title: The synthetic parasite-derived peptide GK1 increases survival in a preclinical mouse melanoma model.
abstract: OBJECTIVE
  The therapeutic efficacy of a synthetic parasite-derived peptide GK1, an immune response booster, was evaluated in a mouse melanoma model. This melanoma model correlates with human stage IIb melanoma, which is treated with wide surgical excision; a parallel study employing a surgical treatment was carried out as an instructive goal.
  
  
  METHODS
  C57BL/6 mice were injected subcutaneously in the flank with 2×10(5) B16-F10 murine melanoma cells. When the tumors reached 20 mm3, mice were separated into two different groups; the GK1 group, treated weekly with peritumoral injections of GK1 (10 μg/100 μL of sterile saline solution) and the control group, treated weekly with an antiseptic peritumoral injection of 100 μL of sterile saline solution without further intervention. All mice were monitored daily for clinical appearance, tumor size, and survival. Surgical treatment was performed in parallel when the tumor size was 20 mm3 (group A), 500 mm3 (group B), and >500 mm3 (group C).
  
  
  RESULTS
  The GK1 peptide effectively increased the mean survival time by 9.05 days, corresponding to an increase of 42.58%, and significantly delayed tumor growth from day 3 to 12 of treatment. In addition, tumor necrosis was significantly increased (p<0.05) in the treated mice. The overall survival rates obtained with surgical treatment at 6 months were 83.33% for group A, 40% for group B, and 0% for group C, with significant differences (p<0.05) among the groups.
  
  
  CONCLUSIONS
  The GK1 peptide demonstrated therapeutic properties in a mouse melanoma model, as treatment resulted in a significant increase in the mean survival time of the treated animals (42.58%). The potential for GK1 to be used as a primary or adjuvant component of chemotherapeutic cocktails for the treatment of experimental and human cancers remains to be determined, and surgical removal remains a challenge for any new experimental treatment of melanoma in mouse models.
authors.affiliation: 1 Department of Cell and Tissue Biology, Facultad de Medicina, Universidad Nacional Autónoma de México , Distrito Federal, Mexico City, México .
authors.forename: Armando
authors.initials: A
authors.lastname: Pérez-Torres
authors.forename: Jesús
authors.initials: J
authors.lastname: Vera-Aguilera
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Hernaiz-Leonardo
authors.forename: Eduardo
authors.initials: E
authors.lastname: Moreno-Aguilera
authors.forename: Diego
authors.initials: D
authors.lastname: Monteverde-Suarez
authors.forename: Carlos
authors.initials: C
authors.lastname: Vera-Aguilera
authors.forename: Daniel
authors.initials: D
authors.lastname: Estrada-Bárcenas
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D008168:Lung / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000473:pathology / Q000628:therapy*; D008546:Melanoma, Experimental / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009336:Necrosis; D009842:Oligopeptides / Q000737:chemistry*; D010271:Parasites / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D010456:Peptides, Cyclic
chemical_list: D000970:Antineoplastic Agents; D009842:Oligopeptides; D010455:Peptides; D010456:Peptides, Cyclic; C534327:cyclo(cysteinyl-glycyl-aspargyl-seryl-aspargyl-prolyl-lysyl-seryl-cysteine)