Gastric Cancer is a lethal malignancy, often detected in advanced stages where the survival rate is low. Because of this, there is urgent need to improve its detection in early stages. Transposable Elements (TEs) have been linked with different types of cancer, yet their activity in Gastric Cancer has not been studied. In this recent study, through analysis of single-cell and spatially-resolved RNA-sequencing, it has been shown that TE activation is a hallmark of Gastric Cancer, and that their expression could be detected in early stages.

Transposable Element expression in early Gastric Cancer

To investigate TE expression, the researcher studied a single-cell dataset spanning the cascade progression from non-atrophic gastritis, to chronic atrophic gastritis, intestinal metaplasia and early gastric cancer. It was found that TE activation could be detected from chronic atrophic gastritis, and continued across all stages. In addition, through pseudotemporal modeling, a trajectory was inferred, an TE activation followed the malignant cell lineages.

Transposable Element expression in the tumor microenvironment

To further confirm TE expression is a hallmark of Gastric Cancer, spatially-resolved data obtained from tumors and its surrounding region was studied. This part of the study confirmed that TE expression occurs in the tumors, and also, that these elements are expressed in the tumor microenvironment. This suggests that TEs could be involved in tumorigenesis.

Why This Research is Important

By leveraging single-cell and spatially-resolved RNA-Seq data, it was shown that TEs become expressed throughout the progression of Gastric Cancer. This in turn, could point out to a role of TE activation in contributing to the progression of this disease, and implicate these elements as potential biomarkers for its early detection.