Barrett’s metaplasia develops from cellular reprograming of esophageal squamous epithelium due to gastroesophageal reflux

Abstract

Gastroesophageal reflux disease (GERD) clinically predisposes to columnar Barrett's metaplasia (BM) in the distal esophagus. We demonstrate evidence supporting the cellular origin of BM from reprograming or transcommitment of resident normal esophageal squamous (NES) epithelial cells in response to acid and bile (A + B) exposure using an in vitro cell culture model. The hTERT-immortalized NES cell line NES-B10T was exposed 5 min/day to an A + B mixture for 30 wk. Morphological changes, mRNA, and protein expression levels for the inflammatory marker cyclooxygenase-2; the lineage-determining transcription factors TAp63 (squamous), CDX2, and SOX9 (both columnar); and the columnar lineage markers Villin, Muc-2, CK8, and mAb Das-1 (incomplete phenotype of intestinal metaplasia) were assessed every 10 wk. Markers of columnar lineage and inflammation increased progressively, while squamous lineage-determining transcriptional factors were significantly decreased both at the mRNA and/or protein level in the NES-B10T cells at/after A + B treatment for 30 wk. Distinct modifications in morphological features were only observed at/after 30 wk of A + B exposure. These changes acquired by the NES-B10T 30-wk cells were retained even after cessation of A + B exposure for at least 3 wk. This study provides evidence that chronic exposure to the physiological components of gastric refluxate leads to repression of the discernable squamous transcriptional factors and activation of latent columnar transcriptional factors. This reflects the alteration in lineage commitment of the precursor-like biphenotypic, NES-B10T cells in response to A + B exposure as the possible origin of BM from the resident NES cells. This study provides evidence of the origins of Barrett's metaplasia from lineage transcommitment of resident esophageal cells after chronic exposure to gastroesophageal refluxate. The preterminal progenitor-like squamous cells alter their differentiation and develop biphenotypic characteristics, expressing markers of incomplete-type columnar metaplasia. Development of these biphenotypic precursors in vitro is a unique model to study pathogenesis of Barrett's metaplasia and esophageal adenocarcinoma.

Metaplasia: tissue injury adaptation and a precursor to the dysplasia–cancer sequence

“…Active Notch signalling may be important in the maintenance of the columnar cell lineage in Barrett oesophagus 61 . Mechanistically, gastro-oesophageal reflux may induce cellular reprogramming of the oesophageal squamous epithelium as a basis for metaplasia 67 . Presumably, this reprogramming could occur in oesophageal stem or progenitor cells or even in differentiated cells.…”

Barretts's carcinogenesis

“…One recent report has described a non‐neoplastic cell line established from the esophageal stratified squamous epithelium of a patient with GERD who experienced bile acid reflux for approximately 5 min daily over a 30‐week period. That cell line exhibited expression of TAp63, CDX2 and SOX9, similar to cell lines established from Barrett's epithelium, as well as similar morphological changes . They suggested that the non‐neoplastic cell line, which was derived from a biopsy specimen of a patient with GERD, may be derived from preterminal parent cells that retain the proliferative capacity and may not represent true ‘fully terminally differentiated’ epithelial cells.…”

“…They suggested that the non‐neoplastic cell line, which was derived from a biopsy specimen of a patient with GERD, may be derived from preterminal parent cells that retain the proliferative capacity and may not represent true ‘fully terminally differentiated’ epithelial cells. Considering their precursor‐like properties, this behavior is more synonymous with reprogramming or transcommitment rather than transdifferentiation . They claimed that these biphenotypic progenitors may be the precursors for the Barrett's columnar epithelium …”

“…That cell line exhibited expression of TAp63, CDX2 and SOX9, similar to cell lines established from Barrett's epithelium, as well as similar morphological changes. 98 They suggested that the non-neoplastic cell line, which was derived from a biopsy specimen of a patient with GERD, may be derived from preterminal parent cells that retain the proliferative capacity and may not represent true 'fully terminally differentiated' epithelial cells. Considering their precursor-like properties, this behavior is more synonymous with reprogramming or transcommitment rather than transdifferentiation.…”

“…98 They claimed that these biphenotypic progenitors may be the precursors for the Barrett's columnar epithelium. 98…”