PubMed Health⌕ Search

Biomedical subjects

S Ferrari

Publications and source records attributed to S Ferrari.

At least 37 records · Page 2Linked to original sources
PubMed1991

Mitogen-activated 70K S6 kinase. Identification of in vitro 40 S ribosomal S6 phosphorylation sites.

Recently we purified and cloned the mitogen/oncogene-activated Mr 70,000 (70K) S6 kinase from the livers of rats treated with cycloheximide (Kozma, S. C., Lane, H. A., Ferrari, S., Luther, H., Siegmann, M., and Thomas, G. (1989) EMBO J. 8, 4125-4132; Kozma, S. C., Ferrari, S., Bassand, P., Siegmann, M., Totty, N., and Thomas, G. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 7365-7369). Prior to determining the ability of this kinase to phosphorylate the same sites observed in S6 in vivo, we established the effects of different cations and autophosphorylation on kinase activity. The results show that the 70K S6 kinase is dependent on Mg2+ for activity and that this requirement cannot be substituted for by Mn2+. Furthermore, 50-fold lower concentrations of Mn2+ block the effect of Mg2+ on the kinase. This effect is not limited to Mn2+ but can be substituted for by a number of cations, with Zn2+ being the most potent inhibitor, IC50 approximately 2 microM. In the presence of optimum Mg2+ concentrations the enzyme incorporates an average of 1.2 mol of phosphate/mol of kinase and an average of 3.7 mol of phosphate/mol of S6. The autophosphorylation reaction appears to be intramolecular and leads to a 25% reduction in kinase activity toward S6. In the case of S6 all of the sites of phosphorylation are found to reside in a 19-amino acid peptide at the carboxyl end of the protein. Four of these sites have been identified as Ser235, Ser236, Ser240, and Ser244, equivalent to four of the five sites previously observed in vivo (Krieg, J., Hofsteenge, J., and Thomas, G. (1988) J. Biol. Chem. 263, 11473-11477). A fifth mole of phosphate is incorporated at low stoichiometry into the peptide, but the amino acid which is phosphorylated cannot be unequivocally assigned. The low level of phosphorylation of the fifth site in vitro is discussed with regard to known results and to a potential three-dimensional model for the carboxyl terminus of S6.

Amino Acid Sequence↗
PubMed1991

Differential expression of transforming growth factor-beta 1 gene in 3LL metastatic variants.

In vitro and in vivo metastatic variants derived from Lewis lung carcinoma (3LL) were examined for the level of the expression of several growth-regulated genes, oncogenes, and transforming growth factor (TGF) genes. To determine whether the proliferative advantage of metastatic cells is due to an increased growth fraction of the cell population or to a deregulated expression of some growth-regulated genes, the mRNA levels of the S-phase-specific H3 histone gene were compared with that of some cell cycle-related genes (vimentin, calcyclin, c-myc, and p53) and oncogenes (Ki-ras, Ha-ras, c-sis, c-src, c-fes, and c-erb). In addition, to evaluate whether an autocrine pattern of cell proliferation is responsible for the proliferative advantage of metastatic cells, the level of the expression of TGF genes (alpha and beta 1) was studied. Northern blot analysis demonstrated that in 3LL metastatic variants the expression of TGF-alpha as well as the expression of all growth-regulated genes and oncogenes studied are similar. Only the TGF-beta 1 gene is expressed at higher levels in highly metastatic 3LL variants maintained either in vitro or in vivo. Data suggest that the proliferative advantage of 3LL metastatic cells is not due to a deregulated expression of some growth-regulated genes and oncogenes, but more likely is acquired through the expression of genes which might interfere with the ability of the tumor cells to escape hostile microenvironmental conditions.

Animals↗
PubMed1991

Human herpesvirus-6 in human lymphomas: identification of specific sequences in Hodgkin's lymphomas by polymerase chain reaction.

