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B Falini

Publications and source records attributed to B Falini.

At least 19 recordsLinked to original sources
PubMed1996

Distinctive expression pattern of the BCL-6 protein in nodular lymphocyte predominance Hodgkin's disease.

The BCL-6 gene encoding a nuclear-located Kruppel-type zinc finger protein is rearranged in about 30% diffuse large B-cell lymphomas and is expressed predominantly in normal germinal center B cells and related lymphomas. These findings suggest that BCL-6 may play a role in regulating differentiation of normal germinal center B cells and that its deregulated expression caused by rearrangements may contribute to lymphomagenesis. This prompted us to investigate the expression of the BCL-6 protein in Hodgkin's disease (HD), focusing on the nodular lymphocyte predominance subtype (NLPHD), which differs from classical HD by virtue of the B-cell nature of the malignant cell population (so-called L&H cells) and its relationship with germinal centers. Forty-one HD samples (19 NLPHD, 12 nodular sclerosis, and 10 mixed cellularity) were immunostained with the monoclonal antibodies PG-B6 and PG-B6p that react with a fixative-sensitive and a formalin-resistant epitope on the aminoterminal region of the BCL-6 gene product, respectively. Strong nuclear positivity for the BCL-6 protein was detected in tumor (L&H) cells in all cases of NLPHD. In contrast, BCL-6 was expressed only in a small percentage of Hodgkin and Reed-Sternberg cells in about 30% of classical HD cases. Notably, the nuclei of reactive CD3+/CD4+ T cells nearby to and rosetting around L&H cells in NLPHD were also strongly BCL-6+, but lacked CD40 ligand (CD40L) expression. This staining pattern clearly differed from that of classical HD, whose cellular background was made up of CD3+/CD4+ T cells showing the BCL-6-/CD40L+ phenotype. These results further support the concept that NLPHD is an histogenetically distinct, B-cell-derived subtype of HD and suggest a role for BCL-6 in its development.

Animals↗
PubMed1996

14q+ chromosome marker in a T-cell-rich B-cell lymphoma.

Cytogenetic, in situ hybridization, and molecular studies were performed in a case of T-cell-rich B-cell lymphoma. Demonstration of Ig gene rearrangements for both heavy and light chains confirmed the B-lineage restriction of the neoplastic cell population. Moreover, as expected in B-cell malignancies, all abnormal karyotypes showed a 14q+ chromosome marker involving 14q32. The origin of the extra material on the derivative 14q+, as defined by chromosome painting with a library for chromosome 11, and Southern blotting for c-myc and bcl-2 rearrangements, remains unknown.

Blotting, Southern↗
PubMed1996

Anti-CD30 (BER=H2) immunotoxins containing the type-1 ribosome-inactivating proteins momordin and PAP-S (pokeweed antiviral protein from seeds) display powerful antitumour activity against CD30+ tumour cells in vitro and in SCID mice.

The anti-CD30 immunotoxin (IT) Ber-H2/saporin is effective in patients with refractory Hodgkin's disease. However, responses are short and partial, one of the main reasons being the inability to repeat IT doses because of formation of human antibodies against the murine antibody and/or the toxin. To overcome this problem, we constructed two new anti-CD30 ITs by covalently linking the mouse monoclonal antibody Ber-H2 to the type 1 ribosome-inactivating proteins (RIPs) momordin (MOM) and pokeweed antiviral protein from seeds (PAP-S), which do not cross-react with each other or with saporin. Both ITs inhibited protein synthesis by Hodgkin's disease and anaplastic large-cell lymphoma (ALCL)-derived CD30+ target cell lines with a very high efficiency (IC50 ranging from < 5 x 10(-13) M to 2.75 x 10(-11) M, as RIP). In a SCID mouse model of xenografted CD30+ human ALCL, a 3d treatment with non-toxin doses of Ber-H2/MOM (50%LD50), started 24 h after transplantation, prevented tumour development in about 40% of the animals and significantly delayed tumour growth rate in the others. Main toxicity signs in mice and rabbits were dose-related increase of serum transaminases (AST and ALT) and creatine phosphokinase (CPK). LD50 (as RIP) in Swiss mice was 7 mg/kg for Ber-H2/MOM and 0.45 mg/kg for Ber-H2/PAP-S. Sequential administration of two anti-CD30 ITs (Ber-H2/MOM and Ber-H2/saporin) was well tolerated and did not result in formation of antibodies cross-reacting and with the two plant toxins. The results presented in this paper suggest that in the future, sequential administration of anti-CD30 humanized antibodies linked to antigenically distinct type 1 RIPs (saporin, MOM, PAP-S) should be feasible.

