EBV infection alters DNA methylation in primary human colon cells: A path to inflammation and carcinogenesis?
Roberta Santarelli, Giuseppe Rubens Pascucci, Salvatore Lo Presti, Michele Di Crosta, Rossella Benedetti, Alessia Neri, Roberta Gonnella, Mara Cirone
Abstract
Epstein-Barr Virus (EBV) is associated with several types of human cancers, and changes in DNA methylation are reported to contribute to viral-driven carcinogenesis, particularly in cancers of epithelial origin. In a previous study, we demonstrated that EBV infects human primary colonic cells (HCoEpC) and replicates within these cells, leading to pro-inflammatory and pro-tumorigenic effects. Notably, these effects were mostly prevented by inhibiting viral replication with PAA. Interestingly, the EBV-induced effects correlated with the upregulation of DNMT1 and were counteracted by pretreating cells with 5-AZA, suggesting a role for DNA hypermethylation. Building on this background, the current study investigates the methylation changes induced by EBV infection in HCoEpC, both in the presence and absence of PAA, or ERK1/2 and STAT3 inhibitors, pathways known to be activated by EBV and involved in the dysregulation of methylation in tumor cells. The genome-wide methylation analysis conducted in this study allowed us to identify several biological processes and genes affected by these epigenetic changes, providing insights into the possible underlying mechanisms leading to the pathological effects induced by EBV. Specifically, we found that the virus induced significant methylation changes, with hypermethylation being more prevalent than hypomethylation. Several genes involved in embryogenesis, carcinogenesis, and inflammation were affected. • EBV infection of HCoEpC has a strong impact on DNA methylation, mainly driving hypermethylation. • PAA-pretreatment and the concomitant inhibition of ERK1/2 and STAT3 prevent several methylation changes induced by EBV-infection. • Among the genes whose methylation is modified by EBV infection are HOX and WNT.