Accelerators of chronic hepatitis B fibrosis cirrhosis CCND1 gene expression and promoter hypomethylation.

This study investigates the relationship between Cyclin D1 (CCND1) gene and promoter methylation and liver fibrosis (LF)/liver cirrhosis (LC)induced by chronic hepatitis B (CHB). Peripheral blood mononuclear cells (PBMCs) are collected from patients diagnosed with chronic hepatitis B (CHB) and hepatitis B-related LF/LC, as well as from healthy individuals. The mRNA levels and promoter methylation of the CCND1 gene are measured. Single-cell analysis is performed to determine the cell types primarily expressing the CCND1 gene in LF/LC. The GSE84044 dataset is utilized to validate the experimental results. Single-gene GSEA and immune infiltration analyses are conducted to identify significant pathways and immune characteristics associated with the CCND1 gene. The mRNA level of CCND1 in PBMCs from patients with hepatitis B-related LF/LC is elevated compared to those with chronic hepatitis B (CHB) and healthy individuals, while the promoter methylation level of CCND1 is reduced. Single-cell analysis indicates high expression of CCND1 in M2 macrophages (M2) and T cells. The GSE84044 dataset confirms higher CCND1 mRNA levels in liver tissues from patients with CHB-related LF/LC compared to CHB patients. Single-gene GSEA analysis associates CCND1 expression with natural killer cell-mediated cytotoxicity, T cell receptor signaling, and B cell receptor signaling pathways. Increased expression of CCND1 enhances immune infiltration during the fibrosis/cirrhosis process of CHB. The CCND1 expression and promoter methylation may be involved in the process of LF/LC in CHB and may be related to the immune response in the course of the disease.