Animals↗
PubMed1996

Sch proteins are localized on endoplasmic reticulum membranes and are redistributed after tyrosine kinase receptor activation.

The intracellular localization of Shc proteins was analyzed by immunofluorescence and immunoelectron microscopy in normal cells and cells expressing the epidermal growth factor receptor or the EGFR/erbB2 chimera. In unstimulated cells, the immunolabeling was localized in the central perinuclear area of the cell and mostly associated with the cytosolic side of rough endoplasmic reticulum membranes. Upon epidermal growth factor treatment and receptor tyrosine kinase activation, the immunolabeling became peripheral and was found to be associated with the cytosolic surface of the plasma membrane and endocytic structures, such as coated pits and endosomes, and with the peripheral cytosol. Receptor activation in cells expressing phosphorylation-defective mutants of Shc and erbB-2 kinase showed that receptor autophosphorylation, but not Shc phosphorylation, is required for redistribution of Shc proteins. The rough endoplasmic reticulum localization of Shc proteins in unstimulated cells and their massive recruitment to the plasma membrane, endocytic structures, and peripheral cytosol following receptor tyrosine kinase activation could account for multiple putative functions of the adaptor protein.

3T3 Cells↗
PubMed1996

Molecular findings and classification of malignant lymphomas.

We review the problem of lymphoma classification in the light of the Revised European-American Lymphoma (REAL) scheme, recently proposed by the International Lymphoma Study Group (ILSG). The REAL classification is a list of clinicopathologic entities, all well known from the literature, upon which the ILSG members agreed. Although it contains nothing new, for the first time all the elements, including immunophenotype and molecular data, which characterise a given lymphoma entity are considered. This approach corresponds to the need for objective criteria integrating the often puzzling morphologic findings. Furthermore, better knowledge of the molecular events which contribute to tumour development and progression if of paramount importance for the development of more specific and successful therapies. Some relevant molecular findings included in the classification and additional data obtained by the ILSG members following its publication are discussed.

Chromosome Aberrations↗
PubMed1996

Anaplastic large-cell lymphoma: clinical and prognostic evaluation of 90 adult patients.

PURPOSE: During the last few years, the application of CD30 monoclonal antibodies has led to the identification of a new lymphoma entity, termed anaplastic large cell lymphoma (ALCL). This tumor includes four distinct histologic subtypes, among which the Hodgkin's-like/Hodgkin's-related one (ALCL-HL) shares morphologic and phenotypic features with Hodgkin's disease (HD). PATIENTS AND METHODS: From September 1988 to October 1993, 90 ALCL patients were treated with third-generation chemotherapy regimens (either vincristine, cyclophosphamide, fluorouracil, cytarabine, doxorubicin, methotrexate with leucovorin, and prednisone [F-MACHOP] or methotrexate with leucovorin, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin [MACOP-B]) during the course of an Italian multicentric randomized trial on high-grade non-Hodgkin's lymphomas (HG-NHL). In particular, 47 patients had ALCL of the common type (ALCL-CT) and 43 ALCL-HL. Null phenotype was the most common (39.8%), while T-cell, B-cell, and hybrid forms accounted for 35.5%, 22.2%, and 2.5%, respectively. RESULTS: Complete remission (CR) was achieved in 66 of 90 (73.5%) patients (33 of 47 [70%] with ALCL-CT and 33 of 43 [77%] with ALCL-HL). The majority of the patients in CR (56.5%) were alive and well at a median follow-up time of 38 months; no significant differences were observed between the two histologic groups, with the rate of complete responders being 49% and 65% in ALCL-CT and ALCL-HL, respectively. The probability of relapse-free survival (RFS), projected at 63 months, was 67% for ALCL-CT and 82% for ALCL-HL. The risk of lower CR and RFS rates was associated with the presence of bulky disease, advanced stage, and B symptoms. CONCLUSION: The data of the present study confirm that ALCL responds to third-generation chemotherapy regimens similarly to other aggressive malignant lymphomas in terms of both CR and RFS rates.

Adolescent↗
PubMed1996

Monoclonal antibodies PG-B6a and PG-B6p recognize, respectively, a highly conserved and a formol-resistant epitope on the human BCL-6 protein amino-terminal region.

