The aggressiveness of pancreatic ductal adenocarcinoma (PDA) is characterized by its high metastatic potential and lack of effective therapies, which is the result of a lack of understanding of the mechanisms involved in promoting PDA metastases. We identified Annexin A2 (ANXA2), a member of the Annexin family of calcium-dependent phospholipid binding proteins, as a new molecule that promotes PDA invasion and metastases. We found ANXA2 to be a PDA-associated antigen recognized by post-treatment sera of patients who demonstrated prolonged survival following treatment with a PDA-specific vaccine. Cell surface ANXA2 increases with PDA development and progression. Knockdown of ANXA2 expression by RNA interference or blocking with anti-ANXA2 antibodies inhibits in vitro invasion of PDA cells. In addition, post-vaccination patient sera inhibits in vitro invasion of PDA cells, suggesting that therapeutic anti-ANXA2 antibodies are induced by the vaccine. Furthermore, cell-surface localization of ANXA2 is tyrosine 23 phosphorylation-dependent; and tyrosine 23 phosphorylation is required for PDA invasion. We demonstrated that tyrosine 23 phosphorylation resulting in surface expression of ANXA2 is required for TGFβ-induced, Rho-mediated epithelial-mesenchymal transition (EMT), linking the cellular function of ANXA2 which was previously shown to be associated with small GTPase-regulated cytoskeletal rearrangements, to the EMT process in PDA. Finally, using mouse PDA models, we showed that shRNA knock-down of ANXA2, a mutation at tyrosine 23, or anti-ANXA2 antibodies, inhibit PDA metastases and prolong mouse survival. Thus, ANXA2 is part of a novel molecular pathway underlying PDA metastases and a new target for development of PDA therapeutics.

SUMMARY Ampullary carcinomas are highly malignant neoplasms that can have either intestinal or pancreatobiliary differentiation. To characterize somatic alterations in ampullary carcinomas, we performed whole-exome sequencing and DNA copy number analysis on 60 ampullary carcinomas resected from clinically well-characterized Japanese and American patients. We next selected 92 genes and performed targeted-sequencing to validate significantly mutated genes in additional 112 cancers. The prevalence of driver gene mutations in carcinomas with the intestinal phenotype is different from those with the pancreatobiliary phenotype. We identified a characteristic significantly mutated driver gene (ELF3) as well as previously known driver genes (TP53, KRAS, APC and others). Functional studies demonstrated that ELF3 silencing in normal human epithelial cells enhances their motility and invasion.

Curcumin or diferuloylmethane is a yellow polyphenol extracted from the rhizome of turmeric (Curcuma longa). A large volume (several hundreds) of published reports has established the anticancer and chemopreventative properties of curcumin in preclinical models of every known major cancer type. Nevertheless, the clinical translation of curcumin has been significantly hampered due to its poor systemic bioavailability, which mandates that patients consume up to 8 to 10 g of the free drug orally each day to achieve detectable levels in circulation. We have engineered a polymeric nanoparticle encapsulated curcumin formulation (NanoCurc) that shows remarkably higher systemic bioavailability in plasma and tissues compared with free curcumin upon parenteral administration. In xenograft models of human pancreatic cancer established in athymic mice, administration of parenteral NanoCurc significantly inhibits primary tumor growth in both subcutaneous and orthotopic settings. The combination of parenteral NanoCurc with gemcitabine results in enhanced tumor growth inhibition versus either single agent, suggesting an additive therapeutic influence in vivo. Furthermore, this combination completely abrogates systemic metastases in orthotopic pancreatic cancer xenograft models. Tumor growth inhibition is accompanied by significant reduction in activation of nuclear factor-κB, as well as significant reduction in expression of matrix metalloproteinase-9 and cyclin D1, in xenografts treated with NanoCurc and gemcitabine. NanoCurc is a promising new formulation that is able to overcome a major impediment for the clinical translation of curcumin to cancer patients by improving systemic bioavailability, and by extension, therapeutic efficacy. Mol Cancer Ther; 9(8); 2255-64. ©2010 AACR.

This regimen has shown promising clinical efficacy with acceptable tolerability in chemotherapy-naive PDAC patients with peritoneal metastasis.