Researchers Discover Potential Target for Gastric Cancers Associated with Epstein-Barr Virus
Published:13 Sep.2023    Source:The Wistar Institute

Now, scientists at The Wistar Institute have discovered a potential target for gastric cancers associated with Epstein-Barr Virus. An epigenetically active compound called decitabine disrupts the genome of EBVaGC by epigenetically modifying the cancer's DNA, a finding that offers the potential for a new approach to treating EBVaGC.

 
In EBVaGC, the cancer cells' DNA is hypermethylated: the DNA contains a high percentage of cytosine with a 5-methyl group attached to it (relative to normal, unmethylated cytosine). As a silencer of gene expression, DNA methylation allows EBV to remain latent. This methylation pattern plays a significant role in regulating the EBV latency-lysis cycle within the cancer cells. DNA methylation, as an epigenetic factor, usually functions as a gene-silencing mechanism, particularly in certain regions of the genome; a methylated gene still exists within the genome -- methylation does not delete the genetic information -- but methylation can prevent the protein the gene encodes from being transcribed.
 
Tempera and his co-authors treated two cell lines that were derived from EBVaGC tumors with decitabine. The cell lines that received the treatment demonstrated massive reductions in DNA methylation across the genome relative to the control as assessed by a variety of epigenetic assay techniques. The hypomethylating effect of decitabine treatment reactivated the lytic cycle of the latent EBV in the cancer cells. Because lysis is lethal to cells, the epigenetic reactivation of lysis within gastric cancer associated with EBV offers a promising potential treatment for the specific subset of EBVaGC.