IDDF2023-ABS-0273 Single-cell transcriptomic profiling reveals molecular heterogeneity of fibroblast in helicobacter pylori-associated gastric carcinogenesis

Background

Helicobacter pylori (H. pylori) infection is the strongest known risk factor for gastric cancer, which is a highly heterogeneous disease.

Methods

In this study, we perform single-cell RNA-sequencing (ScRNA-seq) of 91394 cells (including 5032 fibroblasts) from gastric tissues of 18 patients with gastritis, intestinal metaplasia, and gastric cancer. The UMAP, GSVA, SCENIC, and CellChat analysis were used. Co-immunofluorescence staining was performed to verify the subpopulations.

Results

Our data indicated increased endothelia and myeloid cell proportion, along with decreased epithelial cell proportion (IDDF2023-ABS-0273 Figure 1A-H. SCMA SEQ identified increased endothelia and myeloid cells proportion along with decreased epithelial cell proportion). Furthermore, we found that the molecular features of fibroblast subpopulations in gastric cancer tissues are completely different from those in gastritis and intestinal metaplasia tissues (IDDF2023-ABS-0273 Figure 2C. The transcriptomic heterogeneity of fibroblasts in gastric tissues). The inflammatory cancer-associated fibroblasts (iCAFs), antigen-presented CAFs (apCAFs) and mesenchymal CAFs (mCAFs) were significantly increased in gastric cancer (IDDF2023-ABS-0273 Figure 2A-B. The transcriptomic heterogeneity of fibroblasts in gastric tissues). Pseudotime analysis showed that the iCAFs and mCAFs derived from extracellular matrix (ECM) fibroblasts, the subpopulation expressed in gastritis and intestinal metaplasia tissues (IDDF2023-ABS-0273 Figure 2E. The transcriptomic heterogeneity of fibroblasts in gastric tissues). Combined immunofluorescence staining verified the increased abundance of iCAFs (COL1A1+FBLN1+ or COL1A1+C3+) in gastric cancer tissues (IDDF2023-ABS-0273 Figure 2D. The transcriptomic heterogeneity of fibroblasts in gastric tissues). Functional studies indicated that iCAFs were enriched for the Wnt signaling pathway and stem cell process. SCENIC analysis showed that NFATC1 was the specific transcriptional factor for iCAFs (IDDF2023-ABS-0273 Figure 2F. The transcriptomic heterogeneity of fibroblasts in gastric tissues). CellChat analysis showed that the fibroblast cell subpopulations secreted different ligands, while the tumor cells derived from epithelial cells had their receptors (IDDF2023-ABS-0273 Figure 2G-H. The transcriptomic heterogeneity of fibroblasts in gastric tissues). The differential expressed genes (DEG) of fibroblasts between H. pylori-positive and H. pylori-negative tissues were further compared (IDDF2023-ABS-0273 Figure 3A-B. The differential expressed genes between H pylori positive and H pylori negative patients). We found that some ligand genes, including CD74, CXCL8, IL1B, FN1 and C3, were highly expressed in gastric cancer tissues, especially H. pylori-positive subjects (IDDF2023-ABS-0273 Figure 3C-E. The differential expressed genes between H pylori positive and H pylori negative patients).

Conclusions

Our findings reveal the molecular heterogeneity of fibroblasts in gastric carcinogenesis, and provide a better understanding of the pathogenic biology of H. pylori.