Hyaluronan (HA) is an extracellular matrix component that regulates a variety of physiological and pathological processes. The function of HA depends both on its overall amount and on its size, properties that are controlled by HA synthesizing and degrading enzymes. The lack of inhibitors that can specifically block individual HA degrading enzymes has hampered attempts to understand the contribution of individual hyaluronidases to different physiological and pathological processes.
View Article and Find Full Text PDFASAP1 is a multi-domain adaptor protein that regulates cytoskeletal dynamics, receptor recycling and intracellular vesicle trafficking. Its expression is associated with poor prognosis in a variety of cancers, and can promote cell migration, invasion and metastasis. Although amplification and expression of ASAP1 has been associated with poor survival in breast cancer, we found that in the autochthonous MMTV-PyMT model of luminal breast cancer, ablation of ASAP1 resulted in an earlier onset of tumor initiation and increased metastasis.
View Article and Find Full Text PDFA better understanding of the process of melanoma metastasis is required to underpin the development of novel therapies that will improve patient outcomes. The use of appropriate animal models is indispensable for investigating the mechanisms of melanoma metastasis. However, reliable and practicable quantification of metastases in experimental mice remains a challenge, particularly if the metastatic burden is low.
View Article and Find Full Text PDFExpression of the immediate-early response gene IER2 has been associated with the progression of several types of cancer, but its functional role is poorly understood. We found that increased IER2 expression in human melanoma is associated with shorter overall survival, and subsequently investigated the mechanisms through which IER2 exerts this effect. In experimental melanoma models, sustained expression of IER2 induced senescence in a subset of melanoma cells in a p53/MAPK/AKT-dependent manner.
View Article and Find Full Text PDFMetastasis is a multistep process, during which circulating tumor cells traffic through diverse anatomical locations. Stable inducible marking of tumor cells in a manner that is tightly spatially and temporally controlled would allow tracking the contribution of cells passing through specific locations to metastatic dissemination. For example, tumor cells enter the lymphatic system and can form metastases in regional lymph nodes, but the relative contribution of tumor cells that traffic through the lymphatic system to the formation of distant metastases remains controversial.
View Article and Find Full Text PDFIn the publication of this article (1), there is an error in Fig. 5b. This has now been updated in the original article (1).
View Article and Find Full Text PDFBackground: Although metabolism is profoundly altered in human liver cancer, the extent to which experimental models, e.g. cell lines, mimic those alterations is unresolved.
View Article and Find Full Text PDFPlatelets are thought to play an important role in metastasis formation, although the mechanisms involved remain incompletely understood. Here we studied the influence of platelet numbers on organ-specific metastasis to the lungs and lymph nodes using Tpo deficient mice that have low platelet counts. After tail vein injection of 4T1 breast cancer cells, the number of lung metastases was significantly lower in Tpo mice compared to Tpo mice.
View Article and Find Full Text PDFDuring tissue injury, inflammation, and tumor growth, enhanced production and degradation of the extracellular matrix glycosaminoglycan hyaluronan (HA) can lead to the accumulation of small HA (sHA) oligosaccharides. We have previously reported that accumulation of sHA in colorectal tumors correlates with lymphatic invasion and lymph node metastasis, and therefore, investigated here are the effects of sHA on the lymphatic endothelium. Using cultured primary lymphatic endothelial cells (LECs) and ex vivo and in vivo lymphangiogenesis assays, we found that in contrast to high-molecular-weight HA (HMW-HA), sHA of 4-25 disaccharides in length can promote the proliferation of LECs and lymphangiogenesis in a manner that is dependent on their size and concentration.
View Article and Find Full Text PDFCD24 is a small, heavily glycosylated, GPI-linked membrane protein, whose expression has been associated with the tumorigenesis and progression of several types of cancer. Here, we studied the expression of CD24 in tumors of MMTV-PyMT, Apc1572/T+ and TRAMP genetic mouse models that spontaneously develop mammary or prostate carcinoma, respectively. We found that CD24 is expressed during tumor development in all three models.
