Association of IGF2 DMR0 hypomethylation in esophageal squamous cell carcinoma with poor prognosis.

11065 Background: The insulin-like growth factor 2 gene (IGF2) is normally imprinted. Loss of imprinting (LOI) of IGF2 in humans is associated with an increased risk of cancer and is controlled by CpG-rich regions known as differentially methylated regions (DMRs). Specifically, the methylation level at IGF2 DMR0 is correlated with IGF2 LOI and is a suggested surrogate marker for IGF2 LOI. A relationship between IGF2 DMR0 hypomethylation and poor prognosis has been shown in colorectal cancer. However, no study has examined the relationships among the IGF2 DMR0 methylation level, LOI, and clinical outcome in esophageal squamous cell carcinoma (ESCC). Methods: The IGF2 imprinting status was screened using ApaI polymorphism, and IGF2 protein expression was evaluated by immunohistochemistry with 30 ESCC tissue specimens. For survival analysis, IGF2 DMR0 methylation was measured using a bisulfite-pyrosequencing assay with 216 ESCC tissue specimens. The Cox proportional hazards model was used to calculate mortal...