@article {7731, title = {Applications of nanoparticles in cancer medicine and beyond: optical and multimodal in vivo imaging, tissue targeting and drug delivery.}, journal = {Expert Opin Drug Deliv}, year = {2015}, month = {2015 Aug 9}, pages = {1-13}, abstract = {

INTRODUCTION: Nanotechnology has opened up the way to the engineering of new organized materials endowed with improved performances. In the past decade, engineered nanoparticles (NPs) have been progressively implemented by exploiting synthetic strategies that yield complex materials capable of performing functions with applications also in medicine. Indeed, in the field of {\textquoteright}nanomedicine{\textquoteright} it has been explored the possibility to design multifunctional nanosystems, characterized by high analytical performances and stability, low toxicity and specificity towards a given cell target. Area covered: In this review article, we summarize the advances in the engineering of NPs for biomedical applications, from optical imaging (OI) to multimodal OI and targeted drug delivery. For this purpose, we will provide some examples of how investigations in nanomedicine can support preclinical and clinical research generating innovative diagnostic and therapeutic strategies in oncology. Expert opinion: The progressive breakthroughs in nanomedicine have supported the development of multifunctional and multimodal NPs. In particular, NPs are significantly impacting the diagnostic and therapeutic strategies since they allow the development of: NP-based OI probes containing more than one modality-specific contrast agent; surface functionalized NPs for specific {\textquoteright}molecular recognition{\textquoteright}. Therefore, the design and characterization of innovative NP-based systems/devices have great applicative potential into the medical field.

}, issn = {1744-7593}, author = {Biffi, Stefania and Voltan, Rebecca and Rampazzo, Enrico and Prodi, Luca and Zauli, Giorgio and Secchiero, Paola} } @article {8097, title = {Design, Synthesis, and Biological Characterization of Novel Mitochondria Targeted Dichloroacetate-Loaded Compounds with Antileukemic Activity.}, journal = {J Med Chem}, year = {2015}, month = {2015 Dec 23}, abstract = {

The mitochondrial kinase inhibitor dichloroacetate (DCA) has recently received attention in oncology due to its ability to target glycolysis. However, DCA molecule exhibits poor bioavailability and cellular uptake with limited ability to reach its target mitochondria. To overcome these biases, we have synthesized novel DCA-loaded compounds. The selection of the most promising therapeutic molecule was evaluated by combining in vitro assays, to test the antitumoral potential on leukemic cells, and a preliminary characterization of the molecule stability in vivo, in mice. Among the newly synthesized compounds, we have selected the multiple DCA-loaded compound 10, characterized by a tertiary amine scaffold, because it exhibited enhanced (>30-fold) in vitro antitumor activity with respect to DCA and increased in vivo stability. On the basis of these results, we believe that compound 10 should be considered for further preclinical evaluations for the treatment of cancers and/or other diseases characterized by altered metabolic origin.

}, issn = {1520-4804}, doi = {10.1021/acs.jmedchem.5b01165}, author = {Trapella, Claudio and Voltan, Rebecca and Melloni, Elisabetta and Tisato, Veronica and Celeghini, Claudio and Bianco, Sara and Fantinati, Anna and Salvadori, Severo and Guerrini, Remo and Secchiero, Paola and Zauli, Giorgio} } @article {3544, title = {Heterogeneity of mesenchymal stromal cells in lymphoproliferative disorders.}, journal = {Front Biosci (Landmark Ed)}, volume = {19}, year = {2014}, month = {2014}, pages = {139-51}, abstract = {

Accumulating evidence indicates that bone marrow microenvironment plays an important role in the pathogenesis of some myeloid and lymphoid hematological malignancies (HM). Among different environmental associated parameters, those related to functional, cytogenetic and immunological integrity of mesenchymal stromal cells (MSC) are particularly relevant. Functional alterations and immunophenotypic abnormalities have been described in MSC obtained from HM patients. These data seem to confirm the defective biological pattern of MSC especially in myeloid diseases, while MSC cytogenetic profile in HM is still an open question, because it is not clear whether BM stromal cells are "culprit or bystander" displaying or not an abnormal karyotype. Contradictory findings were reported in different HM but the functional implications of altered MSC karyotype need to be further addressed also in light of a clinical use of MSC. A "pathological" in vivo supportive function of endogenous MSC, which provide important survival and drug resistance signals to leukemic cells especially in lymphoproliferative disorders, is suggested. Thus, the mechanisms underlying these protective versus cytotoxic effects exerted by MSC on leukemic cells need further investigations.

