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Andrea Rinaldi

Publications and source records attributed to Andrea Rinaldi.

At least 19 recordsLinked to original sources
PubMed2007

Molecular characterization of human multiple myeloma cell lines by integrative genomics: insights into the biology of the disease.

To investigate the patterns of genetic lesions in a panel of 23 human multiple myeloma cell lines (HMCLs), we made a genomic integrative analysis involving FISH, and both gene expression and genome-wide profiling approaches. The expression profiles of the genes targeted by the main IGH translocations showed that the WHSC1/MMSET gene involved in t(4;14)(p16;q32) was expressed at different levels in all of the HMCLs, and that the expression of the MAF gene was not restricted to the HMCLs carrying t(14;16)(q32;q23). Supervised analyses identified a limited number of genes specifically associated with t(4;14) and involved in different biological processes. The signature related to MAF/MAFB expression included the known MAF target genes CCND2 and ITGB7, as well as genes controlling cell shape and cell adhesion. Genome-wide DNA profiling allowed the identification of a gain on chromosome arm 1q in 88% of the analyzed cell lines, together with recurrent gains on 8q, 18q, 7q, and 20q; the most frequent deletions affected 1p, 13q, 17p, and 14q; and almost all of the cell lines presented LOH on chromosome 13. Two hundred and twenty-two genes were found to be simultaneously overexpressed and amplified in our panel, including the BCL2 locus at 18q21.33. Our data further support the evidence of the genomic complexity of multiple myeloma and reinforce the role of an integrated genomic approach in improving our understanding of the molecular pathogenesis of the disease. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Cell Line, Tumor↗
PubMed2006

A cyanobacterial LPS antagonist prevents endotoxin shock and blocks sustained TLR4 stimulation required for cytokine expression.

Toll-like receptors (TLRs) function as primary sensors that elicit coordinated innate immune defenses through recognition of microbial products and induction of immune and proinflammatory genes. Here we report the identification and biological characterization of a lipopolysaccharide (LPS)-like molecule extracted from the cyanobacterium Oscillatoria Planktothrix FP1 (cyanobacterial product [CyP]) that is not stimulatory per se but acts as a potent and selective antagonist of bacterial LPS. CyP binds to MD-2 and efficiently competes with LPS for binding to the TLR4-MD-2 receptor complex. The addition of CyP together with LPS completely inhibited both MyD88- and TRIF-dependent pathways and suppressed the whole LPS-induced gene transcription program in human dendritic cells (DCs). CyP protected mice from endotoxin shock in spite of a lower capacity to inhibit LPS stimulation of mouse DCs. Interestingly, the delayed addition of CyP to DCs responding to LPS strongly inhibited signaling and cytokine production by immediate down-regulation of inflammatory cytokine mRNAs while not affecting other aspects of DC maturation, such as expression of major histocompatibility complex molecules, costimulatory molecules, and CCR7. Collectively, these results indicate that CyP is a potent competitive inhibitor of LPS in vitro and in vivo and reveal the requirement of sustained TLR4 stimulation for induction of cytokine genes in human DCs.

Animals↗
PubMed2006

Novel GC-rich DNA-binding compound produced by a genetically engineered mutant of the mithramycin producer Streptomyces argillaceus exhibits improved transcriptional repressor activity: implications for cancer therapy.

The aureolic acid antibiotic mithramycin (MTM) binds selectively to GC-rich DNA sequences and blocks preferentially binding of proteins, like Sp1 transcription factors, to GC-rich elements in gene promoters. Genetic approaches can be applied to alter the MTM biosynthetic pathway in the producing microorganism and obtain new products with improved pharmacological properties. Here, we report on a new analog, MTM SDK, obtained by targeted gene inactivation of the ketoreductase MtmW catalyzing the last step in MTM biosynthesis. SDK exhibited greater activity as transcriptional inhibitor compared to MTM. SDK was a potent inhibitor of Sp1-dependent reporter activity and interfered minimally with reporters of other transcription factors, indicating that it retained a high degree of selectivity toward GC-rich DNA-binding transcription factors. RT-PCR and microarray analysis showed that SDK repressed transcription of multiple genes implicated in critical aspects of cancer development and progression, including cell cycle, apoptosis, migration, invasion and angiogenesis, consistent with the pleiotropic role of Sp1 family transcription factors. SDK inhibited proliferation and was a potent inducer of apoptosis in ovarian cancer cells while it had minimal effects on viability of normal cells. The new MTM derivative SDK could be an effective agent for treatment of cancer and other diseases with abnormal expression or activity of GC-rich DNA-binding transcription factors.

