IN VITRO AND IN VIVO EFFECTS OF A RECOMBINANT RGD-DISINTEGRIN FROM Bothrops alternatus

COMINETTI M. R. (1), RAMOS O. H. P. (2), CREPIN M. (3), BONNEFOY A. (3), SELISTRE DE ARAUJO H. S. (1)

(1) Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos, SP, Brasil; (2) Divisão de Desenvolvimento Científico, Instituto Butantan, São Paulo, SP, Brasil; (3) INSERM, Unité 553, Paris, France.

Disintegrins are a family of low molecular weight, RGD-containing peptides that bind specifically to integrins IIb3, 51, and v3 expressed on platelets and other cells including some tumor cells. In this work, we have produced and characterized a new recombinant RGD-disintegrin called DisBa-01, which interacts with IIb3 integrin, inhibiting the platelet aggregation induced by different agonists and the proliferation of endothelial and tumor cells. DisBa-01 was tested in vivo using a metastasis model with B16F10-2B8 melanoma cells and C57BL6/j mice, Briefly, 5x105 cells previously incubated with different concentrations of DisBa-01 (0, 0.05, 0.5, 2 or 4 mg/Kg) for 5 minutes were injected (100 L) in the mice’s tail vein. The homing and the evolution of pulmonary established metastasis were monitored at day 0, 1, 4, 12, 14 after luciferin injection (150 mg/Kg). By imaging and measuring the lung metastasis homing and the lung metastatic development of B16-F10 melanoma in C57Bl/6 mice we showed a strong antimetastatic activity of a single inoculation of DisBa-01 disintegrin. However, no direct cell toxicity was observed after a short treatment of melanoma cells with DisBa-01. Taking our results together, it is possible to conclude that DisBa-01 prevents melanoma metastasis by blocking adherence mechanisms of tumor cells to vessel endothelium. Since disintegrin peptides may be developed as antimetastatic agents, it is important to understand its functions in vivo in order to develop new strategies and new drugs which could be used in cancer therapy.

KEY WORDS: RGD-disintegrin, snake venom, metastasis, melanoma, cancer.

FINANCIAL SUPPORT: FAPESP.

CORRESPONDENCE TO: Dra. Heloísa S. Selistre de Araújo, Universidade Federal de São Carlos Departamento de Ciências Fisiológicas, Rod. Washington Luis, Km 235, São Carlos, SP, Brasil. Phone: + 55 16 33518333. Fax: + 55 16 33518327. Email: hsaraujo@power.ufscar.br