Abstract 1573: Early angiogenic switch-associated markers in pancreatic cancer development and progression
Authors: Ghosh Sriparna , Steuerwald Nury , Parsons Judith , Bonkovsky Herbert L. , Mukherjee Pinku 
Published: June 2012

Background: There are no warning signs or accurate, noninvasive ways to detect pancreatic cancer (Pc) at early stages. The survival rate at 5 year for patients with Pc is less than 5 percent, and complete remission is rare. Current therapies are inadequate, necessitates development of better diagnostic markers and therapies. Angiogenesis is the process by which tumor cells develop blood supply necessary for their growth and development. Studies have reported an angiogenic switch (AS), a shift of balance occurs between pro-angiogenic and angiogenic state, and is considered a hallmark of cancer progression. Vascular endothelial growth factor (VEGF), the most potent endothelial cell mitogen, is the target for numerous biologic therapies in Pc and other malignancies. We analyzed the expression and sub-cellular localization of VEGF and its receptors1&2, neuropilin (NP-1), matrix mettaloproteinases (MMP) 2 & 9 and epidermal growth factor receptor (EGFR) in pancreatic tumor tissues and serum from 1) a transgenic mouse model of pancreatic ductal adenocarcinoma (PDA) and 2) from a cohort of 80 human Pc patients at various stages of Pc along suitably matched control. Methods: Immunohistochemistry and immunofluorescence staining and quantification of sub-cellular protein expression using ImageJ were performed in tissue samples from PDA mouse and human. Tumor area was distinguished from stroma by tumor “mask,” and sub-cellular locales using DAPI and cytokeratin stains. Scores for the target (i.e. VEGF) were then generated that corresponded to average signal intensity divided by locale area. ELISA and bio-plex cytokine arrays were performed to analyze the serum samples. Statistical analyses were performed using SAS version 9.2. Results: VEGF and other proteins were stained predominantly in the membrane / cytoplasm compartment of malignant epithelium and were over expressed in tumors versus adjacent stroma. Normal epithelium showed lower expression. MMPs specifically MMP-9 showed higher expression at earlier stages of Pc development whereas others showed consistent positive correlation with progression of disease. Using total expression within the tumor, high expressers consistently correlated with worse outcomes and decreased overall survival. These data have been confirmed by serum analyses. Conclusions: VEGF, NP-1, MMP 2 & 9, and EGFR were expressed at varying degrees in Pc and were higher in tumors versus stroma. Higher expression of MMP 2 & 9 showed correlation with earlier stage of Pc development. Further studies of the functional significance of these findings are warranted. The prognostic value of these candidate biomarkers within the tumor microenvironment may facilitate the development of a much needed early stage biomarker and a potential therapeutic target for Pc.

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 1573. doi:10.1158/1538-7445.AM2011-1573