title: Vaccination with ENO1 DNA prolongs survival of genetically engineered mice with pancreatic cancer.
abstract: OBJECTIVE
  Pancreatic ductal adenocarcinoma (PDA) is an aggressive tumor, and patients typically present with late-stage disease; rates of 5-year survival after pancreaticoduodenectomy are low. Antibodies against α-enolase (ENO1), a glycolytic enzyme, are detected in more than 60% of patients with PDA, and ENO1-specific T cells inhibit the growth of human pancreatic xenograft tumors in mice. We investigated whether an ENO1 DNA vaccine elicits antitumor immune responses and prolongs survival of mice that spontaneously develop autochthonous, lethal pancreatic carcinomas.
  
  
  METHODS
  We injected and electroporated a plasmid encoding ENO1 (or a control plasmid) into Kras(G12D)/Cre (KC) mice and Kras(G12D)/Trp53(R172H)/Cre (KPC) mice at 4 weeks of age (when pancreatic intraepithelial lesions are histologically evident). Antitumor humoral and cellular responses were analyzed by histology, immunohistochemistry, enzyme-linked immunosorbent assays, flow cytometry, and enzyme-linked immunosorbent spot and cytotoxicity assays. Survival was analyzed by Kaplan-Meier analysis.
  
  
  RESULTS
  The ENO1 vaccine induced antibody and a cellular response and increased survival times by a median of 138 days in KC mice and 42 days in KPC mice compared with mice given the control vector. On histologic analysis, the vaccine appeared to slow tumor progression. The vaccinated mice had increased serum levels of anti-ENO1 immunoglobulin G, which bound the surface of carcinoma cells and induced complement-dependent cytotoxicity. ENO1 vaccination reduced numbers of myeloid-derived suppressor cells and T-regulatory cells and increased T-helper 1 and 17 responses.
  
  
  CONCLUSIONS
  In a genetic model of pancreatic carcinoma, vaccination with ENO1 DNA elicits humoral and cellular immune responses against tumors, delays tumor progression, and significantly extends survival. This vaccination strategy might be developed as a neoadjuvant therapy for patients with PDA.
authors: Center for Experimental Research and Medical Studies, Città della Salute e della Scienza di Torino, Italy.
authors: Paola
authors: P
authors: Cappello
authors: Simona
authors: S
authors: Rolla
authors: Roberto
authors: R
authors: Chiarle
authors: Moitza
authors: M
authors: Principe
authors: Federica
authors: F
authors: Cavallo
authors: Giovanni
authors: G
authors: Perconti
authors: Salvatore
authors: S
authors: Feo
authors: Mirella
authors: M
authors: Giovarelli
authors: Francesco
authors: F
authors: Novelli
mesh_terms: D000818:Animals; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality; D004797:Enzyme-Linked Immunosorbent Assay; D007111:Immunity, Cellular / Q000276:immunology*; D007150:Immunohistochemistry; D051379:Mice; D008817:Mice, Mutant Strains; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality; D010751:Phosphopyruvate Hydratase / Q000276:immunology*; D015996:Survival Rate; D014611:Vaccination / Q000379:methods*; D019444:Vaccines, DNA / Q000494:pharmacology*
chemical_list: D019444:Vaccines, DNA; C457379:Eno1 protein, mouse; D010751:Phosphopyruvate Hydratase