Search PubMed⌕ Search

Biomedical subjects

M Morini

Publications and source records attributed to M Morini.

At least 19 recordsLinked to original sources
PubMed2006

Deciduoid peritoneal mesothelioma in a dog.

Deciduoid mesothelioma is a rare variant of epithelial mesothelioma, up to now only described in human pathology, which bears remarkable cytomorphologic resemblance to the endometrium of pregnancy, termed decidua. A case of peritoneal mesothelioma with deciduoid features in a 10-year-old, female dog is reported. Multiple whitish-gray nodules (1-5 mm in diameter) in parietal peritoneum and mesentery were histologically composed of large, proliferating, polygonal or ovoid cells with an abundant eosinophilic, glassy cytoplasm. Immunohistochemical evaluation indicated that the neoplastic cells coexpressed cytokeratin and vimentin with strong and diffuse cytoplasmic staining, and ultrastructural analysis showed long and slender mesothelial-type microvilli; these findings confirmed the mesothelial origin of the tumor.

Animals↗
PubMed2004

Expression of CD44v3 protein in human endothelial cells in vitro and in tumoral microvessels in vivo.

The most universal angiogenic cytokines (VEGF, bFGF, HGF) are all heparin-binding proteins, the function of which is dependent on cell surface heparan sulfate proteoglycans (HSPG). Several proteoglycans have been demonstrated in endothelial cells, but only glypican-1 from the cell surface HSPG subfamily was documented at protein level. Here, we show that CD44v3 is expressed in human immortalized endothelial cells [anchorage-dependent human umbilical vein endothelial cells (HUVEC) and anchorage-independent Kaposi sarcoma (KS-Imm)] at mRNA and protein level, but is absent from the primary culture of human brain microvascular endothelial cells. We have shown that CD44v3 has a large cytoplasmic pool in endothelial cells, but a limited surface expression, mainly at filopodia, colocalized with MMP-2. Angiogenic factors like VEGF or bFGF did not affect surface detection of CD44v3 suggesting a constitutive expression. The putative functional role for endothelial cell surface CD44v3 was identified in chemotaxis assay when anti-CD44v3 antibody pretreatment proved to be inhibitory for HUVEC. Furthermore, we provided evidence for the CD44v3 protein expression in human endothelial cells in vivo in peritumoral microvessels of both human melanoma and glottic cancers, suggesting a role for this part-time heparan sulfate proteoglycan in tumor induced angiogenesis.

Base Sequence↗
PubMed2004

Prevention of angiogenesis by naked DNA IL-12 gene transfer: angioprevention by immunogene therapy.

IL-12 is thought to induce a cytokine cascade with antiangiogenic effects mediated by IFN-gamma and angiostatic CXCR3 chemokine ligands. Naked DNA intramuscular injection of an expression vector plasmid producing IL-12 resulted in significant, well-tolerated elevation of serum IL-12 levels. Injection of the IL-12 plasmid at least 2 days, and up to 20 days, before subcutaneous injection of matrigel with angiogenic factors resulted in strong prevention of angiogenesis in both C57/bl and nude mice. A single injection of the IL-12 plasmid contemporarily with the matrigel or 2 days after resulted in partial, statistically not significant, inhibition. Control plasmid injection did not affect either angiogenesis or angiogenesis inhibition by IL-12 protein in vivo. Angiogenesis inhibition was observed in NK cell-depleted C57/bl and nude mice as well as in IFN-gamma(-/-) and CXCR3(-/-) knockout mice, indicating that NK- and/or T-cell-initiated IFN-gamma-chemokine cascades were not involved in the angiogenesis inhibition observed in vivo. Finally, IL-12 plasmid DNA gene transfer significantly prevented the growth and vascularization of highly angiogenic KS-Imm Kaposi's sarcoma and TS/A murine mammary carcinoma tumors in nude and/or syngeneic mice. These data suggest that a preventive gene therapy approach using antiangiogenic cytokines can effectively inhibit tumor angiogenesis and KS, representing an example of angioimmunoprevention.

Animals↗
PubMed2003

Gastrointestinal spindle cell tumours of the dog: histological and immunohistochemical study.

