Dataset Information

Dickkopf-1 induces angiogenesis via VEGF receptor 2 regulation independent of the Wnt signaling pathway.

ABSTRACT: Tumor angiogenesis is essential for invasive tumor growth and metastasis. Dickkopf-1 (DKK-1), an antagonist of Wnt signaling, participates in tumor development and progression. We evaluated whether DKK-1 stimulation induces angiogenesis and the endothelial-mesenchymal transition (EnMT). Human umbilical vein endothelial cells (HUVECs) were stimulated with recombinant DKK-1 (rDDK-1) or conditioned medium from a culture of DKK-1-transfected 293 cells. Following stimulation, the expression levels of angiogenesis-related factors and EnMT related markers were determined by immunoblot assays. In addition, the effects of exogenous DKK-1 on angiogenesis and EnMT were assessed by tube-formation, cell invasion, and wound-healing assays. Human hepatoma cells, such as Hep3B and Huh-7, showed high levels of DKK-1 expression, whereas 293 cells and HUVECs showed little or no DKK-1 expression. Increased endothelial cell tube formation and invasiveness were observed in HUVECs treated with concentrated conditioned medium from DKK-1-overexpressing 293 cells or rDKK-1. DKK-1-stimulated HUVECs also exhibited increased motility in wound-healing assays. Furthermore, the expression levels of angiogenesis-related factors, including vascular endothelial growth factor receptor 2 and vascular endothelial-cadherin, were increased in DKK-1-stimulated HUVECs. The expression of EnMT markers, such as vimentin and Twist, was also increased in DKK-1-stimulated HUVECs. However, no significant change in ?-catenin or GSK3? expression was observed. Our in vitro data suggest that DKK-1 can enhance angiogenesis and EnMT by HUVECs independent of the Wnt signaling pathway. Modulation of DKK-1 expression may facilitate development of novel strategies to control tumor angiogenesis and metastasis.

SUBMITTER: Choi SH

PROVIDER: S-EPMC5601707 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Dickkopf-1 induces angiogenesis via VEGF receptor 2 regulation independent of the Wnt signaling pathway.

Choi Sung Hoon SH Kim Hyemi H Lee Hyun Gyu HG Kim Beom Kyung BK Park Jun Yong JY Kim Do Young DY Ahn Sang Hoon SH Han Kwang-Hyub KH Kim Seung Up SU

Oncotarget 20170801 35

Tumor angiogenesis is essential for invasive tumor growth and metastasis. Dickkopf-1 (DKK-1), an antagonist of Wnt signaling, participates in tumor development and progression. We evaluated whether DKK-1 stimulation induces angiogenesis and the endothelial-mesenchymal transition (EnMT). Human umbilical vein endothelial cells (HUVECs) were stimulated with recombinant DKK-1 (rDDK-1) or conditioned medium from a culture of DKK-1-transfected 293 cells. Following stimulation, the expression levels of ...[more]

PMID: 28938611

Similar Datasets

Project description:AimArgonaute2 (AGO2) protein is the active part of RNA-induced silencing complex, cleaving the target mRNA strand complementary to their bound siRNA. An increasing number of miRNAs has been identified as essential to angiogenesis of hepatocellular carcinoma (HCC). In this study we investigated how AGO2 affected HCC angiogenesis.MethodsHuman HCC cell lines HepG2, Hep3B, Huh7, SMMC-7721, Bel-7404, MHCC97-H and LM-3, and human umbilical vein endothelial cells (HUVEC) were tested. The expression of AGO2 in HCC cells was knocked down with siRNA and restored using recombinant adenovirus expressing Ago2. The levels of relevant mRNAs and proteins were examined using RT-PCR, Western blot and EILSA. Nude mice were implanted with Huh7 or SMMC-7721 cells, and tumor volumes were measured. After the mice were euthanized, the xenograft tumors were used for immunohistological analysis.ResultsIn 6 HCC cell lines, AGO2 protein expression was significantly correlated with VEGF expression (r=+0.79), and with VEGF secretion (r=+0.852). Knockdown of Ago2 in Huh7 cells and SMMC-7721 cells substantially decreased VEGF expression, whereas the restoration of AGO2 reversed both VEGF expression and secretion. Furthermore, knockdown of Ago2 significantly up-regulated the expression of PTEN (a tumor suppressor involved in the inhibition of HCC angiogenesis), and vice versa. Moreover, the specific PTEN inhibitor bisperoxovanadate (7, 14, 28 nmol/L) dose-dependently restored the expression of VEGF and the capacity of HCC cells to induce HUVECs to form capillary tubule structures. In the xenograft nude mice, knockdown of Ago2 markedly suppressed the tumor growth and decreased PTEN expression and CD31-positive microvascular in the xenograft tumors.ConclusionA direct relationship exists between the miRNA processing machinery AGO2 and HCC angiogenesis that is mediated by the AGO2/PTEN/VEGF signaling pathway. The results suggest the high value of Ago2 knockdown in anti-angiogenesis therapy for HCC.

Project description:Bartonella bacilliformis is a Gram-negative bacterial pathogen that provokes pathological angiogenesis and causes Carrion's disease, a neglected tropical disease restricted to South America. Little is known about how B. bacilliformis facilitates vasoproliferation resulting in hemangioma in the skin in verruga peruana, the chronic phase of Carrion's disease. Here, we demonstrate that B. bacilliformis extracellularly secrets a passenger domain of the autotransporter BafA exhibiting proangiogenic activity. The B. bacilliformis-derived BafA passenger domain (BafABba) increased the number of human umbilical endothelial cells (HUVECs) and promoted tube-like morphogenesis. Neutralizing antibody against BafABba detected the BafA derivatives from the culture supernatant of B. bacilliformis and inhibited the infection-mediated hyperproliferation of HUVECs. Moreover, stimulation with BafABba promoted phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) and extracellular-signal-regulated kinase 1/2 in HUVECs. Suppression of VEGFR2 by anti-VEGFR2 antibody or RNA interference reduced the sensitivity of cells to BafABba. In addition, surface plasmon resonance analysis confirmed that BafABba directly interacts with VEGFR2 with lower affinity than VEGF or Bartonella henselae-derived BafA. These findings indicate that BafABba acts as a VEGFR2 agonist analogous to the previously identified B. henselae- and Bartonella quintana-derived BafA proteins despite the low sequence similarity. The identification of a proangiogenic factor produced by B. bacilliformis that directly stimulates endothelial cells provides an important insight into the pathophysiology of verruga peruana. IMPORTANCE Bartonella bacilliformis causes life-threatening bacteremia or dermal eruption known as Carrion's disease in South America. During infection, B. bacilliformis promotes endothelial cell proliferation and the angiogenic process, but the underlying molecular mechanism has not been well understood. We show that B. bacilliformis induces vasoproliferation and angiogenesis by producing the proangiogenic autotransporter BafA. As the cellular/molecular basis for angiogenesis, BafA stimulates the signaling pathway of vascular endothelial growth factor receptor 2 (VEGFR2). Identification of functional BafA protein from B. bacilliformis in addition to B. henselae and B. quintana, the causes of cat scratch disease and trench fever, raises the possibility that BafA is a common virulence factor for human-pathogenic Bartonella.

Dataset Information

Dickkopf-1 induces angiogenesis via VEGF receptor 2 regulation independent of the Wnt signaling pathway.

Publications

Dickkopf-1 induces angiogenesis via VEGF receptor 2 regulation independent of the Wnt signaling pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets