Abstract 5145: Nestin as a novel angiogenic marker and target for anti-angiogenic therapy in human pancreatic cancer

Abstract

Abstract Background: Tumor angiogenesis is an important factor in the proliferation and metastasis of pancreatic ductal adenocarcinoma (PDAC). CD34, CD31 and factor VIII-related antigen are commonly used as endothelial cell markers for tumor vessels. However, these markers identify not only newly formed small tumor vessels, but also pre-existing large blood vessels. Nestin, a class VI intermediate filament protein, has been reported to be up-regulated in endothelial cells accompanying the process of angiogenesis. In an acute pancreatitis murine model, we have previously reported that nestin is strongly expressed in proliferating endothelial cells. Furthermore, we have reported that nestin-positive blood vessels correlated with a poor prognosis in colorectal cancer. In this study, we examined the effectiveness of nestin as an angiogenic marker and potent target for anti-angiogenic therapy in PDAC. Methods: Tissues from 45 patients with PDAC were immunostained with nestin and other common vascular endothelial markers including CD34, CD31 and factor VIII-related antigen. We measured the number and dimension of the nestin- and CD34-positive blood vessels using image analyzing software. In addition, we compared proliferation activity between nestin- and CD34-positive vessels as determined by PCNA-labeling indices. To clarify the roles of nestin in endothelial cells, we transfected siRNA targeting nestin transcripts to mouse endothelial TKD2cells, and performed cell growth and migration assays. Results: Immunohistochemically, CD34, CD31 and factor VIII-related antigen were localized in blood vessels of all sizes, while nestin was localized only in the small blood vessels in PDAC tissues. Nestin was also expressed in myofibroblasts and nerve fibers, but not in lymphatic vessels. In image analyzing software, nestin-positive vessels were small in number, and they formed small lumen compare with CD34-positive blood vessels. Nestin-positive vessels showed higher PCNA-labeling indices than those of CD34-positive vessels. Nestin was expressed in small and proliferating blood vessels in PDAC tissues, suggesting that nestin plays important roles in tumor angiogenesis in cancer. Knock down of nestin in mouse endothelial cells using siRNA inhibited the cell growth, but not cell migration in vitro. Conclusion: Nestin was specifically expressed in small and proliferating blood vessels in pancreatic cancer tissues, indicating that nestin is a useful angiogenic marker in cancer. Furthermore, nestin may be a novel therapeutic target for inhibition of tumor angiogenesis in pancreatic cancer patients. 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 5145. doi:10.1158/1538-7445.AM2011-5145