Gabriella Bianchino

Positive effects on hematopoiesis in patients with myelodysplastic syndrome receiving deferasirox as oral iron chelation therapy: A brief review

Iron overload is a frequent consequence in transfusion-dependent myelodysplastic syndromes (MDSs), which often requires iron chelation therapy (ICT). Interestingly, ICT may sometimes induce a hematologic improvement that leads to significant reduction or complete interruption of blood transfusions. This phenomenon has been recently described in MDS treated with the new oral chelator deferasirox. Here we briefly review the literature about this phenomenon and discuss the possible biological mechanisms underlying hematologic effects of deferasirox in MDS, starting from a new paradigmatic case in whom both hemoglobin level and platelet count improved, inducing transfusion-independence, soon after starting the treatment with deferasirox.

Targeted inhibition of the epidermal growth factor receptor‐tyrosine kinase by ZD1839 (‘Iressa’) induces cell‐cycle arrest and inhibits proliferation in prostate cancer cells

The epidermal growth factor (EGF) plays a role in the development of prostate cancer, which becomes essential after androgen resistance has emerged. The EGF receptor (EGFR) is therefore a potential target for anticancer therapy. We evaluated the effects of ZD1839 (‘Iressa’), an orally active EGFR—tyrosine kinase inhibitor, on prostate cancer cell lines. The effects of ZD1839 were evaluated on the anchorage dependent and independent growth of androgen‐responsive (LNCaP) and androgen‐independent (DU145 and PC3) cells by a cell proliferation assay, cell counting, and soft agar analysis. Flow cytometric analysis and Western blotting were used to assess the effects on the cell‐cycle and on protein expression levels, respectively. ZD1839 caused a dose‐ and time‐dependent growth inhibition in all three cell lines. A dose‐dependent supra‐additive increase in growth inhibition was observed when ZD1839 was combined with the antiandrogen flutamide or ionizing radiation (IR). The antiproliferative effect of ZD1839 was mainly cytostatic and associated with a block in the G0/G1 phase of the cell‐cycle, evident after about 12 h of treatment. In the DU145 cells this block was associated with an increase in expression of the CDK inhibitor p27Kip1, both in the cytoplasmic and nuclear fractions. The increase in p27Kip1 was not evident in the LNCaP and PC3 cells. No changes were observed in the expression of cyclin D1 protein. These results demonstrate the antiproliferative effects of ZD1839 on the growth of prostate cancer cells and suggest that inhibition of EGFR‐associated signal transduction pathway might represent a promising novel therapeutic strategy for the treatment of prostate cancer. J. Cell. Physiol. 201: 97–105, 2004.

Biological and clinical relevance of miRNA expression signatures in primary plasma cell leukemia

Purpose: Primary plasma cell leukemia (pPCL) is a rare and very aggressive form of plasma cell dyscrasia. To date, no information on microRNA (miRNA) expression in pPCL has been reported. This study aimed at investigating the involvement of miRNAs in pPCL and their possible relationship with higher tumor aggressiveness. Experimental design: Global miRNA expression profiles were analyzed in highly purified malignant plasma cells from 18 pPCL untreated patients included in a prospective clinical trial. MiRNA expression patterns were evaluated in comparison with a representative series of multiple myeloma patients, in relation to the most recurrent chromosomal abnormalities (as assessed by fluorescence in situ hybridization and single-nucleotide polymorphism-array analysis), and in association with clinical outcome. MiRNA expression was also integrated with gene expression profiles in pPCL and multiple myeloma samples. Results: We identified a series of deregulated miRNAs in pPCL (42 upregulated and 41 downregulated) in comparison with multiple myeloma. Some of them, on the basis of their reported functions and putative target genes computed by integrative analysis, might have a role in the pathobiology of pPCL. As regards chromosomal aberrations, the expression of some miRNAs mapped to hotspot altered regions was associated with DNA copy number of the corresponding loci. Finally, 4 miRNA (miR-497, miR-106b, miR-181a*, and miR-181b) were identified as having expression levels that correlated with treatment response, and 4 (miR-92a, miR-330-3p, miR-22, and miR-146a) with clinical outcome. Conclusions: Overall, our study provides insights into the possible contribution of miRNAs in the pathogenesis of pPCL and suggests targets for future therapeutic investigations. Clin Cancer Res; 19(12); 3130–42. ©2013 AACR.

