In vitro antiproliferative and antiangiogenic effects of synthetic chalcone analogues

As flavonoids, chalcones possess a wide variety of biological activities including anticancer properties. In the present study we have investigated the in vitro antiproliferative and antiangiogenic effects of four synthetic chalcones. E-2-(4'-methoxybenzylidene)-1-benzosuberone (3) was the most active compound with IC(50)=10(-7)mol l(-1) in Jurkat cells. In both Jurkat and HeLa chalcone 3-treated cells we found a significant increase in the proportion of cancer cells in the G(2)/M phase of the cell cycle as well as an increase in cells having sub-G(0)/G(1) DNA content which is considered to be a marker of apoptotic cell death. Apoptosis was also confirmed by annexin V staining and DNA fragmentation. These effects were associated with reduced expression of the anti-apoptotic gene, Bcl-2, and increased expression of the pro-apoptotic gene, Bax. Furthermore, chalcone 3 was selected to evaluate its effect on some angiogenic events. In non-toxic concentrations, chalcone 3 inhibited VEGF-induced migration of human umbilical vein endothelial cells. Moreover, it also decreased secretion of matrix metalloproteinase (mainly MMP-9) and vascular endothelial growth factor (VEGF). In conclusion, the present study has assessed the in vitro antiproliferative/antiangiogenic potential of chalcone 3. This results generate a rationale for in vivo efficacy studies with this compound in preclinical cancer models.