Biomedical subjects

R Ria

Publications and source records attributed to R Ria.

28 records · Page 2Linked to original sources

PubMed1999

Bone marrow neovascularization, plasma cell angiogenic potential, and matrix metalloproteinase-2 secretion parallel progression of human multiple myeloma.

To assess whether the progression of plasma cell tumors is accompanied by angiogenesis and secretion of matrix-degrading enzymes, bone marrow biopsy specimens from 20 patients with monoclonal gammopathy of undetermined significance (MGUS), 18 patients with nonactive multiple myeloma (MM), and 26 patients with active MM were evaluated for their angiogenic potential and matrix-metalloproteinase (MMP) production. A fivefold increase of the factor VIII+ microvessel area was measured by a planimetric method of point counting in the bone marrow of patients with active MM as compared with nonactive MM and MGUS patients (P <.01). When serum-free conditioned media (CM) of plasma cells isolated from the bone marrow of each patient were tested in vivo for their angiogenic activity in the chick embryo chorioallantoic membrane (CAM) assay, the incidence of angiogenic samples was significantly higher (P <. 01) in the active MM group (76%) compared with nonactive MM (33%) and MGUS (20%) groups. Moreover, a linear correlation (P <.01) was found between the extent of vascularization of the bone marrow of a given patient and the angiogenic activity exerted in the CAM assay by the plasma cells isolated from the same bone marrow. In vitro, a significantly higher fraction of the plasma cell CM samples from the active MM group stimulated human umbilical vein endothelial cell (HUVEC) proliferation (53%, P <.01), migration (42%, P <.05), and/or monocyte chemotaxis (38%, P <.05) when compared with nonactive MM and MGUS groups (ranging between 5% and 15% of the samples). Also, immunoassay of plasma cell extracts showed significantly higher (P <. 01) levels of the angiogenic basic fibroblast growth factor (FGF)-2 in the active MM patients than in nonactive MM and MGUS patients (153 +/- 59, 23 +/- 17, and 31 +/- 18 pg FGF-2/100 micrograms of protein, respectively). Accordingly, neutralizing anti-FGF-2 antibody caused a significant inhibition (ranging from 54% to 68%) of the biological activity exerted on cultured endothelial cells and in the CAM assay by plasma cell CM samples from active MM patients. Finally, in situ hybridization of bone marrow plasma cells and gelatin-zymography of their CM showed that active MM patients express significantly higher (P <.01) levels of MMP-2 mRNA and protein when compared with nonactive MM and MGUS patients, whereas MMP-9 expression was similar in all groups. Taken together, these findings indicate that the progression of plasma cell tumors is accompanied by an increase of bone marrow neovascularization. This is paralleled by an increased angiogenic and invasive potential of bone marrow plasma cells, which is dependent, at least in part, by FGF-2 and MMP-2 production. Induction of angiogenesis and secretion of MMPs by plasma cells in active disease may play a role in their medullary and extramedullary dissemination, raising the hypothesis that angiostatic/anti-MMP agents may be used for therapy of MM.

Adult↗

PubMed1999

Human erythropoietin induces a pro-angiogenic phenotype in cultured endothelial cells and stimulates neovascularization in vivo.

Hematopoietic and endothelial cell lineages share common progenitors. Accordingly, cytokines formerly thought to be specific for the hematopoietic system have been shown to affect several functions in endothelial cells, including angiogenesis. In this study, we investigated the angiogenic potential of erythropoietin (Epo), the main hormone regulating proliferation, differentiation, and survival of erythroid cells. Epo receptors (EpoRs) have been identified in the human EA.hy926 endothelial cell line by Western blot analysis. Also, recombinant human Epo (rHuEpo) stimulates Janus Kinase-2 (JAK-2) phosphorylation, cell proliferation, and matrix metalloproteinase-2 (MMP-2) production in EA.hy926 cells and significantly enhances their differentiation into vascular structures when seeded on Matrigel. In vivo, rHuEpo induces a potent angiogenic response in the chick embryo chorioallantoic membrane (CAM). Accordingly, endothelial cells of the CAM vasculature express EpoRs, as shown by immunostaining with an anti-EpoR antibody. The angiogenic response of CAM blood vessels to rHuEpo was comparable to that elicited by the prototypic angiogenic cytokine basic fibroblast growth factor (FGF2), it occurred in the absence of a significant mononuclear cell infiltrate, and it was not mimicked by endothelin-1 (ET-1) treatment. Taken together, these data demonstrate the ability of Epo to interact directly with endothelial cells and to elicit an angiogenic response in vitro and in vivo and thus act as a bona fide direct angiogenic factor.

