title: The combination of Cl-IB-MECA with paclitaxel: a new anti-metastatic therapeutic strategy for melanoma.
abstract: OBJECTIVE
  Metastatic melanoma is considered one of the most aggressive malignant tumours, representing the deadliest form of skin cancer. Melanoma progression is associated with the abrogation of normal controls that limit cell proliferation, migration, and invasion, eventually leading to metastasis. Based on the variety of cellular mechanisms involved in metastatic progression, we aimed to evaluate the effect of inosine (50 μM) and of the combination of Cl-IB-MECA (10 μM) with paclitaxel (10 ng/mL) on several stages of melanoma progression.
  
  
  METHODS
  Proliferation, migration, adhesion, invasion, and colony formation assays were performed on human C32 and A375 metastatic melanoma cells. Levels of ERK1/2 were also determined using an ELISA kit. Moreover, mouse aortic rings were treated with vascular endothelial growth factor in order to assess the microvessel sprouting (an indicator of angiogenesis) in the presence of the referred compounds.
  
  
  RESULTS
  We demonstrate that inosine induced, through A3 adenosine receptor activation, proliferation, migration, adhesion, and invasion on C32 and A375 melanoma cells, although with dissimilar importance on the two melanoma cell lines. Inosine also increased colony formation on A375 cells. Levels of ERK1/2 were increased after inosine exposure and that increase was dependent on A3 adenosine receptor activation in both cell lines. Moreover, microvessel sprouting stimulated by inosine was decreased by the combination of Cl-IB-MECA with paclitaxel.
  
  
  CONCLUSIONS
  Cl-IB-MECA combined with paclitaxel was able to impair almost all of the referred metastatic related mechanisms induced by inosine, making this approach a valuable tool for combinatory therapy against metastatic melanoma.
authors.affiliation: REQUIMTE/Laboratório de Farmacologia, Departamento de Ciências do Medicamento, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Soares
authors.forename: Vera M
authors.initials: VM
authors.lastname: Costa
authors.forename: Carmen
authors.initials: C
authors.lastname: Diniz
authors.forename: Paula
authors.initials: P
authors.lastname: Fresco
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002468:Cell Physiological Phenomena / Q000187:drug effects; D018450:Disease Progression; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007288:Inosine / Q000494:pharmacology; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D051379:Mice; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology*; D043684:Receptor, Adenosine A3 / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D043684:Receptor, Adenosine A3; D007288:Inosine; D000241:Adenosine; D017239:Paclitaxel; C090034:2-chloro-N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide