Abstract 390: Impact of loss of IGF2 genomic imprinting on IGF1R signaling and cancer stem cell-associated biomarkers in gastric cancer

Aim: To investigate the association between loss of genomic imprinting (LOI) of insulin-like growth factor 2 (IGF-2) gene and the expressions of genes related with insulin-like growth factor type I receptor (IGF1R) signaling and the cancer stem cell associated genes (CD133 and Musashi I), in gastric cancer (GC) and its adjacent normal mucosa in GC patients with and without IGF-2 LOI. Patients and methods: Patients with pathological diagnosis of GC and underwent surgical resection in Department of Surgery of Potuo Hospital from 2006 to 2012 were recruited. Demographic and clinical pathological data were retrieved from medical records. The IGF-2 genomic imprinting status was determined by PCR and RT-PCR followed by restrictive endonuclease (Apa I) digestion. mRNA expression of IGF1R was evaluated with reverse transcription and real time PCR. Protein expressions of IGF-2, IGF1R, phosphorylated Akt (Ser-473), CD133, and Musashi 1 in tumor and adjacent mucosa were detected by immunohistochemical staining on tissue sections cut from formalin fixed and paraffin embedded cancer tissue blocks. All staining results were assessed by a qualified pathologist and marked as positive or negative. Statistical analysis was done by using SPSS (19.0) with a significant level of p