Single-cell transcriptomics reveals over-activated reactive oxygen species pathway in hepatocytes in the development of hepatocellular carcinoma.

backgroundHepatocellular carcinoma (HCC) is a highly heterogeneous tumor and a primary cause of cancer-relevant deaths worldwide. The role of reactive oxygen species (ROS) in HCC development is less studied.

methodsSeurat package and CellMarker database were employed for single-cell RNA sequencing (scRNA-seq) analysis based on the GSE189175 dataset from Gene Expression Omnibus (GEO). DAVID and MsigDB database were utilized for pathway analysis. SCENIC analysis was performed to map a transcription factors (TFs) regulatory network. CellChat was used for cellular communication analysis.

resultsSix major cell subpopulations were identified, among which hepatocytes accounted for the highest proportion in both cancer and adjacent tissues. The enrichment scores of the 50 hallmark gene sets showed that the ROS pathway was abnormally activated in HCC hepatocytes and positively correlated with energy metabolism-related pathways (glucose metabolism, lipid metabolism, amino acid metabolism, etc.). Then, the hepatocytes were divided into four subgroups. Noticeably, GPX4+  hepatocytes with the highest activity of the ROS pathway was related to a worse prognosis of HCC. Mechanism analysis revealed that JUND was involved in the positive regulation of the ROS pathway in GPX4+  hepatocytes. It was found that the interdependent ligand-receptor interaction between GPX4+  liver cells and immune cells facilitated the malignant development of HCC.

conclusionROS pathway was over-activated in the hepatocytes of HCC tissues. GPX4+  hepatocytes having the highest activity of the ROS pathway closely interacted with T cells and M2 macrophage cells. Molecular subtypes and risk score signature based on the ROS pathway and its potential target gene JUND are encouraged to be developed for improving the precision treatment of HCC.