Biomedical subjects

S Ferrari

Publications and source records attributed to S Ferrari.

At least 55 records · Page 3Linked to original sources

PubMed2000

Degradation of B-Myb by ubiquitin-mediated proteolysis: involvement of the Cdc34-SCF(p45Skp2) pathway.

B-Myb, a highly conserved member of the Myb oncoprotein family, is a 110 kDa sequence-specific DNA binding protein expressed in virtually all proliferating cells. B-myb expression reaches its maximum at the G1/S phase boundary and during the S phase of the cell cycle. We have previously shown that B-Myb activity is cell cycle regulated and it is controlled by the antagonistic effects of cyclin D1 and A. Here we show that ectopic expression of cyclin A causes a pronounced reduction of B-Myb protein level. We provide evidence that in addition to triggering B-Myb activity an important effect of cyclin A is to facilitate multiple ubiquitination of B-Myb. The C-terminal domain of B-Myb is of key importance in mediating this effect of cyclin A. Contrary to full-length B-Myb, a C-terminal deletion mutant displays activity irrespective of cyclin A expression, does not undergo ubiquitination, and its half-life is not affected by cyclin A. Ectopic expression of either Cdc34 or the F-box protein p45Skp2, respectively the E2 and E3 components of a ubiquitination pathway that regulates the G1/S transition, accelerates degradation of B-Myb. We show that B-Myb physically and functionally interacts with components of the Cdc34-SCFp45Skp2 ubiquitin pathway and propose that B-Myb degradation may be required for controlling the correct alternation of events during progression through the cell division cycle. Oncogene (2000).

Anaphase-Promoting Complex-Cyclosome↗

PubMed2000

Two histone fold proteins, CHRAC-14 and CHRAC-16, are developmentally regulated subunits of chromatin accessibility complex (CHRAC).

The ISWI ATPase of Drosophila is a molecular engine that can drive a range of nucleosome remodelling reactions in vitro. ISWI is important for cell viability, developmental gene expression and chromosome structure. It interacts with other proteins to form several distinct nucleosome remodelling machines. The chromatin accessibility complex (CHRAC) is a biochemical entity containing ISWI in association with several other proteins. Here we report on the identification of the two smallest CHRAC subunits, CHRAC-14 and CHRAC-16. They contain histone fold domains most closely related to those found in sequence-specific transcription factors NF-YB and NF-YC, respectively. CHRAC-14 and CHRAC-16 interact directly with each other as well as with ISWI, and are associated with functionally active CHRAC. The developmental expression profiles of both subunits suggest specialized roles in chromatin remodelling reactions in the early embryo for both histone fold subunits.

Adenosine Triphosphatases↗

PubMed2000

PTK787/ZK 222584, a novel and potent inhibitor of vascular endothelial growth factor receptor tyrosine kinases, impairs vascular endothelial growth factor-induced responses and tumor growth after oral administration.

PTK787/ZK 222584 (1-[4-chloroanilino]-4-[4-pyridylmethyl] phthalazine succinate) is a potent inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, active in the submicromolar range. It also inhibits other class III kinases, such as the platelet-derived growth factor (PDGF) receptor beta tyrosine kinase, c-Kit, and c-Fms, but at higher concentrations. It is not active against kinases from other receptor families, such as epidermal growth factor receptor, fibroblast growth factor receptor-1, c-Met, and Tie-2, or intracellular kinases such as c-Src, c-Abl, and protein kinase C-alpha. PTK787/ZK 222584 inhibits VEGF-induced autophosphorylation of kinase insert domain-containing receptor (KDR), endothelial cell proliferation, migration, and survival in the nanomolar range in cell-based assays. In concentrations up to 1 microM, PTK787/ZK 222584 does not have any cytotoxic or antiproliferative effect on cells that do not express VEGF receptors. After oral dosing (50 mg/kg) to mice, plasma concentrations of PTK787/ZK 222584 remain above 1 microM for more than 8 h. PTK787/ZK 222584 induces dose-dependent inhibition of VEGF and PDGF-induced angiogenesis in a growth factor implant model, as well as a tumor cell-driven angiogenesis model after once-daily oral dosing (25-100 mg/kg). In the same dose range, it also inhibits the growth of several human carcinomas, grown s.c. in nude mice, as well as a murine renal carcinoma and its metastases in a syngeneic, orthotopic model. Histological examination of tumors revealed inhibition of microvessel formation in the interior of the tumor. PTK787/ZK 222584 is very well tolerated and does not impair wound healing. It also does not have any significant effects on circulating blood cells or bone marrow leukocytes as a single agent or impair hematopoetic recovery after concomitant cytotoxic anti-cancer agent challenge. This novel compound has therapeutic potential for the treatment of solid tumors and other diseases where angiogenesis plays an important role.

