Cancer Vaccines/genetics; DNA Methylation/genetics; Epigenesis, Genetic/genetics; Pancreatic Neoplasms/immunology; Animals; Cancer Vaccines/immunology; Cell Death/drug effects; Cell Death/genetics; Cell Line, Tumor; Cell Proliferation/drug effects; Cells, Cultured; Cytokines/analysis; Cytokines/metabolism; DNA (Cytosine-5-)-Methyltransferases/antagonists & inhibitors; DNA Methylation/drug effects; Enzyme Inhibitors/pharmacology; Epigenesis, Genetic/drug effects; Genes, MHC Class II/drug effects; Genes, MHC Class II/genetics; Histone Deacetylase Inhibitors/pharmacology; Humans; Mice; Mice, Inbred C57BL; Nuclear Proteins/drug effects; Nuclear Proteins/genetics; Pancreatic Neoplasms/genetics; Spleen/cytology; Th1 Cells/metabolism; Th2 Cells/metabolism; Trans-Activators/drug effects; Trans-Activators/genetics