Antibiotics, Antineoplastic↗
PubMed2006

Update on the molecular biology of mantle cell lymphoma.

Mantle cell lymphoma (MCL) accounts for 5-10% of non-Hodgkin's lymphomas and it bears the worst prognosis among B cell lymphomas. Even more than in the other lymphomas, new insights in MCL biology are needed. In this review we will discuss the most recent published data. Immunoglobulin sequencing data suggest that the MCL cell of origin is a mature B cell which might have undergone an extra-follicular T-cell independent antigen maturation. The main aberrations that affect cell cycle and DNA repair pathways in MCL are summarized, also discussing the need of the t(11;14)(q13;q32) to make diagnosis of MCL. After the gene expression studies of the last years, now the research focus has moved towards the new opportunities provided by arrayCGH technique for gene discovery and for identification of therapeutic targets. Examples of genes identified because deleted or amplified at DNA level and that might be relevant for MCL pathogenesis are presented.

Cell Cycle↗
PubMed2006

The phantom menace.

Explore the source record for details and available documents.

Antiviral Agents↗
PubMed2006

Losartan and prevention of atrial fibrillation recurrence in hypertensive patients.

The aim of the study was to evaluate the effect of losartan as compared with amlodipine, both associated with amiodarone, in preventing the recurrence of atrial fibrillation (AF) in hypertensive patients with a history of recent paroxysmal atrial fibrillation. Two hundred and fifty mild hypertensive (SBP > 140 mm Hg and/or DBP > 90 < 100 mm Hg) outpatients in sinus rhythm but with at least two ECG-documented episodes of symptomatic atrial fibrillation in the previous 6 months and in treatment with amiodarone were randomized to losartan or amlodipine and were followed up for 1 year. Clinic blood pressure (BP) and a 24-hour ECG was evaluated every month; the patients were asked to report any episode of symptomatic atrial fibrillation and to perform an ECG as early as possible. Two hundred and thirteen patients completed the study, 107 in the losartan group and 106 in the amlodipine group. After 12 months the SBP/DBP mean values were significantly reduced by both losartan (from 151.4/95.6 to 135.5/83.7 mm Hg, P < 0.001 versus baseline) and amlodipine (from 152.3/96.5 to 135.2/83.4 mm Hg, P < 0.001 versus baseline), with no difference between the two treatments. At least one ECG-documented episode of atrial fibrillation was reported in 13% of the patients treated with losartan and in 39% of the patients treated with amlodipine. The use of losartan in combination with amiodarone seems more effective than amlodipine/amiodarone combination in preventing new episodes of atrial fibrillation in hypertensive patients with recurrent atrial fibrillation. This might be related to possible favorable impact of angiotensin II receptor blockers (ARB) on the atrial electrical and structural remodeling in this type of patients.

Adult↗
PubMed2006

Genomic and expression profiling identifies the B-cell associated tyrosine kinase Syk as a possible therapeutic target in mantle cell lymphoma.

Among B-cell lymphomas mantle cell lymphoma (MCL) has the worst prognosis. By using a combination of genomic and expression profiling (Affymetrix GeneChip Mapping 10k Xba131 and U133 set), we analysed 26 MCL samples to identify genes relevant to MCL pathogenesis and that could represent new therapeutic targets. Recurrent genomic deletions and gains were detected. Genes were identified as overexpressed in regions of DNA gain on 3q, 6p, 8q, 9q, 16p and 18q, including the cancer genes BCL2 and MYC. Among the transcripts with high correlation between DNA and RNA, we identified SYK, a tyrosine kinase involved in B-cell receptor signalling. SYK was amplified at DNA level, as validated by fluorescence in situ hybridisation (FISH) analysis, and overexpressed at both RNA and protein levels in the JeKo-1 cell line. Low-level amplification, with protein overexpression of Syk was demonstrated by FISH in a small subset of clinical samples. After treatment with low doses of the Syk inhibitor piceatannol, cell proliferation arrest and apoptosis were induced in the cell line overexpressing Syk, while cells expressing low levels of Syk were much less sensitive. A combination of genomic and expression profiling suggested Syk inhibition as a new therapeutic strategy to be explored in lymphomas.

Apoptosis↗
PubMed2006

Comparative genome-wide profiling of post-transplant lymphoproliferative disorders and diffuse large B-cell lymphomas.

