CCNE1 Promotes the Progression of Hepatic Precancerous Lesion and the Malignant Phenotype of Hepatocellular Carcinoma.

Background and aims: The diagnosis of hepatic precancerous lesions (HPC) and early hepatocellular carcinoma (HCC) has significant public health implications and holds the potential to reduce the global burden of HCC. This study aimed to identify molecular features and biomarkers associated with HPC progression and early HCC development.

Methods: RNA sequencing was used to identify differentially expressed genes in mouse HPC tissues and normal liver tissues. Cyclin E1 (CCNE1) expression in HPC tissues and HCC cells was assessed using immunohistochemistry, Western blotting, and real-time polymerase chain reaction. The effects of CCNE1 on HCC cell proliferation, migration, invasion, and apoptosis were evaluated using colony formation, wound healing, Transwell assays, and flow cytometry. The mechanism of CCNE1 was explored through Kyoto Encyclopedia of Genes and Genomes pathway analysis and gene set enrichment analysis and further validated through in vitro experiments. The interaction between CCNE1 and tumor-associated macrophages (TAMs) was investigated by co-culturing HCC cells with macrophages.

Results: RNA sequencing and TCGA database analysis showed that CCNE1 expression was significantly elevated in mouse HPC tissues and human HCC samples and was associated with reduced survival rates. In vitro assays demonstrated that CCNE1 promoted HCC cell proliferation, migration, invasion, and survival by activating the PI3K/Akt signaling pathway. Additionally, CCNE1 induced TAM polarization toward the M2 phenotype by promoting the expression of CCL2 and CCL5 in HCC cells.

Conclusions: CCNE1 promotes HPC progression and HCC cell proliferation, migration, invasion, and survival by activating the PI3K/Akt signaling pathway. Furthermore, CCNE1 enhances the secretion of CCL2 and CCL5 by HCC cells, promoting TAM infiltration and M2 polarization, thereby contributing to tumor progression.