Angiogenesis Inhibitors↗

PubMed2000

Regulation of B-Myb activity by cyclin D1.

Evidence obtained during recent years suggests that B-Myb, a highly conserved member of the Myb transcription factor family, plays a key role in cell proliferation. We have shown previously that the activity of B-Myb is stimulated by cyclin A/Cdk2-dependent phosphorylation of the carboxyl-terminus of B-Myb. We have now investigated in more detail the effect of other cyclins on B-Myb. Here, we show that cyclin D1, in contrast to cyclin A, strongly inhibits the activity of B-Myb. This inhibitory effect does not involve increased phosphorylation of B-Myb but seems to rely on the formation of a specific complex of B-Myb and cyclin D1. Our work identifies B-Myb as an interacting partner for cyclin D1 and suggest that the activity of B-Myb during the cell cycle is controlled by the antagonistic effects of cyclin D1 and A. The results presented here suggest a more general role of cyclin D1 as regulator of transcription in addition to the known effect on RB phosphorylation.

3T3 Cells↗

PubMed2000

Interleukin-2 induces cell cycle perturbations leading to cell growth inhibition and death in malignant mesothelioma cells in vitro.

Previous report indicated that Interleukin-2 (IL-2) is able to inhibit the growth of IL-2-receptor-positive cancer cell lines without any involvement of the immune system, through IL-2-induced alterations of the cell cycle kinetics. In this study we provide evidence that IL-2 exerts anti-proliferative effect on three human malignant mesothelioma (MMe) cells in vitro, while no effects were observed on normal human mesothelial cell (HMC) primary cultures. The growth inhibitory effect of IL-2 on neoplastic cells appeared to depend on the baseline proliferative status of these cells. Indeed, in highly proliferating MMe cells, we observed a reduction of malignant cells in the S-phase of the cell cycle, with an accumulation in G0/G1, followed by apotosis for longer incubations or exposure to higher doses. On the contrary, in MMe cells proliferating at lower rate, IL-2 induces only a late cytotoxic effect, leading to apoptosis, without significantly affecting the cell cycle. IL-2Rbeta mRNA was detectable by RT-PCR in all MMe cells, IL-2Ralpha mRNA in one only out the three assayed and IL-2Rgamma mRNA in none. In addition, mRNA specific for the IL-2Rbeta-associated Jak-1 tyrosine kinase was expressed in all MMe cell lines, further suggesting that IL-2Rbeta may play a role in the observed effects. Very low, albeit detectable, levels of IL-2Rbeta chain appeared to be expressed at the cell surface of MMe cells by indirect immunofluorescence and FACS analyses. Finally, Ca(++) fluxes were rapidly induced when MMe cells were exposed to exogenous IL-2.

Apoptosis↗

PubMed2000

Granisetron, tropisetron, and ondansetron in the prevention of acute emesis induced by a combination of cisplatin-Adriamycin and by high-dose ifosfamide delivered in multiple-day continuous infusions.