}, keywords = {Humans, Immunophenotyping, Karyotyping, Lymphoproliferative Disorders, Mesenchymal Stromal Cells}, issn = {1093-4715}, author = {Campioni, Diana and Voltan, Rebecca and Tisato, Veronica and Zauli, Giorgio} } @article {3540, title = {In vitro endothelial cell proliferation assay reveals distinct levels of proangiogenic cytokines characterizing sera of healthy subjects and of patients with heart failure.}, journal = {Mediators Inflamm}, volume = {2014}, year = {2014}, month = {2014}, pages = {257081}, abstract = {

Although myocardial angiogenesis is thought to play an important role in heart failure (HF), the involvement of circulating proinflammatory and proangiogenic cytokines in the pathogenesis and/or prognosis of HF has not been deeply investigated. By using a highly standardized proliferation assay with human endothelial cells, we first demonstrated that sera from older (mean age 52 {\textpm} 7.6 years; n = 46) healthy donors promoted endothelial cell proliferation to a significantly higher extent compared to sera obtained from younger healthy donors (mean age 29 {\textpm} 8.6 years; n = 20). The promotion of endothelial cell proliferation was accompanied by high serum levels of several proangiogenic cytokines. When we assessed endothelial cell proliferation in response to HF patients{\textquoteright} sera, we observed that a subset of sera (n = 11) promoted cell proliferation to a significantly lesser extent compared to the majority of sera (n = 18). Also, in this case, the difference between the patient groups in the ability to induce endothelial cell proliferation correlated to significant (P < 0.05) differences in serum proangiogenic cytokine levels. Unexpectedly, HF patients associated to the highest endothelial proliferation index showed the worst prognosis as evaluated in terms of subsequent cardiovascular events in the follow-up, suggesting that high levels of circulating proangiogenic cytokines might be related to a worse prognosis.

}, keywords = {Adult, Cell Proliferation, Cells, Cultured, Chemokines, Cytokines, Heart Failure, Human Umbilical Vein Endothelial Cells, Humans, Middle Aged, Neovascularization, Pathologic, Prognosis}, issn = {1466-1861}, doi = {10.1155/2014/257081}, author = {Voltan, Rebecca and Zauli, Giorgio and Rizzo, Paola and Fucili, Alessandro and Pannella, Micaela and Marci, Roberto and Tisato, Veronica and Ferrari, Roberto and Secchiero, Paola} } @article {8098, title = {The p53 transcriptional pathway is preserved in ATMmutated and NOTCH1mutated chronic lymphocytic leukemias.}, journal = {Oncotarget}, volume = {5}, year = {2014}, month = {2014 Dec 30}, pages = {12635-45}, abstract = {

By using next generation sequencing, we have analyzed 108 B chronic lymphocytic leukemia (B-CLL) patients. Among genes involved in the TP53 pathway, we found frequent mutations in ATM (n=18), TP53 (n=10) and NOTCH1 (n=10) genes, rare mutations of NOTCH2 (n=2) and CDKN1A/p21 (n=1) and no mutations in BAX, MDM2, TNFRSF10A and TNFRSF10B genes. The in vitro treatment of primary B-CLL cells with the activator of p53 Nutlin-3 induced the transcription of p53 target genes, without significant differences between the B-CLL without mutations and those harboring either ATM or NOTCH1mutations. On the other hand, the subgroup of TP53mutated B-CLL exhibited a significantly lower induction of the p53 target genes in response to Nutlin-3 as compared to the other B-CLL samples. However, among the TP53mutated B-CLL, those showing mutations in the high hot spot region of the DNA binding domain [273-280 aa] maintained a significantly higher p53-dependent transcriptional activity as compared to the other TP53mutated B-CLL samples. Since the ability to elicit a p53-dependent transcriptional activity in vitro has a positive prognostic significance, our data suggest that ATMmutated, NOTCH1mutated and surprisingly, also a subset of TP53mutated B-CLL patients might benefit from therapeutic combinations including small molecule activator of the p53 pathway.