Post-transplant lymphoproliferative disorders (PTLD) are a major complication of solid organ transplantation, representing a cause of severe morbidity and mortality. Apart from Epstein-Barr virus infection, knowledge of the pathogenesis of monoclonal PTLD is limited. Powerful analysis techniques, such as whole genomic DNA profiling (array comparative genomic hybridisation), can improve our understanding of PTLD pathogenesis. Whole genome profiling using the Affymetrix GeneChip Human Mapping 10 k 2.0 was performed on 20 PTLD cases and 25 cases of diffuse large B-cell lymphoma (DLBCL) from immunocompetent patients as a control group. Recurrent lesions were detected among all the samples. Chromosome 18q, 7q, 3q and 12 were the most common gains in the control group. Chromosomes 5p and 11p were commonly gained in PTLD-DLBCL. The latter had frequent losses of 6q, 17p, 1p and 9p. Chromosome 12p was the most frequent target of deletions among PTLD-DLBCL cases. Loss of heterozygosity (LOH) did not always match DNA loss: chromosome 10 seemed to be targeted by uniparental disomy in PTLD. Small deletions and gains, involving both known (BCL2 and PAX5) and unknown genes (ZDHHC14), were identified. These data suggest that PTLD share, at a lower frequency, common genetic aberrations with DLBCL from immunocompetent patients. The demonstration of 9p13 amplification emphasises the importance of PAX5 in PTLD. The combination of DNA copy number and LOH assessment lead to the hypothesis that uniparental disomy may be a potential mechanism in B-cell lymphomagenesis.

Chromosome Aberrations↗
PubMed2006

Cellular and molecular consequences of peroxisome proliferator-activated receptor-gamma activation in ovarian cancer cells.

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a ligand-activated transcription factor. In addition to its canonical role in lipid and glucose metabolism, PPAR-gamma controls cell proliferation, death, and differentiation in several tissues. Here we have examined the expression of PPAR-gamma in ovarian tumors and the cellular and molecular consequences of its activation in ovarian cancer cells. PPAR-gamma was expressed in a large number of epithelial ovarian tumors and cell lines. The PPAR-gamma ligand ciglitazone inhibited the growth and clonogenic survival of ovarian cancer cells, inducing cell cycle arrest and cell death. Growth inhibition by ciglitazone was reversed by the PPAR-gamma antagonist GW9662, indicating the involvement of PPAR-gamma-dependent mechanisms. Microarray-based gene profiling revealed complex changes in the transcriptional program of ovarian cancer cells on treatment with ciglitazone and identified multiple pathways that may contribute to PPAR-gamma ligands' antitumor activity. Genes upregulated by ciglitazone were predominantly associated with metabolic, differentiation, and tumor-suppressor pathways, whereas downregulated genes were involved in cell proliferation, cell cycle, cell organization, and steroid biosynthesis. Collectively, our data indicate that PPAR-gamma activation by selective agonists is a valid strategy for ovarian cancer therapy and prevention, and should be tested alone and in combination with other anticancer drugs.

Cell Cycle↗
PubMed2006

Validation by RQ-PCR and flow cytometry of alpha-defensin1-3 (DEFA1-3) overexpression in relapsed and refractory acute lymphoblastic leukemia.

In spite of high cure rates and improved overall survival, 25% of pediatric patients with acute lymphoblastic leukemia (ALL) relapse after obtaining complete remission. Additionally a small proportion of patients are refractory and do not attain remission. Microarray expression analysis of matched diagnosis-relapse B-lineage ALL sample pairs identified DEFA1-3 as a potential marker of relapse. Here, validation of DEFA1-3 as a marker for therapy resistance is explored. DEFA1-3 expression was analysed by RQ-PCR in patient paired samples at diagnosis and relapse of 6 early-relapse (within 18 months) and 8 late-relapse (beyond 18 months) B-lineage ALL. Diagnostic samples of 19 patients with ALL who are in continuous complete remission (median time from diagnosis 47 month) and diagnostic samples of 5 refractory patients who had not achieved remission at day 35 of therapy were also analyzed. In addition, overexpression of alpha-defensin1-3 proteins in blast cells at relapse was analysed by flow cytometry. DEFA1-3 was overexpressed at relapse as compared to diagnosis in 12 of 14 samples. At diagnosis, the expression of DEFA1-3 was significantly higher in samples from refractory patients as compared to those of patients who are in CR and to those of patients who experienced late relapse. At diagnosis, patients who relapsed early after diagnosis could not be distinguished from refractory patients based on DEFA1-3 expression levels. Results suggest that high levels of DEFA1-3 mRNA and alpha-defensin1-3 protein expression are correlated with disease progression and failure of adequate response to conventional chemotherapy.

Adolescent↗
PubMed2005

Identification of T cell-restricted genes, and signatures for different T cell responses, using a comprehensive collection of microarray datasets.

