Time filter

Source Type

Bergamo, Italy

Boross P.,University Utrecht | Jansen J.H.M.,University Utrecht | de Haij S.,Genmab | Beurskens F.J.,Genmab | And 8 more authors.
Haematologica | Year: 2011

Background CD20 monoclonal antibodies are widely used in clinical practice. Antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity and direct cell death have been suggested to be important effector functions for CD20 antibodies. However, their specific contributions to the in vivo mechanism of action of CD20 immunotherapy have not been well defined. Design and Methods Here we studied the in vivo mechanism of action of type I (rituximab and ofatumumab) and type II (HuMab-11B8) CD20 antibodies in a peritoneal, syngeneic, mouse model with EL4- CD20 cells using low and high tumor burden. Results Interestingly, we observed striking differences in the in vivo mechanism of action of CD20 antibodies dependent on tumor load. In conditions of low tumor burden, complement was sufficient for tumor killing both for type I and type II CD20 antibodies. In contrast, in conditions of high tumor burden, activating FcγR (specifically FcγRIII), active complement and complement receptor 3 were all essential for tumor killing. Our data suggest that complement-enhanced antibody-dependent cellular cytotoxicity may critically affect tumor killing by CD20 antibodies in vivo. The type II CD20 antibody 11B8, which is a poor inducer of complement activation, was ineffective against high tumor burden. Conclusions Tumor burden affects the in vivo mechanism of action of CD20 antibodies. Low tumor load can be eliminated by complement alone, whereas elimination of high tumor load requires multiple effector mechanisms. © 2011 Ferrata Storti Foundation. Source

Carella A.M.,Azienda Ospedaliera Universitaria San Martino | De Souza C.A.,University of Campinas | Luminari S.,University of Modena and Reggio Emilia | Marcheselli L.,University of Modena and Reggio Emilia | And 15 more authors.
Leukemia and Lymphoma | Year: 2013

Male gender was recently reported as an adverse prognostic factor in patients with diffuse large B-cell lymphoma (DLBCL) treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). We conducted a retrospective study of adult patients with DLBCL initially treated with rituximab containing regimens between 2001 and 2007. Patients were identified from the clinical archives of 43 Italian and Brazilian institutions. The principal endpoint was overall survival (OS). One thousand seven hundred and ninety-three patients were fully eligible for the study. Thirty-eight percent, 27%, 22% and 12% of patients had an International Prognostic Index (IPI) score of 0-1, 2, 3 and 4-5, respectively; 53% were males. After a median follow-up of 36 months (1-106), the 5-year OS was 76% (95% confidence interval 74-78%). In univariate analysis, male gender was an adverse prognostic factor with a hazard ratio of 1.52. In multivariate analysis, when adjusted by IPI, again gender maintained its prognostic relevance, showing an independent additive effect. In conclusion, in patients with DLBCL treated with rituximab containing regimens, gender may increase the predictive power of the IPI. Based on these results, given possible differences in blood clearance of rituximab between males and females, the benefit of higher doses of rituximab in males should be explored. © 2013 Informa UK, Ltd. Source

Capelli C.,Laboratory Of Cell Therapy G Lanzani | Gotti E.,Laboratory Of Cell Therapy G Lanzani | Morigi M.,Mario Negri Institute for Pharmacological Research | Rota C.,Mario Negri Institute for Pharmacological Research | And 9 more authors.
Cytotherapy | Year: 2011

Background aims. Mesenchymal stromal cells (MSC) have recently been identified as a therapeutic option in several clinical conditions. Whereas bone marrow (BM) is considered the main source of MSC (BM-MSC), the invasive technique required for collection and the decline in allogeneic donations call for alternative sources. Human umbilical cord (UC) represents an easily available source of MSC (UC-MSC). Methods. Sections of full-term UC were transferred to cell culture flasks and cultured in 5% human platelet lysate (PL)-enriched medium. Neither enzymatic digestion nor blood vessel removal was performed. After 2 weeks, the adherent cells were harvested (P1), replated at low density and expanded for two consecutive rounds (P2 and P3). Results. We isolated and expanded MSC from 9/9 UC. UC-MSC expanded with a mean fold increase (FI) of 42 735 ± 16 195 from P1 to P3 in a mean of 29 ± 2 days. By processing the entire cord unit, we theoretically could have reached a median of 9.5 × 1010 cells (ranging from 1.0 × 1010 to 29.0 × 1010). UC-MSC expressed standard surface markers; they contained more colony-forming unit (CFU)-fibroblast (F) and seemed less committed towards osteogenic, chondrogenic and adipogenic lineages than BM-MSC. They showed immunosuppressive properties both in vitro and in an in vivo chronic Graft versus Host disease (cGvHD) mouse model. Both array-Comparative Genomic Hybridization (CGH) analysis and karyotyping revealed no chromosome alterations at the end of the expansion. Animal studies revealed no tumorigenicity in vivo. Conclusions. UC constitute a convenient and very rich source of MSC for the production of third-party 'clinical doses' of cells under good manufacturing practice (GMP) conditions. © 2011 Informa Healthcare. Source

