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Highly Invasive (highly + invasive)
Selected AbstractsDominant-negative CREB inhibits heparanase functionality and melanoma cell invasionJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2004Rebecca Aucoin Abstract Heparanase (HPSE-1) is an endo-,- d -glucuronidase involved in the degradation of cell-surface/extracellular matrix heparan sulfate (HS) in normal and neoplastic tissues. HPSE-1 represents the first example of purification and cloning of a mammalian HS-degradative enzyme. Elevated HPSE-1 levels are known to be associated with metastatic cancers, directly implicating HPSE-1 in metastatic events. The purpose of this study was to determine the role of cAMP response element-binding protein (CREB) in modulating HPSE-1-mediated effects on human melanoma cell invasion. Highly invasive, brain-metastatic melanoma cells (70W) were transfected with the dominant-negative CREB (KCREB) and subsequently analyzed for changes in their HPSE-1 content, functionality, and cell invasive properties. KCREB-transfected cells showed a decrease in HPSE-1 mRNA expression and activity. This correlated with a significantly decreased invasion of these cells through MatrigelÔ-coated filters. Furthermore, adenoviral vectors containing the full-length human HPSE-1 cDNA in sense orientation (Ad-S/hep) were constructed to investigate CREB effects on HPSE-1. Restoration of HPSE-1 expression and functionality following Ad-S/hep infection of KCREB-transfected 70W cells recovered melanoma cell invasiveness. These results demonstrate that KCREB inhibits HPSE-1 and suggest that one of the roles CREB plays in the acquisition of melanoma cells metastatic phenotype is affecting HPSE-1 activity. © 2004 Wiley-Liss, Inc. [source] The small-scale spatiotemporal pattern of the seedbank and vegetation of a highly invasive weed, Centaurea solstitialis: strength in numbersOIKOS, Issue 3 2010Christopher J. Lortie The dynamics of invasive plant populations are intriguing and informative of the importance of population and community-level processes. A dominant approach to understanding and describing invasion has been the development of unique hypotheses to explain invasion. However, here we directly explore the relevance of the small-scale, spatiotemporal pattern in seedbanks and plants of the highly invasive weed, Centaurea solstitialis, to determine whether pattern can be used to contrast predictions associated with the simple ecological hypotheses of seed versus microsite limitations. At three invaded grasslands in California, highly invaded (> 20 adult plants present), invaded (< 10 adults), and uninvaded (no C. solstitialis plants) sites were selected. The spatial pattern of the seedbank was assessed using fine-scale, 2 cm diameter contiguous cores and geostatistical statistics, and the number of C. solstitialis seeds in the seedbank was recorded in addition to the total community seedbank density. Three of the four critical predictions associated with the seed limitation hypothesis were clearly supported as an explanation for the patterns of C. solstitialis invasion observed in the field. The density of C. solstitialis seeds decreased from high to low extents of invasion, there was no relationship between the community seedbank and C. solstitialis seeds, and the distances between C. solstitialis plants was inversely related to the density of C. solstitialis seeds. However, both the persistent and transient seedbanks of C. solstitialis were spatially aggregated with autocorrelation up to 12 cm2 which suggests that aggregation is a consistent attribute of this species in the seedbank regardless of extent of invasion. This basic pattern-based approach clearly detected an ecological signal of invasive seedbank dynamics and is thus a useful tool for subsequent studies of invasions in grasslands. [source] Epstein-Barr Virus (EBV) Latent Membrane Protein 1 Induces Interleukin-8 through the Nuclear Factor-,B Signaling Pathway in EBV-Infected Nasopharyngeal Carcinoma Cell LineTHE LARYNGOSCOPE, Issue 5 2004Qingchun Ren MD Abstract Background/Objectives: Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic malignant tumor and is associated with Epstein-Barr virus (EBV) infection that exhibits type II latency. Angiogenesis is essential for tumor growth, invasion, and metastasis. Our previous studies have indicated that interleukin (IL)-8 was over-expressed in many NPC tissues and was found to be significantly correlated with angiogenesis by immunohistochemistry. Study Design: In vitro design. Methods: The influence of the EBV genome for IL-8 gene expression was studied using the EBV,genome-positive and -negative epithelial/NPC hybrid cell line NPC-KT. The EBV-positive and -negative clones were selected by polymerase chain reaction and in situ hybridization. Results: EBV-positive clones expressed abundant IL-8 mRNA compared with EBV-negative clones. This result indicated that over-expression of IL-8 depended on the presence of EBV genomes in NPC-KT cells. Two encoded genes, latent membrane protein (LMP)1 and EBV-encoded small RNAs (EBERs), expressed in NPC were transfected in EBV-negative NPC-KT cells. LMP1 transactivated the IL-8 promoter, whereas EBERs did not. Moreover, the nuclear factor (NF)- ,B binding site in the IL-8 promoter was essential for the response to LMP1, and the activator protein (AP)-1 binding site played only a partial role. Conclusions: LMP1 induces IL-8 mainly through the activation of NF-,B and partly through AP-1 in NPC model cell lines, NPC-KT, and this suggests that LMP1 plays an important role in the angiogenesis of NPC. [source] Association between laminin-8 and glial tumor grade, recurrence, and patient survival,CANCER, Issue 3 2004Julia Y. Ljubimova M.D., Ph.D. Abstract BACKGROUND The authors previously sought to identify novel markers of glioma invasion and recurrence. Their research demonstrated that brain gliomas overexpressed a subset of vascular basement components, laminins, that contained the ,4 chain. One of these laminins, laminin-8, was found to be present in highly invasive and malignant glioblastoma multiforme (GBM) (Grade 4 astrocytoma); its expression was associated with a decreased time to tumor recurrence, and it was found in vitro to promote invasion of GBM cell lines. METHODS In the current study, the authors studied glial tumors of different grades in an attempt to correlate laminin-8 expression with tumor recurrence and patient survival. Immunohistochemistry and Western blot analysis were used to detect laminin isoforms of interest. RESULTS Using immunohistochemistry and Western blot analysis, the authors confirmed high levels of laminin-8 expression in approximately 75% of the GBM cases examined and in their adjacent tissues, whereas astrocytomas of lower grades expressed for the most part a different isoform, laminin-9, which also was found in low amounts in normal brain tissue and benign meningiomas. Overexpression of laminin-8 in GBM was found to be associated with a statistically significant shorter time to tumor recurrence (P < 0.0002) and a decreased patient survival time (P < 0.015). CONCLUSIONS The data suggest that laminin-8, which may facilitate tumor invasion, contributes to tumor regrowth after therapy. Laminin-8 may be used as a predictor of tumor recurrence and patient survival and as a potential molecular target for glioma therapy. Cancer 2004. © 2004 American Cancer Society. [source] | |||||||||||||