}, keywords = {Aged, Aged, 80 and over, Ataxia Telangiectasia Mutated Proteins, Base Sequence, Female, Genes, p53, Humans, Leukemia, Lymphocytic, Chronic, B-Cell, Male, Models, Molecular, Molecular Sequence Data, Mutation, Receptor, Notch1, Signal Transduction, Tumor Suppressor Protein p53}, issn = {1949-2553}, doi = {10.18632/oncotarget.2211}, author = {Athanasakis, Emmanouil and Melloni, Elisabetta and Rigolin, Gian Matteo and Agnoletto, Chiara and Voltan, Rebecca and Vozzi, Diego and Piscianz, Elisa and Segat, Ludovica and dal Monego, Simeone and Cuneo, Antonio and Secchiero, Paola and Zauli, Giorgio} } @article {1769, title = {Activation of the p53 pathway induces α-smooth muscle actin expression in both myeloid leukemic cells and normal macrophages.}, journal = {J Cell Physiol}, volume = {227}, year = {2012}, month = {2012 May}, pages = {1829-37}, abstract = {

A range of cell types of mesenchymal origin express α-smooth muscle actin (α-SMA), a protein that plays a key role in controlling cell motility and differentiation along the fibrocyte and myofibroblast lineages. Although α-SMA is often expressed in stromal cells associated to a variety of cancers including hematological malignancies, up to now the role of anti-cancer drugs on α-SMA has not been deeply investigated. In this study, we demonstrated that Nutlin-3, the small molecule inhibitor of the MDM2/p53 interactions, significantly up-regulated the mRNA and protein levels of α-SMA in normal macrophages as well as in p53(wild-type) but not in p53(mutated/null) myeloid leukemic cells. The p53-dependence of α-SMA up-regulation induced by Nutlin-3 was demonstrated in experiments performed with siRNA for p53. Of note, Nutlin-3 mediated up-regulation of α-SMA in OCI leukemic cells was accompanied by cell adhesion to plastic substrate and by reduced cell migratory response in transwell assays. Notably, the role of α-SMA induction in the modulation of myeloid cell migration was clearly documented in α-SMA gene knockdown experiments. In addition, Nutlin-3 significantly up-regulated α-SMA expression in primary endothelial cells, but not in fibroblasts and mesenchymal stem cells (MSC). Conversely, transforming growth factor-β1 up-regulated α-SMA in fibroblasts and MSC, but not in macrophages and endothelial cells. Taken together, these data indicate that Nutlin-3 is a potent inducer of α-SMA in both normal and leukemic myeloid cells as well as in endothelial cells.

}, keywords = {Actins, Cell Movement, Cells, Cultured, Endothelial Cells, Fibroblasts, Humans, Imidazoles, Leukemia, Myeloid, Macrophages, Mesenchymal Stromal Cells, Piperazines, Proto-Oncogene Proteins c-mdm2, RNA, Small Interfering, Signal Transduction, Transforming Growth Factor beta1, Tumor Suppressor Protein p53}, issn = {1097-4652}, doi = {10.1002/jcp.22910}, author = {Secchiero, Paola and Rimondi, Erika and di Iasio, Maria Grazia and Voltan, Rebecca and Gonelli, Arianna and Zauli, Giorgio} } @article {1625, title = {Anti-leukemic activity of dasatinib in both p53(wild-type) and p53(mutated) B malignant cells.}, journal = {Invest New Drugs}, volume = {30}, year = {2012}, month = {2012 Feb}, pages = {417-22}, abstract = {

The multi-kinase inhibitor dasatinib induced a variable but significant decrease of viability in both p53(wild-type) (EHEB, JVM-2, JVM-3) and p53(mutated) (MEC-1, MEC-2, BJAB) prolymphocytic B leukemic cells, due to a combination of cell cycle block in G1 and apoptosis. Antibody phospho-kinase array analysis revealed that dasatinib inhibited the phosphorylation of various kinases, including ERK1/2 and p38/MAPK as well as of STAT3 transcription factors, in both p53(wild-type) and p53(mutated) cells. Therefore, dasatinib might offer a novel therapeutic strategy not only for p53(wild-type), but also for p53(mutated) B malignancies that have the worst prognosis and urgently need innovative therapeutic approaches.

}, keywords = {Antineoplastic Agents, Apoptosis, B-Lymphocytes, Cell Line, Tumor, Cell Survival, G1 Phase Cell Cycle Checkpoints, Granulocyte Precursor Cells, Humans, Leukemia, Prolymphocytic, B-Cell, Mitogen-Activated Protein Kinase 1, Mitogen-Activated Protein Kinase 3, Mutation, p38 Mitogen-Activated Protein Kinases, Phosphorylation, Protein Kinase Inhibitors, Pyrimidines, STAT3 Transcription Factor, Thiazoles, Time Factors, Tumor Suppressor Protein p53}, issn = {1573-0646}, doi = {10.1007/s10637-010-9564-6}, author = {Bosco, Raffaella and Rabusin, Marco and Voltan, Rebecca and Celeghini, Claudio and Corallini, Federica and Capitani, Silvano and Secchiero, Paola} } @article {1927, title = {Endothelial cells obtained from patients affected by chronic venous disease exhibit a pro-inflammatory phenotype.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012}, pages = {e39543}, abstract = {

BACKGROUND: The inflammatory properties of vein endothelium in relation to chronic venous disease (CVD) have been poorly investigated. Therefore, new insights on the characteristics of large vein endothelium would increase our knowledge of large vessel physiopathology.

