Sanguinarine inhibits VEGF-induced Akt phosphorylation
ABSTRACT Angiogenesis is the process of vascular growth by sprouting of preexisting vessels. This process impacts significantly on many important disease states including cancer, diabetic retinopathy, and arthritis. Endothelial cells receive multiple information from their environment, which leads them to progress along all stages of new vessel formation. Vascular endothelial growth factor (VEGF), in particular appears to be a master regulator of this process. This molecule interacts with cellular receptors and communicates with cell nucleus through a network of intracellular signaling, most of all by activating Akt pathway. This activation accounts for many of VEGF effects, including cell survival, migration, tube formation, and promotion of NO release. Sanguinarine (SA), an alkaloid isolated from Sanguinaria canadensis, is known for its antiangiogenetic effects by suppressing basal and VEGF-induced new vessel growth. This article was aimed to evaluate the possible effect of SA (300 nM) on Akt phosphorylation in a porcine aortic endothelial cell line. The alkaloid significantly (P < 0.001) inhibited the VEGF-induced Akt increase, thus suggesting that this mode of action could be responsible, at least partially, for the antiangiogenetic effect of SA.
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ABSTRACT: Vascular endothelial growth factor (VEGF) is a main angiogenic factor which is known to be upregulated in lung cancer. In the present study, it was demonstrated that sanguinarine, an alkaloid obtained from the bloodroot plant, markedly repressed the VEGF-induced tube formation of human microvascular endothelial cells (HMVECs) and the migration of human A549 lung cancer cells. Furthermore, sanguinarine decreased VEGF secretion and expression in HMVECs and A549 lung cancer cells in a dose- and time-dependent manner. Additionally, sanguinarine inhibited the activation of serum starvation- and hypoxia-induced VEGF promoter activity. Sanguinarine also inhibited the VEGF-mediated Akt and p38 activation, as well as VE-cadherin protein phosphorylation. To the best of our knowledge, this is the first study demonstrating that VEGF inhibition appears to be an important mechanism involved in the antiangiogenic and anti-invasive activities of sanguinarine in lung cancer treatment.Molecular and Clinical Oncology 01/2013; 1(2):331-336. DOI:10.3892/mco.2012.41
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ABSTRACT: The effects of sanguinarine on IgE mediated early signaling mechanisms leading to inflammatory mediators release were investigated. Pretreatment of RBL 2H3 cells with sanguinarine inhibited IgE induced activation of type II PtdIns 4-kinase activity. Concomitant with type II PtdIns 4-kinase inhibition, sanguinarine also inhibited IgE induced degranulation and β hexosaminidase release in RBL 2H3 cells. In vitro assays showed sanguinarine inhibited type II PtdIns 4-kinase activity in a dose dependent fashion with no effect on PtdIns 3-kinase activity. Fluorescence spectroscopic studies suggested that sanguinarine binds to type II PtdIns 4-kinases α and β isoforms with a Kd of 2.4 and 1.8 μM, respectively. Kinetic studies showed that sanguinarine competes with PtdIns binding site of type II PtdIns 4-kinase β. These results suggest that the anti-inflammatory effects of sanguinarine on PtdIns 3-kinase signaling pathway are more likely an indirect effect and emphasize the importance of the cross talk between type II PtdIns 4-kinases and PtdIns 3-kinases.Archives of Biochemistry and Biophysics 07/2013; DOI:10.1016/j.abb.2013.07.017 · 3.04 Impact Factor