Genome‐wide analysis of primary plasma cell leukemia identifies recurrent imbalances associated with changes in transcriptional profiles

Primary plasma cell leukemia (pPCL) is a rare, yet aggressive form of de novo plasma cell tumor, distinct from secondary PCL (sPCL) which represents a leukemic transformation of pre‐existing multiple myeloma (MM). Herein, we performed a comprehensive molecular analysis of a prospective series of pPCLs by means of FISH, single nucleotide polymorphism (SNP) array and gene expression profiling (GEP). IGH@ translocations were identified in 87% of pPCL cases, with prevalence of t(11;14) (40%) and t(14;16) (30.5%), whereas the most frequent numerical alterations involved 1p (38%), 1q (48%), 6q (29%), 8p (42%), 13q (74%), 14q (71%), 16q (53%), and 17p (35%). We identified a minimal biallelic deletion (1.5 Mb) in 8p21.2 encompassing the PPP2R2A gene, belonging to a family of putative tumor suppressors and found to be significantly down‐regulated in deleted cases. Mutations of TP53 were identified in four cases, all but one associated with a monoallelic deletion of the gene, whereas activating mutations of the BRAF oncogene occurred in one case and were absent in N‐ and K‐RAS. To evaluate the influence of allelic imbalances in transcriptional expression we performed an integrated genomic analysis with GEP data, showing a significant dosage effect of genes involved in transcription, translation, methyltransferase activity, apoptosis as well as Wnt and NF‐kB signaling pathways. Overall, we provide a compendium of genomic alterations in a prospective series of pPCLs which may contribute to improve our understanding of the pathogenesis of this aggressive form of plasma cell dyscrasia and the mechanisms of tumor progression in MM. Am. J. Hematol. 2013.

Transcriptional characterization of a prospective series of primary plasma cell leukemia revealed signatures associated with tumor progression and poorer outcome

Purpose: Plasma cell leukemia (PCL) is a rare form of plasma cell dyscrasia that presents either as a progression of previously diagnosed multiple myeloma, namely secondary PCL, or as initial manifestation of disease, namely primary PCL (pPCL). Although the presenting signs and symptoms include those seen in multiple myeloma, pPCL is characterized by several aspects that define a more aggressive course. Here, we have investigated the transcriptome of pPCLs and correlated differential expression profiles with outcome to provide insights into the biology of the disease. Experimental Design: The expression profiles of 21 newly diagnosed pPCLs included in a multicenter prospective clinical trial were generated using high-density microarray, then evaluated in comparison with a representative series of patients with multiple myeloma and in association with clinical outcome. Results: All but one of the pPCLs had one of the main immunoglobulin heavy-chain locus translocations, whose associated transcriptional signatures resembled those observed in multiple myeloma. A 503-gene signature distinguished pPCL from multiple myeloma, from which emerged 26 genes whose expression trend was associated with progressive stages of plasma cells dyscrasia in a large dataset from multiple institutions, including samples from normal donors throughout PCL. Finally, 3 genes were identified as having expression levels that correlated with response to the first-line treatment with lenalidomide/dexamethasone, whereas a 27-gene signature was associated with overall survival independently of molecular alterations, hematologic parameters, and renal function. Conclusions: Overall, our data contribute to a fine dissection of pPCL and may provide novel insights into the molecular definition of patients with poorer prognosis. Clin Cancer Res; 19(12); 3247–58. ©2013 AACR.

Response to recombinant erythropoietin alpha, without the adjunct of granulocyte-colony stimulating factor, is associated with a longer survival in patients with transfusion-dependent myelodysplastic syndromes

This was a retrospective, comparative study focused on the extended follow-up of 192 transfusion-dependent patients with myelodysplastic syndromes treated (n. 83) or not treated (n. 109) with recombinant erythropoietin alpha (r-EPO) as single agent during the course of their disease. The results supported the safety of this treatment in the long term and also showed a significant survival advantage (median 52 months vs. 31 months, p<0.0095) in responding patients as compared to non-responding ones or to subjects never treated with r-EPO. At multivariate analysis, response to r-EPO maintained an independent prognostic value on OS.

Differential toxic effects of methyl tertiary butyl ether and tert-butanol on rat fibroblasts in vitro

