Stromal-derived factor (SDF)-1α, insulin-like growth factor (IGF)-1 and hepatocyte growth factor (HGF) are potent mediators of cell migration. We studied the effect of combinations of these cytokines on the migration of myeloma cells. When SDF-1α was combined with either HGF or IGF-1, we found a striking synergy in the cytokines' ability to guide cells across a transwell membrane.
View Article and Find Full Text PDFObjectives: The receptor tyrosine kinase c-Met and its ligand, hepatocyte growth factor (HGF), play key roles in tumour genesis and metastasis and contribute in multiple myeloma pathogenesis. Substantial data support that a soluble extracellular fragment of c-Met may function as a decoy receptor that downregulates the biological effects of HGF and c-Met. We examined serum levels of soluble c-Met in patients with myeloma and healthy individuals and investigated a possible relationship with clinical disease parameters and survival.
View Article and Find Full Text PDFObjectives: Hepatocyte growth factor (HGF) is a constituent of the myeloma microenvironment and is elevated in sera from myeloma patients compared to healthy individuals. Increased levels of serum HGF predict a poor prognosis. It has previously been shown by us and others HGF can act as a growth factor to myeloma cells in vitro although these effects have been moderate.
View Article and Find Full Text PDFAdhesion of multiple myeloma (MM) cells in the bone marrow (BM) is important for the growth and survival of the myeloma cells. Very late antigen-4 (VLA-4) is one of the main adhesion receptors that mediate MM cell binding to fibronectin (FN). In this study we have examined the effect of divalent cations on adhesion of MM cells to FN, and compared this type of adhesion with the adhesion induced by the cytokines HGF, IGF-1 and SDF-1alpha.
View Article and Find Full Text PDFMultiple myeloma is characterized by the accumulation and dissemination of malignant plasma cells in the bone marrow. Cell migration is thought to be important for these events. We studied migration in a Transwell two-chamber assay and tested the motogenic effect of various cytokines.
View Article and Find Full Text PDFMultiple myeloma (MM) is characterized by accumulation and dissemination of malignant plasma cells (PCs) in the bone marrow (BM). Gene expression profiling of 2 MM cell lines (OH-2 and IH-1) indicated that expression of PRL-3, a metastasis-associated tyrosine phosphatase, was induced by several mitogenic cytokines. Cytokine-driven PRL-3 expression could be shown in several myeloma cell lines at both the mRNA and protein levels.
View Article and Find Full Text PDFTyrosine kinase inhibitors (TKIs) are thought to have potential as a new generation of anti-cancer drugs. Since invasiveness, the main characteristic of malignant behaviour, is believed to depend on altered cell-matrix interactions, we investigated the effect of two potent TKIs, genistein and tyrphostin AG-1478, on the interaction of prostate cancer cells with extracellular matrix components. PC-3 and DU-145 cells were treated with various concentrations of genistein and tyrphostin AG-1478.
View Article and Find Full Text PDFBackground And Objectives: Multiple myeloma is characterized by an accumulation of malignant plasma cells in the bone marrow. Inside the bone marrow, adhesion of myeloma cells to extracellular matrix proteins such as fibronectin may promote cell survival and induce drug resistance. In this work we examined the effect of hepatocyte growth factor (HGF) on the adhesion of myeloma cells and the signaling pathways involved.
View Article and Find Full Text PDFPurpose: We wanted to examine the role of the hepatocyte growth factor (HGF) receptor c-Met in multiple myeloma by applying a novel selective small molecule tyrosine kinase inhibitor, PHA-665752, directed against the receptor.
Experimental Design: Four biological sequels of HGF related to multiple myeloma were studied: (1) proliferation of myeloma cells, (2) secretion of interleukin-11 from osteogenic cells, (3) migration of myeloma cells, and (4) adhesion of myeloma cells to fibronectin. We also examined effects of the c-Met inhibitor on intracellular signaling pathways in myeloma cells.
Previously, bone morphogenetic protein (BMP)-2 and -4 have been shown to inhibit proliferation and induce apoptosis in human myeloma cells. BMP-2 and -4 belong to a subgroup of BMPs using the BMP receptors Alk-3 or -6. In this study, we examined the effects on human myeloma cells of BMP-6 and -7, members of a different BMP subgroup, which mainly utilize Alk-2 as their receptor.
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