Search PubMed⌕ Search

Biomedical subjects

M Ponzoni

Publications and source records attributed to M Ponzoni.

At least 55 records · Page 3Linked to original sources
PubMed1998

Human neuroblastoma cells produce extracellular matrix-degrading enzymes, induce endothelial cell proliferation and are angiogenic in vivo.

Direct experimental evidence shows that tumor growth and metastases are angiogenesis-dependent. Neuroblastoma (NB) is the most common extracranial malignant solid tumor of childhood. In this study, we investigated 2 human NB cell lines, LAN-5 and GI-LI-N, for their capacity to secrete 2 extracellular matrix-degrading enzymes, MMP-2 and MMP-9, and to induce in vitro human microvascular endothelial cells (EC) to proliferate and in vivo angiogenesis in the chick embryo chorio-allantoic membrane (CAM) assay. Conditioned medium (CM) from both cell lines stimulated in vitro EC proliferation and the effect of LAN-5 CM was higher than that of GI-LI-N cells. Moreover, anti-VEGF, but not anti-FGF2 antibodies, prevented growth increment of EC. NB cell lines secreted the active form of MMP-2 almost exclusively, LAN-5 cells more than GI-LI-N cells. Both cell lines, LAN-5 cells more than GI-LI-N ones, induced angiogenesis in the CAM assay. Our data suggest that the 2 NB cell lines are angiogenic, to LAN-5 cells more than GI-LI-N ones. LAN-5 cells are indeed endowed with a more aggressive and invasive phenotype.

Allantois↗
PubMed1998

Low sensitivity of computed tomography in the staging of gastric lymphomas of mucosa-associated lymphoid tissue: impact on prospective trials and ordinary clinical practice.

The natural history and management of gastric lymphomas of mucosa-associated lymphoid tissue (MALTomas) are not completely understood. Most stage I cases are now entered into prospective trials to confirm the excellent results obtained with conservative treatment, whereas current therapeutic policies are based on accumulated experience. The limits of staging work-ups may have a significant impact on prospective trials and ordinary clinical practice. The authors explore the sensitivity of computed tomography scanning in detecting perigastric adenopathy in 20 patients with gastric MALToma treated by gastrectomy. Clinical staging identified 17 patients as having stage I MALTomas and three patients as having stage II1 MALTomas. Histopathologic staging showed that 8 of 17 patients formerly diagnosed with stage I MALToma had perigastric nodal involvement, whereas the three patients with clinical stage II1 were confirmed as such. Computed tomography scanning has low sensitivity in detecting perigastric lymphadenopathy in gastric MALTomas. This leads to understaging, with a significant impact on therapeutic decision, and distorts newly acquired knowledge about the disease's natural history and management, introducing a bias in prospective clinical trials. Endoscopic ultrasonography should be tested as a staging procedure both in prospective trials and in ordinary clinical practice.

Adolescent↗
PubMed1998

Erythrocytosis in a patient with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) can be accompanied by compensatory secondary erythrocytosis. However, the exact prevalence of secondary erythrocytosis in COPD is unknown. Although diagnostic criteria for polycythemia vera versus secondary erythrocytosis are mutually exclusive, we describe here the coexistence of polycythemia vera and COPD in the same patient.

Aged↗
PubMed1997

Primary cardiac lymphoma in immunocompetent patients: diagnostic and therapeutic management.