The human BCL-6 gene, which is rearranged in approximately 30% of diffuse large B cell lymphomas, encodes a 706-amino-acid nuclear protein of the Kruppel-type zinc finger transcription factors mainly expressed in normal germinal center B cells and related lymphomas. Four monoclonal antibodies (PG-B6, PG-B6a, PG-B6p, and PG-B6m), specifically directed against the human BCL-6 protein, were generated by immunizing BALB/c mice with a recombinant protein corresponding to the BCL-6 amino-terminal region (amino acids 3 to 484). The PG-B6 monoclonal antibody reacted with a BCL-6 epitope sensitive to fixatives and preserved in all mammalian species. PG-B6a (a is for avian) recognized the most evolutionarily conserved BCL-6 epitope (expressed in all animal species including avian). PG-B6p (p is for paraffin) recognized a fixative-resistant epitope of BCL-6 that was detectable on paraffin sections after microwave heating in 1 mmol/L EDTA buffer. PG-B6m (m is for mantle) was the least specific monoclonal antibody as, in addition to BCL-6, it reacted with a yet undefined antigen selectively located in the cytoplasm of mantle and marginal zone B cells. All monoclonal antibodies detected strong nuclear expression of BCL-6 in follicular lymphomas, diffuse large B cell lymphomas, Burkitt's lymphomas, and nodular, lymphocyte-predominance Hodgkin's disease. In diffuse large B cell lymphomas, BCL-6 expression was independent of BCL-6 gene rearrangements and did not correlate with expression of other markers or the proliferation index. BCL-6 was not expressed in B-CLL, hairy cell leukemia, mantle-cell- and marginal-zone-derived lymphomas. Labeling of paraffin sections with PG-B6p proved useful for differentiating proliferation centers in B-CLL (BCl-2+/BCL-6-) from trapped germinal centers in mantle cell lymphomas (BCL-2-/BCL-6+) and for identifying neoplastic cells in cases of nodular, lymphocyte-predominance Hodgkin's disease. Because of their high specificity, wide reactivity in humans and animal species including avians (PG-B6a), and suitability for labeling routine paraffin sections (PG-B6p), the reagents described in this paper should prove valuable in both research and diagnostics.

Amino Acid Sequence↗
PubMed1995

The acute promyelocytic leukaemia-associated PML gene is induced by interferon.

The PML protein concentrates within discrete nuclear structures known as nuclear bodies, also called NDs or PODs, which contain several proteins including the interferon (IFN)-inducible SP100 product. The function of these structures remains elusive. We and others have shown recently that they represent specific targets for adenovirus and herpes simplex virus. This prompted us to investigate whether PML, like SP100, might be induced by IFN and to explore the role of PML in viral infection. Here we report that PML mRNA levels increase rapidly in response to interferon treatment. This accumulation of PML transcripts is a primary IFN response since it does not require de novo protein synthesis. The IFN-induced activation of the PML gene is accompanied by enhanced protein expression as revealed by immunolabelling. Both the intensity of the staining and the number of labelled structures increased upon interferon exposure. To probe the role of PML in IFN action, we compared the antiviral state established by alpha-interferon in embryonic fibroblasts (EFs) derived from null mutant mice for PML and from wild-type control mice. The resistance to viral infection conferred by IFN-alpha was identical in both PML+/+ and PMLm/m fibroblasts indicating that PML is not an essential mediator of the antiviral effect of interferon. We also noted that DNA-binding factors are normally activated by IFN in PMLm/m cells.

Base Sequence↗
PubMed1995

BCL-6 protein is expressed in germinal-center B cells.

Structural alterations of the 5' noncoding region of the BCL-6 gene have been found in 40% of diffuse large cell lymphoma (DLCL) and 5% to 10% of follicular lymphomas (FL), suggesting that deregulated BCL-6 expression may play a role in lymphomagenesis. Nucleotide sequencing of BCL-6 cDNA predicted a protein containing six zinc-finger domains, suggesting that it may function as a transcription factor. Using antisera raised against N- and C-terminal BCL-6 synthetic oligopeptides in immunoprecipitation, immunoblot, and immunocytochemical assays, this study identifies the BCL-6 gene product as a 95-kD nuclear protein. Western blot analysis of human tumor cell lines representative of various hematopoietic lineages/stages of differentiation showed that the BCL-6 protein is predominantly expressed in the B-cell lineage where it was found in mature B cells. Immunohistochemical analysis of normal human lymphoid tissues indicated that BCL-6 expression is topographically restricted to germinal centers including all centroblasts and centrocytes. The BCL-6 protein was also detectable in inter- and intra-follicular CD4+ T cells, but not in other follicular components including mantle-zone B cells, plasma cells, dendritic cells, and macrophages. Immunohistochemical analysis of DLCL and FL biopsy samples showed that the BCL-6 protein is detectable in these tumors independent of the presence of BCL-6 gene rearrangements. These results indicate that the expression of the BCL-6 gene is specifically regulated during B-cell differentiation and suggest a role for BCL-6 in germinal center development or function. Because DLCL derive from germinal-center B cells, deregulated BCL-6 expression may contribute to lymphomagenesis by preventing postgerminal center differentiation.

