ONCOmmunity

LINE-1 Hypomethylation Is Associated With Malignant Traits and Cell Proliferation in Lung Adenocarcinoma.

By: Hirokazu Kitahara, Tatsuro Okamoto, Shinichiro Shimamatsu, Mikihiro Kohno, Yosuke Morodomi, Tetsuzo Tagawa, Hiroyuki Kitao, Shinji Okano, Yoshinao Oda, Yoshihiko Maehara, Masaki Mori

Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
2020-07-19; doi: 10.21873/anticanres.14579

Abstract

Background/aim

Long interspersed nuclear element-1 (LINE-1) methylation status is a marker for global DNA methylation. However, the relationship between LINE-1 methylation and the biology of lung adenocarcinoma remains unclear. Here, we aimed to examine the role of LINE-1 in lung cancer.

Materials

LINE-1 methylation levels were quantified by bisulfite pyrosequencing of resected tumor specimens from 162 patients with lung adenocarcinoma. The relationships of LINE-1 methylation with clinicopathological factors, gene mutations, and Ki-67 immunoreactivity were investigated.

Results

LINE-1 hypomethylation was associated with tumor invasion and advanced stage. TP53 mutations were more frequently detected in the LINE-1 hypomethylation group than in the hypermethylation group. LINE-1 hypomethylation was associated with poor recurrence-free survival, high maximum standardized uptake value in positron-emission tomography, and high Ki-67 expression in tumors.

Conclusion

LINE-1 hypomethylation was associated with high-grade malignancy and poor prognosis in lung adenocarcinoma, but was not related to driver mutations.