METHODOLOGY/PRINCIPAL FINDINGS: Surgical specimens of veins were obtained from the tertiary venous network (R3) and/or saphenous vein (SF) of patients affected by CVD and from control individuals. Highly purified venous endothelial cell (VEC) cultures obtained from CVD patients were characterized for morphological, phenotypic and functional properties compared to control VEC. An increase of CD31/PECAM-1, CD146 and ICAM-1 surface levels was documented at flow cytometry in pathological VEC with respect to normal controls. Of note, the strongest expression of these pro-inflammatory markers was observed in VEC obtained from patients with more advanced disease. Similarly, spontaneous cell proliferation and resistance to starvation was higher in pathological than in normal VEC, while the migratory response of VEC showed an opposite trend, being significantly lower in VEC obtained from pathological specimens. In addition, in keeping with a higher baseline transcriptional activity of NF-kB, the release of the pro-inflammatory cytokines osteoprotegerin (OPG) and vascular endothelial growth factor (VEGF) was higher in pathological VEC cultures with respect to control VEC. Interestingly, there was a systemic correlation to these in vitro data, as demonstrated by higher serum OPG and VEGF levels in CVD patients with respect to normal healthy controls.

CONCLUSION/SIGNIFICANCE: Taken together, these data indicate that large vein endothelial cells obtained from CVD patients exhibit a pro-inflammatory phenotype, which might significantly contribute to systemic inflammation in CVD patients.

}, keywords = {Adult, Antigens, CD146, Antigens, CD31, Body Mass Index, Cell Culture Techniques, Endothelial Cells, Female, Flow Cytometry, Humans, Inflammation, Intercellular Adhesion Molecule-1, Kinetics, Male, Microscopy, Electron, Scanning, Middle Aged, Phenotype, Saphenous Vein, Vascular Diseases}, issn = {1932-6203}, doi = {10.1371/journal.pone.0039543}, author = {Tisato, Veronica and Zauli, Giorgio and Voltan, Rebecca and Gianesini, Sergio and di Iasio, Maria Grazia and Volpi, Ilaria and Fiorentini, Guido and Zamboni, Paolo and Secchiero, Paola} } @article {1892, title = {MCL1 down-regulation plays a critical role in mediating the higher anti-leukaemic activity of the multi-kinase inhibitor Sorafenib with respect to Dasatinib.}, journal = {Br J Haematol}, volume = {157}, year = {2012}, month = {2012 May}, pages = {510-4}, keywords = {Antineoplastic Agents, Benzenesulfonates, Cell Line, Tumor, Down-Regulation, Humans, Leukemia, Myeloid, Acute, Myeloid Cell Leukemia Sequence 1 Protein, Niacinamide, Phenylurea Compounds, Protein Kinase Inhibitors, Proto-Oncogene Proteins c-bcl-2, Pyridines, Pyrimidines, Thiazoles}, issn = {1365-2141}, doi = {10.1111/j.1365-2141.2012.09042.x}, author = {Secchiero, Paola and Melloni, Elisabetta and Voltan, Rebecca and Norcio, Alessia and Celeghini, Claudio and Zauli, Giorgio} } @article {1766, title = {Nutlin-3 differentially modulates miRNA34a and miRNA181 versus miR26a and miR155 in p53 proficient and p53 deficient B chronic lymphocytic leukemia (B-CLL) samples.}, journal = {Invest New Drugs}, volume = {30}, year = {2012}, month = {2012 Aug}, pages = {1761-5}, keywords = {Down-Regulation, Gene Expression Profiling, Gene Expression Regulation, Leukemic, Humans, Imidazoles, Leukemia, Lymphocytic, Chronic, B-Cell, MicroRNAs, Piperazines, Proto-Oncogene Proteins c-mdm2, Tumor Suppressor Protein p53}, issn = {1573-0646}, doi = {10.1007/s10637-011-9695-4}, author = {di Iasio, Maria Grazia and Addobbati, Riccardo and Radillo, Oriano and Voltan, Rebecca} } @article {1926, title = {The sorafenib plus nutlin-3 combination promotes synergistic cytotoxicity in acute myeloid leukemic cells irrespectively of FLT3 and p53 status.}, journal = {Haematologica}, volume = {97}, year = {2012}, month = {2012 Nov}, pages = {1722-30}, abstract = {

