Preclinical evaluation of the antimetastatic efficacy of Pentoxifylline on A375 human melanoma cell line

Melanoma is the most common malignant skin cancer, appears indestructible and is notoriously resistant to all current modalities of cancer treatment strategies. Pentoxifylline (PTX), a non-specific phosphodiesterase inhibitor, has shown to have radiosensitizing properties for a variety of cancers. Recently, we have shown that PTX exhibits antimetastatic and anti-angiogenic activities in B16F10 melanoma cells in vitro as well as in vivo. In the present study, we have demonstrated the anticancer and antimetastatic potential of PTX against A375 human melanoma cell line at sub-toxic doses. The results implicate that PTX at sub-toxic doses exhibited an inhibitory effect on the ability of cellular proliferation as shown by MTT and colony formation assay. It impedes migration and also induces apoptosis. A375 cells pretreated with PTX showed decrease in adhesion to both Matrigel and Collagen type IV. Further, Gelatin zymography result reveals that PTX treatment decreases the secretion of MMP2 and MMP9. Finally, PTX significantly inhibited A375 subcutaneous tumour xenograft growth without having any toxicity. Thus PTX at sub-toxic doses affected melanoma metastasis at multiple steps in vitro as well as tumour growth in vivo. These data demonstrate its antimetastatic potential and provide preclinical evidence for the development of PTX as a potential agent against metastatic melanoma.