Methylation status of long interspersed element-1 in advanced gastric cancer and its prognostic implication

Abstract
Reportedly, the pyrosequencing methylation assay can produce inconsistent results between paired snap-frozen and formalin-fixed paraffin-embedded archival tissue samples. In this study, we assayed the methylation levels at four individual CpG sites of L1 using pyrosequencing and found that the methylation levels at individual CpG sites were different but were closely correlated between paired snap-frozen and formalin-fixed paraffin-embedded tissue samples. We aimed to determine whether low methylation status of L1 is associated with gastric cancer patient prognosis.