Allantois↗

PubMed1999

Bone marrow angiogenesis and mast cell density increase simultaneously with progression of human multiple myeloma.

Immunohistochemical, cytochemical and ultrastructural data showing vivid angiogenesis and numerous mast cells (MCs) in the bone marrow of 24 patients with active multiple myeloma (MM) compared with 34 patients with non-active MM and 22 patients with monoclonal gammopathy of undetermined significance (MGUS) led us to hypothesize that angiogenesis parallels progression of MM, and that MCs participate in its induction via angiogenic factors in their secretory granules.

Adult↗

PubMed1999

Angiogenesis extent and macrophage density increase simultaneously with pathological progression in B-cell non-Hodgkin's lymphomas.

Node biopsies of 30 benign lymphadenopathies and 71 B-cell non-Hodgkin's lymphomas (B-NHLs) were investigated for microvessel and macrophage counts using immunohistochemistry and morphometric analysis. Both counts were significantly higher in B-NHL. Moreover, when these were grouped into low-grade and high-grade lymphomas, according to the Kiel classification and Working Formulation (WF), statistically significant higher counts were found in the high-grade tumours. Immunohistochemistry and electron microscopy revealed a close spatial association between microvessels and macrophages. Overall, the results suggest that, in analogy to what has already been shown in solid tumours, angiogenesis occurring in B-NHLs increases with tumour progression, and that macrophages promote the induction of angiogenesis via the release of their angiogenic factors.

Antigens, CD↗

PubMed1999

Angiogenesis extent and expression of matrix metalloproteinase-2 and -9 correlate with upgrading and myometrial invasion in endometrial carcinoma.

BACKGROUND: Changes in angiogenesis and expression of extracellular matrix-degrading enzymes have been substantiated during tumour changeover and progression. METHODS: Tissues from 64 biopsies of endometrial carcinoma (EC) and 15 biopsies of normal (control) endometrium were investigated immunohistochemically to determine their microvessel number, and by in situ hybridisation to determine the expression of mRNA of the matrix metalloproteinase-2 (MMP-2, gelatinase A) and metalloproteinase-9 (MMP-9 gelatinase B). EC were grouped according to both histological grade (G) G1 to G3 and depth of myometrial (M) invasion M1 to M3. RESULTS: EC as a whole gave significantly higher counts over control endometria. Counts of the G1 group overlapped those of the control group, increased significantly in the G2 and even more in the G3 group. G3 biopsies in particular also displayed most microvessels widely scattered in the tumour tissue, in close association with tumour cells, and as winding and arborized tubes, often dilated in microaneurysmatic segments. Counts also increased in M2 and M3. Expression of the MMP-2 and MMP-9 mRNA, evaluated as percentages of positive biopsies and intensity of expression, were upregulated with the transition from control and G1 groups to G2 and G3, and in relation to advancing depth of invasion. In EC, MMP-2 and MMP-9 mRNA were also expressed by host stromal cells, including microvascular endothelial cells, fibroblasts and macrophages. In the control biopsies, poor expression of MMP-2 mRNA in few endothelial cells and no expression of MMP-9 mRNA were detected. CONCLUSION: These in situ data suggest that angiogenesis and degradation of extracellular matrix occur simultaneously with EC upgrading and advancing depth of invasion, and that EC cells and some host stromal cell populations cooperate in tumour progression.