In search of a possible involvement of the human herpesvirus type 6 (HHV-6) in human Hodgkin's and non-Hodgkin's lymphomas, we studied the levels of anti-HHV-6 antibodies in the sera of 94 cases by an immunofluorescence assay, as well as the presence of HHV-6 sequences in the affected tissues of 66 cases by polymerase chain reaction, using one set of primer oligonucleotides. Our results showed higher anti-HHV-6 antibody titers in human lymphomas than in normal blood donors, but the difference is statistically significant only when normal donors are compared with Hodgkin's lymphoma cases. HHV-6 sequences were detected in 3 of 25 Hodgkin's lymphomas and 0 of the 41 cases of non-Hodgkin's lymphomas studied. The three cases positive for HHV-6 sequences belong to the nodular sclerosis-lymphocyte depletion histologic subtype and share remarkable similarities in their clinical features. Furthermore, Southern blot analysis of total genomic DNA obtained from the neoplastic tissues of two of the three patients showed the same restriction fragment length polymorphism. Our results suggest that: (1) the high level of anti-HHV-6 antibodies in Hodgkin's disease is due to an activation of the immune system not related to the presence of HHV-6 sequences in affected lymph nodes; (2) the presence of HHV-6 sequences in human lymphoid tissues is not a frequent event, rather it is in fact a very rare event in non-Hodgkin's lymphomas, while in Hodgkin's cases it is more frequent than previously reported on the basis of Southern blot analysis; and (3) the presence of HHV-6 sequences in Hodgkin's lymphomas may have a relation with the clinical presentation of the disease.

Adult↗
PubMed1991

The substrate specificity of protein kinases which phosphorylate the alpha subunit of eukaryotic initiation factor 2.

The alpha subunit of eukaryotic protein synthesis initiation factor (eIF-2 alpha) is phosphorylated at a single serine residue (Ser51) by two distinct and well-characterized protein kinase, the haem-controlled repressor (HCR) and the double-stranded RNA-activated inhibitor (dsI). The sequence adjacent to Ser51 is rich in basic residues (Ser51-Arg-Arg-Arg-Ile-Arg) suggesting that they may be important in the substrate specificity of the two kinases, as is the case for several other protein kinases. A number of proteins and synthetic peptides containing clusters of basic residues were tested as substrates for HCR and dsI. Both kinases were able to phosphorylate histones and protamines ar multiple sites as judged by two-dimensional mapping of the tryptic phosphopeptides. These data also showed that the specificities of the two kinases were different from one another and from the specificities of two other protein kinases which recognise basic residues, cAMP-dependent protein kinase and protein kinase C. In histones, HCR phosphorylated only serine residues while dsI phosphorylated serine and threonine. Based on phosphoamino acid analyses and gel filtration of tryptic fragments, dsI was capable of phosphorylating both 'sites' in clupeine Y1 and salmine A1, whereas HCR acted only on the N-terminal cluster of serines in these protamines. The specificities of HCR and dsI were further studied using synthetic peptides with differing configurations of basic residues. Both kinases phosphorylated peptides containing C-terminal clusters of arginines on the 'target' serine residue, provided that they were present at positions +3 and/or +4 relative to Ser51. However, peptides containing only N-terminal basic residues were poor and very poor substrates for dsI and HCR, respectively. These findings are consistent with the disposition of basic residues near the phosphorylation site in eIF-2 alpha and show that the specificities of HCR and dsI differ from other protein kinases whose specificities have been studied.

Amino Acid Sequence↗
PubMed1991

Erythrocyte and platelet fatty acids in retinitis pigmentosa.

