The influential role of Wnt5a in tumor progression underscores the requirement for developing molecules that can target Wnt5a-mediated cellular responses. In the aggressive skin cancer, melanoma, elevated Wnt5a expression promotes cell motility and drives metastasis. Two approaches can be used to counteract these effects: inhibition of Wnt5a expression or direct blockade of Wnt5a signaling. We have investigated both options in the melanoma cell lines, A2058 and HTB63. Both express Frizzled-5, which has been implicated as the receptor for Wnt5a in melanoma cells. However, only the HTB63 cell line expresses and secretes Wnt5a. In these cells, the cytokine, TGF1, controlled the expression of Wnt5a, but due to the unpredictable effects of TGF1 signaling on melanoma cell motility, targeting Wnt5a signaling via TGF1 was an unsuitable strategy to pursue. We therefore attempted to target Wnt5a signaling directly. Exogenous Wnt5a stimulation of A2058 cells increased adhesion, migration and invasion, all crucial components of tumor metastasis, and the Wnt5a-derived N-butyloxycarbonyl hexapeptide (Met-Asp-Gly-Cys-Glu-Leu; 0.766 kDa) termed Box5, abolished these responses. Box5 also inhibited the basal migration and invasion of Wnt5a-expressing HTB63 melanoma cells. Box5 antagonized the effects of Wnt5a on melanoma cell migration and invasion by directly inhibiting Wnt5a-induced protein kinase C and Ca 2؉ signaling, the latter of which we directly demonstrate to be essential for cell invasion. The Box5 peptide directly inhibits Wnt5a signaling, representing an approach to anti-metastatic therapy for otherwise rapidly progressive melanoma, and for other Wnt5a-stimulated invasive cancers.inhibitory peptide ͉ malignant melanoma ͉ tumor cell invasion W nt ligands comprise a family of 19 human secreted signaling proteins, which coordinate essential processes required for development and maintenance of tissue homeostasis. Misregulation of Wnt signaling can lead to cancer progression (1). The Wnt ligands are secreted glycoproteins that can be divided based on their ability to activate different intracellular signals, in a tissue-dependent manner. One group primarily activates canonical signaling that controls -catenin stability, while the other is loosely described as -catenin-transcriptionally independent (non-canonical Wnt signaling). However, cross-talk between the two signaling networks does exist (2).Wnt5a is in most situations characterized as a non-canonical Wnt ligand that elicits intracellular signals through association with distinct receptors and co-receptors in a cell specific manner. Wnt5a has been shown to stimulate increases in intracellular Ca 2ϩ levels in developmental models (3) and mammalian cell lines, including breast and thyroid cancer cells (4-6), giving rise to the model of a non-canonical Wnt/Ca 2ϩ signaling pathway. Wnt5a-mediated intracellular increases in Ca 2ϩ levels enables the activation of Ca 2ϩ -regulated proteins, such as protein kinase C (PKC) in a context dependent manner, as reviewed recen...
Our study demonstrated that markers for systemic leukocyte activation, ie, plasma levels of cytokines and proteases, were higher in patients with acute ischemic cerebrovascular disease than in healthy control subjects. Activated leukocytes and leukocytic mediators may have an important role in acute cerebrovascular ischemia and its consequences.
A 24-kDa protein was purified from human neutrophil extracts and shown to be the newly discovered neutrophil gelatinase-associated lipocalin (NGAL), based on structural and immunochemical data. A specific enzyme-linked immunosorbent assay (ELISA) was developed for the determination of NGAL in human plasma and tissue fluids. Normal human plasma contains 72 micrograms l-1 of NGAL (range 40-109 micrograms l-1) in two main forms, monomer and dimer. 35S-methionine metabolic studies of human neutrophils showed that granulocyte macrophagecolony-stimulating factor (GMCSF) stimulated significant synthesis and secretion of NGAL in a dose- and time-dependent fashion. NGAL was rapidly released as monomer and dimer on incubation of heparinized whole blood with opsonized yeast, reaching a plateau corresponding to about 35% of total cell content after 30 min. Following intravenous injection of 125-iodine labelled NGAL there was a more rapid initial clearance of the monomeric than of the dimeric form; t1/2 10 min vs. 20 min. During the second phase the two forms cleared at similar rates. Severe acute peritonitis was accompanied by a 10-fold increase in NGAL plasma levels and the NGAL level in peritoneal exudates, which reached about 40 mg l-1. There was a good linear correlation between the concentrations of NGAL, leucocyte elastase and NP4 (neutrophil proteinase 4 = P3).
Findings contribute to an increased awareness of the complexities of these patients' life worlds and their meanings, and thus of the importance to listen to their experiences and their understandings. Findings suggest that to integrate the philosophy of palliative care in haemodialysis units may improve care for patients who are living with haemodialysis and approaching the end of their lives.