Adult↗

PubMed1998

Systemic sclerosis stimulates angiogenesis in the chick embryo chorioallantoic membrane.

Skin biopsies from patients with systemic sclerosis (SSc) were investigated for their angiogenic activity by using the chick embryo chorioallantoic membrane (CAM) assay. Ten samples of SSc and 10 of normal skin from age- and sex-matched subjects were grafted onto the CAM, and the angiogenic response in pathological and control implants was assessed on histological sections by a planimetric point-count method 4 days after grafting. The vascular counts in the area underlying the SSc were significantly higher than those of normal skin and a dense mononuclear cell infiltrate was detectable around the blood vessels in pathological specimens. These results suggest that SSc may promote angiogenesis, perhaps leading to the release of several angiogenic factors. Moreover, the role played in the angiogenic response by the inflammatory cells forming the cellular infiltrate is suggested by this study.

Adult↗

PubMed1998

Human lymphoblastoid cells produce extracellular matrix-degrading enzymes and induce endothelial cell proliferation, migration, morphogenesis, and angiogenesis.

Human lymphoproliferative diseases can be hypothesized to invade locally and to metastatize via mechanisms similar to those developed by a variety of solid tumors, i.e., the secretion of extracellular matrix-degrading enzymes and stimulation of angiogenesis. To assess this hypothesis, Namalwa, Raji, and Daudi cell lines (Burkitt's lymphoma), LIK and SB cell lines (B-cell lymphoblastic leukemia), CEM and Jurkat cell lines (T-cell lymphoblastic leukemia), and U266 cell line (multiple myeloma) were evaluated for their capacity to produce matrix metalloproteinase-2 and -9, and urokinase-type plasminogen activator. These cell lines were also assessed for their ability: (1) to produce the angiogenic basic fibroblast growth factor and vascular endothelial growth factor; (2) to induce an angiogenic phenotype in cultured endothelial cells, represented by cell proliferation, chemotaxis, and morphogenesis; (3) to stimulate angiogenesis in different in vivo experimental models. All cell lines expressed the mRNA for one or both metalloproteinases. Namalwa, Raji, LIK, SB, and U266 cells secreted the active form of both metalloproteinases, while Daudi, CEM, and Jurkat cells produced metalloproteinase-2 but not-9. In contrast, urokinase-type plasminogen activator was secreted only by SB cells. While Raji, LIK, SB, CEM, and Jurkat cells secreted both basic fibroblast growth factor and vascular endothelial growth factor, Daudi and U266 cells produced only the former, and Namalwa cells only the latter. Accordingly, the conditioned medium of all cell lines stimulated cell proliferation and/or chemotaxis in cultured endothelial cells, with the exception of that of Namalwa cells which was ineffective. The conditioned medium of CEM and Jurkat cells induced morphogenesis in cultured endothelial cells grown on a reconstituted basement membrane (Matrigel). Lastly, Namalwa, Raji, LIK, SB, U266, CEM, and Jurkat cells induced angiogenesis and mononuclear cell recruitment in the murine Matrigel sponge model and in a chick embryo chorioallantoic membrane assay. The extent of angiogenesis in both models was strictly correlated with the density of the mononuclear cell infiltrate. The results indicate that human lymphoproliferative disease cells possess both local and remote invasive ability via the secretion of matrix-degrading enzymes and the induction of angiogenesis which is fostered by host inflammatory cells and by an intervening ensemble of angiogenic factors.

Animals↗

PubMed1998

Role of basic fibroblast growth factor in the formation of the capillary plexus in the chick embryo chorioallantoic membrane. An in situ hybridization, immunohistochemical and ultrastructural study.