BACKGROUND: Primary cardiac lymphoma (PCL) is extremely rare in immunocompetent patients. Different definition criteria have been employed in published series. Prognosis is poor due to diagnostic delay and relevance of the site of disease. METHODS: Two cases observed at the study institution are reported, with a review of 48 cases published in the literature from 1980 to 1996. Only patients with lymphoma confined to the heart and/or pericardium and those with a single and asymptomatic extracardiac site were considered for analysis. RESULTS: Eight patients had minimal extracardiac disease. The most common presentation was unresponsive heart failure. Electrocardiography findings were not specific. PCL usually arose in the right chambers as a mass, with or without pericardial effusion (> 80%). Chest X-rays, transthoracic echocardiography, and computed tomography scans are standard in diagnostic workup, but transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) showed a sensitivity > 90%. Cytology of pericardial effusion was diagnostic in 67% of cases. Thoracotomy was diagnostic in all cases, whereas less invasive procedures had high false-negative rates. Gross resection has no role. Early anthracycline-containing chemotherapy appears to improve survival, whereas the role of radiotherapy has not yet been defined. CONCLUSIONS: The diagnosis of PCL should be considered in patients with a cardiac mass and/or unexplained refractory pericardial effusion. Adequate diagnostic workup, including TEE and MRI, allows confirmation of the early suspicion of PCL. In the absence of a diagnostic cytology, an open biopsy may be indicated to avoid treatment delay. There is no evidence that PCL should be treated differently from other bulky aggressive lymphomas arising at other anatomic sites.

Adolescent↗
PubMed1997

HSV-TK gene transfer into donor lymphocytes for control of allogeneic graft-versus-leukemia.

In allogeneic bone marrow transplantation (allo-BMT), donor lymphocytes play a central therapeutic role in both graft-versus-leukemia (GvL) and immune reconstitution. However, their use is limited by the risk of severe graft-versus-host disease (GvHD). Eight patients who relapsed or developed Epstein-Barr virus-induced lymphoma after T cell-depleted BMT were then treated with donor lymphocytes transduced with the herpes simplex virus thymidine kinase (HSV-TK) suicide gene. The transduced lymphocytes survived for up to 12 months, resulting in antitumor activity in five patients. Three patients developed GvHD, which could be effectively controlled by ganciclovir-induced elimination of the transduced cells. These data show that genetic manipulation of donor lymphocytes may increase the efficacy and safety of allo-BMT and expand its application to a larger number of patients.

Bone Marrow Transplantation↗
PubMed1997

Induction of apoptosis in human neuroblastoma cells by abrogation of integrin-mediated cell adhesion.

The survival, proliferation and differentiation of neuroblastoma (NB) cells are largely dependent on adhesion to extracellular matrix (ECM) proteins. Integrin occupancy seems to play a primary role. To elucidate the role of integrin heterodimers during neuronal cell death, we have analysed the changes in integrin expression in 2 human NB cell lines which represent different stages of neuronal maturation. Retinoic acid (RA) had different effects on the 2 NB cell lines: on LAN-5 cells it acted as a differentiation-promoting agent, while it had an anti-proliferative effect on GI-LI-N cells, driving them to apoptosis. Indeed, this occurrence was evidenced by the visualization of a "DNA ladder" on gel electrophoresis, by propidium iodide staining, and by DNA flow cytofluorimetric analysis. RA treatment rapidly and drastically decreased integrin expression and cell adhesion on GI-LI-N cells. These findings were also obtained by treating both NB cell lines with the apoptotic agent fenretinide. Furthermore, treatment of NB cells with anti-sense oligonucleotides to beta 1 integrin chain specifically induced chromatin condensation and nucleosomal DNA laddering. Moreover, blocking cell-matrix interactions by means of perturbing antibody against beta 1 subunit resulted in the induction of typical features of apoptotic cells. In conclusion, these findings indicate that abrogation of cell adhesion through down-modulation of integrin receptors plays a crucial role in the induction of neuroblastoma programmed cell death.

Antibodies, Monoclonal↗
PubMed1997

Bioavailability of antisense oligonucleotides in neuroblastoma cells: comparison of efficacy among different types of molecules.

