Basic Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Mar 27, 2023; 15(3): 346-361
Published online Mar 27, 2023. doi: 10.4240/wjgs.v15.i3.346
Differential expression and significance of 5-hydroxymethylcytosine modification in hepatitis B virus carriers and patients with liver cirrhosis and liver cancer
Yue-Cui Li, Wei-Yue Hu, Cheng-Hang Li, Li-Li Zhang, Xiang-Wei Xu, Jin Li, Hong-Xia Luo
Yue-Cui Li, Wei-Yue Hu, Cheng-Hang Li, Li-Li Zhang, Xiang-Wei Xu, Jin Li, Hong-Xia Luo, Department of Infectious Diseases, The First People’s Hospital of Yongkang, Jinhua 321300, Zhejiang Province, China
Author contributions: Li YC and Hu WY conceived the experimental ideas; Hu WY and Li CH performed the data collection; Zhang LL, Xu XW, Li J and Luo HX completed data sorting and analysis; Li YC wrote this manuscript.
Supported by Science and Technology Planning Project of Zhejiang Province, No. LGF20H160001.
Institutional review board statement: The study was reviewed and approved by The First People’s Hospital of Yongkang Institutional Review Board.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yue-Cui Li, MBChB, Chief Physician, Department of Infectious Diseases, The First People’s Hospital of Yongkang, No. 599 Jinshan West Road, Yongkang, Jinhua 321300, Zhejiang Province, China. liyuecui02@yeah.net
Received: December 12, 2022
Peer-review started: December 12, 2022
First decision: January 5, 2023
Revised: January 17, 2023
Accepted: February 16, 2023
Article in press: February 16, 2023
Published online: March 27, 2023
Processing time: 105 Days and 4.4 Hours
Abstract
BACKGROUND

The relationship between hepatitis B surface antigen (HBsAg)-positive carrier status and liver cancer has been extensively studied. However, the epigenetic changes that occur during progression from HBsAg-positive carrier status or cirrhosis to liver cancer are unknown. The epigenetic modification of DNA hydroxymethylation is critical in tumor development. Further, 5-hydroxymethylcytosine (5hmC) is an important base for DNA demethylation and epigenetic regulation. It is also involved in the assembly of chromosomes and the regulation of gene expression. However, the mechanism of action of 5hmC in HBsAg-positive carriers or patients with cirrhosis who develop liver cancer has not been fully elucidated.

AIM

To investigate the possible epigenetic mechanism of HBsAg-positive carriers and hepatocellular carcinoma (HCC) progression from cirrhosis.

METHODS

Forty HBsAg-positive carriers, forty patients with liver cirrhosis, and forty patients with liver cancer admitted to the First People's Hospital of Yongkang between March 2020 and November 2021 were selected as participants. Free DNA was extracted using a cf-DNA kit. cfDNA was extracted by 5hmC DNA sequencing for principal component analysis, the expression profiles of the three groups of samples were detected, and the differentially expressed genes (DEGs) modified by hydroxymethylation were screened. Bioinformatic analysis was used to enrich DEGs, such as in biological pathways.

RESULTS

A total of 16455 hydroxymethylated genes were identified. Sequencing results showed that 32 genes had significant 5hmC modification differences between HBsAg carriers and liver cancer patients, of which 30 were upregulated and 2 downregulated in patients with HCC compared with HBsAg-positive carriers. Significant 5hmC modification differences between liver cirrhosis and liver cancer patients were identified in 20 genes, of which 17 were upregulated and 3 were downregulated in patients with HCC compared with those with cirrhosis. These genes may have potential loci that are undiscovered or unelucidated, which contribute to the development and progression of liver cancer. Analysis of gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes showed that the major signaling pathways involved in the differential genes were biliary secretion and insulin secretion. The analysis of protein interactions showed that the important genes in the protein-protein interaction network were phosphoenolpyruvate carboxykinase and solute carrier family 2.

CONCLUSION

The occurrence and development of liver cancer involves multiple genes and pathways, which may be potential targets for preventing hepatitis B carriers from developing liver cancer.

Keywords: Hepatitis B surface antigen; 5-hydroxymethylcytosine; Hepatocellular carcinoma; Liver cancer; DNA sequencing; Differentially expressed genes

Core Tip: Major signaling pathways involved in differentially expressed genes are biliary secretion and insulin secretion. Abnormal secretion of bile and insulin in tumor cells may promote or symbolize the occurrence and development of liver cancer. SLC2A2 and PCK1 are the central nodes of the differential genes, which may be most closely related to the occurrence of liver cancer. FABP1, APOC3, SI, KRT20, SLC5A1, SLC10A2, RBP2, and AKR1B10 may be key genes in the protein regulatory network, and these genes may play regulatory roles after modification by 5-hydroxymethylcytosine (5hmC). Therefore, we suggest that the difference in 5hmC modification levels is related to the occurrence and progression of liver cancer.