To assess the relevance of spindle cell tumours in the canine gastrointestinal (GI) tract and to classify them, a retrospective study was carried out on haematoxylin and eosin-stained sections from formalin-fixed paraffin wax-embedded samples of 105 primary GI tumours. Seventeen out of 105 (16%) GI tumours were mesenchymal, 48% were epithelial and 36% were round cell tumours. Spindle cell tumours were stained by Masson trichrome, Orcein-Van Gieson and labelled immunohistochemically (vimentin, desmin, smooth muscle actin, protein S100, glial fibrillar acid protein, CD117 and MIB-1) and the histological grade, mitotic index, nuclear size and cellular density were also assessed. The 17 gastrointestinal mesenchymal tumours were classified as 10 leiomyomas (10/10 positive for desmin and smooth muscle actin; 6/10 positive for vimentin) 2 leiomyosarcomas (2/2 positive for desmin, smooth muscle actin and vimentin) and 5 gastrointestinal stromal tumours (GISTs) (5/5 positive for CD117 and vimentin; 3/5 positive for smooth muscle actin). Canine GISTs appeared as densely packed spindle cell tumours, with a diffuse, strong, cytoplasmic immunopositivity for c-kit protein (CD117). GISTs, defined as CD117-positive spindle cell or epithelioid or pleomorphic neoplasms that presumably derive from interstitial cells of Cajal, are reported in recent medical studies as the most common mesenchymal tumours of the GI tract. Our data suggest that GISTs represent a significant portion of canine GI spindle cell tumours, which can be definitely distinguished from leiomyosarcomas only by their expression of CD117.

Animals↗
PubMed2003

Hypertrophy of intestinal smooth muscle in cats.

Pathological findings of four cats with severe and diffuse smooth muscle hypertrophy of the small intestine (MHSI) are reported and compared to those of five cats with segmental MHSI secondary to neoplastic obstruction and four controls. Histology demonstrated a constant association between idiopathic MHSI and submucosal fibrosis and chronic lymphoplasmacytic enteritis. Morphometry (gut diameter, thickness and area of muscular layers, number and density of smooth muscle nuclei) and MIB-1-immunolabelling showed that the thickness increase was mostly due to hypertrophy, but hyperplasia was also evident. Microbiology from ileal content samples was performed in two cats with primary MHSI, and Campylobacter spp. were isolated, which were also demonstrated by immunohistochemistry and ultrastructure. The association of chronic enteritis with idiopathic MHSI suggests that factors released in intestinal inflammation may also act as hypertrophy stimuli for smooth muscle cells.

Animals↗
PubMed2003

Somatostatin inhibits tumor angiogenesis and growth via somatostatin receptor-3-mediated regulation of endothelial nitric oxide synthase and mitogen-activated protein kinase activities.

Somatostatin was reported to inhibit Kaposi's sarcoma (KS) cell (KS-Imm) xenografts through an antiangiogenic activity. Here, we show that somatostatin blocks growth of established KS-Imm tumors with the same efficacy as adriamycin, a clinically effective cytotoxic drug. Whereas KS-Imm cells do not express somatostatin receptors (SSTRs), endothelial cells express several SSTRs, in particular SSTR3. We investigated the molecular mechanisms and receptor specificity of somatostatin inhibition of angiogenesis. Somatostatin significantly inhibited angiogenesis in vivo in the matrigel sponge assay; this inhibition was mimicked by the SSTR3 agonist L-796778 and reversed by the SSTR3 antagonist BN81658, demonstrating involvement of SSTR3. In vitro experiments showed that somatostatin directly affected different endothelial cell line proliferation through a block of growth-factor-stimulated MAPK and endothelial nitric oxide (NO) synthase (eNOS) activities. BN81658 reversed somatostatin inhibition of cell proliferation, NO production, and MAPK activity, indicating that SSTR3 activation is required for the effects of somatostatin in vitro. Finally in vivo angiogenesis assays demonstrated that eNOS inhibition was a prerequisite for the antiangiogenic effects of somatostatin, because high concentrations of sodium nitroprusside, an NO donor, abolished the somatostatin effects. In conclusion, we demonstrate that somatostatin is a powerful antitumor agent in vivo that inhibits tumor angiogenesis through SSTR3-mediated inhibition of both eNOS and MAPK activities.

