title: Local and systemic effect of transfection-reagent formulated DNA vectors on equine melanoma.
abstract: BACKGROUND
  Equine melanoma has a high incidence in grey horses. Xenogenic DNA vaccination may represent a promising therapeutic approach against equine melanoma as it successfully induced an immunological response in other species suffering from melanoma and in healthy horses. In a clinical study, twenty-seven, grey, melanoma-bearing, horses were assigned to three groups (n = 9) and vaccinated on days 1, 22, and 78 with DNA vectors encoding for equine (eq) IL-12 and IL-18 alone or in combination with either human glycoprotein (hgp) 100 or human tyrosinase (htyr). Horses were vaccinated intramuscularly, and one selected melanoma was locally treated by intradermal peritumoral injection. Prior to each injection and on day 120, the sizes of up to nine melanoma lesions per horse were measured by caliper and ultrasound. Specific serum antibodies against hgp100 and htyr were measured using cell based flow-cytometric assays. An Analysis of Variance (ANOVA) for repeated measurements was performed to identify statistically significant influences on the relative tumor volume. For post-hoc testing a Tukey-Kramer Multiple-Comparison Test was performed to compare the relative volumes on the different examination days. An ANOVA for repeated measurements was performed to analyse changes in body temperature over time. A one-way ANOVA was used to evaluate differences in body temperature between the groups. A p-value < 0.05 was considered significant for all statistical tests applied.
  
  
  RESULTS
  In all groups, the relative tumor volume decreased significantly to 79.1 ± 26.91% by day 120 (p < 0.0001, Tukey-Kramer Multiple-Comparison Test). Affiliation to treatment group, local treatment and examination modality had no significant influence on the results (ANOVA for repeated measurements). Neither a cellular nor a humoral immune response directed against htyr or hgp100 was detected. Horses had an increased body temperature on the day after vaccination.
  
  
  CONCLUSIONS
  This is the first clinical report on a systemic effect against equine melanoma following treatment with DNA vectors encoding eqIL12 and eqIL18 and formulated with a transfection reagent. Addition of DNA vectors encoding hgp100 respectively htyr did not potentiate this effect.
authors.affiliation: Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. kathrin.maehlmann@vetsuisse.unibe.ch.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Mählmann
authors.affiliation: Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. karsten.feige@tiho-hannover.de.
authors.forename: Karsten
authors.initials: K
authors.lastname: Feige
authors.affiliation: Mologen AG, Berlin, Germany. juhls@mologen.com.
authors.forename: Christiane
authors.initials: C
authors.lastname: Juhls
authors.affiliation: Mologen AG, Berlin, Germany. endmann@mologen.com.
authors.forename: Anne
authors.initials: A
authors.lastname: Endmann
authors.affiliation: Immunology Unit, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. hans-joachim.schuberth@tiho-hannover.de.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Schuberth
authors.affiliation: Mologen AG, Berlin, Germany. Oswald@mologen.com.
authors.forename: Detlef
authors.initials: D
authors.lastname: Oswald
authors.affiliation: Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. maren.hellige@tiho-hannover.de.
authors.forename: Mareu
authors.initials: M
authors.lastname: Hellige
authors.affiliation: Institute for Veterinary Epidemiology and Biostatistics, Free University of Berlin, Berlin, Germany. marcus.doherr@fu-berlin.de.
authors.forename: Marcus
authors.initials: M
authors.lastname: Doherr
authors.affiliation: Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. jessika.cavalleri@tiho-hannover.de.
authors.forename: Jessika-M V
authors.initials: JM
authors.lastname: Cavalleri
mesh_terms: D000818:Animals; D000906:Antibodies; D019496:Cancer Vaccines / Q000008:administration & dosage / Q000276:immunology*; D004273:DNA, Neoplasm / Q000276:immunology; D005260:Female; D005822:Genetic Vectors; D006734:Horse Diseases / Q000628:therapy*; D006736:Horses; D015552:Injections, Intralesional; D007273:Injections, Intramuscular; D008297:Male; D008545:Melanoma / Q000628:therapy / Q000662:veterinary*; D009363:Neoplasm Proteins; D014162:Transfection / Q000662:veterinary*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000906:Antibodies; D019496:Cancer Vaccines; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D019444:Vaccines, DNA