‘Jumping’ L1 elements implicated in esophageal cancer

In excess of 75% of esophageal cancers may be driven in part by ‘jumping genes’, suggests a new study. This new finding, published recently in BMC Genomics, sheds further light on the genetic disorder underlying the disease and could in future contribute to the development of better therapies.

This research was carried out by Paul Edwards and colleagues at the Cancer Research UK Cambridge Institute, and represents a part of the global International Cancer Genome Consortium project – an initiative that is utilizing cutting-edge sequencing technology to reveal the genetic rearrangements behind various malignancies.

“These jumping genes play hopscotch across our genetic code in cancer cells more than in normal cells. When one of these mobile genetic sequences plants itself in the middle of a gene that controls the cell’s growth it radically alters how the cell behaves, which can sometimes cause cancer. Research has shown that this might also happen in lung and bowel cancers. So it’s vital we find out more about how the cells do this in a bid to find ways to treat these cancers,” remarked Edwards.

‘Jumping genes’, or L1 elements, hold the ability to move through DNA into new areas, occasionally inserting into genes that are responsible for the control of cell growth. The Cambridge team studied these mobile elements in 43 esophageal adenocarcinoma tumor samples and associated blood samples through whole genome paired-end sequencing, uncovering approximately 100 insertions in each sample. Notably, insertion of mobile L1 elements into the genome occurred approximately 700 times in one of the samples.

The authors conclude that this abundance of mobile element insertions in esophageal adenocarcinomas is likely to impact the mutation burden of the disease, potentially contributing to the mutation of cancer-driving genes.

Kat Arney of Cancer Research UK commented: “Esophageal cancer is one of the hardest cancers to treat, and we are committed to funding more research to find out its underlying causes. These new findings reveal more about the genetic chaos that underpins esophageal tumors, and could one day help us develop better ways to diagnose, treat and monitor the disease.”

Sources: Paterson AL, Weaver JMJ, Eldridge MD et al. Mobile element insertions are frequent in oesophageal adenocarcinomas and can mislead paired-end sequencing analysis. BMC Genomics doi: 10.1186/s12864-015-1685-z (2015); Cancer Research UK press release