunohistochemistry to examine protein expression of tissue-restricted genes. Results: Barrett’s esophagus bears epigenome fingerprints of human stomach and intestinal columnar, but not esophageal squamous, epithelia. Mutational patterns were best explained as arising on the epigenome background of active gastric cis-elements, supporting the view that adjoining stomach epithelium is a likely tissue source. Individual cells in Barrett’s metaplasia co-express gastric and intestinal genes, reflecting concomitant chromatin access at enhancers ordinarily restricted to one or the other epithelium. Protein expression of stomach-specific mucins, CLDN18, and a novel gastric marker, ANXA10, revealed extensive tissue and sub-clonal heterogeneity of dual stomach-intestinal cell states. Conclusions: These findings reveal mixed and dynamic tissue-restricted chromatin states and phenotypic heterogeneity in Barrett’s esophagus. Pervasive intra-gland variation argues against stem-cell governance of this phenotype.

Dataset Information

ScATAC-seq analysis using gastric mucosa with intestinal metaplasia

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