To evaluate the real effectiveness of various chemical modifications in enhancing the ability of antisense molecules to inhibit gene expression, the toxicity, stability, uptake, and intracellular localization of an identical sequence, synthetized either with a phosphodiester or a phosphorothioate backbone, with or without a cholesteryl moiety linked to the 3'-end, were compared in three different human neuroblastoma cell lines. The toxicity, assessed by inhibition of cell viability, greatly depend on the presence of the lipid moiety and to a less extent on the cell line used. At high doses all the antisenses caused a necrotic lysis of plasma membranes. Typical features of apoptotic cell death were never observed. The presence of the lipid moiety enhanced the uptake of antisense molecules while the phosphorothioate backbone, as expected, conferred higher stability. At late times, therefore, the combination of lipid conjugation and phosphorothioate backbone seems to be the most effective in obtaining a consistent antisense accumulation inside the cells. The presence of the cholesteryl moiety also caused a stronger association of the antisense to membraneous compartments, so that a quite different biodistribution occurred among the four antisenses tested. However, the actual amount of antisense molecules found inside NB cells was low in all the conditions tested. Only following cellular permeabilization a significant uptake was obtained, making the use of delivery system mandatory to achieve an efficient inhibition of highly expressed genes.

Autoradiography↗
PubMed1997

Induction of differentiation and apoptosis by interferon-gamma in human neuroblastoma cells in vitro as a dual and alternative early biological response.

Interferon-gamma (IFN-gamma) has a well known differentiation-promoting activity on several neuroblastoma (NB) cell lines and has also been reported to induce apoptosis in different cellular models. We have investigated the potential of IFN-gamma to trigger, besides differentiation, programmed cell death in NB cells and the relationship between these processes. Nine NB cell lines, characterized by different phenotypic and maturational features, were cultured in the presence of IFN-gamma (1000 IU/ml) for up to 5 days with either only one treatment at the start of the culture or renewing the culture medium (with or without IFN-gamma) every other day. Neuronal differentiation was assessed by evaluation of morphological changes and expression of mature cytoskeletal proteins, while apoptosis was evaluated at the desired times by fluorescent and electronic microscopy, DNA content analysis and DNA fragmentation assay. Our findings show that apoptosis is an early (mainly non post-differentiative) event and is much more evident following a single IFN-gamma administration. Moreover, IFN-gamma-triggered apoptosis is independent of the cellular phenotype (schwannian or neuronal) and appears to be mutually exclusive with respect to differentiation at the single cell level. Our results strengthen the potential of IFN-gamma as a promising therapeutic agent for NB.

Journal Article↗
PubMed1997

Integrin up-regulation as marker of neuroblastoma cell differentiation: correlation with neurite extension.

We have characterized the adhesion properties, integrin expression, and morphological changes due to extracellular matrix (ECM)-integrin interactions in a neuronal model. We showed that a modulation of some integrin heterodimers occurs during interferon-gamma (IFN-gamma) induced neuroblastoma (NB) cell differentiation. To better elucidate the possible implication and function of integrin receptors during neuronal maturation, we analyzed the changes in integrin expression in two human NB cell lines, LAN-5 and GI-LI-N, which represent different stages of neuronal differentiation. These models show opposite morphological maturation after interferon-gamma and tumor necrosis factor-alpha (IFN-gamma+TNF) treatment. While LAN-5 cells acquired the ability to extend long and branched neurites, GI-LI-N cells did not. Both cell lines showed enhanced expression of phenotypical and biochemical markers of neural maturation. Moreover, retinoic acid (RA) had different effects on the two NB cell lines: on LAN-5 cells it acts as a differentiation-promoting agent, while on GI-LI-N cells it has an antiproliferative effect, driving them to apoptosis. RT-PCR experiments and immunoprecipitation assays showed a late but marked increase in the expression of alpha1, alpha2, alpha3, and beta1 chains after IFN-gamma+TNF treatment of LAN-5 cells, and only alpha1 and beta1 chains upon RA induction. Treatment with IFN-gamma+TNF induced GI-LI-N cells to show only a late and remarkable increase of alpha1/beta1 heterodimer; on the contrary, RA treatment caused a decrease in all integrin chains. These changes are accompanied in differentiated cells by substantial increases in cell attachment to all purified ECM components tested and an increase of neurite-bearing cells and of average neurite length. In conclusion, these findings indicate a close correlation between up-regulation of integrins and neuronal morphogenesis.

Journal Article↗
PubMed1996

Increase of metaiodobenzylguanidine uptake and intracellular half-life during differentiation of human neuroblastoma cells.

