ALBERT

Description: by Ana L. M. Batista de Carvalho, Paula S. C. Medeiros, Francisco M. Costa, Vanessa P. Ribeiro, Joana B. Sousa, Carmen Diniz, Maria P. M. Marques The present work is aimed at evaluating the antitumour properties of a Pd(II) dinuclear complex with the biogenic polyamine spermine, by investigating: i) the anti-angiogenic and anti-migration properties of a Pd(II) dinuclear complex with spermine (Pd 2 Spm); ii) the anti-proliferative activity of Pd 2 Spm against a triple negative human breast carcinoma (MDA-MB-231); and finally iii) the putative interaction mediated by combination of Pd 2 Spm with Docetaxel. Anti-invasive (anti-angiogenic and anti-migratory) as well as anti-proliferative capacities were assessed, for different combination schemes and drug exposure times, using the CAM assay and VEGFR2 activity measurement, the Matrigel TM method and the SRB proliferation test. The results thus obtained evidence the ability of Pd 2 Spm to restrict angiogenesis and cell migration: Pd 2 Spm induced a marked inhibition of migration (43.8±12.2%), and a higher inhibition of angiogenesis (81.8±4.4% for total length values, at 4 μM) as compared to DTX at the clinical dosage 4x10 -2 μM (26.4±14.4%; n = 4 to 11). Combination of Pd 2 Spm/DTX was more effective as anti-invasive and anti-proliferative than DTX or Pd 2 Spm in sole administration, which is compatible with the occurrence of synergism: for the anti-angiogenic effect, IC 50(Pd2Spm/DTX) = 0.5/0.5x10 -2 μM vs IC 50(DTX) = 1.7x10 -2 μM and IC 50(Pd2Spm) = 1.6 μM. In conclusion, the reported effects of Pd 2 Spm on angiogenesis, migration and proliferation showed that this compound is a promising therapeutic agent against this type of breast cancer. Moreover, combined administration of Pd 2 Spm and DTX was found to trigger a substantial synergetic effect regarding angiogenesis inhibition as well as anti-migratory and anti-proliferative activities reinforcing the putative use of Pd(II) complexes in chemotherapeutic regimens. This is a significant outcome, aiming at the application of these combined strategies towards metastatic breast cancer (or other type of resistant cancers), justifying further studies that include pre-clinical trials.