Abstract 4184: Expression analysis of iPS inductive gene in gastrointestinal cancer by tissue microarray

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Background: Recent progress is enabling us to induce iPS cells using somatic differentiated cells. We are now establishing iPS cells from normal gastrointestinal epithelial cells. However, the risks associated with transfection of iPS inductive genes (Sox2, Oct 3/4, klf4 and c-Myc) to somatic differentiated cells has not been well examined. Thus, in order to understand the role of iPS inductive genes in gastrointestinal cancer, we examined the expression of Sox2, Oct3/4, klf4, c-Myc and Nanog by cancer tissue microarray. Methods: We examined gene expression in 86 esophageal cancers, 50 gastric cancers, 80 colorectal cancers, 37 biliary tract cancers and 34 pancreatic cancers. Immunohistochemical expression levels of 5 genes were evaluated by the combination of their intensity and distribution. The expression level was compared to the clinico-pathological data of the patients. Results: Klf4 reduction was associated with lymph node metastasis of colorectal cancer which resulted in a poor prognosis for the patients (p=0.02). Klf4 reduction also tended to indicate a poor prognosis in esophageal cancer (P=0.06). Furthermore, Sox2 reduction was an independent prognostic factor in gastric cancer (p=0.03) and a high expression of OCT3/4 tended to indicate a poor prognosis in esophageal cancer (p=0.07). Nanog reduction was associated with poor prognosis in biliary tract and pancreatic cancer(p=0.02). On the other hand, c-Myc did not have any association with clinico-pathological factors of gastrointestinal cancer. Clustering analysis revealed that prognosis of the subgroup of simultaneous positive expressions of iPS inductive genes was better than that of other subgroups in colon cancer, however there was no difference among subtypes in esophageal cancer. Conclusions: The role of iPS inductive genes may differ in various gastroenterological cancer patients. However, further large-scale analysis is needed to elucidate this issue. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4184. doi:10.1158/1538-7445.AM2011-4184