Nestin as a novel therapeutic target for pancreatic cancer via tumor angiogenesis.

The class VI intermediate filament protein, nestin is reported to be a progenitor cell marker in various tissues. In the present study, we analyzed the expression and roles of nestin in angiogenesis of pancreatic ductal adenocarcinomas, and determined whether nestin is a potential target for inhibiting tumor angiogenesis using a gene silencing strategy. Nestin expression was detected only in small vessels, whereas CD34, CD31 and factor VIII were also expressed in large-sized blood vessels in PDAC. The number of nestin-positive vessels was approximately 20% the number of CD34-positive vessels, and the average dimension of nestin-positive vessels was approximately 75% that of CD34-positive vessels. The PCNA labeling indices of nestin-positive vessels were higher than those of CD34-positive vessels and nestin-negative vessels. Reducing nestin expression by use of siRNA targeting nestin transcripts inhibited growth of the vascular endothelial cell lines, but there was no difference in cell motility. In xenograft models, administration of siRNA targeting mouse-nestin suppressed subcutaneous human pancreatic cancer cell growth in nude mice. In conclusion, nestin was expressed in small proliferating blood vessels in pancreatic cancer tissues and may be a useful marker of angiogenesis in pancreatic ductal adenocarcinoma tissues. Furthermore, nestin is a potential novel therapeutic target in pancreatic cancers to inhibit tumor angiogenesis.