Methyl tertiary butyl ether (MTBE) is the most widely used motor vehicle fuel oxygenate since it reduces harmful emissions due to gasoline combustion. However, the significant increase in its use in recent years has raised new questions related to its potential toxicity. In fact, although available data are somehow conflicting, there is evidence that MTBE is a toxic substance that may have harmful effects on both animals and humans and an unresolved problem is the role played by MTBE metabolites, especially tertiary butyl alcohol (TBA), in determining toxic effects due to MTBE exposure. In this study, the toxic effects of MTBE have been analyzed on a normal diploid rat fibroblast cell line (Rat-1) and compared to the effects of TBA. The results obtained suggest that both MTBE and TBA inhibit cell growth in vitro but with different mechanisms in terms of effects on the cell cycle progression and on the modulation of cell cycle regulatory proteins. In fact, MTBE caused an accumulation of cells in the S-phase of the cell cycle, whereas TBA caused an accumulation in the G0/G1-phase with different effects on the expression of cyclin D1, p27Kip1, and p53. Moreover, both MTBE and TBA were also shown to induce DNA damage, as assessed in terms of oxidative DNA damage and nuclear DNA fragmentation, that appeared to be susceptible of repair by the cell DNA-repair machinery. In conclusion, these findings suggest that both MTBE and TBA can exert, by acting through different molecular mechanisms, important biological effects on fibroblasts in vitro. Further studies are warranted to shed light on the mechanisms responsible for the observed effects and on their potential significance for the in-vivo exposure.

Human skin-derived keratinocytes and fibroblasts co-cultured on 3D poly ε-caprolactone scaffold support in vitro HSC differentiation into T-lineage committed cells

In humans, the thymus is the primary lymphoid organ able to support the development of T cells through its three-dimensional (3D) organization of the thymic stromal cells. Since a remarkable number of similarities are shared between the thymic epithelial cells (TECs) and skin-derived keratinocytes and fibroblasts, in this study we used human keratinocytes seeded with fibroblasts on the 3D poly ε-caprolactone scaffold to evaluate their ability to replace TECs in supporting T-cell differentiation from human haematopoietic stem cells (HSCs). We observed that in the multicellular biocomposite, early thymocytes expressing CD7(+)CD1a(+), peculiar markers of an initial T-cell commitment, were de novo generated. Molecular studies of genes selectively expressed during T-cell development revealed that TAL1 was down-regulated and Spi-B was up-regulated in the cell suspension, consistently with a T-cell lineage commitment. Moreover, PTCRA and RAG2 expression was detected, indicative of a recombinant activity, required for the generation of a T-cell receptor repertoire. Our results indicate that in the multicellular biocomposite, containing skin-derived elements in the absence of thymic stroma, HSCs do start differentiating toward a T-cell lineage commitment. In conclusion, the construct described in this study exerts some properties of a lymphoid organoid, suitable for future clinical applications in cell-based therapies.

Modulation of CD20 antigen expression after rituximab treatment: a retrospective study in patients with chronic lymphocytic leukemia.

BACKGROUND CD20 antigen down-modulation by anti-CD20 rituximab treatment is a well-recognized phenomenon in patients with non-Hodgkins lymphoma. However, few data are currently available on this topic in other lymphoproliferative disorders, in particular in chronic lymphocytic leukemia (CLL). OBJECTIVE The aim of this study was to establish how many patients with CLL show a disappearance of CD20 antigen after salvage treatment with rituximab and its possible clinical significance. METHODS We sequentially analyzed CD20 expression by flow cytometry in patients treated with rituximab in combination with other agents for relapsed/resistant disease. RESULTS Eleven white patients with CLL (6 females, 5 males; median age, 71.6 years [range, 60-84 years]) were included in the study. Three of the 11 patients were not positive for CD20 due to complete response at baseline. Four of the remaining 8 patients (50%) lacked CD20 antigen on neoplastic cells after monoclonal antibody treatment. Two of them developed Richters syndrome and died within 4 months. The phenomenon was transient in the other 2 patients, who were alive after a follow-up of 25 and 26 months, respectively, with CD20-positive recurrent disease. CONCLUSIONS In this study, CD20 antigen disappearance in patients with CLL treated with rituximab-containing salvage regimens occurred in 4 of 8 (50%) tested patients, half of whom developed Richters syndrome. [Note: Since the initial writing and submission, a third patient developed Richters syndrome.] In 2 patients (50%), CD20 returned at progression.

Myelodysplastic disorders carrying both isolated del(5q) and JAK2(V617F) mutation: concise review, with focus on lenalidomide therapy.

The concomitant presence of del(5q) and JAK2V617F mutation is an infrequent event which occurs in rare patients with peculiar cytogenetic, molecular, morphological and clinical features, resembling those of both myelodysplastic syndromes and myeloproliferative neoplasms. Lenalidomide may induce rapid, profound, and long-lasting responses in a subset of these patients. However, the mechanism(s) by which the drug acts in these conditions remain not completely elucidated. A new case report and a review of all cases published so far in this setting are provided. Furthermore, the possibility of categorizing – from a clinical, pathological, and biological point of view – for at least some of these patients as a potential distinct entity is discussed.