The chick embryo chorioallantoic membrane (CAM) is supplied by an extensive capillary network. We have previously demonstrated that a Mr 16,000 basic fibroblast growth factor (FGF2)-like molecule is present in the CAM. At present, no data are available on the cellular source(s) of FGF2 in the CAM. In this work, CAM has been investigated by in situ hybridization with the aim to identify the source(s) of endogenous FGF2 during development. The immunohistochemical expression of fibronectin, laminin and type IV collagen in the CAM extracellular matrix (ECM) and the ultrastructural relationships between chorionic epithelium and the underlying capillary plexus were also studied. Our findings strongly suggest that FGF2 regulates the development of the capillary plexus by two sequential steps. In an early paracrine phase, chorionic epithelial cells secrete FGF2, thus eliciting an angiogenic response in the undifferentiated mesodermal blood vessels. In response to this paracrine signalling, the newly formed endothelial cells move through a permissive ECM and migrate beneath the chorion. Here, they synthesize an autocrine supply of FGF2 necessary to further proliferate and differentiate, thus originating the capillary plexus.

Allantois↗

PubMed1997

Progression of mycosis fungoides is associated with changes in angiogenesis and expression of the matrix metalloproteinases 2 and 9.

Changes in angiogenesis and expression of extracellular matrix-degrading enzymes have been substantiated during progression of solid tumours, whereas information on haematological tumours remains circumstantial. In this study, 57 biopsies of mycosis fungoides (MF), a haematological tumour of T-cell lineage, were investigated immunohistochemically for the extent of angiogenesis, and by in situ hybridisation for the expression of matrix metalloproteinases 2 (MMP-2, collagenase A) and 9 (MMP-9, collagenase B). The biopsies we grouped according to the stage of progression: patch-->plaque-->nodular (most advanced). The extent of angiogenesis, as microvessel area, of MF lesions as a whole was significantly higher than that of normal uninjured skin, used as a control. When the stages of MF progression were compared, the values of MF patch stage overlapped that of control skin, while values were significantly higher in the plaque stage and even higher in the nodular stage. In these stages, microvessels were widely scattered in the tumour tissue, in close association with tumour cells, and they frequently displayed arborisation and microaneurysmatic dilation. In contrast, in the patch stage microvessels were irregularly distributed around the tumour aggregates, and arborisation or dilated structures were only rarely seen. The expression of MMP-2 and MMP-9 mRNAs underwent significant upregulation in relation to advancing stage. Indeed, the upstaging was significantly associated with higher proportions of lesions positive for each mRNA or for both, and with lesions with the greatest intensity of expression for each mRNA. Besides tumour cells, the MMP-2 mRNA was expressed by microvascular endothelial cells of intratumour and peri-tumour vessels, and by fibroblasts which were especially abundant in the stroma adjacent to the tumour nodules. The MMP-9 mRNA was found to be present in a subset of tissue macrophages which were more frequently located in close vicinity to the tumour nodules. In contrast, in control skin, a weak positivity for the MMP-2 mRNA in very few microvascular endothelial cells and no signal for the MMP-9 mRNA were observed. These in situ data suggest that angiogenesis and degradation of the extracellular matrix occur simultaneously during MF progression. They imply that interaction between tumour cells and their microvasculature are all the more likely to occur during progression, occasionally with the contribution of tumour-associated stromal cells.

Aged↗

PubMedDate not supplied

Human recombinant interferon alpha-2a inhibits angiogenesis of chick area vasculosa in shell-less culture.

In vivo suppression of neovascularization by in situ administration of human recombinant interferon alpha 2a (hrIFN-alpha 2a) was tested on the chick embryo area vasculosa (AV). Methylcellulose discs, each containing 5 IU of hrIFN-alpha 2a were implanted onto the AV at Hamburger-Hamilton (HH) stage 13, and inhibition of blood vessel growth was morphometrically evaluated between HH stages 20 and 27. Our results show: (i) a decreased extent of the AV; (ii) a decreased AV total vessel length; (iii) modified percent ratios of different classes of AV vessels having a definite length. The observed effects of treating with hrIFN-alpha 2a are likely attributable to inhibition of endothelial cell proliferation.

Animals↗