Dissecting The Cell Heterogeneity Of Intestinal Gastric Cancer Using Single-cell Transcriptomes Sequencing

Objective: Using single-cell transcriptome sequencing,our study explores the heterogeneity in intestinal gastric cancer,including cell composition,function and state of subgroup cells,as well as key cell types and transcription factors that play major regulatory roles and the intercellular interaction ligand receptor pairs,which will provide insight into the mechanism of intestinal gastric cancer development and a theoretical basis for identifying new targets in intestinal gastric cancer.Methods: Our study screened and merged 20 samples of single-cell transcriptome sequencing from 14 intestinal gastric cancer patients.Data from intestinal gastric cancer were read,quality control,dimension reduction,clustering to obtain a single-cell transcriptome profile.Cells are annotated according to cell signature genes to explore the cell type composition of intestinal gastric cancer and the differences in distribution across samples and tissue types.Different cell types were re-dimensioned and clustered to identify their cell subgroups.Further exploration of functional and state heterogeneity of different cell subpopulations was conducted using enrichment analysis and pseudo-time analysis.Analysis of transcription factors and cell-cell communication was also conducted to uncover the main transcription factors,and ligand receptor pairs potentially important for cell-cell communication.Results: The transcriptome of intestinal gastric cancer was mapped and a number of tissue types were identified,including chief cells,neck cells,intestinal cell,enteroendocrine cells,macrophages,dendritic cells,mast cells,endothelial cells,fibroblasts and pericytes.In tumor tissues,myeloid cells increased significantly,while epithelial cells decreased.Our study explored the intrinsic differences in oncogenic pathways and the degree of copy number variation in epithelial cells,with Epi Int cells having higher oncogenic activity and copy number variation.In the Epi Int subpopulation,enrichment analysis showed that the I2 subpopulation was enriched in immune-related pathways that may be associated with an active immune response.Among lymphocytes,some CD8+ T cells are depleted,but most remain in a functional state and show expression of cytotoxic genes.T cells are regulated by B cell subset B2,and transcription factors such as TGIF1,YY1,ELF1 and BCLAF1 may be the main transcription factors regulating B cells.In myeloid cells,the macrophage subpopulation Ma3 is predominantly present in tumor tissues,which may be associated with poor prognosis.Among stromal cells,fibroblasts also have high copy number variation and oncogenic pathway activity.Epithelial cells,macrophages and fibroblasts interact actively with other cell types,and may play a crucial role in intestinal gastric cancers.Several ligand-receptor pairs with strong interactions were predicted,which may facilitate the development of new gastric cancer targets.Conclusion: In intestinal gastric cancer,there is heterogeneity in the cell type composition of different patients.In epithelial cells,Epi Int has a high oncogenic activity and copy number variation,which suggests it is the key epithelial cell type.The expression of functional genes in immune cells is related to the functional status of cell subpopulations,which are regulated by each other.It is important to note that epithelial cells,macrophages and fibroblasts are key types of cells,which are significantly increased in gastric tumors and have active intercellular communication.