Amino Acid Sequence↗
PubMed1995

Antitumor activity of anti-CD30 immunotoxin (Ber-H2/saporin) in vitro and in severe combined immunodeficiency disease mice xenografted with human CD30+ anaplastic large-cell lymphoma.

To develop a novel adjunctive therapy for CD30 (Ki-1)+ anaplastic large-cell lymphoma (ALCL), we investigated in preclinical studies the antitumor activity of an immunotoxin (IT) constructed by coupling the plant ribosome-inactivating protein saporin (SO6) to the monoclonal antibody (MoAb) Ber-H2 that is directed against the CD30 molecule, a new member of the tumor necrosis factor receptor (TNFR) super-family. The activity of Ber-H2/SO6 IT was tested both in vitro against the CD30+ ALCL-derived cell line JB6 and in vivo using our severe combined immunodeficiency disease (SCID) mouse model of human xenografted CD30+ ALCL. In vitro, the Ber-H2/SO6 IT was selectively and highly toxic to the JB6 cell line [50% inhibiting concentration (IC50), 3.23 x 10(-12) mol/L as SO6]. In vivo, a 3-day treatment with nontoxic doses of Ber-H2/SO6 (50% of LD50) induced lasting complete remissions (CR) in 80% of mice when started 24 hours after tumor transplantation. In contrast, injection of the IT at later stages of tumor growth (mice bearing subcutaneous tumors of 40- to 60-mm3 volume), induced CR in only 6 of 21 (approximately 30%) mice and significantly delayed tumor growth rate (P < .01). This finding suggests that maximum effect of the anti-CD30 IT is observed when tumor cell burden is small. Persistent tumors from IT-treated mice consisted of CD30+ cells, thus excluding the possibility that selection of CD30-negative mutant clones during IT therapy was responsible for resistance to treatment. We conclude that Ber-H2/SO6 IT is an effective agent against CD30+ ALCL growing in SCID mice, suggesting its possible role as adjuvant therapy in patients with CD30+ ALCL refractory to standard treatments.

Animals↗
PubMed1995

Mediastinal large B-cell lymphoma: clinical and immunohistological findings in 18 patients treated with different third-generation regimens.

We report on the immunophenotype, clinical findings and response to aggressive chemotherapy of 18 patients with mediastinal large B-cell lymphoma (MLCL). Cases were collected from a series of 286 high-grade non-Hodgkin's lymphomas (HG-NHL) which, in the period September 1988 to August 1991, were enrolled in a prospective multicentre trial designed to compare the MACOP-B and F-MACHOP regimens. Immunostaining on frozen sections revealed a previously unrecognized phenotype, i.e. co-expression of B-cell (CD19, CD20, CD22, Ig-associated dimer) and activation-associated antigens (CD30 and CDw70) in about 60% of MLCL cases; in contrast, the activation-associated antigens CD25 and Ki-27 (unclustered) were consistently negative. This peculiar phenotype may reflect a derivation of the tumour from a subset of thymic activated B cells. Clinically, the patients (median age 31 years; F/M ratio 2.6) presented with bulky mediastinal mass (72%) associated with mediastinal syndrome in > 50% cases; disease was stage IIA in most cases. All 18 patients received aggressive chemotherapy (F-MACHOP 11; MACOP-B 7). Complete response (CR) was achieved in 57.1% of cases treated with MACOP-B. In contrast, the response of the 11 MLCL treated with F-MACHOP was poor (CR 18.2%) as compared to that of the 135 HG-NHL treated with the same regimen during the trial (CR 69.6%). This difference was still statistically significant after adjusting for negative prognostic factors (mediastinal mass > 10 cm plus increased LDH) and suggests that F-MACHOP might not be the most appropriate regimen for this kind of lymphoma.