Iodine-labelled metaiodobenzylguanidine (MIBG) is a radiopharmaceutical used for diagnostic imaging and targeted radiotherapy of neuroendocrine tumors. We previously reported that the ability of a neuroblastoma (NB) cell line, LAN-5, to accumulate MIBG was powerfully stimulated by interferon-gamma (IFN-gamma), a well-known NB differentiation-promoting agent. To extend the above findings, we have investigated 5 NB cell lines for their ability to accumulate 125I-MIBG in basal conditions or after various combinations of differentiative stimuli. Our results show that association of IFN-gamma and tumor necrosis factor-alpha boosts MIBG uptake in the early times of incubation in LAN-5 and GI-LI-N cells, while both SK-N-SH and SK-N-BE(2)c cells are strongly stimulated by co-treatment with IFN-gamma and all-trans retinoic acid. Moreover, although only LAN-5 and GI-LI-N cells are sensitive to IFN-gamma alone, the combination of IFN-gamma and IFN-alpha causes a synergistic increase in MIBG uptake in all the NB cell lines tested. From experiments on MIBG release we conclude that no intracellular storage within specialized structures took place during differentiation. The observed enhancement in MIBG accumulation results from an increased uptake of the drug only. This conclusion was confirmed by analyzing MIBG-transporter gene expression, which was increased in cells subjected differentiative regimens. According to these findings, inducing differentiation of NB cells in vitro appears to improve their MIBG incorporation ability powerfully.

3-Iodobenzylguanidine↗
PubMed1996

Molecular characterization of the t(2;5) (p23; q35) translocation in anaplastic large cell lymphoma (Ki-1) and Hodgkin's disease.

The precise cellular origin and the pathogenetic mechanism(s) leading to the neoplastic transformation of anaplastic large cell lymphoma (ALCL) and the Reed-Sternberg cell of Hodgkin's disease (HD) remains largely uncertain. Classical cytogenetic analysis has shown a unique translocation involving bands 2p23 and 5q35 bands in a variable number of ALCLs. It has been recently shown that the nucleophosmin/B23 (NPM) gene (5q35) and a novel anaplastic lymphoma kinase (ALK; 2p23) are the fused genes of t(2;5). To investigate the presence and the precise frequency of NPM-ALK gene products among ALCL and HD cases, a large and well-characterized panel of ALCL (n = 49) and HD (n = 72) cases was studied using multiple strategies including reverse transcriptase-polymerase chain reaction (RT-PCR), Southern blot analysis, and immunohistochemistry. Overall, 6 (3 T and 3 null) of 49 ALCL and 3 (2 nodular sclerosis and 1 mixed cellularity) of 72 HD showed the presence of NPM-ALK transcripts by RT-PCR. NPM-ALK gene rearrangements were detected in all RT-PCR, NPM-ALK-positive ALCL by Southern blot analysis. Furthermore, in all the available cases we were able to show the presence of ALK-related protein using a specific polyclonal antiserum recognizing the cytoplasmic domain of ALK by immunohistochemistry. Our data show that NPM-ALK gene transcripts are identified in a subpopulation of ALCL, almost exclusively in T or null cell in origin, and in rare cases of HD. These findings show that some HD may be closely related to ALCL, giving us new insights on the pathogenesis and possibly biologic evolution of HD.

Anaplastic Lymphoma Kinase↗
PubMed1995

Induction of 2.5 OAS gene expression and activity is not sufficient for IFN-gamma-induced neuroblastoma cell differentiation.