BACKGROUND: Both the multi-kinase inhibitor sorafenib and the small molecule inhibitor of the MDM2/p53 interaction, nutlin-3, used alone, have shown promising anti-leukemic activity in acute myeloid leukemia cells. Thus, in this study we investigated the effect of the combination of sorafenib plus nutlin-3 in acute myeloid leukemia.

DESIGN AND METHODS: Primary acute myeloid leukemia blasts (n=13) and FLT3(wild-type)/p53(wild-type) (OCI-AML3), FLT3(mutated)/p53(wild-type) (MOLM), FLT3(mutated)/p53(mutated) (MV4-11), FLT3(wild-type)/p53(deleted) (HL60) or FLT3(wild-type)/p53(mutated) (NB4) acute myeloid cell lines were exposed to sorafenib, used alone or in association with nutlin-3 at a 1:1 ratio, in a range of clinically achievable concentrations (1-10 μM). Induction of apoptosis and autophagy was evaluated by transmission electron microscopy and by specific flow cytometry analyses. The levels of Mcl-1, p53 and Bak proteins were analyzed by western blotting. Knock-down of Bax and Bak gene expression was performed in transfection experiments with specific short interfering RNA.

RESULTS: The sorafenib+nutlin-3 drug combination exhibits synergistic cytotoxicity in primary acute myeloid leukemia blasts and in acute myeloid leukemia cell lines with maximal cytotoxicity in FLT3(mutated) MV4-11 and MOLM, followed by the FLT3(wild-type) OCI-AML3, HL60 and NB4 cell lines. The cytotoxic activity of sorafenib+nutlin-3 was characterized by an increase of both apoptosis and autophagy. Moreover, Bax and Bak showed prominent roles in mediating the decrease of cell viability in response to the drug combination in p53(wild-type) OCI-AML3 and p53(deleted) HL-60 cells, respectively, as demonstrated in transfection experiments performed with specific short interfering RNA.

CONCLUSIONS: Our data demonstrate that acute myeloid leukemia cells show a variable but overall good susceptibility to the innovative therapeutic combination of sorafenib+nutlin-3, which differentially involves the pro-apoptotic Bcl-2 family members Bax and Bak in p53(wild-type) and p53(deleted) cells.

}, keywords = {Antineoplastic Agents, Drug Synergism, Female, fms-Like Tyrosine Kinase 3, HL-60 Cells, Humans, Imidazoles, Leukemia, Myeloid, Acute, Male, Niacinamide, Phenylurea Compounds, Piperazines, Tumor Suppressor Protein p53}, issn = {1592-8721}, doi = {10.3324/haematol.2012.062083}, author = {Zauli, Giorgio and Celeghini, Claudio and Melloni, Elisabetta and Voltan, Rebecca and Ongari, Manuele and Tiribelli, Mario and di Iasio, Maria Grazia and Lanza, Francesco and Secchiero, Paola} } @article {1739, title = {Dasatinib plus Nutlin-3 shows synergistic antileukemic activity in both p53 wild-type and p53 mutated B chronic lymphocytic leukemias by inhibiting the Akt pathway.}, journal = {Clin Cancer Res}, volume = {17}, year = {2011}, month = {2011 Feb 15}, pages = {762-70}, abstract = {

PURPOSE: To analyze the effect of the combination of Dasatinib, a multikinase inhibitor, plus Nutlin-3, a nongenotoxic activator of the p53 pathway, in primary B chronic lymphocytic leukemia (B-CLL) patient samples and B leukemic cell line models.

EXPERIMENTAL DESIGN: The induction of cytotoxicity was evaluated in both primary B-CLL cell samples (n = 20) and in p53(wild-type) (EHEB, JVM-2) and p53(deleted/mutated) (MEC-2, BJAB) B leukemic cell lines. The role of Akt in modulating leukemic cell survival/apoptosis in response to Dasatinib or Dasatinib + Nutlin-3 was documented by functional experiments carried out using specific pharmacological inhibitors and by overexpression of membrane-targeted constitutively active form of Akt.

