ZFIN ID: ZDB-PUB-120611-8
A novel microtubule-modulating agent EM011 inhibits angiogenesis by repressing the HIF-1alpha axis and disrupting cell polarity and migration
Karna, P., Rida, P.C., Turaga, R.C., Gao, J., Gupta, M.V., Fritz, A., Werner, E., Yates, C., Zhou, J., and Aneja, R.
Date: 2012
Source: Carcinogenesis   33(9): 1769-1781 (Journal)
Registered Authors: Fritz, Andreas
Keywords: cancer, cell cycle, cytoskeleton, apoptosis, drug resistance, tubulin binding drugs, DNA repair, DNA damage, hepatitis, aflatoxin, p53, transgenics, microtubules, ubiquitination, proteasome, mitosis, meiosis, cancer prevention, skin cancer, antioxidant, HIF, angiogenesis, microtubule modulating, cell polarity
MeSH Terms:
  • Angiogenesis Inhibitors/pharmacology*
  • Animals
  • Cell Movement/drug effects
  • Cell Polarity/drug effects
  • Cells, Cultured
  • Centrosome/drug effects
  • Dioxoles/pharmacology*
  • Endothelial Cells/drug effects
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors*
  • Isoquinolines/pharmacology*
  • Male
  • Mice
  • Microtubules/drug effects
  • Paxillin/physiology
  • Transcriptional Activation
  • rho GTP-Binding Proteins/metabolism
PubMed: 22678119 Full text @ Carcinogenesis
ABSTRACT

Endothelial tubular morphogenesis relies on an exquisite interplay of microtubule dynamics and actin remodeling to propel directed cell migration. Recently, the dynamicity and integrity of microtubules have been implicated in the trafficking and efficient translation of the mRNA for HIF-1α (hypoxia-inducible factor), the master regulator of tumor angiogenesis. Thus, microtubule-disrupting agents that perturb the HIF-1α axis and neovascularization cascade are attractive anticancer drug candidates. Here we show that EM011 (9-bromonoscapine), a microtubule-modulating agent, inhibits a spectrum of angiogenic events by interfering with endothelial cell invasion, migration and proliferation. Employing green-fluorescent transgenic zebrafish, we found that EM011 not only inhibited vasculogenesis but also disrupted preexisting vasculature. Mechanistically, EM011 caused proteasome-dependent, VHL-independent HIF-1α degradation and repressed expression of HIF-1α downstream targets, namely VEGF and survivin. Furthermore, EM011 inhibited membrane ruffling and impeded formation of filopodia, lamellipodia and stress fibers, which are critical for cell migration. These events were associated with a drug-mediated decrease in activation of Rho GTPases- RhoA, Cdc42 and Rac1, and correlated with a loss in the geometric precision of centrosome reorientation in the direction of movement. This is the first report to describe a previously unrecognized, antiangiogenic property of a noscapinoid, EM011, and provides evidence for novel anticancer strategies recruited by microtubule-modulating drugs.

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