The antiemetic efficacy of granisetron, ondansetron and tropisetron was evaluated in patients treated with cisplatin-Adriamycin (CDP/ADM) and ifosfamide (IFO) by continuous infusion (CI). In all, 90 patients with osteosarcoma were randomly assigned to receive granisetron (2 mg/m2), or ondansetron (5.3 mg/m2), or tropisetron (3.3 mg/m2) plus dexamethasone 8 mg/m2. Chemotherapy consisted of CDP (120 mg/m2, 48-h CI) followed by ADM (75 mg/m2, 24-h CI) and then, in the second cycle, delivered 3 weeks later, IFO 15 g/m2 (120-h CI). Complete protection (CP) from emesis was obtained on 59% of the 717 days of treatment, without significant differences among the three study drugs. A significantly higher rate of CP was obtained during chemotherapy with IFO than with CDP/ ADM (69% vs 44%; P<0.0001). The rate of CP declined from the first to the last day of treatment for both CDP/ADM (61% to 27%, P<0.0001) and IFO (95% to 43%) cycles (P<0.0001). When CDP/ ADM and IFO are delivered on multiple days by CI, granisetron, ondansetron and tropisetron have the same antiemetic efficacy, which declines from the first day onward through successive days.

Acute Disease↗

PubMed2000

Peripheral-type benzodiazepine receptors in human blood cells of patients affected by migraine without aura.

The kinetic parameters at equilibrium of peripheral benzodiazepine receptors in platelets, lymphocytes and granulocytes of 15 patients affected by migraine without aura were tested using [3H]PK 11195, a specific radioligand for this receptor and compared with the same number of healthy controls: a statistically significant increase (platelets 212%, lymphocytes 203%, granulocytes 171%, as absolute percentage) in the maximal number of binding sites (B(max)) in all three patient samples, compared with healthy controls was detected; on the contrary, the values of the dissociation constant (K(d)) at equilibrium do not show any statistically significant variations between the two groups. These data further confirm the presence of peripheral biochemical alterations in migraine without aura. As peripheral benzodiazepine receptors appear to be involved in the regulation of the mitochondrial respiratory chain, the observed increase in B(max) might be related to the mitochondrial anomalies found in migraine disorders.

Adult↗

PubMed2000

BRCA1 mutations and clinicopathological features in a sample of Italian women with early-onset breast cancer.

Breast cancer in young women is uncommon and often presents with unfavourable biopathological features. Although early age at onset could suggest a genetic susceptibility to cancer, the appropriateness of BRCA1 testing for women with early-onset breast cancer and modest family history (FH) is controversial. 40 Women diagnosed with breast cancer at the age of 35 years or less, unselected for FH, were screened for germ line BRCA1 mutations by automated sequencing of exons 2, 5, 6, 11, 13 and 20. Overall, deleterious mutations were evidenced in 6 (15%) patients. With regard to FH, mutations were detected in 14%, 11% and 29% of women with none, weak and strong FH, respectively. Large tumour size, grade 3, lack of oestrogen receptors and high proliferation rate were significantly more common in mutation carriers (MC). Our data support both the appropriateness of testing young breast cancer patients and the frequency of unfavourable features in BRCA1-related breast cancer. It is hypothesised that BRCA1 mutations partially justify the high rate of aggressive breast cancer in young patients and that combining age and breast cancer phenotype could help to identify probable MC.

Adult↗

PubMed2000

Efficient gene transfer to airway epithelium using recombinant Sendai virus.

Clinical studies of gene therapy for cystic fibrosis (CF) suggest that the key problem is the efficiency of gene transfer to the airway epithelium. The availability of relevant vector receptors, the transient contact time between vector and epithelium, and the barrier function of airway mucus contribute significantly to this problem. We have recently developed recombinant Sendai virus (SeV) as a new gene transfer agent. Here we show that SeV produces efficient transfection throughout the respiratory tract of both mice and ferrets in vivo, as well as in freshly obtained human nasal epithelial cells in vitro. Gene transfer efficiency was several log orders greater than with cationic liposomes or adenovirus. Even very brief contact time was sufficient to produce this effect, and levels of expression were not significantly reduced by airway mucus. Our investigations suggest that SeV may provide a useful new vector for airway gene transfer.

Adenoviridae↗

PubMed2000

Expression of myelin basic protein (MBP) epitopes in human non-neural cells revealed by two anti-MBP IgM monoclonal antibodies.

