10 research outputs found

    A review of genetic epidemiology of head and neck cancer related to polymorphisms in metabolic genes, cell cycle control and alcohol metabolism

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    The purpose of this report is to review the relationship between genetic polymorphisms involved in carcinogen metabolism, alcohol metabolism and cell-cycle control with the risk of head and neck cancer. The review was performed on available studies on genetic polymorphisms and head and neck cancer (HNC) published in PubMed up to September 2011. 246 primary articles and 7 meta-analyses were published. Among these, a statistically significant association was reported for glutathione S-transferases (GSTM1), glutathione S-transferases (GSTT1) and human microsomal epoxide hydrolase (EPHX1) genes. An increased risk for HNC was also associated reported for P53 codon 72 Pro/Pro, ALDH2 and three variants of the ADH gene: ADH1B (rs1229984), ADH7 (rs1573496) and ADH1C (rs698)

    Sirtinol Treatment Reduces Inflammation in Human Dermal Microvascular Endothelial Cells

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    Histone deacetylases (HDAC) are key enzymes in the epigenetic control of gene expression. Recently, inhibitors of class I and class II HDAC have been successfully employed for the treatment of different inflammatory diseases such as rheumatoid arthritis, colitis, airway inflammation and asthma. So far, little is known so far about a similar therapeutic effect of inhibitors specifically directed against sirtuins, the class III HDAC. In this study, we investigated the expression and localization of endogenous sirtuins in primary human dermal microvascular endothelial cells (HDMEC), a cell type playing a key role in the development and maintenance of skin inflammation. We then examined the biological activity of sirtinol, a specific sirtuin inhibitor, in HDMEC response to pro-inflammatory cytokines. We found that, even though sirtinol treatment alone affected only long-term cell proliferation, it diminishes HDMEC inflammatory responses to tumor necrosis factor (TNF)α and interleukin (IL)-1β. In fact, sirtinol significantly reduced membrane expression of adhesion molecules in TNFã- or IL-1β-stimulated cells, as well as the amount of CXCL10 and CCL2 released by HDMEC following TNFα treatment. Notably, sirtinol drastically decreased monocyte adhesion on activated HDMEC. Using selective inhibitors for Sirt1 and Sirt2, we showed a predominant involvement of Sirt1 inhibition in the modulation of adhesion molecule expression and monocyte adhesion on activated HDMEC. Finally, we demonstrated the in vivo expression of Sirt1 in the dermal vessels of normal and psoriatic skin. Altogether, these findings indicated that sirtuins may represent a promising therapeutic target for the treatment of inflammatory skin diseases characterized by a prominent microvessel involvement

    Effects of mitochondrial ferritin overexpression in normal and sideroblastic erythroid progenitors.

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    In myelodysplastic syndromes with ring sideroblasts (MDS-RS), the iron deposited in the mitochondria of RS is present in the form of mitochondrial ferritin (FTMT), but it is unknown whether FTMT overexpression is the cause or the result of mitochondrial iron deposition. Lentivirus FTMT-transduced CD34(+) bone marrow cells from seven healthy donors and CD34(+) cells from 24 patients with MDS-RS were cultured according to a procedure that allowed the expansion of high numbers of erythroid progenitors. These cells were used to investigate the possible influence of experimentally-induced FTMT overexpression on normal erythropoiesis and the functional effects of FTMT in sideroblastic erythropoiesis. In MDS-RS progenitors, FTMT overexpression was associated with reduced cytosolic ferritin levels, increased surface transferrin receptor expression and reduced cell proliferation; FTMT effects were independent of SF3B1 mutation status. Similarly, FTMT overexpressing normal erythroid progenitors were characterized by reduced cytosolic ferritin content and increased CD71 expression, and also by higher apoptotic rate in comparison with the FTMT- controls. Significantly lower levels of STAT5 phosphorylation following erythropoietin stimulation were found in both sideroblastic and normal FTMT(+) erythroid cells compared to the FTMT- cells. In conclusion, experimental overexpression of FTMT may modify mitochondrial iron availability and lead to ineffective erythropoiesis

    Flow cytometry evaluation of erythroid dysplasia in patients with myelodysplastic syndrome.