We showed earlier that interferon-gamma is a powerful inducer of differentiation of human neuroblastoma (NB) cells. Although 2',5' oligo-adenylate synthetase (2,5 OAS) may play a role in mediating the anti-proliferative and/or differentiative effects of interferons (IFNs), direct evidence is lacking. We have investigated gene and protein expression of the 4 different 2,5 OAS isoforms and their cumulative enzymatic activity in a previously characterized IFN-gamma-sensitive human NB cell line, LAN-5. Analysis of total and poly(A)+ RNA by Northern blot and RT-PCR indicated that expression of the mRNA coding for the 40-, 46-and 69-kDa isoforms was induced in a time- and dose-dependent manner, reaching a maximum after a 36-hr treatment with 1000 IU/ml of IFN-gamma. In the absence of treatment, only the mRNA for the 69-kDa isoform was detectable by RT-PCR. Inhibition of transcription with actinomycin D showed that 2,5 OAS mRNA was quite stable, with a half-life of about 4 hr. With respect to the protein content, no 2,5 OAS isoform was present in proliferating LAN-5 cells; following IFN-gamma treatment, the 100-, 69-and 46-kDa isoforms became detectable. Accordingly, 2,5 OAS enzymatic activity, virtually undetectable in untreated LAN-5 cells, increased up to 132 pmol oligoadenylate/micrograms protein/hr after 48 hr of treatment, then slowly decreased, remaining detectable up to 96 hr. However, the 2,5 OAS proteins required an exogenous activation by synthetic dsRNA to exert enzymatic activity. It is therefore conceivable that they do not play a biological role in NB cell functions. Moreover, an increase in 2,5 OAS enzymatic activity was also observed in NB cells resistant to the differentiation-promoting activity of IFN-gamma, further suggesting that 2,5 OAS induction was not sufficient to trigger IFN-gamma-dependent neuronal maturation. Furthermore, other differentiation-inducing agents, such as retinoic acid and cytosine arabinoside, or complete proliferative arrest produced by serum deprivation, failed to enhance 2,5 OAS activity, thus indicating that the 2,5 OAS system is not directly involved in mediating other differentiative pathways of NB cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1995

Differential effects of N-(4-hydroxyphenyl)retinamide and retinoic acid on neuroblastoma cells: apoptosis versus differentiation.

Retinoids exert various important biological effects in the control of normal growth, differentiation, and fetal development. While retinoic acid (RA) has entered clinical trials as a differentiation-promoting agent, it is only recently that the synthetic retinoid N-(4-hydroxyphenyl)retinamide (HPR) has been shown to be of potential clinical interest in cancer chemoprevention and treatment. Since thus far no data exist on the effects of HPR on neural crest cell-derived tumors, we have examined its in vitro effects on neuroblastoma (NB) cell lines and found that at relevant pharmacological concentrations it induces a dose-dependent growth inhibition. The antiproliferative effects of HPR were, in six of six cell lines tested, drastically more potent that those induced by an equimolar dose of RA. Time course growth analysis showed that HPR at 3 x 10(-6) M induces a very rapid (24-72 h) fall in thymidine uptake (> 90%), whereas at 3 x 10(-7) M it exhibits cytostatic effects. In contrast to RA, HPR did not show morphological changes typical of NB cell maturation nor did it induce the expression of any cytoskeletal protein associated with neuronal differentiation. DNA flow cytofluorimetric analysis revealed that HPR did not induce an arrest in a specific phase of the cell cycle while triggering apoptosis. This phenomenon was evidenced both by the visualization of "DNA ladders" on gel electrophoresis and by a quantitative assay for evaluating programmed cell death based upon the labeling of DNA breaks with tritiated thymidine. With the latter method, apoptotic cells were detectable as early as 3-6 h after treatment of NB cells with 10(-5) M HPR, while more than 50% of cells were apoptotic by 24-72 h following exposure to 3 x 10(-6) M HPR. In contrast, RA induced a low rate of apoptosis in NB cells only after 3-5 days. Time lapse photomicroscopy showed that NB cells treated with HPR underwent a death process highly reminiscent of apoptosis, with progressive condensation of the cytoplasm around the nucleus and intense cell shrinkage. The cells then rounded up and detached from the plate. Furthermore, propidium iodide staining of the DNA showed that a high proportion of cells treated with HPR displayed a small and brightly staining nucleus; chromatin appeared aggregated into dense masses in the nuclear periphery, a typical feature of apoptotic cells. In conclusion, our study demonstrates that contrary to the differentiation-promoting activity of RA, HPR dramatically suppresses NB cell growth by inducing programmed cell death.(ABSTRACT TRUNCATED AT 400 WORDS)

Apoptosis↗
PubMed1995

Hairy cell leukemia without splenomegaly nor myelofibrosis in a patient with gastric adenocarcinoma: early phase of the disease or a variant?