Two monoclonal antibodies (1H6.2 and 45.30) were raised against MBP purified from human brain under experimental conditions that allowed MBP to retain binding to surrounding myelin lipids (human lipid-bound MBP (hLB-MBP)). 1H6.2 and 45.30 MoAbs were selected on the basis of their different binding properties to: hLB-MBP, human lipid-free-MBP (hLF-MBP) and bovine lipid-free-MBP (bLF-MBP). Although the isotype of both MoAbs was IgM, their specificity, as tested in ELISA assays against chemical haptens and unrelated protein antigens, was restricted to MBP. 1H6.2 and 45.30 MoAbs stained MBP from human brain white matter tissue extracts, as well as bLF-MBP, in Western blot assays. Both MoAbs stained oligodendrocytes and myelin in immunohistochemical analysis of white matter from human brain. Tissue sections from human peripheral nerves were labelled by 1H6.2 only, however, demonstrating that the MoAbs recognize two different epitopes. Epitopes recognized by 1H6.2 and 45.30 MoAbs were also expressed by a wide array of human non-neural cells of either normal or pathological origin, as evidenced by cytofluorimetric assays. In particular, MBP epitopes (MEs) were expressed by lymphoid cells as well as by cells which play a pivotal role in immune homeostasis and in the immune response, such as thymic epithelial cells and professional antigen-presenting cells. Both MoAbs were efficiently internalized by cells from a human B cell line, suggesting trafficking of MEs along the endocytic pathways. These findings support hypotheses regarding the role of MEs expressed by non-neural cells in establishing self-tolerance and/or in triggering the immune response against MBP antigen.

3T3 Cells↗

PubMed2000

Neoadjuvant chemotherapy for Ewing's sarcoma of bone in patients older than thirty-nine years.

The aim of this study was to determine whether the behaviour of Ewing's sarcoma of bone in adult patients is the same as that observed in children and adolescents. We reviewed the clinical features and outcomes of 23 patients over the age of 39 (17 males, 6 females) who had been treated with neoadjuvant chemotherapy between 1983 and 1995 at our institution. The most common primary sites of tumor were the extremities (16 cases); tumor volume was more than 100 ml in 17 patients, and elevated serum LDH levels were found in 6 cases. The local treatment was surgery in 8 cases, surgery plus radiotherapy in 8, and radiotherapy alone in 7 cases. Chemotherapy comprised a 4-drug regimen in 10 patients, while the other 13 patients received 6 drugs. At a follow-up of 8.8 years (3.5-15) 13 patients remained continuously free of disease and 10 relapsed. The 5-year disease-free survival and overall survival rates were 53% and 59%, respectively. Clinical features, dose intensity, and toxicity of chemotherapy, as well as the outcome of these 23 patients were found to be exactly comparable to the findings observed in 327 patients younger than 40 years treated at our institution in the same period, with the same therapy. We conclude that Ewing's sarcoma of bone in adults is no different from that occurring in children, and we therefore recommend the inclusion of all adult patients in multidisciplinary treatment trials of this tumor.

Adult↗

PubMed2000

Prognostic factors in nonmetastatic Ewing's sarcoma of bone treated with adjuvant chemotherapy: analysis of 359 patients at the Istituto Ortopedico Rizzoli.

PURPOSE: The identification of prognostic factors in patients with nonmetastatic Ewing's sarcoma could allow the use of risk-adapted therapeutic strategies of treatment. PATIENTS AND METHODS: Data on 359 patients with nonmetastatic Ewing's sarcoma of bone treated at a single institution between January 1979 and April 1995 were retrospectively considered. The influence of clinical, hematologic, therapeutic, and histologic parameters on event-free survival was assessed. RESULTS: By univariate analysis, the following features were found to be associated with a poor prognosis: male sex (P <.02), age older than 12 years (P <.006), fever (P <.0001), anemia (P <.0025), high serum lactate dehydrogenase (LDH) level (P <.0001), axial location (P <.04), radiation therapy only for local control (P <.009), type of chemotherapy regimen (P <.0001), and poor chemotherapy-induced necrosis (P <.001). After multivariate analysis, the adverse independent prognostic factors were male sex (P <.04), age older than 12 years (P <.001), fever (P <.0002), anemia (P <.02), high serum LDH level (P <.0003), axial location (P <.02), and type of chemotherapy regimen (P <.0003). When the multivariate analysis was restricted to surgically treated patients, the adverse independent prognostic factors were poor chemotherapy-induced necrosis (P <.0001), fever (P <.015), anemia (P <.02), and high serum LDH level (P <.025). CONCLUSION: The prognosis in cases of nonmetastatic Ewing's sarcoma is influenced by many different clinical and hematologic variables, all of which are to be considered when patients are being stratified according to the risk of relapse. In surgically treated patients, the most important prognostic factor is chemotherapy-induced necrosis.

