In vivo selection for metastasis promoting genes in the mouse

The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 05/2007; 104(16):6696-701. DOI: 10.1073/pnas.0701145104
Source: PubMed


Here, we report the identification of a metastasis promoting factor by a forward genetic screen in mice. A retroviral cDNA library was introduced into the nonmetastatic cancer cell line 168FARN, which was then orthotopically transplanted into mouse mammary fat pads, followed by selection for cells that metastasize to the lung. The genes encoding the disulfide isomerase ERp5 and beta-catenin were found to promote breast cancer invasion and metastasis. Disulfide isomerases (thiol isomerases), which catalyze disulfide bond formation, reduction, and isomerization, have not previously been implicated in cancer cell signaling and tumor metastasis. Overexpression of ERp5 promotes both in vitro migration and invasion and in vivo metastasis of breast cancer cells. These effects were shown to involve activation of ErbB2 and phosphoinositide 3-kinase (PI3K) pathways through dimerization of ErbB2. Activation of ErbB2 and PI3K subsequently stimulates RhoA and beta-catenin, which mediate the migration and invasion of tumor cells. Inhibition of ErbB2 and PI3K reverses the phenotypes induced by ERp5. Finally, ERp5 was shown to be up-regulated in human surgical samples of invasive breast cancers. These data identify a link between disulfide isomerases and tumor development, and provide a mechanism that modulates ErbB2 and PI3K signaling in the promotion of cancer progression.

Download full-text


Available from: Aleister J Saunders, Jan 26, 2015
  • Source
    • "With respect to the effect on the inflammatory response, the decrease in Prdx1and Pdia1 can have a pro-inflammatory effect on RAW 264.7 macrophages, as it has been described that both proteins can suppress the NF-κB pathway and the consequent inflammatory response [37] [38] [39] [40]. Also important are the decrease in Pdia6 [41] and Hspd1 [42] and the increase in Galectin-3 and Vimentin. Galectin-3 has been described as an important contributor to the development of a proinflammatory response to C. albicans [43] and to the increase in the oxidative response of macrophages [44]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In previous proteomic studies on the response of murine macrophages against Candida albicans, many differentially expressed proteins involved in processes like inflammation, cytoskeletal rearrangement, stress response and metabolism were identified. In order to look for proteins important for the macrophage response, but in a lower concentration in the cell, 3 sub-cellular extracts were analyzed: cytosol, organelle/membrane and nucleus enriched fractions from RAW 264.7 macrophages exposed or not to C. albicans SC5314 for 3 h. The samples were studied using DIGE technology, and 17 new differentially expressed proteins were identified. This sub-cellular fractionation permitted the identification of 2 mitochondrion proteins, a membrane receptor, Galectin-3, and some ER related proteins, that are not easily detected in total cell extracts. Besides, the study of different fractions allowed us to detect, not only total increase in Galectin-3 protein amount, but its distinct allocation along the interaction. The identified proteins are involved in the pro-inflammatory and oxidative responses, immune response, unfolded protein response and apoptosis. Some of these processes increase the host response and others could be the effect of C. albicans resistance to phagocytosis. Thus, the sub-proteomic approach has been a very useful tool to identify new proteins involved in macrophage-fungus interaction. This article is part of a Special Issue entitled: Translational Proteomics.
    Full-text · Article · Feb 2012 · Journal of proteomics
  • Source
    • "Her2 overexpression is a major risk factor for various types of cancer [5], [32], [33]. Intracellular signaling pathways of Her2 have been extensively studied, and Her2 may promote invasive and metastatic activities through Ras- and Rho-family small GTPases [34], [35], PI3K/Akt pathway [36], MMP [25], and also miR21 [37]. Here we show that overexpressed Her2 activates another small GTPase, Arf6, via its association with GEP100, and induces cancer cell invasion. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Overexpression of Her2/ErbB2/Neu in cancer is often correlated with recurrent distant metastasis, although the mechanism still remains largely elusive. We have previously shown that EGFR, when tyrosine-phosphorylated, binds to GEP100/BRAG2 to activate Arf6, which induces cancer invasion and metastasis. We now show that overexpressed Her2 in lung adenocarcinoma cells also employs GEP100. Like EGFR-GEP100 binding, this association is primarily mediated by the pleckstrin homology (PH) domain of GEP100 and Tyr1139/Tyr1196 of Her2. Tyr1139/Tyr1196 are autonomously phosphorylated, when Her2 is overexpressed. Accordingly, invasive activities mediated by the Her2-GEP100 pathway are not dependent on external factors. Blocking Her2-GEP100 binding, as well as its signaling pathway all inhibit cancer invasive activities. Moreover, our clinical study indicates that co-overexpression of Her2 with GEP100 in primary lung adenocarcinomas of patients is correlated with the presence of their node-metastasis with a statistical significance. Since the GEP100 PH domain interacts with both Her2 and EGFR, targeting this domain may provide novel cancer therapeutics.
    Full-text · Article · Sep 2011 · PLoS ONE
  • Source
    • "Indeed, the significance of RhoA/ROCK-2 in VEGF signalling has been displayed in endothelial cells, where RhoA/ROCK-2 mediates VEGF functions on microvascular permeability [44], endothelial migration and angiogenesis [45]. More importantly, the overexpression of RhoA is often observed in clinical cancers [46] and it has been repeatedly identified as a gene associated with metastasis [47,48]. These findings may partly be elucidated by our data that RhoA/ROCK-2 was able to activate moesin and finally led to enhanced cell motility. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The elevated expression of vascular endothelial growth factor C (VEGF-C) is correlated with clinical cervical cancer metastasis and patient survival, which is interpreted by VEGF-C functions to stimulate angiogenesis and lymphatic genesis. However, the direct impact of VEGF-C on cervical cancer cell motility remains largely unknown. In this study, we investigated the effects of VEGF-C on actin cytoskeleton remodeling and on cervical cancer cell migration and invasion and how the actin-regulatory protein, moesin regulated these effects through RhoA/ROCK-2 signaling pathway. On cervical carcinoma cell line SiHa cells, exposure of VEGF-C triggered remodeling of the actin cytoskeleton and the formation of membrane ruffles, which was required for cell movement. VEGF-C significantly enhanced SiHa cells horizontal migration and three-dimensional invasion into matrices. These actions were dependent on increased expression and phosphorylation of the actin-regulatory protein moesin and specific moesin siRNA severely impaired VEGF-C stimulated-cell migration. The extracellular small GTPase RhoA/ROCK-2 cascade mediated the increased moesin expression and phosphorylation, which was discovered by the use of Y-27632, a specific inhibitor of Rho kinase and by transfected constitutively active, dominant-negative RhoA as well as ROCK-2 SiRNA. Furthermore, in the surgical cervical specimen from the patients with FIGO stage at cervical intra-epithelial neoplasia and I-II cervical squamous cell carcinoma, the expression levels of moesin were found to be significantly correlated with tumor malignancy and metastasis. These results implied that VEGF-C promoted cervical cancer metastasis by upregulation and activation of moesin protein through RhoA/ROCK-2 pathway. Our findings offer new insight into the role of VEGF-C on cervical cancer progression and may provide potential targets for cervical cancer therapy.
    Full-text · Article · Apr 2010 · BMC Cancer
Show more