Constructing Single-cell Atlas Of Bladder Urothelial Carcinoma

Purpose: To investigate the tumor microenvironment of bladder urothelial carcinoma with single cell sequencing.Methods: We performed single cell RNA sequencing on 8 bladder cancer(BC)and 3 non-malignant tissues,captured over 50000 single cells.Bioinformatic analysis was conducted to investigate the intratumor heterogeneity of bladder cancer.With immunofluorescence,FACS sorting and co-culture assay,we confirmed the role of inflammatory cancer associated fibroblasts in progression of bladder cancer.Results: In this study,we identified 19 different cell types inside the BC microenvironment,indicating high intra-tumoral heterogeneity of bladder carcinoma.We also find that monocytes underwent M2 polarization in the tumor region and differentiated.Furthermore,the LAMP3+ DC subgroup,which has not been described in BC,may be able to recruit regulatory T cells via secreting multiple cytokines,including CCL17,CCL19 and CCL22,potentially takes part in the formation of an immunosuppressive TME.Most importantly,through correlation analysis using public datasets containing over 3,000 BC samples,we identified a role for inflammatory cancer-associated fibroblasts(i CAFs)in tumor progression,which was significantly related to poor prognosis.Co-culture and colony formation assay confirmed the pro-tumor role of i CAFs in BC.Conclusion: In summary,we identified the expression profiles of subsets of cells in bladder urothelial carcinoma,confirmed the characteristics of these tumor-associated subsets and highlighted the role of a special fibroblast subset in BC.