Adolescent↗

PubMed2000

Neoadjuvant chemotherapy for peripheral malignant neuroectodermal tumor of bone: recent experience at the istituto rizzoli.

PURPOSE: The results achieved in 44 patients with nonmetastatic peripheral neuroectodermal tumor (PNET) of bone treated with neoadjuvant chemotherapy are reported. PATIENTS AND METHODS: A six-drug regimen of chemotherapy (vincristine, doxorubicin, dactinomycin, cyclophosphamide, ifosfamide, and etoposide) was administered to all patients. Local treatment consisted of surgery in 20 patients, surgery followed by radiotherapy in 13, and radiotherapy only in 11. RESULTS: At a mean follow-up of 4.5 years (range, 2 to 7 years), 23 patients (52%) remain event-free, 20 have relapsed (45%), and one has died of chemotherapy-related toxicity. The 5-year event-free survival and overall survival were 54.2% and 62.7%, respectively. To assess the prognostic significance of neural differentiation in the family of Ewing's sarcoma, these results have been compared with the outcomes of 138 concomitant patients with typical Ewing's sarcoma (TES) who were treated according to the same protocol. Of these, 103 (75%) remained continuously event-free, 34 (24%) relapsed, and one died of chemotherapy-related toxicity. It follows that PNET patients treated with this chemotherapy regimen have a significantly worse prognosis than typical ES patients (5-year event-free survival, 54.2% v 70.6%, P <.012; 5-year overall survival, 62.7% v 78.3%, P <.002). CONCLUSION: The authors conclude that studies into new adjuvant therapy for Ewing's sarcoma modulated according to risk of relapse should also consider neural differentiation as a risk factor.

Adolescent↗

PubMed2000

Comparison between genotype and phenotype identifies a high-risk population carrying BRCA1 mutations.

Hereditary breast carcinomas constitute about 10% of all malignant mammary tumors, but the selection criteria to identify a high-risk population carrying BRCA1 mutations are not yet well-defined. We have collected 51 pedigrees of familial breast cancer, 16 pedigrees of familial breast and ovarian cancer, and 30 cases of early-onset breast cancer (<35 years of age) without any family history of breast cancer. The index cases of the 97 selected families were further subdivided into three groups based on histopathological parameters: group A (n = 19) was characterized by tumor grade III, negative estrogen and progesterone receptors, and high proliferative rate; group B (n = 20) was characterized by grade I-II tumors, positive hormonal receptors, and low proliferative rate; and group C (n = 58) was not homogeneous for the histopathological criteria. The aim of our study was to evaluate, in patients with a family history of breast cancer or with early diagnosis of breast cancer, the incidence of BRCA1 mutation on the basis of tumor phenotype. We found the highest rate of BRCA1 mutations in group A (53%), and low frequencies in groups B (5%) and C (0%). Our data strongly indicate that an aggressive tumor phenotype in patients with a positive family history or early diagnosis identifies a population with high probability of carrying BRCA1 mutations. Genes Chromosomes Cancer 27:130-135, 2000.

Adult↗

PubMed2000

[The use of erythropoietin alpha in programs of high-dose chemotherapy].

Epoetin (Epo) is physiologically present in the human body, stimulating erythropoiesis from bone marrow. Anemia is observed in cancer patients submitted to high-dose chemotherapy (HDCT), mainly caused by myelosuppression. Epoetin alfa has been widely used to treat the anemia that develops in the HDCT setting. Controlled studies in patients with hematologic malignancies or solid tumors who received Epo following HDCT have shown a decreased red blood cell transfusion requirement at least in patients receiving allogeneic bone marrow transplantation (BMT), while results in patients receiving autologous BMT have been disappointing. The administration of Epo before HDCT, in a period when bone marrow is still responsive to growth factors, may represent a new strategy aimed at decreasing the degree of anemia in these patients. A combination of granulocyte-colony stimulating factor and Epo has proved to be effective in mobilizing stem cell and committed myeloid/erythroid precursors.

