The unique characteristics of the tumor vasculature offer the possibility to selectively target tumor growth and vascularization using tubulin-destabilizing agents. Evidence accumulated with combretastatin A-4 (CA-4) and its prodrug CA-4P support the therapeutic value of compounds sharing this mechanism of action. However, the chemical instability and poor solubility of CA-4 demand alternative compounds that are able to surmount these limitations. This Perspective illustrates the different classes of compounds that behave similar to CA-4, analyzes their binding mode to αβ-tubulin according to recently available structural complexes, and includes described approaches to improve their delivery. In addition, dissecting the mechanism of action of CA-4 and analogues allows a closer insight into the advantages and drawbacks associated with these tubulin-destabilizing agents that behave as vascular disrupting agents (VDAs).

Antivascular and antitumor properties of the tubulin-binding chalcone TUB091

Thymidine Phosphorylase (TPase) catalyses the reversible phosphorolysis of pyrimidine 2- deoxynucleosides to 2-deoxyribose-1-phosphate and their respective pyrimidine bases, including the phosphorolysis of nucleoside analogues with important antiviral or anticancer properties. Moreover, TPase, identified also as the angiogenic platelet-derived endothelial cell growth factor (PD-ECGF), stimulates endothelial cell migration in vitro and angiogenesis in vivo and plays an important role in tumour progression and metastasis. Here we have summarized the most recent approaches in the search for novel TPase inhibitors together with the potential therapeutic applications of such inhibitors.