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    Erythroid dysplasia is the pathologic hallmark of myelodysplastic syndromes (MDS). To develop a quantitative flow-cytometry approach to its evaluation, we analyzed the expression of CD71, CD105, cytosolic H-ferritin (HF), cytosolic L-ferritin (LF) and mitochondrial ferritin (MtF) in erythroblasts from 104 MDS patients, 69 pathologic control patients and 19 healthy subjects. Six-parameter, 4-color flow cytometry was employed, and data were expressed as mean fluorescence intensity. Compared with pathologic and healthy controls, MDS patients had higher expression of HF (P < 0.001) and CD105 (P < 0.001), and lower expression of CD71 (P < 0.001). MtF was specifically detected in MDS with ringed sideroblasts, and there was a close relationship between its expression and Prussian blue staining (r = 0.89, P < 0.001). In vitro cultures of myelodysplastic hematopoietic progenitors showed that both HF and MtF were expressed at a very early stage of erythroid differentiation, and that MtF expression is specifically related to mitochondrial iron loading. A classification function based on expression levels of HF, CD71 and CD105 allowed us to correctly classify > 95% of MDS patients. This flow-cytometry approach provides an accurate quantitative evaluation of erythroid dysplasia and allows a reliable diagnosis of sideroblastic anemia, and may therefore be a useful tool in the work-up of patients with MDS

    Clinical significance of SF3B1 mutations in myelodysplastic syndromes and myelodysplastic/myeloproliferative neoplasms

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    In a previous study, we identified somatic mutations of SF3B1, a gene encoding a core component of RNA splicing machinery, in patients with myelodysplastic syndrome (MDS). Here, we define the clinical significance of these mutations in MDS and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). The coding exons of SF3B1 were screened using massively parallel pyrosequencing in patients with MDS, MDS/MPN, or acute myeloid leukemia (AML) evolving from MDS. Somatic mutations of SF3B1 were found in 150 of 533 (28.1%) patients with MDS, 16 of 83 (19.3%) with MDS/MPN, and 2 of 38 (5.3%) with AML. There was a significant association of SF3B1 mutations with the presence of ring sideroblasts (P < .001) and of mutant allele burden with their proportion (P = .002). The mutant gene had a positive predictive value for ring sideroblasts of 97.7% (95% confidence interval, 93.5%-99.5%). In multivariate analysis including established risk factors, SF3B1 mutations were found to be independently associated with better overall survival (hazard ratio = 0.15, P = .025) and lower risk of evolution into AML (hazard ratio = 0.33, P = .049). The close association between SF3B1 mutations and disease phenotype with ring sideroblasts across MDS and MDS/MPN is consistent with a causal relationship. Furthermore, SF3B1 mutations are independent predictors of favorable clinical outcome, and their incorporation into stratification systems might improve risk assessment in MDS

    Tie2 expressing monocytes in the spleen of patients with primary myelofibrosis

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    Primary myelofibrosis (PMF) is a Philadelphia-negative (Ph-) myeloproliferative disorder, showing abnormal CD34 + progenitor cell trafficking, splenomegaly, marrow fibrosis leading to extensive extramedullary haematopoiesis, and abnormal neoangiogenesis in either the bone marrow or the spleen. Monocytes expressing the angiopoietin-2 receptor (Tie2) have been shown to support abnormal angiogenic processes in solid tumors through a paracrine action that takes place in proximity to the vessels. In this study we investigated the frequency of Tie2 expressing monocytes in the spleen tissue samples of patients with PMF, and healthy subjects (CTRLs), and evaluated their possible role in favouring spleen angiogenesis. We show by confocal microscopy that in the spleen tissue of patients with PMF, but not of CTRLs, the most of the CD14 + cells are Tie2 + and are close to vessels; by flow cytometry, we found that Tie2 expressing monocytes were Tie2 + CD14 low CD16 bright CDL62 - CCR2 - (TEMs) and their frequency was higher (p = 0.008) in spleen tissue-derived mononuclear cells (MNCs) of patients with PMF than in spleen tissue-derived MNCs from CTRLs undergoing splenectomy for abdominal trauma. By in vitro angiogenesis assay we evidenced that conditioned medium of immunomagnetically selected spleen tissue derived CD14 + cells of patients with PMF induced a denser tube like net than that of CTRLs; in addition, CD14 + Tie2 + cells sorted from spleen tissue derived single cell suspension of patients with PMF show a higher expression of genes involved in angiogenesis than that found in CTRLs. Our results document the enrichment of Tie2 + monocytes expressing angiogenic genes in the spleen of patients with PMF, suggesting a role for these cells in starting/maintaining the pathological angiogenesis in this organ
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