Abstract: Objective To investigate the changes of gene expression profiles of peripheral blood B cells in hepatocellular carcinoma (HCC) patients before and after surgery. Methods Peripheral blood samples of 3 HCC patients who underwent hepatectomy for treatment at the Guangxi Medical University Cancer Hospital in September 2022 were collected before and after surgery, peripheral blood monoculear cell (PBMC) were extracted and single⁃cell RNA sequencing (scRNA⁃seq) was performed. B cell number analysis, up⁃ and down⁃regulated gene difference analysis, KEGG analysis, GSEA⁃KEGG and GSEA⁃GO analysis, and cell communication analysis were performed based on the sequencing data to compare the dynamic changes of B cells before and after surgery. Results PBMC was analyzed by scRNA⁃seq to identify clusters of cells with marker genes MS4A1 and CD79A, namely, B⁃cell clusters. After regrouping analysis, the B⁃cell clusters were classified into three cell subpopulations, namely, memory B cells, naive B cells, and plasmablasts. Compared with pre⁃operative group, the percentage of naive B cells and plasmablasts increased, and the percentage of memory B cells decreased after operation. A total of 285 significantly differentially expressed genes (DEGs) were screened in B cells before and after surgery, of which 152 genes including S100A8, S100A9, IL1R2 and MALAT1 were significantly up⁃regulated after surgery (P<0.05), and 133 genes including RPS27A, RPS3A, RPS12 and RPS3 were significantly down⁃regulated after surgery(P<0.05). KEGG analysis revealed that significantly down⁃regulated DEGs in post⁃operative B cells were mainly enriched in ribosomal, antigen processing and presentation pathways. GSEA⁃KEGG analysis revealed that the gene set up⁃regulated in post⁃operative B cells was significantly enriched in transcriptional dysregulation and P53 signaling pathway in cancer, while the gene set down⁃regulated was significantly enriched in ribosomal, antigen processing and presentation pathways. GSEA⁃GO analysis revealed that the gene set up⁃regulated in post⁃operative B cells was significantly enriched in cyclooxygenase P450 pathway, signaling pattern recognition receptor activity, and the down⁃regulated gene set was significantly enriched in immunoglobulin complex and T⁃cell receptor complex. Communication between B cells and T cells was enhanced after surgery, and the communication probability of post⁃operative ligand and receptor pairs of CD22⁃PTPRC between B cells and B cells, and between B cells and Mono cells was up⁃regulated (P<0.01). Either before or after surgery, the CD22 signaling pathway had a strongly ability to regulate the communication between B cells and T cells. Conclusions The gene expression profile of peripheral blood B cells in HCC patients changes dynamically before and after surgery, and is correlated with the immune function of peripheral blood B cells. This result provides a new reference for the study of the anti⁃tumor immune function of peripheral blood B cells.

Key words: Single-cell RNA sequencing, B cells, Hepatocellular carcinoma, Gene expression profiling