Extensive research has demonstrated a tumor‐promoting role of increased WNT5A expression in malignant melanoma. However, very little light has been shed upon how WNT5A expression is up‐regulated in melanoma. A potential regulator of WNT5A expression is the pro‐inflammatory cytokine Interleukin (IL)‐6, which shares the ability of WNT5A to increase melanoma cell invasion. Here, we investigate whether IL‐6 can promote melanoma cell motility through an increased expression of WNT5A. We clearly demonstrate that the WNT5A‐antagonistic peptide Box5 could inhibit IL‐6‐induced melanoma cell migration and invasion. Furthermore, IL‐6 stimulation of the human melanoma cell lines HTB63 and A375 increased the expression of WNT5A in a dose‐dependent manner. To identify the signaling mechanism responsible for this up‐regulation, we explored the involvement of the three main signals induced by IL‐6; STAT3, Akt and ERK 1/2. Of these, only STAT3 was activated by IL‐6 in the melanoma cell lines tested. However, the STAT3 inhibitor S3I‐201 failed to inhibit IL‐6‐induced WNT5A up‐regulation in HTB63 and A375 cells. Nor did STAT3 siRNA silencing affect the expression of WNT5A. In search of an alternative signaling mechanism, we detected IL‐6‐induced activation of p38‐MAPK in HTB63 and A375 cells. The p38‐MAPK inhibitor SB203580 abolished the IL‐6‐induced WNT5A up‐regulation and blocked IL‐6‐induced melanoma cell invasion. The latter effect could be rescued by the addition of recombinant WNT5A. Notably, immunoprecipitation analysis revealed that only the p38α‐MAPK isoform was activated by IL‐6, and subsequent siRNA silencing of p38α‐MAPK abolished the IL‐6‐induced up‐regulation of WNT5A. Taken together, we demonstrate a novel link between the two melanoma pro‐metastatic agents IL‐6 and WNT5A explaining how IL‐6 can increase melanoma cell invasion and thus promote the metastatic process. This finding provides a basis for future therapeutic intervention of melanoma progression.
An important role for WNT‐5A is implicated in a variety of tumors, including breast carcinoma. We previously showed that WNT‐5A signaling inhibits migration and metastasis of breast cancer cells, and that patients with primary breast cancer in which WNT‐5A was expressed have a better prognosis. Despite the fact that RhoGTPase Cdc42 is commonly associated with increased cell migration, we here show that recombinant WNT‐5A activates the Cdc42 in breast cancer cells (lines MDA‐MB468 and MDA‐MB231) in a time‐dependent manner. Activation of Cdc42 was also observed in MDA‐MB468 cells that were stably transfected with a WNT‐5A plasmid (MDA‐MB468‐5A). In all situations, increased Cdc42 activity was accompanied by decreased migration and invasion of the breast cancer cells. To explore these findings further we also investigated the effect of WNT‐5A signaling on ERK1/2 activity. Apart from an initial Ca2+‐dependent rWNT‐5A‐induced activation of ERK1/2, Cdc42 activity was inversely correlated with ERK1/2 activity in both rWNT‐5A‐stimulated parental MDA‐MB468 and MDA‐MB468‐5A cells. We also demonstrated increased ERK1/2 activity in MDA‐MB468‐5A cells following siRNA knockdown of Cdc42. Consistent with these results, breast cancer cells transfected with constitutively active Cdc42 exhibited reduced ERK1/2 activity, migration and invasion, whereas cells transfected with dominant negative Cdc42 had increased ERK1/2 activity in response to rWNT‐5A. To gain information on how ERK1/2 can mediate its effect on breast cancer cell migration and invasion, we next investigated and demonstrated that WNT‐5A signaling and constitutively active Cdc42 both decreased matrix metalloproteinase 9 (MMP9) activity. These data indicate an essential role of Cdc42 and ERK1/2 signaling and MMP9 activity in WNT‐5A‐impaired breast cancer cells.
Nurses and other healthcare professionals in haemodialysis settings need to combine technical and medical abilities with committed listening and communication skills and be open to talking about death and dying, with sensitivity to individual and changeable needs.
In human neutrophils,  2 integrin engagement mediated a decrease in GTP-bound Rac1 and Rac2. Pretreatment of neutrophils with LY294002 or PP1 (inhibiting phosphatidylinositol 3-kinase (PI 3-kinase) and Src kinases, respectively) partly reversed the  2 integrin-induced down-regulation of Rac activities. In contrast,  2 integrins induced stimulation of Cdc42 that was independent of Src family members. The PI 3-kinase dependence of the  2 integrin-mediated decrease in GTP-bound Rac could be explained by an enhanced Rac-GAP activity, since this activity was blocked by LY204002, whereas PP1 only had a minor effect. The fact that only Rac1 but not Rac2 (the dominating Rac) redistributed to the detergent-insoluble fraction and that it was independent of GTP loading excludes the possibility that down-regulation of Rac activities was due to depletion of GTPbound Rac from the detergent-soluble fraction. The  2 integrin-triggered relocalization of Rac1 to the cytoskeleton was enabled by a PI 3-kinase-induced dissociation of Rac1 from LyGDI. The dissociations of Rac1 and Rac2 from LyGDI also explained the PI 3-kinase-dependent translocations of Rac GTPases to the plasma membrane. However, these accumulations of Rac in the membrane, as well as that of p47 phox and p67 phox , were also regulated by Src tyrosine kinases. Inasmuch as Rac GTPases are part of the NADPH oxidase and the respiratory burst is elicited in neutrophils adherent by  2 integrins, our results indicate that activation of the NADPH oxidase does not depend on the levels of Rac-GTP but instead requires a  2 integrin-induced targeting of the Rac GTPases as well as p47 phox and p67 phox to the plasma membrane.
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