The first case of patient affected both by gastric carcinoma and hairy cell leukemia (HCL) is reported. From a clinical standpoint, this 54-year old man presented with striking leukopenia without splenomegaly. From a morphological point of view, the infiltration by leukemic cells occurred in the hypoplasic areas of the bone marrow biopsy (BMB) without increase in reticulin fibers. From these observations the authors deduce that: 1) BMB in many cases is the only morphologic tool for diagnosis and prognosis of HCL; 2) probably the "hypoplasic" variant of HCL will become more frequent, because of the increasing indication to BMB in course of pancytopenia, even in absence of splenomegaly; 3) our case is probably related more to an early phase of the disease than to a distinct variant. In addition, we propose that the co-existence of an aggressive solid tumor and HCL could be related to the immunosuppressive action by hairy cells.

Adenocarcinoma↗
PubMed1995

Bone marrow biopsy in 50 AIDS patients: a diagnostic approach.

Fifty bone marrow biopsies (BMB) and aspirates (BMA) of AIDS patients were examined to identify possible morphologic signs of HIV infection. The following parameters were evaluated: 1) cellularity; 2) myelo-erythroid ratio (M:E); 3) morphology of haemopoietic lineages; 4)plasmacell amount; 5) lymphocytes amount; 6)reticulin content. Hypercellularity, increase in number and morphological alterations of megakaryocytes, raised reticulin content, mild plasmacytosis and frequent presence of reactive lymphoid aggregates are features suggestive, thought not diagnostic, for HIV infection on BMB. It results that bone marrow morphologic examination in HIV-positive patients plays a distinctive role in ruling out the presence of opportunistic infections or associated neoplasias (haematologic or not) and in contributing to clarify the significance of a peripheral pancytopenia.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Synergistic differentiation-promoting activity of interferon gamma and tumor necrosis factor-alpha: role of receptor regulation on human neuroblasts.

BACKGROUND: Interferon gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF) synergize in inducing human neuroblastoma cells to differentiate terminally in vitro into mature nonproliferating neurons. The mechanisms by which this synergistic activity takes place are still obscure. PURPOSE: To understand the basis of IFN-gamma-TNF synergism, we investigated the constitutive equipment of receptors to IFN-gamma and TNF in two human neuroblastoma cell lines (i.e., LAN-5 and GI-LI-N) and their quantitative and functional variations following treatment with IFN-gamma or TNF. METHODS: IFN-gamma receptors and TNF receptors were assessed and functionally characterized by radioreceptor-binding assay before and after treatment of the cells with IFN-gamma or TNF. The TNF receptor subtypes were identified by the reverse transcriptase-polymerase chain reaction, chemical cross-linking of receptors to iodinated TNF, and inhibition of TNF binding by type-specific anti-TNF receptor monoclonal antibodies. The effects of cytokines on cell differentiation were assessed by thymidine incorporation inhibition and morphologic maturation. RESULTS: No quantitative or functional modification of IFN-gamma receptors was observed in TNF-treated cells. However, after treatment with IFN-gamma, TNF receptor numbers were enhanced to a different extent in both cell lines. The two neuroblastoma cell lines expressed, both constitutively and after IFN-gamma induction, only one species of TNF receptor, i.e., the p80 form in LAN-5 and the p60 form in GI-LI-N. Sequential treatment with IFN-gamma followed by TNF, but not in the opposite order, could reproduce the early effects of differentiation in neuroblastoma cells, supporting a role for TNF receptor up-regulation as a basis for the cooperation between the two cytokines. CONCLUSION: The results strongly suggest that receptor regulation can be at least one mechanism by which IFN-gamma and TNF exert their synergistic effects. Moreover, it appears that the two TNF receptor types are redundant in signaling neuroblastoma cell differentiation. IMPLICATIONS: Our findings can provide a guideline for a rational design of experimental differentiation-based therapeutic protocols in patients with neuroblastoma.

Base Sequence↗