Anemia↗

PubMed1999

Polyethylenimine shows properties of interest for cystic fibrosis gene therapy.

Before being considered for a cystic fibrosis (CF) gene therapy trial, any gene delivery agent must be able to show that it produces low levels of toxicity as well as being able to protect the DNA from nuclease degradation. Here we show that complexes of linear polyethylenimine (L-PEI) and DNA can repeatedly be administered to animals (up to 21 consecutive days) without eliciting an immune response against PEI/DNA particles or inducing toxic side effects due to accumulation of PEI in the lungs. However, the host response to the exogenous protein resulted in some decrease of expression. PEI-mediated transfection was unaffected by treatment of the complexes with DNase (frequently used to reduce the viscosity of lung secretions in CF patients). Taken together, these properties make L-PEI a valuable vector for gene therapy of CF.

Cystic Fibrosis↗

PubMed1999

Glutamatergic synaptic responses and long-term potentiation are impaired in the CA1 hippocampal area of calbindin D(28k)-deficient mice.

The contribution of the cytosolic calcium binding protein calbindin D(28K) (CaBP) to glutamatergic neurotransmission and synaptic plasticity was investigated in hippocampal CA1 area of wild-type and antisense transgenic CaBP-deficient mice, with the use of extracellular recordings in the ex vivo slice preparation. The amplitude of non-N-methyl-D-aspartate receptor (non-NMDAr)-mediated extracellular field excitatory postsynaptic potentials (fEPSPs) recorded in control medium was significantly greater in CaBP-deficient mice, whereas the afferent fiber volley was not affected. In contrast, the amplitude of NMDAr-mediated fEPSPs isolated in a magnesium-free medium after blockade of non-NMDAr and GABAergic receptors was significantly depressed in these animals. No alteration in the magnitude of paired-pulse facilitation was found, indicating that the presynaptic calcium mechanisms controlling glutamate release were not altered in CaBP-deficient mice. The magnitude and time course of the short-term potentiation (STP) of fEPSPs induced by a 30 Hz conditioning stimulation, which was blocked by the NMDAr antagonist 2-amino-5-phosphonovalerate acid (2-APV), was not impaired in the transgenic mice, whereas long-term potentiation (LTP) induced by a 100 Hz tetanus was not maintained. The long-term depression (LTD) induced by low-frequency stimulation (1 Hz, 15 min) in the presence of the GABA antagonist bicuculline was not altered. These results argue for a contribution of CaBP to the mechanisms responsible for the maintenance of long-term synaptic potentiation, at least in part by modulating the activation of NMDA receptors.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1999

Proteasomal degradation and N-terminal protease resistance of the codon 145 mutant prion protein.

An amber mutation at codon 145 (Y145stop) of the prion protein gene results in a variant of an inherited human prion disease named Gerstmann-Sträussler-Scheinker syndrome. The characteristic features of this disorder include amyloid deposits of prion protein in cerebral parenchyma and vessels. We have studied the biosynthesis and processing of the prion protein containing the Y145stop mutation (PrP(145)) in transfected human neuroblastoma cells in an attempt to clarify the effect of the mutation on the metabolism of PrP(145) and to gain insight into the underlying pathogenetic mechanism. Our results demonstrate that 1) a significant proportion of PrP(145) is not processed post-translationally and retains the N-terminal signal peptide, 2) most PrP(145) is degraded very rapidly by the proteasome-mediated pathway, 3) blockage of proteasomal degradation results in intracellular accumulation of PrP(145), 4) most of the accumulated PrP(145) is detergent-insoluble, and both the detergent-soluble and -insoluble fractions are resistant to mild proteinase K (PK) treatment, suggesting that PK resistance is not simply because of aggregation. The present study demonstrates for the first time that a mutant prion protein is degraded through the proteasomal pathway and acquires PK-resistance if degradation is impaired.

Cell Compartmentation↗