View Article and Find Full Text PDFThe microRNA (miRNA) landscape changes during the progression of cancer. We defined a metastasis-associated miRNA landscape using a systematic approach. We profiled and validated miRNA and mRNA expression in a unique series of human colorectal metastasis tissues together with their matched primary tumors and corresponding normal tissues.
View Article and Find Full Text PDFThe lymphatic system plays a key role in tissue homeostasis, fatty acid transport, and immune surveillance. Pathologically, dysfunction of the lymphatic system results in edema, and increased lymphangiogenesis can contribute to tumor metastasis. Lymphatic vessels are composed of lymphatic endothelial cells (LECs) that can be identified by distinct marker molecules such as Prox-1, podoplanin, VEGFR-3 and LYVE-1.
View Article and Find Full Text PDFBackground: Association studies have implicated the glycosaminoglycan hyaluronan (hyaluronic acid, HA) and its degrading enzymes the hyaluronidases in tumour progression and metastasis. Oligosaccharides of degraded HA have been ascribed a number of biological functions that are not exerted by high-molecular-weight HA (HMW-HA). However, whether these small HA oligosaccharides (sHA) have a role in tumour progression currently remains uncertain due to an inability to analyse their concentration in tumours.
View Article and Find Full Text PDFWe have recently demonstrated that the anthocyanidin delphinidin (DEL), one of the most abundant dietary flavonoids, inhibits activation of ErbB and vascular endothelial growth factor receptor family members. These receptors play crucial roles in the context of tumor progression and the outgrowth of blood and lymphatic vessels. Here, we have developed an improved chemical synthesis for DEL in order to study the effects of the aglycon and its degradation product gallic acid (GA) on endothelial and tumor cells in vitro and in vivo.
View Article and Find Full Text PDFIntroduction: Intervertebral disc (IVD) degeneration is characterized by extracellular matrix breakdown and is considered to be a primary cause of discogenic back pain. Although increases in pro-inflammatory cytokine levels within degenerating discs are associated with discogenic back pain, the mechanisms leading to their overproduction have not yet been elucidated. As fragmentation of matrix components occurs during IVD degeneration, we assessed the potential involvement of hyaluronic acid fragments (fHAs) in the induction of inflammatory and catabolic mediators.
View Article and Find Full Text PDFVEGFR-3 is a transmembrane receptor tyrosine kinase that is activated by its ligands VEGF-C and VEGF-D. Although VEGFR-3 has been linked primarily to the regulation of lymphangiogenesis, in the present study, we demonstrate a role for VEGFR-3 in megakaryopoiesis. Using a human erythroleukemia cell line and primary murine BM cells, we show that VEGFR-3 is expressed on megakaryocytic progenitor cells through to the promegakaryoblast stage.
View Article and Find Full Text PDFWe have previously reported that over-expression of a panel of 119 genes correlates with the metastatic potential of pancreatic carcinoma cells. We sought to identify and functionally characterize candidate tumour metastasis promoting genes among this library using a secondary phenotype-assisted screen. Here we report the discovery of the metastasis-promoting function of a hitherto not characterized gene located on chromosome 14 (ORF138), which we have named 'novel metastasis-promoting gene 1' (NVM-1).
View Article and Find Full Text PDFWe have previously performed an unbiased screen to identify genes whose expression is associated with the metastatic phenotype. Secondary screening of these genes using custom microarray chips identified ASAP1, a multi-domain adaptor protein with ADP-ribosylation factor-GAP activity, as being potentially involved in tumor progression. Here, we show that at least three different splice forms of ASAP1 are upregulated in rodent tumor models in a manner that correlates with metastatic potential.
View Article and Find Full Text PDFThe phloroglucinol derivative hyperforin, a major bioactive constituent of St. John's wort, is increasingly recognized as being able to regulate a variety of pathobiological processes and, thus, to possess potential therapeutic properties. In the context of cancer, hyperforin induces the apoptosis of cancer cells, inhibits angiogenesis and suppresses metastasis formation.
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