Alteration of protein expression and spliceosome pathway activity during Barrett\u2019s carcinogenesis

Christoph Stingl,Sybren Lodewijk Meijer,Angela Bureo Gonzalez,Jacques Johannes Bergman,Coşkun Güzel,Kai Yi Nadine Phoa,Michail Doukas,Theo Marten Luider,Gerben Eise Breimer

doi:10.1007/s00535-021-01802-2

Abstract

BackgroundBarrett’s esophagus (BE) is a known precursor lesion and the strongest risk factor for esophageal adenocarcinoma (EAC), a common and lethal type of cancer. Prediction of risk, the basis for efficient intervention, is commonly solely based on histologic examination. This approach is challenged by problems such as inter-observer variability in the face of the high heterogeneity of dysplastic tissue. Molecular markers might offer an additional way to understand the carcinogenesis and improve the diagnosis—and eventually treatment. In this study, we probed significant proteomic changes during dysplastic progression from BE into EAC.MethodsDuring endoscopic mucosa resection, epithelial and stromal tissue samples were collected by laser capture microdissection from 10 patients with normal BE and 13 patients with high-grade dysplastic/EAC. Samples were analyzed by mass spectrometry-based proteomic analysis. Expressed proteins were determined by label-free quantitation, and gene set enrichment was used to find differentially expressed pathways. The results were validated by immunohistochemistry for two selected key proteins (MSH6 and XPO5).ResultsComparing dysplastic/EAC to non-dysplastic BE, we found in equal volumes of epithelial tissue an overall up-regulation in terms of protein abundance and diversity, and determined a set of 226 differentially expressed proteins. Significantly higher expressions of MSH6 and XPO5 were validated orthogonally and confirmed by immunohistochemistry.ConclusionsOur results demonstrate that disease-related proteomic alterations can be determined by analyzing minute amounts of cell-type-specific collected tissue. Further analysis indicated that alterations of certain pathways associated with carcinogenesis, such as micro-RNA trafficking, DNA damage repair, and spliceosome activity, exist in dysplastic/EAC.

Highlights

In Barrett’s esophagus (BE), the normal squamous lining of the lower esophagus is replaced by gastric type columnar epithelium [1]
Our results demonstrate that disease-related proteomic alterations can be determined by analyzing minute amounts of cell-type-specific collected tissue
Further analysis indicated that alterations of certain pathways associated with carcinogenesis, such as micro-RNA trafficking, DNA damage repair, and spliceosome activity, exist in dysplastic/esophageal adenocarcinoma (EAC)

Summary

Introduction

In Barrett’s esophagus (BE), the normal squamous lining of the lower esophagus is replaced by gastric type columnar epithelium [1] This condition is considered a consequence of chronic gastroesophageal reflux disease (GERD). BE is considered a premalignant precursor for esophageal adenocarcinoma (EAC), which might progress continuously through the sequence of low-grade dysplasia (LGD), highgrade dysplasia (HGD) and adenocarcinoma. It follows that both non-dysplastic BE and dysplastic BE are important risk factors for EAC [6]. Prediction of risk, the basis for efficient intervention, is commonly solely based on histologic examination This approach is challenged by problems such as interobserver variability in the face of the high heterogeneity of dysplastic tissue. We probed significant proteomic changes during dysplastic progression from BE into EAC

Methods

Results

Discussion

Conclusion