The fatty acid composition and the glutathione-peroxidase activity (GSH-Px) of erythrocytes and platelets, the production of malondialdehyde (MDA) by platelets and the activity of the main systems of transmembrane cation transport in erythrocyte have been studied in 12 patients (5 males and 7 females) affected by retinitis pigmentosa (RP). A remarkable increase of saturated fatty acids (SFA), particularly of stearic acid (C18:0), has been noted in these patients. The reduced unsaturated/saturated fatty acids ratio (PUFA/SFA) observed in both erythrocytes and platelets and the decrease of arachidonic acid in platelets may depend by an active peroxidation process as documented by the increase of MDA. Platelet glutathione-peroxidase (PTL-GSH-PX) and plasma retinol were in the normal range, whereas erythrocyte glutathione-peroxidase (E-GSH-PX), MDA and plasma alfa-toco-pherol were increased in patients with RP. The activities of Na(+)-K+ pump, cotransport and Na(+)-Li+ countertransport were normal in RP erythrocytes.

Adult↗
PubMed1991

The role of lipophilicity in the inhibition of polymorphic cytochrome P450IID6 oxidation by beta-blocking agents in vitro.

The importance of lipophilicity as a determinant of the affinity of beta-adrenoceptor blocking agents for a specific human hepatic monooxygenase--cytochrome P450IID6 (responsible for the debrisoquine-type of oxidation polymorphism)--was investigated in vitro by estimating the inhibition constants of a series of compounds in a microsomal system with monitoring of the kinetics of dextromethorphan O-demethylation. Lipophilicity is a key predictor of the affinity of beta-blocking drugs for cytochrome P450IID6 and of their potential to cause specific competitive drug interactions, but more complex structural factors appear to be important as well. A high lipophilicity is also a necessary, but not a sufficient condition for these compounds to be metabolized by cytochrome P450IID6.

Adrenergic beta-Antagonists↗
PubMed1991

Transcription of N-myc and proliferation-related genes is linked in human neuroblastoma.

A definite association between the transcription of N-myc oncogene and proliferation-related genes, histone H3, c-myc and p53, was found in a set of 12 primary untreated neuroblastomas and a metastasis of one of these at relapse. Molecular analysis allowed us to discriminate between actually proliferating and non-proliferating tumors, and suggested a link between N-myc and proliferation. Flow cytometric analysis of DNA distribution was less reliable for assessing tumor proliferative activity. Our data also seem to indicate a down-regulation of c-myc by N-myc in human neuroblastoma.

Blotting, Northern↗
PubMed1991

Primary lymphoma of bone: long term results in patients treated with vincristine--adriamycin--cyclophosphamide and local radiation.

Primary lymphoma of bone (PLB) is an unusual but well-recognized extranodal presentation of non-Hodgkin's lymphoma. In most series treatment with radiotherapy alone results in a cure rate of approximately 40%. Between January 1972 and December 1982, 26 patients with biopsy proven PLB were treated at the Rizzoli Institute with radiotherapy (4000-5,500 rad) and chemotherapy (vincristine, cyclophosphamide and adriamycin). The minimal clinical staging included complete blood cell counts and serum chemistries, bone radiography, full lung tomography, isotope bone scan, bone marrow biopsy and bipedal lymphoangiograms. At a median follow-up of 13 years (8.5-18.5) there were only three relapses (2 cases of meningeal involvement and 1 recurrence in another bone). No local recurrences nor second tumor in the irradiated field were observed. We conclude that the addition of chemotherapy to radiotherapy results in an excellent cure rate for patients with PLB.

Adolescent↗
PubMed1991

Mitochondrial DNA deletion in oculoskeletal myopathy.

The case of a patient showing bilateral ophthalmoplegia with proximal limb weakness, severe dysphagia and short stature, without family history, is described. The diagnosis of Kearns-Sayre syndrome was excluded because of the absence of pigmentary retinopathy and of all other common manifestations except short stature. The analysis of mitochondrial DNA of the patient's muscle revealed a deleted form accounting for 65% of the total mitochondrial DNA. The deletion, undetectable in the mitochondrial DNA of peripheral blood leukocytes, was apparently indistinguishable from that already described by others in a far more severe form of classic Kearns-Sayre syndrome.