Amides↗
PubMed2003

Bile duct dysplasia and congenital hepatic fibrosis associated with polycystic kidney (Caroli syndrome) in a rat.

Hepatic fibrosis with bile duct ectasia and hyperplasia associated with polycystic kidney disease, analogous to Caroli syndrome in humans, was observed in a rat used as a control in a subchronic toxicity study. Light microscopy of liver sections showed multiple cystic and segmental saccular dilatations and hyperplasia of the intrahepatic bile ducts associated with overgrowth of portal connective tissue; the kidneys had diffuse cystic dilatation of cortical renal tubules. The lesions resembled those of human cases of the fibropolycystic disease termed as Caroli syndrome, which is thought to be the result of a pathologic developmental process known as ductal plate malformation. Recently, an animal model of Caroli syndrome has been described in mutant rats from a colony that constantly showed renal and hepatic cysts and an autosomal recessive mode of inheritance. The finding in our case of identical hepatorenal lesions suggests that the same mutation has occurred incidentally in a standard colony.

Animals↗
PubMed2002

Differential effects of angiostatin, endostatin and interferon-alpha(1) gene transfer on in vivo growth of human breast cancer cells.

The administration of different angiogenesis inhibitors by gene transfer has been shown to result in inhibition of tumor growth in animal tumor models, but the potency of these genes has been only partially evaluated in comparative studies to date. To identify the most effective anti-angiogenic molecule for delivery by retroviral vectors, we investigated the effects of angiostatin, endostatin and interferon(IFN)-alpha(1) gene transfer in in vivo models of breast cancer induced neovascularization and tumor growth. Moloney leukemia virus-based retroviral vectors for expression of murine angiostatin, endostatin and IFN-alpha(1) were generated, characterized, and used to transduce human breast cancer cell lines (MCF7 and MDA-MB435). Secretion of the recombinant proteins was confirmed by biological and Western blotting assays. Their production did not impair in vitro growth of these breast cancer cells nor their viability, and did not interfere with the expression of angiogenic factors. However, primary endothelial cell proliferation and migration in vitro were inhibited by supernatants of the transduced cells containing angiostatin, endostatin, and IFN-alpha(1). Stable gene transfer of the IFN-alpha(1) cDNA by retroviral vectors in both MCF7 and MDA-MB435 cells resulted in a marked and long-lasting inhibition of tumor growth in nude mice that was associated with reduced vascularization. Endostatin reduced the in vivo growth of MDA-MB435, but not MCF7 cells, despite similar levels of in vivo production, and angiostatin did not impair the in vivo growth of either cell line. These findings indicate heterogeneity in the therapeutic efficacy of angiostatic molecules delivered by viral vectors and suggest that gene therapy with IFN-alpha(1) and endostatin might be useful for treatment of breast cancer.

Angiogenesis Inhibitors↗
PubMed2002

Low molecular weight hyaluronic acid prevents oxygen free radical damage to granulation tissue during wound healing.

Hyaluronic acid protects granulation tissue from oxygen free radical damage and stimulates wound healing, but its molecular weight prevents it from permeating the epidermal barrier A low molecular weight hyaluronic acid preparation is able to permeate the skin, but it is unknown whether or not it retains the scavenging effects of oxygen free radicals in granulation tissue. Our experiments were conducted in rats with excisional or incisional wounds. Wound contraction over 11 days and breaking strength on the fifth day were measured. Oxygen free radical production was induced by intraperitoneal administration of two different xenobiotics: phenazine methosulfate and zymosan. The wounds were treated topically with low molecular weight hyaluronic acid (0.2%) cream or placebo. In the incisional wound group, the effects of superoxide dismutase were also determined. Absolute controls received wounds and placebo but no xenobiotics. Wound healing was significantly slower in the xenobiotic group than in the control groups. These effects were strongly reduced by topical administration of low molecular weight hyaluronic acid (0.2%) cream and in incisional wounds by topically injected superoxide dismutase. Low molecular weight hyaluronic acid is effective as the native compound against oxygen free radicals. Its pharmacological effects through transdermal administration should be tested in appropriate models.

Granulation Tissue↗
PubMed2001

Inhibition of angiogenesis-driven Kaposi's sarcoma tumor growth in nude mice by oral N-acetylcysteine.