We used a comprehensive collection of Affymetrix microarray datasets to ascertain which genes or molecules distinguish the known major subsets of human T cells. Our strategy allowed us to identify the genes expressed in most T cell subsets: TCR alphabeta+ and gammadelta+, three effector subsets (Th1, Th2, and T follicular helper cells), T central memory, T effector memory, activated T cells, and others. Our genechip dataset also allowed for identification of genes preferentially or exclusively expressed by T cells, compared with numerous non-T cell leukocyte subsets profiled. Cross-comparisons between microarray datasets revealed important features of certain subsets. For instance, blood gammadelta T cells expressed no unique gene transcripts, but did differ from alphabeta T cells in numerous genes that were down-regulated. Hierarchical clustering of all the genes differentially expressed between T cell subsets enabled the identification of precise signatures. Moreover, the different T cell subsets could be distinguished at the level of gene expression by a smaller subset of predictor genes, most of which have not previously been associated directly with any of the individual subsets. T cell activation had the greatest influence on gene regulation, whereas central and effector memory T cells displayed surprisingly similar gene expression profiles. Knowledge of the patterns of gene expression that underlie fundamental T cell activities, such as activation, various effector functions, and immunological memory, provide the basis for a better understanding of T cells and their role in immune defense.

Cluster Analysis↗
PubMed2005

Effect of successful hypertension control by manidipine or lisinopril on albuminuria and left ventricular mass in diabetic hypertensive patients with microalbuminuria.

OBJECTIVE: The aim of this open-labelled, randomised, parallel-group study was to evaluate the effect of long-term monotherapy with manidipine or lisinopril on albumin excretion rate (AER) and left ventricular mass index (LVMI) in hypertensive patients with type-2 diabetes and microalbuminuria. METHODS: After a 4-week wash-out period, 174 patients with essential hypertension [diastolic blood pressure (DBP) >80 mmHg and <100 mmHg], type-2 diabetes and microalbuminuria were randomised to manidipine 10 mg o.d. or lisinopril 10 mg o.d.; after 8 weeks, the dose was doubled in non-responders (DBP >80 mmHg); after 3 months, treatment was discontinued in the non-responder patients and in those complaining of side effects; the remaining 121 patients continued their therapy with manidipine or lisinopril, and 99 completed the 2-year study. At the end of the wash-out period, of the titration period and after 6, 12, 18 and 24 months of treatment, BP was measured, AER, creatinine clearance, glycosylated haemoglobin (HbA1c) and body mass index (BMI) were evaluated and an echocardiographic evaluation was performed. RESULTS: The 99 patients who completed the study were statistically analysed according to a per-protocol evaluation. Manidipine and lisinopril significantly reduced systolic blood pressure (SBP) and DBP levels (at 24 months, --22.3/15.5 mmHg, P<0.001 versus baseline and --21.4/15.7 mmHg, P<0.01 versus baseline, respectively). Both drugs provided a significant decrease in AER, but it was significantly more pronounced with lisinopril (at 24 weeks, --37.2 mg/24 h, P<0.001 versus baseline) than with manidipine (--29.9 mg/24 h, P<0.05 versus baseline) and became evident earlier in the lisinopril group (after 3 months versus 6 months of treatment). Manidipine produced a greater reduction of LVMI than lisinopril (--14.9 g/m(2) versus --10.8 g/m(2) at 24 months). The effect was more pronounced in patients with left ventricular hypertrophy at baseline (--19.8 g/m(2) versus --12.8 g/m(2), P<0.05). CONCLUSION: These data suggest that, despite similar BP lowering, non-haemodynamic factors play an important role in the pharmacological reduction of AER and LVMI in diabetic hypertensive patients.

Aged↗
PubMed2005

Selected Toll-like receptor agonist combinations synergistically trigger a T helper type 1-polarizing program in dendritic cells.

Toll-like receptors (TLRs) sense microbial products and initiate adaptive immune responses by activating dendritic cells (DCs). As pathogens may contain several TLR agonists, we sought to determine whether different TLRs cooperate in DC activation. In human and mouse DCs, TLR3 and TLR4 potently acted in synergy with TLR7, TLR8 and TLR9 in the induction of a selected set of genes. Synergic TLR stimulation increased production of interleukins 12 and 23 and increased the Delta-4/Jagged-1 ratio, leading to DCs with enhanced and sustained T helper type 1-polarizing capacity. Global gene transcriptional analysis showed that TLR synergy 'boosted' only approximately 1% of the transcripts induced by single TLR agonists. These results identify a 'combinatorial code' by which DCs discriminate pathogens and suggest new strategies for promoting T helper type 1 responses.

Animals↗