RESULTS: The combination of Dasatinib + Nutlin-3 exhibited a synergistic cytotoxicity in the majority (19 out of 20) of B-CLL samples, including patients carrying 17p- (n = 4), and in both p53(wild-type) and p53(deleted/mutated) B leukemic cell lines. At the molecular level, Dasatinib significantly counteracted the Nutlin-3-mediated induction of the p53 transcriptional targets MDM2 and p21 observed in p53(wild-type) leukemic cells. Conversely, Nutlin-3 did not interfere with the ability of Dasatinib to decrease the phosphorylation levels of ERK1/2, p38/MAPK, and Akt in both p53(wild-type) and p53(deleted/mutated) B leukemic cell lines. A critical role of Akt downregulation in mediating the antileukemic activity of Dasatinib and Dasatinib + Nutlin-3 was demonstrated in experiments carried out by specifically modulating the Akt pathway.

CONCLUSIONS: These findings suggest that Dasatinib + Nutlin-3 might represent an innovative therapeutic combination for both p53(wild-type) and p53(deleted/mutated) B-CLL.

}, keywords = {Antineoplastic Agents, Apoptosis, Cell Line, Tumor, Cell Survival, Down-Regulation, Drug Synergism, Humans, Imidazoles, Leukemia, Lymphocytic, Chronic, B-Cell, Mutation, Piperazines, Protein Kinase Inhibitors, Protein Kinases, Proto-Oncogene Proteins c-akt, Pyrimidines, Thiazoles, Transcription, Genetic, Tumor Suppressor Protein p53}, issn = {1078-0432}, doi = {10.1158/1078-0432.CCR-10-2572}, author = {Zauli, Giorgio and Voltan, Rebecca and Bosco, Raffaella and Melloni, Elisabetta and Marmiroli, Sandra and Rigolin, Gian Matteo and Cuneo, Antonio and Secchiero, Paola} } @article {1729, title = {miR-34a induces the downregulation of both E2F1 and B-Myb oncogenes in leukemic cells.}, journal = {Clin Cancer Res}, volume = {17}, year = {2011}, month = {2011 May 1}, pages = {2712-24}, abstract = {

PURPOSE: To elucidate new molecular mechanisms able to downregulate the mRNA levels of key oncogenes, such as B-Myb and E2F1, in a therapeutic perspective.

EXPERIMENTAL DESIGN: B-Myb and E2F1 mRNA levels were evaluated in primary B chronic lymphocytic leukemia (B-CLL, n = 10) and acute myeloid leukemia (AML, n = 5) patient cells, in a variety of p53(wild-type) and p53(mutated/deleted) leukemic cell lines, as well as in primary endothelial cells and fibroblasts. Knockdown experiments with siRNA for p53 and E2F1 and overexpression experiments with miR34a were conducted to elucidate the role of these pathways in promoting B-Myb downregulation.

RESULTS: In vitro exposure to Nutlin-3, a nongenotoxic activator of p53, variably downregulated the expression of B-Myb in primary leukemic cells and in p53(wild-type) myeloid (OCI, MOLM) and lymphoblastoid (SKW6.4, EHEB) but not in p53(mutated) (NB4, BJAB, MAVER) or p53(deleted) (HL-60) leukemic cell lines. The transcriptional repression of B-Myb was also observed in primary normal endothelial cells and fibroblasts. B-Myb downregulation played a critical role in the cell-cycle block in G(1) phase induced by Nutlin-3, as shown by transfection experiments with specific siRNA. Moreover, we have provided experimental evidence suggesting that miR-34a is a central mediator in the repression of B-Myb both directly and through E2F1.

CONCLUSIONS: Owing to the role of B-Myb and E2F1 transcription factors in controlling cell-cycle progression of leukemic cells, the downregulation of these oncogenes by miR-34a suggests the usefulness of therapeutic approaches aimed to modulate the levels of miR-34a.

}, keywords = {Base Sequence, Cell Cycle Proteins, Cell Line, Tumor, Cells, Cultured, Down-Regulation, E2F1 Transcription Factor, Gene Expression Regulation, Leukemic, HCT116 Cells, HL-60 Cells, Humans, Imidazoles, Leukemia, MicroRNAs, Models, Biological, Oncogenes, Piperazines, Sequence Homology, Nucleic Acid, Trans-Activators, Transfection}, issn = {1078-0432}, doi = {10.1158/1078-0432.CCR-10-3244}, author = {Zauli, Giorgio and Voltan, Rebecca and di Iasio, Maria Grazia and Bosco, Raffaella and Melloni, Elisabetta and Sana, Maria Elena and Secchiero, Paola} }