The thiol N-acetyl-L-cysteine (NAC), an analogue and precursor of reduced glutathione, has cancer chemopreventive properties attributable to its nucleophilicity, antioxidant activity, and a variety of other mechanisms. We demonstrated recently that NAC has anti-invasive, antimetastatic, and antiangiogenic effects in in vitro and in vivo test systems. In the present study, s.c. transplantation of KS-Imm cells in (CD-1)BR nude mice resulted in the local growth of Kaposi's sarcoma, a highly vascularized human tumor. The daily administration of NAC with drinking water, initiated after the tumor mass had become established and detectable, produced a sharp inhibition of tumor growth, with regression of tumors in half of the treated mice along with a markedly prolonged median survival time. The production of vascular endothelial growth factor (VEGF) and certain proliferation markers (proliferating cell nuclear antigen and Ki-67) were significantly lower in Kaposi's sarcomas from NAC-treated mice than from control mice. Treatment of KS-Imm cells with NAC in vitro resulted in a dose-dependent inhibition of chemotaxis and invasion through inhibition of gelatinase-A (matrix metalloproteinase-2, MMP-2) activity without altering MMP-2 or MMP-9 mRNA levels. NAC also significantly inhibited VEGF production but did not affect proliferation markers in vitro. Reverse transcription-PCR analysis indicated that total VEGF mRNAs were reduced by 10 mM NAC. Taken together, these findings provide evidence that NAC, the safety of which even at high doses has been established in almost 40 years of clinical use, in addition to its chemopreventive action, has a strong antiangiogenic potential that could be exploited for preventing cancer progression as well as used in cancer adjuvant therapy.

Acetylcysteine↗
PubMed2001

Effects of angiostatin gene transfer on functional properties and in vivo growth of Kaposi's sarcoma cells.

Gene transfer delivery of endogenous angiogenesis inhibitors such as angiostatin would circumvent problems associated with long-term administration of proteins. Kaposi's sarcoma (KS), a highly vascular neoplasm, is an excellent model for studying tumor angiogenesis and antiangiogenic agent efficacy. We investigated the effects of angiostatin gene transfer in in vitro and in vivo models of KS-induced neovascularization and tumor growth. A eukaryotic expression plasmid and a Moloney leukemia virus-based retroviral vector for expression of murine angiostatin were generated harboring the angiostatin cDNA with cleavable leader signals under the control of either the strong cytomegalovirus promoter/enhancer or the Moloney leukemia virus long terminal repeat. Angiostatin secretion was confirmed by radioimmunoprecipitation and Western blot analysis. Supernatants of angiostatin-transfected cells inhibited endothelial cell migration in vitro. Stable gene transfer of the angiostatin cDNA by retroviral vectors in KS-IMM cells resulted in sustained angiostatin expression and delayed tumor growth in nude mice, which was associated with reduced vascularization. These findings suggest that gene therapy with angiostatin might be useful for treatment of KS and possibly other highly angiogenic tumors.

Angiostatins↗
PubMed2000

Hyperplasia and impaired involution in the mammary gland of transgenic mice expressing human FGF4.

Fgf4, a member of the fibroblast growth factor family, is frequently amplified in a variety of human cancers, however, its expression in neoplastic tissues is rarely detectable. This makes uncertain its involvement in tumour aetiology, although several in-vitro studies link Fgf4 overexpression to malignant transformation and metastatization of culture cells. We generated a transgenic mouse model in which the whey acidic protein (WAP) promoter directs expression of human Fgf4 to mammary tissues during late pregnancy and throughout lactation, with the purpose of studying the involvement of this growth factor in mammary tumorigenesis. Expression of the transgene was specifically detected in lobular-alveolar cells of lactating mammary glands that, by histological analysis, displayed hyperplastic areas and a disorganized structure. This was accompanied by an increased number of red blood cells and expression, in alveolar epithelial cells, of the vascular endothelial growth factor, which is absent in wild type controls. The most striking effect caused by FGF4 overexpression was on the remodelling of mammary tissue at the end of lactation. Indeed, transgenic animals showed a delayed involution of the gland due to a dramatic reduction in the overall number of apoptotic cells, which are normally present in the organ after weaning. Nevertheless, none of the animals examined developed neoplastic lesions of the mammary gland even after several pregnancies and at old age. Our work represents the first in-vivo demonstration of the anti-apoptotic and angiogenic properties of FGF4.

