Dataset Information

RNA N6-Methyladenosine Patterns in Hepatocellular Carcinoma Reveal a Distinct Immune Infiltration Landscape and Clinical Significance

ABSTRACT:

Background

RNA N6-methyladenosine (m6A) methylation, the most abundant and prominent form of epigenetic modification, is involved in hepatocellular carcinoma (HCC) initiation and progression. However, the role of m6A methylation in HCC tumor microenvironment (TME) formation is unexplored. This study aimed to reveal the TME features of HCC patients with distinct m6A expression patterns and establish a prognostic model based on m6A signatures for HCC cohorts.

Material/Methods

We classified the m6A methylation patterns in 365 HCC samples based on 21 m6A modulators using a consensus clustering algorithm. Single-sample gene set enrichment analysis algorithm was used to quantify the abundance of immune cell infiltration. Gene set variation analysis revealed the biological characteristics between the m6A modification patterns. The m6A-based prognostic model was constructed using a training set with least absolute shrinkage and selection operator regression and validated in internal and external datasets.

Results

Two distinct m6A modification patterns exhibiting different TME immune-infiltrating characteristics, heterogeneity, and prognostic variations were identified in the HCC cohort. After depicting the immune landscape of TME in HCC, we found patients with high LRPPRC m6A modulator expression had depletion of T cells, cytotoxic cells, dendritic cells, and cytolytic activity response. A high m6A score, characterized by suppression of immunity, indicated an immune-excluded TME phenotype, with poor survival. A nomogram was developed to facilitate HCC clinical decision making.

Conclusions

Our results highlight the nonnegligible role of m6A methylation in TME formation and reveal a potential clinical application of the m6A-associated prognostic model for patients with HCC.

SUBMITTER: Zhao H

PROVIDER: S-EPMC8555444 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background: N6-methyladenosine (m6A) is the most prevalent modification of mammalian RNA. Emerging evidence suggest that m6A has critical roles in multiple biological activities, but little is known about its roles in cancer pathogenesis. Herein, we report the expression profiles and prognostic relevance of twelve m6A-related genes in hepatocellular carcinoma (HCC) by analyzing four independent datasets. Materials and methods: RNA levels of twelve m6A-related genes were detected in samples of 162 HCC patients who underwent curative resection (the Guangdong General Hospital dataset). We additionally analyzed the expression profiles of m6A-related genes in The Cancer Genome Atlas liver HCC dataset and two Gene Expression Omnibus datasets (GSE14520, GSE63898). Prognostic value of genes was evaluated by Kaplan-Meier curves of overall survival (OS) with the log-rank test and multivariate Cox regression analysis. Gene set enrichment analysis (GSEA) was conducted to identify associated KEGG pathways. Results: Five genes (METTL3, YTHDF1, YTHDF2, YTHDF3, and EIF3) showed consistent upregulation in all four datasets. Abnormal expressions of either METTL3 or YTHDF1 but not the other ten genes were associated with OS. Protein expression of METTL3 and YTHDF1 were confirmed in HCC tissues by immunohistochemical staining. Multivariate Cox regression analysis confirmed the independent predictive value of both METTL3 and YTHDF1 on OS. We further divided patients into three groups based on the median expression values of METTL3 and YTHDF1. In all datasets, the low METTL3/low YTHDF1 group showed a consistent better prognosis than other groups. GSEA revealed that both METTL3 and YTHDF1 regulate HCC cell cycle, RNA splicing, DNA replication, base excision repair, and RNA degradation. Conclusion: Both METTL3 and YTHDF1 were upregulated in HCC, and they were independent poor prognostic factors. Combination of METTL3 and YTHDF1 can be regarded as the biological marker that reflect malignant degree and evaluate prognosis in HCC.