Adult↗
PubMed1991

Decrease of proliferation rate and induction of differentiation by a MYCN antisense DNA oligomer in a human neuroblastoma cell line.

The effects of an antisense oligodeoxynucleotide to codons 2-7 of the oncogene MYCN on the human neuroblastoma cell line LAN-5 were studied. Treated cells showed a decreased MYCN protein expression and synthesis by immunoperoxidase staining and immunoprecipitation. At the same time, the replication rate was inhibited, and the phenotype was modified toward a more differentiated type. Our data suggest the involvement of oncogene MYCN in both proliferative and differentiative processes.

Base Sequence↗
PubMed1991

Non-metastatic Ewing's sarcoma: results in 98 patients treated with neoadjuvant chemotherapy.

From June 1983 to December 1987, 98 patients with non-metastatic Ewing's sarcoma of bone were treated by a protocol of neoadjuvant chemotherapy consisting of two months of preoperative chemotherapy with vincristine, adriamycin, and cyclophosphamide followed by local treatment and one year of chemotherapy aimed at preventing recurrence using the same drugs plus dactinomycin. Local treatment consisted of surgery in 39 cases (40%), radiation in 34 (34%), and both surgery and radiation in 25 (26%). After an average follow-up of five years, 51 patients (52%) had remained continuously disease-free (CDF), 46 had developed metastasis, of which 20 with local recurrence, and one had developed a radioinduced sarcoma. The site of the tumor (61% of patients with Ewing's sarcoma of the extremities were CDF vs. 35% with tumor of the pelvis) and the kind of local treatment (61% of patients who underwent surgery with or without radiation therapy were CDF vs. 35% of patients treated with radiation therapy alone) were important prognostic factors. These results are similar to those obtained in 59 patients treated from 1979 to 1982 (average follow-up, 10 years) using the same drugs administered according to adjuvant chemotherapy procedure as well as those reported in the only other large study on this subject in the literature (the multi-institution German study CESS-81). The authors conclude that even though neoadjuvant chemotherapy makes surgery possible and easier in Ewing's sarcoma, it does not significantly increase survival when compared to traditional adjuvant treatment.

Adolescent↗
PubMed1990

Primary chemotherapy and delayed surgery for malignant fibrous histiocytoma of bone in the extremity.

Between March 1983 and September 1988, 22 patients with non-metastatic malignant fibrous histiocytoma MFH of bone of the extremities were treated with two regimens of neo-adjuvant chemotherapy successively activated. Preoperatively, the patients received moderate doses of methotrexate and cisplatinum-Regimen 1- or high dose methotrexate, cisplatinum and adriamycin-Regimen 2. Cisplatinum was delivered intraarteriously, the other drugs intravenously. Limb salvage surgery was performed in 20 patients, and 2 patients were amputated. The surgical margins were adequate (radical or wide) in 18 cases and inadequate (marginal) in 4. The histologic response to chemotherapy was good (90% or more tumor necrosis) in 8 patients. In both regimens postoperative chemotherapy was tailored according to the grade of necrosis determined by preoperative treatment on the primary tumor. At an average follow-up of 40 months (15-70), 15 patients (68%) remained continuously disease-free and 7 relapsed with metastases. No local recurrences were observed. Regimen 2 was slightly more effective than Regimen 1 in terms of good histologic response (5/10 vs 1/12) and continuous disease-free survival (8/10 vs 7/127). The results demonstrate that, as in osteosarcoma, in non-metastatic malignant fibrous histiocytoma of bone in the extremities a high percentage of patients can be cured with neoadjuvant chemotherapy and that in most of them limb sparing surgery is possible and safe.

Adolescent↗
PubMed1990

Noncoordinated expression of S6, S11, and S14 ribosomal protein genes in leukemic blast cells.