Aging↗
PubMed2000

The alpha 3 beta 1 integrin is associated with mammary carcinoma cell metastasis, invasion, and gelatinase B (MMP-9) activity.

The alpha 3 beta 1 integrin is elevated in several types of metastatic tumor and has been associated with increased migration and invasion. Our analysis of a series of mammary carcinomas of different histotypes and their corresponding metastases demonstrated significantly increased expression of alpha 3 beta 1 in the tumor metastases. We therefore studied alpha 3 beta 1 expression of several human breast carcinoma cell lines and its association with the invasive phenotype. The MDA-MB-231 cell line expressed high levels of the beta1, alpha 2, alpha 3, alpha 5, and alpha 6 integrin subunits along with moderate levels of the alpha v beta 3 integrin. This line was highly migratory and the most invasive using a chemo-invasion assay. In contrast, the other lines tested, MDA-MB-145, MCF-7, and SK-BR-3, showed lower migratory and invasive activity and reduced alpha 3 integrin subunit expression. Metalloproteases capable of degrading collagen IV are necessary for the invasive process. RT-PCR showed that MDA-MB-231 cells expressed MMP-9, but not MMP-2, gelatinase/collagenase IV. Gelatin zymography demonstrated that invading MDA-MB-231 cells released high levels of MMP-9 gelatinase activity. A direct role for this gelatinase in MDA-MB-231 cell invasion was confirmed by inhibition of invasion using the metalloprotease inhibitor Batimastat. Treatment of MDA-MB-231 cells with a function-blocking anti-alpha 3 antibody strongly inhibited migration and invasion. This correlated with a marked reduction in MMP-9 activity produced by MDA-MB-231 cells, suggesting a role for alpha 3 beta 1 ligand binding in cell signaling and regulation of extracellular matrix degradation.

Adult↗
PubMed2000

Kaposi's sarcoma cells of different etiologic origins respond to HIV-Tat through the Flk-1/KDR (VEGFR-2): relevance in AIDS-KS pathology.

Kaposi's sarcoma (KS) is an hyperplastic lesion whose main histological features are typical spindle shaped cells with a mixed endothelial-mesenchymal-macrophage phenotype, an intense vascularization and an inflammatory infiltrate. The etiology of KS appears to be linked to activation of a latent HHV8 infection. Sporadic and iatrogenic KS are slow progressing lesions that can undergo spontaneous regression. In contrast, KS, which is frequently associated with HIV infection, is found in a highly aggressive form in AIDS patients. The HIV-1 Tat has been shown to activate the VEGF receptor KDR in endothelial and KS spindle cells, suggesting this HIV protein could contribute to KS pathogenesis. We used primary 'reactive' KS cell culture from sporadic and epidemic KS, and an immortal KS-line (KS-Imm) isolated in our laboratory from a iatrogenic KS lesion, to verify if Tat-induced cell signaling is able to mediate cellular responses. We demonstrate that KS cells migrated in response to Tat and that VEGF is able to compete with the Tat chemotactic activity towards these cells. A function-blocking anti-KDR antibody was able to abrogate both VEGF and Tat-induced KS chemotactic response, indicating a direct involvement of this receptor. Our data show that HIV-Tat can also activate KS cells derived from sporadic or iatrogenic lesions, suggesting that in AIDS patients Tat could cooperate with VEGF in activation of KDS on KS precursor spindle and endothelial cells, and contribute to the aggressiveness of AIDS-KS lesions.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Inhibition of CXCR4-dependent HIV-1 infection by extracellular HIV-1 Tat.

