N-WASP-mediated invadopodium formation is involved in intravasation and lung metastasis of mammary tumors

Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Journal of Cell Science (Impact Factor: 5.43). 02/2012; 125(Pt 3):724-34. DOI: 10.1242/jcs.092726
Source: PubMed


Invadopodia are proteolytic membrane protrusions formed by highly invasive cancer cells, commonly observed on substrate(s) mimicking extracellular matrix. Although invadopodia are proposed to have roles in cancer invasion and metastasis, direct evidence has not been available. We previously reported that neural Wiskott-Aldrich syndrome protein (N-WASP), a member of WASP family proteins that regulate reorganization of the actin cytoskeleton, is an essential component of invadopodia. Here, we report that N-WASP-mediated invadopodium formation is essential in breast cancer invasion, intravasation and lung metastasis. We established stable cell lines based on MTLn3 rat mammary adenocarcinoma cells that either overexpressed a dominant-negative (DN) N-WASP construct or in which N-WASP expression was silenced by a pSuper N-WASP shRNA. Both the N-WASP shRNA and DN N-WASP cells showed a markedly decreased ability to form invadopodia and degrade extracellular matrix. In addition, formation of invadopodia in primary tumors and collagen I degradation were reduced in the areas of invasion (collagen-rich areas in the invasive edge of the tumor) and in the areas of intravasation (blood-vessel-rich areas). Our results suggest that tumor cells in vivo that have a decreased activity of N-WASP also have a reduced ability to form invadopodia, migrate, invade, intravasate and disseminate to lung compared with tumor cells with parental N-WASP levels.

Download full-text


Available from: Bojana Gligorijevic, Oct 11, 2015
32 Reads
  • Source
    • "Some data also support the existence of podosome-like structures within tissue collected from mice and fixed without culturing (Quintavalle et al., 2010). To dissect the function of podosomes/invadopodia in vivo, several groups disrupted their formation by genetically manipulating the genes that are crucial for their assembly, such as Tks5 (Blouw et al., 2008; Murphy et al., 2011), N-WASP (Gligorijevic et al., 2012), and Arg kinase (Gil-Henn et al., 2013). Nevertheless, evidence of podosome function in vivo is still scarce. "
  • Source
    • "As in 2D, how the cellular localization of invadopodia is determined in 3D is unknown. However, invadopodia are composed of actin, cortactin, cofilin, Tks5, and MT1-MMP in both 2D and 3D cultures and in vivo settings (Blouw et al., 2008; Lizarraga et al., 2009; Magalhaes et al., 2011; Gligorijevic et al., 2012; Yu Machesky, 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The leading cause of death in cancer patients is metastasis. Invasion is an integral part of metastasis and is carried out by proteolytic structures called invadopodia at the cellular level. In this introductory review, we start by evaluating the definition of invadopodia. While presenting the upstream signaling events involved, we integrate current models on invadopodia. In addition, we discuss the significance of invadopodia in 2D and 3D and in vivo. We finally point out technical challenges and conclude with open questions in the field.
    Turkish Journal of Biology 11/2014; 38(6):740-747. DOI:10.3906/biy-1404-110 · 1.34 Impact Factor
  • Source
    • "Loss of N-WASP expression reduced the number of invadopodia structures seen in vivo in mammary glands. Loss of N-WASP impacts the metastatic ability of cancer cells navigated by the localization of invadopodia , further implicating the WASP proteins in metastatic disease [29] "
    [Show abstract] [Hide abstract]
    ABSTRACT: Prostate cancer is a disease that affects hundreds of thousands of men in the United States each year. In the early stages of advanced prostate cancer, the disease can be suppressed by androgen deprivation therapy (ADT). Eventually, however, most patients experience resistance to androgen deprivation, and their treatment transitions to alternative targeting of the androgen axis with abiraterone and enzalutamide, as well as taxane-based chemotherapy. Development of advanced castration-resistant prostate cancer (CRPC) is a consequence of lack of an apoptotic response by the tumor cells to treatment. Understanding the mechanisms contributing to prostate tumor therapeutic resistance and progression to metastasis requires dissection of the signaling mechanisms navigating tumor invasion and metastasis as mediated by cell-matrix interactions engaging components of the extracellular matrix (ECM), to form adhesion complexes. For a tumor call to metastasize from the primary tumor, it requires disruption of cell-cell interactions from the surrounding cells, as well as detachment from the ECM and resistance to anoikis (apoptosis upon cell detachment from ECM). Attachment, movement and invasion of cancer cells are functionally facilitated by the actin cytoskeleton and tubulin as the structural component of microtubules. Transforming growth factor (TGF)-β has tumor-inhibitory activity in the early stages of tumorigenesis, but it promotes tumor invasive characteristics in metastatic disease. Recent evidence implicates active (dephosphorylated) cofilin, an F-actin severing protein required for cytoskeleton reorganization, as an important contributor to switching TGF-β characteristics from a growth suppressor to a promoter of prostate cancer invasion and metastasis. Cancer cells eventually lose the ability to adhere to adjacent neighboring cells as well as ECM proteins, and via epithelial-mesenchymal transition (EMT), acquire invasive and metastatic characteristics. Microtubule-targeting chemotherapeutic agents, taxanes, are used in combination with antiandrogen strategies to increase the survival rate in patients with CRPC. This review addresses the development of therapeutic platform for targeting the integrity of actin cytoskeleton to impair prostate cancer progression.
    11/2014; 2(1):15-26.
Show more