Ontology highlight
ABSTRACT: Background & aims
Approximately one-third of colorectal cancers develop from serrated lesions (SLs), including hyperplastic polyp (HP), sessile serrated lesion (SSL), traditional serrated adenoma (TSA), and SSL with dysplasia (SSLD) through the serrated neoplasia pathway, which progresses faster than the conventional adenoma-carcinoma pathway. We sought to depict the currently unclarified molecular and immune alterations by the single-cell landscape in SLs.Methods
We performed single-cell RNA sequencing of 16 SLs (including 4 proximal HPs, 5 SSLs, 2 SSLDs, and 5 TSAs) vs 3 normal colonic tissues.Results
A total of 60,568 high-quality cells were obtained. Two distinct epithelial clusters with redox imbalance in SLs were observed, along with upregulation of tumor-promoting SerpinB6 that regulated ROS level. Epithelial clusters of SSL and TSA showed distinct molecular features: SSL-specific epithelium manifested overexpressed proliferative markers with Notch pathway activation, whereas TSA-specific epithelium showed Paneth cell metaplasia with aberrant lysozyme expression. As for immune contexture, enhanced cytotoxic activity of CD8+ T cells was observed in SLs; it was mainly attributable to increased proportion of CD103+CD8+ tissue-resident memory T cells, which might be regulated by retinoic acid metabolism. Microenvironment of SLs was generally immune-activated, whereas some immunosuppressive cells (regulatory T cells, anti-inflammatory macrophages, MDK+IgA+ plasma cells, MMP11-secreting PDGFRA+ fibroblasts) also emerged at early stage and further accumulated in SSLD.Conclusion
Epithelial, immune, and stromal components in the serrated pathway undergo fundamental alterations. Future molecular subtypes of SLs and potential immune therapy might be developed.
SUBMITTER: Zhou YJ
PROVIDER: S-EPMC9791140 | biostudies-literature | 2023
REPOSITORIES: biostudies-literature
Zhou Yu-Jie YJ Lu Xiao-Fan XF Chen Huimin H Wang Xin-Yuan XY Cheng Wenxuan W Zhang Qing-Wei QW Chen Jin-Nan JN Wang Xiao-Yi XY Jin Jing-Zheng JZ Yan Fang-Rong FR Chen Haoyan H Li Xiao-Bo XB
Cellular and molecular gastroenterology and hepatology 20221008 2
<h4>Background & aims</h4>Approximately one-third of colorectal cancers develop from serrated lesions (SLs), including hyperplastic polyp (HP), sessile serrated lesion (SSL), traditional serrated adenoma (TSA), and SSL with dysplasia (SSLD) through the serrated neoplasia pathway, which progresses faster than the conventional adenoma-carcinoma pathway. We sought to depict the currently unclarified molecular and immune alterations by the single-cell landscape in SLs.<h4>Methods</h4>We performed si ...[more]