Todoerti K.,University of Milan | Barbui V.,USC Hematology | Pedrini O.,USC Hematology | Lionetti M.,University of Milan | And 7 more authors.
Haematologica | Year: 2010

Background: The histone deacetylase inhibitor ITF2357 has potent cytotoxic activity in multiple myeloma in vitro and has entered clinical trials for this disease. Design and Methods: In order to gain an overall view of the activity of ITF2357 and identify specific pathways that may be modulated by the drug, we performed gene expression profiling of the KMS18 multiple myeloma cell line treated with the drug. The modulation of several genes and their biological consequence were verified in a panel of multiple myeloma cell lines and cells freshly isolated from patients by using polymerase chain reaction analysis and western blotting. Results: Out of 38,500 human genes, we identified 140 and 574 up-regulated genes and 102 and 556 down-modulated genes at 2 and 6 h, respectively, with a significant presence of genes related to transcription regulation at 2 h and to cell cycling and apoptosis at 6 h. Several of the identified genes are particularly relevant to the biology of multiple myeloma and it was confirmed that ITF2357 also modulated their encoded proteins in different multiple myeloma cell lines. In particular, ITF2357 down-modulated the interleukin-6 receptor α (CD126) transcript and protein in both cell lines and freshly isolated patients' cells, whereas it did not significantly modify interleukin-6 receptor β (CD130) expression. The decrease in CD126 expression was accompanied by decreased signaling by interleukin-6 receptor, as measured by STAT3 phosphorylation in the presence and absence of interleukin-6. Finally, the drug significantly down-modulated the MIRHG1 transcript and its associated microRNA, miR-19a and miR-19b, known to have oncogenic activity in multiple myeloma. Conclusions: ITF2357 inhibits several signaling pathways involved in myeloma cell growth and survival. ©2010 Ferrata Storti Foundation. Source

Amaru Calzada A.,USC Hematology | Todoerti K.,University of Milan | Donadoni L.,USC Hematology | Pellicioli A.,USC Hematology | And 9 more authors.
Experimental Hematology | Year: 2012

We investigated the mechanism of action of the histone deacetylase inhibitor Givinostat (GVS) in Janus kinase 2 (JAK2) V617F myeloproliferative neoplasm (MPN) cells. GVS inhibited colony formation and proliferation and induced apoptosis at doses two- to threefold lower in a panel of JAK2 V617F MPN compared to JAK2 wild-type myeloid leukemia cell lines. By global gene expression analysis, we observed that at 6 hours, GVS modulated 293 common genes in the JAK2 V617F cell lines HEL and UKE1, of which 19 are implicated in cell cycle regulation and 33 in hematopoiesis. In particular, the hematopoietic transcription factors NFE2 and C-MYB were downmodulated by the drug specifically in JAK2 V617F cells at both the RNA and protein level. GVS also inhibited JAK2-signal transducer and activator of transcription 5-extracellular signal-regulated kinase 1/2 phosphorylation, but modulation of NFE2 and C-MYB was JAK2-independent, as shown using the JAK2 inhibitor TG101209. GVS had a direct effect on the NFE2 promoters, as demonstrated by specific enrichment of associated histone H3 acetylated at lysine 9. Modulation by GVS of NFE2 was also observed in freshly isolated CD34 + cells from MPN patients, and was accompanied by inhibition of their proliferation and differentiation toward the erythroid lineage. We conclude that GVS acts on MPN cells through dual JAK2-signal transducer and activator of transcription 5-extracellular signal-regulated kinase 1/2 inhibition and downmodulation of NFE2 and C-MYB transcription. © 2012 ISEH - Society for Hematology and Stem Cells. Source

Discover hidden collaborations