Squalamines in Blockade of Tumor-Associated Angiogenesis and Cancer Progression

Mechanisms of action of squalamine in human vascular endothelial cells indicate that this compound attaches to cell membranes, potentially interacting with calmodulin, Na⁺/H⁺ exchanger isoform NHE3 and other signaling pathways involved in the angiogenic process. Thus, squalamine elicits blockade of VEGF-induced endothelial tube-like formation in vitro. Further, squalamine reduces growth of several preclinical models of human cancers in vivo and acts to stop metastatic tumor spread, actions due largely to blockade of angiogenesis induced by the tumor and tumor microenvironment. Squalamine in Phase I/II trials, alone or combined with standard care, shows promising antitumor activity with limited side-effects in patients with advanced solid cancers. Increased attention on squalamine regulation of signaling pathways with or without combination treatments in solid malignancies deserves further study.