Background and Objectives
The aim of our study was to test a platelet‐rich plasma releasate (PRP‐R/SRGF) from CaCl2‐activated platelets as a source of growth factors for the expansion of mesenchymal ...stromal cells (MSCs). PRP‐R/SRGF, obtained with a low‐cost procedure, is characterized by a reduced variability of growth factor release.
Materials and Methods
PRP‐R/SRGF is a clinical‐grade quality solution obtained from CaCl2‐activated platelets. Its activity was evaluated by measuring the proliferation, the phenotype, the differentiation potential and the immunosuppressive properties of MSCs derived from bone marrow (BM) and adipose tissue (AT).
Results
PRP‐R/SRGF was more active than FBS to expand BM‐ and AT‐derived MSCs. PRP‐R/SRGF treatment did not affect the expression of typical MSCs surface markers, neither MSCs differentiation potential nor their capability to inhibit activated T‐cell proliferation.
Conclusions
The clinical‐grade PRP‐R/SRGF may be used in the clinical setting for the expansion of MSCs.
Significant relief of bone pain in patients with bone metastases was observed in a clinical trial of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor gefitinib in breast cancer. ...Osteoclast activation and differentiation are regulated by bone marrow stromal cells (BMSC), a heterogeneous cell compartment that comprehends undifferentiated mesenchymal stem cells (MSC) and their specialized progeny. In this regard, we found that human primary BMSCs express immunoreactive EGFR. Expression of EGFR mRNA and protein was also demonstrated in two human, continuous MSC-like cell lines, HDS-1 and HDS-2 cells. Treatment of HDS cells with EGF produced a significant increase in the levels of activated EGFR which was not observed in the presence of gefitinib. A significant reduction in the basal levels of activation of the EGFR and of Akt was observed in HDS cells following treatment with gefitinib. Treatment of HDS cells with gefitinib produced a significant reduction in the levels of secreted macrophage colony-stimulating factor (M-CSF) and cell-associated receptor activator of NF-κB ligand (RANKL) in both cell lines, as assessed by using specific ELISA and Western blotting techniques. Finally, the ability to sustain the differentiation of pre-osteoclasts of conditioned medium from gefitinib-treated HDS cells was reduced by approximately 45% as compared with untreated HDS cells. These data have demonstrated for the first time that the EGFR regulates the ability of BMSCs to induce osteoclast differentiation and strongly support clinical trials of gefitinib in breast cancer patients with bone disease.
CD40 is a member of the nerve growth factor receptor family, showing a significant homology to the Hodgkin's disease (HD)-associated antigen CD30 and is capable of transduce growth signals in a ...number of cell types. A series of 312 lymphoma samples, including 139 cases of HD, 32 cases of CD30+ anaplastic large cell (ALC) lymphomas, 141 cases of other non-Hodgkin's lymphomas (NHLs), and a panel of HD-or NHL-derived cell lines, were evaluated for CD40 expression by immunostaining of paraffin embedded sections, cell smears and flow cytometry. CD40 was strongly expressed with a highly distinct pattern of staining on Reed-Sternberg (RS) cells and variants in 100% (139/139) of HD cases, irrespective of their antigenic phenotype (T, B, non T-non B) and histologic subtype of HD. Conversely, CD40 was immunodetected on only one third (12/32; 37%) of ALC lymphoma cases and on 105 of 127 B-cell NHLs. The relative cell density of CD40 on HD cell lines (L-428, KM-H2, HDLM-2) as assessed by flow cytometry was significantly higher than on all other lymphoma cells analyzed. Engagement of CD40 by its soluble ligand (CD40L) enhanced both clonogenic capacity and colony cell survival of HD cell lines. Such effect was potentiated by interteukin-9 costimulation in KM-H2 cells. Finally, we have shown that in vitro rosetting of activated CD4+ T cells to HD cells (L-428) is mediated in part by the CD40/ CD40L adhesion pathway. Our data indicate that CD40 is a useful antigen for immunodetection and identification of tumor cells in all subtypes of HD, and suggest that it may play a role in the regulation of RS cell expansion and the contact-dependent interactions of these cells with cytokine-producing T lymphocytes.
This work reports on the synthesis, characterization, and in vitro cytotoxic activity of some new platinum(II), palladium(II), and gold(III) derivatives of methylsarcosinedithiocarbamate and its ...S-methyl ester, to study their behavior as potential antitumor agents. The biological activity of these compounds, as determined by growth inhibition and apoptosis induction, has been investigated in both human leukemic promyelocites HL60 and human squamous cervical adenocarcinoma HeLa cell lines, and their activity has been compared to the well-known platinum-based anticancer agent cisplatin. On the basis of these experimental results, Pd(MSDT)X n (MSDT = methylsarcosinedithiocarbamate; X = Cl, Br) complexes show a strong dose-dependent growth inhibition of both HL60 and HeLa cells, with IC50 values slightly higher than those recorded for cisplatin; moreover, Au(MSDT)X2 activity appears significantly higher or, at least, comparable to that of the reference drug. Exposure of both cell lines to Pd(MSDT)X n and Au(MSDT)X2 complexes induces apoptosis, as determined by an Apo2.7 assay.