The steady state levels of mRNAs codying for the ribosomal proteins S6, S11, and S14 have been evaluated in quiescent and proliferating human fibroblasts and in resting and proliferating human peripheral blood mononuclear cells. It was found that the amounts of ribosomal protein mRNA are very similar and are not increased by serum or mitogen stimulation. The constitutive expression of these genes appears to be coordinately regulated and it is not modified after protein synthesis inhibition by cycloheximide. The ribosomal protein mRNA was also assayed in 15 different populations of human leukemic blast cells. In these populations the abundance of each ribosomal protein mRNA is remarkably different from the other. The results of our present experiments indicate that the expression of the three ribosomal protein genes undergoes independent noncoordinated changes in the large majority of the leukemic populations studied.

Blast Crisis↗
PubMed1990

Protein phosphorylation in rat liver mitochondria.

Incubation of rat liver mitochondria in the presence of either [32P] Pi or [y32-P] ATP resulted in a phosphorylation of four proteins with Mr 50, 47, 44 and 36 kDa, respectively. The endogenous phosphorylation of these proteins in the presence of [32P] Pi was markedly influenced by the osmolarity of the incubation medium and differentially affected by various effectors of mitochondrial functions, such as Ca2+, oligomycin, FCCP, arsenite and dichloroacetate. In particular, the 36 kDa protein, unlike the other proteins, appears to be phosphorylated also by direct incorporation of [32P], independently of respiratory chain-linked ATP synthesis. The four proteins, located in the mitoplasts, seem to be phosphorylated by different protein kinases, as suggested by the observation that the endogenous phosphorylation of 36 kDa protein resulted selectively increased by addition of exogenous protein kinases, such as casein kinases S and TS. A tentative identification of these phosphorylatable protein is discussed.

Adenosine Triphosphate↗
PubMed1990

Identification of chicken calbindin D28K pre-messenger RNA sequences by polymerase chain reaction.

A transcribed RNA sequence encompassing the junction between the first intron and the second exon of the chicken calbindin D28K gene was copied in a cDNA fragment and subsequently amplified by polymerase chain reaction. When intestinal RNA is used as template, the appearance of the 161 bp amplified fragment is strictly dependent on the vitamin D status of the animal. In fact no amplified fragment is obtained when the RNA is extracted from the intestine of vitamin D-deficient chickens, while it is easily detected when the RNA is extracted only 30 min after injection with 1,25-dihydroxycholecalciferol. Conversely, the amplified fragment is obtained, irrespectively of the vitamin D status of the animal, when the RNA template is extracted from the brain. The appearance of unspliced RNA sequences upon vitamin D induction is followed, after a 30 min lag, by the appearance of the corresponding mature mRNA sequences.

Animals↗
PubMed1990

Ratios between the abundance of messenger RNA and the corresponding protein of two growth-related genes, c-myc and vimentin, in leukemia blast cells.

The abundance of the mRNAs of two growth-related genes, vimentin and c-myc, and that of the corresponding proteins have been studied in unstimulated and phytohemagglutinin-stimulated lymphocytes as well as in 18 populations of leukemic blast cells. The quantitative assay was carried out by densitometric scanning of Northern and Western blots. In normal lymphocytes the mRNA and the protein of both genes were almost undetectable. The phytohemagglutinin stimulation led to a sharp increase of the mRNA and the proteins of vimentin and c-myc. The increase was followed by a progressive fall of the gene products. The rate of decrease of the two mRNAs was similar to that of the corresponding proteins. In some leukemic populations very similar amounts of the vimentin protein were accompanied by amounts of the mRNA differing at least 25 times. Not unlikely, very similar amounts of p62c-myc corresponded to mRNA abundances differing at least 16 times. The coordinated biogenesis of both messenger RNAs and proteins, which occurs in mitogen-stimulated lymphocytes, is substituted, in approximately 30% of the leukemic blast cell populations, by molecular events leading to the accumulation of an excess of mRNA.

Blast Crisis↗