A Chemical and Genetic Approach to the Mode of Action of Fumagillin

Abstract

Previous mode of action studies identified methionine aminopeptidase 2 (MetAP-2) as the target of the antiangiogenic natural product fumagillin and its drug candidate analog, TNP-470. We report here that TNP-470-mediated MetAP-2 inhibition blocks noncanonical Wnt signaling, which plays a critical role in development, cell differentiation, and tumorigenesis. Consistent with this finding, antisense MetAP-2 morpholino oligonucleotide injection in zebrafish embryos phenocopies gastrulation defects seen in noncanonical Wnt5 loss-of-function zebrafish mutants. MetAP-2 inhibition or depletion blocks signaling downstream of the Wnt receptor Frizzled, but upstream of Calmodulin-dependent Kinase II, RhoA, and c-Jun N-terminal Kinase. Moreover, we demonstrate that TNP-470 does not block the canonical Wnt/beta-catenin pathway. Thus, TNP-470 selectively regulates noncanonical over canonical Wnt signaling and provides a unique means to explore and dissect the biological systems mediated by these pathways.

Chick pulmonaryWnt5adirects airway and vascular tubulogenesis

“…The number of vascular spaces is increased in Wnt5a-mis/overexpressing lungs, suggesting an angiogenic effect of Wnt5a, a property that has been suggested by others as well (Cheng et al, 2008;Masckauchan et al, 2006;Zhang et al, 2006), but we also show that the affected vessels are malpatterned. Results presented herein suggest that sprouting…”

Wnt/Planar cell polarity signaling: A new paradigm for cancer therapy

“…First, unlike the field of canonical Wnt/β-catenin signaling in which a straightforward readout system has been used to identify small molecule compounds targeting this pathway (74), the field of PCP signaling lacks a well-established pathway readout system, hindering the utilization of small molecule screening to discover compounds that specifically modulate PCP signaling for cancer therapy. Fortunately, TNP-470 was serendipitously identified as the first small molecule capable of specifically inhibiting PCP signaling (58,59). This example provides guidance for future small molecule screening for PCP signaling modulators using zebrafish high resolution phenotyping resources until a better PCP pathway readout system is developed.…”

“…Wnts have emerged as a novel class of angiogenic factors that promote angiogenesis, and recent evidence indicates that both Wnt/β-catenin and noncanonical Wnt signaling are involved in angiogenesis (56,57). Using a chemical genetic approach, the potent anti-angiogenic natural product fumagillin was identified as a specific inhibitor of noncanonical Wnt signaling, suggesting a link between noncanonical Wnt signaling and angiogenesis (58). Further study showed that inhibition of PCP signaling by the fumagillin analog TNP-470 disrupts endothelial cell growth, polarity, and migration.…”

Regulated tissue fluidity steers zebrafish body elongation

“…Conditional knockout (cKO) of Fgfr1 or Fgf4 and Fgf8 in the mouse mesoderm leads to axis truncation accompanied by a reduction in mesoderm differentiation (Naiche et al, 2011;Niwa et al, 2007;Wahl et al, 2007). In zebrafish, short and/or bent embryos are commonly caused by mutation or overexpression of cell signaling and adhesion genes, but the mechanics of such defects are poorly understood (Draper et al, 2001;Flowers et al, 2012;Hammerschmidt et al, 1996;Jülich et al, 2005;Kawamura et al, 2008;Keegan et al, 2002;Lele et al, 2002;Marlow et al, 2004;Okuda et al, 2010;Rauch et al, 1997a;Row and Kimelman, 2009;Shimizu et al, 2005;Stoick-Cooper et al, 2007;Tucker et al, 2008;Weidinger et al, 2005;Zhang et al, 2006).…”

“…The non-canonical Wnt pathway establishes cell polarity, which is necessary for efficient mesoderm migration towards the dorsal midline (Roszko et al, 2009;Wallingford et al, 2002). Non-canonical Wnt signaling is also required for zebrafish trunk and tail elongation (Marlow et al, 2004;Rauch et al, 1997b;Zhang et al, 2006).…”