Proliferation of endothelial cells is regulated through the autocrine production of growth factors and the expression of cognate surface receptors. In this study, we demonstrate that interleukin 1 ...(IL-1) is an inhibitor of endothelial growth in vitro and in vivo. IL-1 arrested growing, cultured endothelial cells in G1phase; inhibition of proliferation was dose dependent and occurred in parallel with occupancy of endothelial surface IL-1 receptors. In an angiogenesis model, IL-1 could inhibit fibroblast growth factor-induced vessel formation. The autocrine nature of the IL-1 effect on endothelial proliferation was demonstrated by the observation that occupancy of cell-surface receptors by endogenous IL-1 depressed cell growth. The potential significance of this finding was emphasized by the detection of IL-1 in the native endothelium of human umbilical veins. A mechanism by which IL-1 may exert its inhibitory effect on endothelial cell growth was suggested by studies showing that IL-1 decreased the expression of high-affinity fibroblast growth factor binding sites on endothelium. These results point to a potentially important role of IL-1 in regulating blood vessel growth and suggest that autocrine production of inhibitory factors may be a mechanism controlling proliferation of normal cells.
The presence of a prominent tissue eosinophilia represents a typical histopathologic hallmark of Hodgkin's disease (HD). To evaluate the putative role of eosinophils on tumor cell regulation in HD, ...we have analyzed these cells for the functional expression of CD30 ligand (CD30L), a surface molecule able to transduce CD30-mediated proliferation signals on Hodgkin's (H) and Reed-Stemberg (RS) cells. The results demonstrate that circulating and tissue eosinophils from normal donors and patients with HD or hypereosinophilic syndrome (HES), display CD30L mRNA and express CD30L protein, as shown by immunostaining with a specific monoclonal antibody (M80) and with a biotinylated soluble CD30-Fc fusion protein. The surface density of CD30L on eosinophils from HD and HES patients was remarkably higher compared with healthy donors, probably reflecting a cytokine-mediated upregulation in these pathologic conditions. Accordingly, we provide evidence that cytokines regulating eosinophils proliferation and activation, ie, interleukin-5 (IL-5), IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF), are able to enhance the cellular density of CD30L on purified eosinophils from normal subjects. Finally, we show that native CD30L on human eosinophils is a functionally active surface structure able to transduce proliferative signals on CD30+ target cells, including cultured H-RS cells. Our data suggest that eosinophils may not merely represent innocent bystanders, but rather act as important elements in the pathology of HD by contributing to the deregulated network of CD30/CD30L-mediated interactive signals between H-RS cells and surrounding reactive cells.
Superoxide dismutase (EC 1.15.1.1) has been assayed by a spectrophotometric method based on the inhibition of a superoxide-driven NADH oxidation. The assay consists of a purely chemical reaction ...sequence which involves EDTA, Mn(II), mercaptoethanol, and molecular oxygen, requiring neither auxiliary enzymes nor sophisticated equipment. The method is very flexible and rapid and is applicable with high sensitivity to the determination of both pure and crude superoxide dismutase preparations. The decrease of the rate of NADH oxidation is a function of enzyme concentration, and saturation levels are attainable. Fifty percent inhibition, corresponding to one unit of the enzyme, is produced by approximately 15 ng of pure superoxide dismutase. Experiments on rat liver cytosol have shown the specificity of the method for superoxide dismutase. Moreover, common cellular components do not interfere with the measurement, except for hemoglobin when present at relatively high concentrations. The assay is performed at physiological pH and is unaffected by catalase.
Background and Objectives The aim of our study was to test a platelet-rich plasma releasate (PRP-R/SRGF) from CaCl sub(2)-activated platelets as a source of growth factors for the expansion of ...mesenchymal stromal cells (MSCs). PRP-R/SRGF, obtained with a low-cost procedure, is characterized by a reduced variability of growth factor release. Materials and Methods PRP-R/SRGF is a clinical-grade quality solution obtained from CaCl sub(2)-activated platelets. Its activity was evaluated by measuring the proliferation, the phenotype, the differentiation potential and the immunosuppressive properties of MSCs derived from bone marrow (BM) and adipose tissue (AT). Results PRP-R/SRGF was more active than FBS to expand BM- and AT-derived MSCs. PRP-R/SRGF treatment did not affect the expression of typical MSCs surface markers, neither MSCs differentiation potential nor their capability to inhibit activated T-cell proliferation. Conclusions The clinical-grade PRP-R/SRGF may be used in the clinical setting for the expansion of MSCs.
Background and Objectives
The aim of our study was to test a platelet‐rich plasma releasate (PRP‐R/SRGF) from CaCl
2
‐activated platelets as a source of growth factors for the expansion of ...mesenchymal stromal cells (MSCs). PRP‐R/SRGF, obtained with a low‐cost procedure, is characterized by a reduced variability of growth factor release.
Materials and Methods
PRP‐R/SRGF is a clinical‐grade quality solution obtained from CaCl
2
‐activated platelets. Its activity was evaluated by measuring the proliferation, the phenotype, the differentiation potential and the immunosuppressive properties of MSCs derived from bone marrow (BM) and adipose tissue (AT).
Results
PRP‐R/SRGF was more active than FBS to expand BM‐ and AT‐derived MSCs. PRP‐R/SRGF treatment did not affect the expression of typical MSCs surface markers, neither MSCs differentiation potential nor their capability to inhibit activated T‐cell proliferation.
Conclusions
The clinical‐grade PRP‐R/SRGF may be used in the clinical setting for the expansion of MSCs.
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