Certain chemokines inhibit HIV replication through binding to cell surface receptors which also act as viral coreceptors. Based on our previous observations that HIV-1 Tat can interact with alpha- and beta-chemokine receptors, we investigated the potential effect of extracellular Tat (ecTat) on infection and replication of CCR5-dependent (R5) and CXCR4-using (X4) HIV-1 strains in primary activated peripheral blood mononuclear cells (PBMC) of uninfected donors. Receptor desensitization and binding competition studies were used to determine chemokine receptor binding by ecTat. Standard HIV replication assays based on reverse transcriptase (RT) activity determination in culture supernatants of PBMC and real time PCR for HIV-1 gag DNA were used to determine potential effects on early (entry or RT) steps of infection. ecTat bound to CXCR4 expressing monocytes and mitogen-activated PBMC, and competed with the natural ligand of CXCR4, SDF-1alpha (stromal cell-derived factor-1alpha) in calcium mobilization assays. EcTat inhibited replication of the X4 HIV-1 (LAI/IIIB strain) in activated PBMC at concentrations close to those of SDF-1alpha, whereas it only modestly interfered with R5 HIV-1 (BaL) replication in PBMC. Both SDF-1alpha and ecTat inhibited accumulation of X4 HIV-1 gag DNA, indicating interference with viral entry and/or RT. Our data show the surprising and counter-intuitive observation that ecTat selectively represses X4 HIV replication. This could favour spreading of R5 viruses, a condition observed in vivo immediately after transmission and in the early asymptomatic phase of infection.

Calcium↗
PubMed2000

Expression of functional tyrosine kinases on immortalized Kaposi's sarcoma cells.

Kaposi's sarcoma (KS) is the most frequent malignant lesion in patients with AIDS and is characterized by spindle cell proliferation, inflammatory cell infiltration, angiogenesis, edema, and invasiveness. KS origin is still debated. The complex aspect of this disease is probably supported by multiple concomitant pathogenetic factors, among which growth factors and their cognate tyrosine kinase receptors are deeply involved. Here we have investigated the expression status and functional integrity of KDR and Met receptors, as well as of their ligands, in an immortalized KS cell line (KS-IMM). The MET and KDR genes encode the tyrosine kinase receptors for Hepatocyte Growth Factor (HGF) and Vascular Endothelial Growth Factor (VEGF) respectively. Both factors are pleiotropic cytokines controlling growth, survival, motility, invasive migration and differentiation of endothelial cells. We have found that KS-IMM cells, which retain most of the features of the parental tumor and can induce KS-like sarcomas when injected subcutaneously in nude mice, express the Met receptor, but not its ligand. The receptor, which is basally inactive, is functional, being tyrosine phosphorylated in response to ligand stimulation and mediating the expected HGF-dependent biological responses of motility, invasion and proliferation. Moreover, we report that KS-IMM cells coexpress VEGF and KDR and that KDR is constitutively tyrosine phosphorylated, possibly as a consequence of the establishment of an autocrine loop. The receptor, however, maintains responsiveness to exogenously added ligand, by increasing the level of tyrosine phosphorylation and by responding in biological assays of motility, invasion and proliferation. Finally, we have found that the two growth factors synergize in a motility assay. These data show that HGF and VEGF are growth factors active on KS-IMM cells.

Animals↗
PubMed1999

Localization and expression of integrin subunits in the embryoid bodies of F9 teratocarcinoma cells.

F9 embryonal carcinoma cells can differentiate in vitro into either parietal (PE) or visceral (VE) endoderm, depending upon specific retinoic acid (RA) treatment and growth conditions. In differentiated aggregates of F9 cells (EB), the VE is a polarized monolayer surrounding a core of undifferentiated cells. Within 7 days of treatment the cells organize their cytoskeleton and synthesize large amounts of extracellular matrix proteins to form a basal lamina under the newly formed epithelium. All these changes are likely to involve integrin expression and organization. In this study we have analyzed the spatio-temporal changes in the pattern and level of expression of beta1, beta4, alpha5, alpha6A, and alpha6B integrin subunits. We found that the organization of the VE monolayer in F9 aggregates involves both qualitative and quantitative changes in integrin expression. beta1 is downregulated and accumulates in the forming epithelium. The same occurs for alpha5, although its location on the surface of the aggregate appears to be transient as in fully differentiated EB its distribution is uniform. beta4 and alpha6A are also mainly localized in the VE but they are undetectable in undifferentiated aggregates and their expression is induced by RA treatment. An important exception is represented by alpha6B whose distribution and expression remain almost unchanged throughout treatment.

Animals↗