Adolescent↗
PubMed1995

High levels of the soluble form of CD30 molecule in rheumatoid arthritis (RA) are expression of CD30+ T cell involvement in the inflamed joints.

The CD30 is a surface molecule expressed by Th2-type lymphokine-producing T cells upon activation. CD30-expressing activated T cells release a soluble form of the molecule, which can be detectable both in vitro and in vivo. In the present study, high levels of soluble CD30 were found in peripheral blood and synovial fluid from patients with RA. However, CD30+ CD3+ cells, either CD4+ or CD8+, were significantly present in synovial fluid, but not in peripheral blood, of RA patients. Serum values of soluble CD30 were higher in active than inactive RA patients and directly correlated with rheumatoid factor serum titres. These data strongly support an involvement of CD30+ T cells in the immune processes of rheumatoid synovitis, and may suggest a relationship between Th2-type cytokine-secreting T cells and the pathological response in RA.

Adult↗
PubMed1995

Is Hodgkin's disease a unique entity?

The theoretical bases of Hodgkin's disease (HD) have recently been revised in the light of new findings obtained by means of immunohistochemistry and molecular analysis. These findings have questioned the concept that HD is a unique entity and have made the borders between HD and non-Hodgkin's lymphomas unclear. The clinical relevance of nodular lymphocyte predominance HD (LP-HD), the distinction between T-cell rich B-cell lymphoma and diffuse LP-HD, and the relationships between HD and anaplastic large cell lymphoma are reviewed and discussed.

Biomarkers, Tumor↗
PubMed1995

MACOP-B vs F-MACHOP regimen in the treatment of high-grade non-Hodgkin's lymphomas.

A prospective randomized study on aggressive non-Hodgkin's lymphomas was conducted by investigators at several Italian institutions with the intent of comparing two third-generation conceptually different regimens: the regimen containing methotrexate with leucovorin rescue, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B), a short-term continuous twelve-week therapy, and F-MACHOP (5-fluorouracil, methotrexate with leucovorin rescue, cytarabine, cyclophosphamide, doxorubicin, vincristine, and prednisone), a monthly intensive cyclic treatment combining prednisone with six active non-cross-resistant cytotoxic drugs. The goals of this study were the response rate, relapse-free survival, and incidence of hematologic and nonhematologic toxicities. Two hundred-eighty-six patients included between 15 and 60 years fulfilled the criteria for entry to the study; 140 patients were treated with MACOP-B and 146 with F-MACHOP. The minimum follow-up was 24 months. Clinical characteristics of all patients were similar and known prognostic factors were equally distributed between the two groups. Complete remission (CR) was achieved by 61% and 67% of the patients treated with MACOP-B and F-MACHOP, respectively; 4% and 6% were primarily resistant, 2% and 5%, respectively, died of causes directly related to therapy. At 50 months, 74% of all CR patients were alive without disease and there were no significant differences in relapse-free survival between the two groups: 75% in the F-MACHOP group and 73% in the MACOP-B group at 50 months. There was a higher incidence of mucositis among patients treated with MACHOP-B than among those given F-MACHOP (11% vs 3.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Bone marrow findings further support the hypothesis that essential mixed cryoglobulinemia type II is characterized by a monoclonal B-cell proliferation.

One-hundred-sixteen consecutive bone-marrow biopsies were taken from 76 patients with essential mixed cryoglobulinemia type II (type II cryo), whose median follow-up was 97 months. Fifty-four out of fifty-six subjects who underwent ELISA and RIBA tests for HCV, were found to be positive. At conventional light microscopic examination, 64/76 patients showed discrete lymphoid infiltrates consisting of small elements with plasmacytoid differentiation and with frequent paratrabecular location. Thirty-nine biopsies were studied by immunohistochemistry that revealed the B-cell nature of the infiltrates (CD20+, CD45RA+, CD79 alpha+, CD3-, CD45RO-), with demonstrable monotypic Ig light-chain restriction in 22 cases. It is worthy of note that the lymphoid elements usually appeared protected against apoptosis, because of the strong expression of the bcl-2 oncogene product, and provided with a very low proliferative capacity, the Ki-67 index being lower that 3%. The latter findings are in keeping with the indolent behaviour of the clonal lymphoid population observed in type II cryo and allow some speculation as to the need for environmental stimuli for its maintenance as well as further mutagenic events for its eventual transformation into an overt lymphoma.

Adult↗