title: Antiproliferative effect of the jararhagin toxin on B16F10 murine melanoma.
abstract: BACKGROUND
  Malignant melanoma is a less common but highly dangerous form of skin cancer; it starts in the melanocytes cells found in the outer layer of the skin. Jararhagin toxin, a metalloproteinase isolated from Bothrops jararaca snake venom acts upon several biological processes, as inflammation, pain, platelet aggregation, proliferation and apoptosis, though not yet approved for use, may one day be employed to treat tumors.
  
  
  METHODS
  B16F10 murine melanoma cells were treated with jararhagin (jara), a disintegrin-like metalloproteinase isolated from Bothrops jararaca snake venom, and jari (catalytic domain inactivated with 1,10-phenanthroline). Viability and adhesion cells were evaluated by MTT assay. The expression of caspase-3 active, phases of the cell cycle and apoptosis were assessed by flow cytometry. We analyze in vivo the effects of jararhagin on melanoma growth, apoptosis and metastasis.
  
  
  RESULTS
  The tumor cells acquired round shapes, lost cytoplasmic expansions, formed clusters in suspension and decreased viability. Jari was almost 20 times more potent toxin than jara based on IC50 values and on morphological changes of the cells, also observed by scanning electron microscopy. Flow cytometry analysis showed 48.3% decrease in the proliferation rate of cells and 47.2% increase in apoptosis (jara) and necrosis (jari), following 1.2 μM jara and 0.1 μM jari treatments. Caspase-3 activity was increased whereas G0/G1 cell cycle phase was on the decline. Proliferative rate was assessed by staining with 5,6-carboxyfluoresceindiacetate succinimidyl ester, showing a significant decrease in proliferation at all concentrations of both toxins.
  
  
  CONCLUSIONS
  In vivo treatment of the toxins was observed reduction in the incidence of nodules, and metastasis and antiproliferative inhibition capacity. This data strengthens the potential use jararhagin as an anti-neoplastic drug.
authors.affiliation: Biochemistry and Biophysics Laboratory, Butantan Institute, Av, Vital Brasil 1500, CEP 05503-900 Sao Paulo, SP, Brazil. durvanei.maria@butantan.gov.br.
authors.forename: Durvanei Augusto
authors.initials: DA
authors.lastname: Maria
authors.forename: Manuela Garcia Laveli
authors.initials: MG
authors.lastname: da Silva
authors.forename: Mario Cesar
authors.initials: MC
authors.lastname: Correia Junior
authors.forename: Itamar Romano Garcia
authors.initials: IR
authors.lastname: Ruiz
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D017837:Bothrops; D053148:Caspase 3 / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003435:Crotalid Venoms / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism; D008666:Metalloendopeptidases / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D045726:Metalloproteases / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D010974:Platelet Aggregation; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D000097146:Bothrops jararaca Venom; D000096142:Cutaneous Malignant Melanoma
chemical_list: D000970:Antineoplastic Agents; D053148:Caspase 3; D003435:Crotalid Venoms; D008666:Metalloendopeptidases; D045726:Metalloproteases; D010975:Platelet Aggregation Inhibitors; D000097146:Bothrops jararaca Venom