Article

Endothelial Cell Migration and Vascular Endothelial Growth Factor Expression Are the Result of Loss of Breast Tissue Polarity

Department of Surgery, University of California at San Francisco, 94143, USA.
Cancer Research (Impact Factor: 9.28). 09/2009; 69(16):6721-9. DOI: 10.1158/0008-5472.CAN-08-4069
Source: PubMed

ABSTRACT Recruiting a new blood supply is a rate-limiting step in tumor progression. In a three-dimensional model of breast carcinogenesis, disorganized, proliferative transformed breast epithelial cells express significantly higher expression of angiogenic genes compared with their polarized, growth-arrested nonmalignant counterparts. Elevated vascular endothelial growth factor (VEGF) secretion by malignant cells enhanced recruitment of endothelial cells (EC) in heterotypic cocultures. Significantly, phenotypic reversion of malignant cells via reexpression of HoxD10, which is lost in malignant progression, significantly attenuated VEGF expression in a hypoxia-inducible factor 1alpha-independent fashion and reduced EC migration. This was due primarily to restoring polarity: forced proliferation of polarized, nonmalignant cells did not induce VEGF expression and EC recruitment, whereas disrupting the architecture of growth-arrested, reverted cells did. These data show that disrupting cytostructure activates the angiogenic switch even in the absence of proliferation and/or hypoxia and restoring organization of malignant clusters reduces VEGF expression and EC activation to levels found in quiescent nonmalignant epithelium. These data confirm the importance of tissue architecture and polarity in malignant progression.

Download full-text

Full-text

Available from: Paraic A Kenny, Aug 18, 2015
0 Followers
 · 
173 Views
  • Source
    • "Both inhibitors induced striking morphological reversion of the malignant phenotype in contrast to vehicle-treated cells. The reversion was similar to that obtained with other signaling inhibitors, including inhibitory antibodies and small molecule inhibitors targeting b1-integrin and EGFR (Weaver et al. 1997; Wang et al. 1998), PI3K (Liu et al. 2004), TACE (Kenny and Bissell 2007), Rap-1 (Itoh et al. 2007), and HoxD10 (Chen et al. 2009), among others (Bissell et al. 2005). Zymography of CM revealed that S1 cells produced a small amount of MMP9 in 2D cultures, but no detectable MMP9 following acinar morphogenesis in 3D lrECM cultures. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Organization into polarized three-dimensional structures defines whether epithelial cells are normal or malignant. In a model of morphogenesis, we show that inhibiting key signaling pathways in human breast cancer cells leads to "phenotypic reversion" of the malignant cells. Using architecture as an endpoint, we report that, in all cases, signaling through Raf/MEK/ERK disrupted tissue polarity via matrix metalloproteinase9 (MMP9) activity. Induction of Raf or activation of an engineered, functionally inducible MMP9 in nonmalignant cells led to loss of tissue polarity, and reinitiated proliferation. Conversely, inhibition of Raf or MMP9 with small molecule inhibitors or shRNAs restored the ability of cancer cells to form polarized quiescent structures. Silencing MMP9 expression also reduced tumor growth dramatically in a murine xenograft model. LC-MS/MS analysis comparing conditioned medium from nonmalignant cells with or without active MMP9 revealed laminin 111 (LM1) as an important target of MMP9. LM1 has been implicated in acinar morphogenesis; thus, its degradation by MMP9 provides a mechanism for loss of tissue polarity and reinitiation of growth associated with MMP9 activity. These findings underscore the importance of the dynamic reciprocity between the extracellular matrix integrity, tissue polarity, and Raf/MEK/ERK and MMP9 activities, providing an axis for either tissue homeostasis or malignant progression.
    Genes & development 12/2010; 24(24):2800-11. DOI:10.1101/gad.1990410 · 12.64 Impact Factor
  • Source
    • "With cells grown in 3D culture models, the multicellular tumour spheroids (spheroids) have a well-organized spherical symmetry, with different cell populations arranged concentrically (Mueller- Klieser, 2000; Friedrich et al. 2007). Topics studied in this model of breast carcinoma include analysis of the alterations of the activation of HER2 in the 3D environment (Pickl and Ries, 2009), the effect of marine compounds on the cytoskeleton (Freitas et al., 2008), the role of the stroma in carcinogenesis (Weigelt and Bissell, 2008), drug screening (Friedrich et al. 2009), angiogenic factors/polarity (Chen et al., 2009) and morphogenesis (Yamada and Cukierman, 2007; Mailleux et al., 2008). In the present study, we monitored luminal morphogenesis by taking advantage of the integrative vision provided by this model. "
    [Show abstract] [Hide abstract]
    ABSTRACT: 3D (three-dimensional) cell culture permits a more integrated analysis of the relationship between cells, inserting them into a structure more closely resembling the cellular microenvironment in vivo. The development of in vitro parameters to approximate in vivo 3D cellular environments makes a less reductionist interpretation of cell biology possible. For breast cells, in vitro 3D culture has proven to be an important tool for the analysis of luminal morphogenesis. A greater understanding of this process is necessary because alterations in the lumen arrangement are associated with carcinogenesis. Following lumen formation in 3D cell culture using laser scanning confocal microscopy, we observed alterations in the arrangement of cytoskeletal components (F-actin and microtubules) and increasing levels of cell death associated with lumen formation. The formation of a polarized monolayer facing the lumen was characterized through 3D reconstructions and the use of TEM (transmission electron microscopy), and this process was found to occur through the gradual clearing of cells from the medullary region of the spheroids. This process was associated with different types of cell death, such as apoptosis, autophagy and entosis. The present study showed that changes in the extracellular matrix associated with long periods of time in 3D cell culture lead to the formation of a lumen in MCF-7 cell spheroids and that features of differentiation such as lumen and budding formation occur after long periods in 3D culture, even in the absence of exogenous extracellular compounds.
    Cell Biology International 03/2010; 34(3-(3)):267-74.. DOI:10.1042/CBI20090024 · 1.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Delineation of the mechanisms that establish and maintain the polarity of epithelial tissues is essential to understanding morphogenesis, tissue specificity and cancer. Three-dimensional culture assays provide a useful platform for dissecting these processes but, as discussed in a recent study in BMC Biology on the culture of mammary gland epithelial cells, multiple parameters that influence the model must be taken into account. See research article http://www.biomedcentral.com/1741-7007/7/77.
    Journal of Biology 01/2010; 9(1):2. DOI:10.1186/jbiol213
Show more