69 research outputs found
Digital PCR in Myeloid Malignancies: Ready to Replace Quantitative PCR?
No full textNew techniques are on the horizon for the detection of small leukemic clones in both, acute leukemias and myeloproliferative disorders. A promising approach is based on digital polymerase chain reaction (PCR). Digital PCR (dPCR) is a breakthrough technology designed to provide absolute nucleic acid quantification. It is particularly useful to detect a low amount of target and therefore it represents an alternative method for detecting measurable residual disease (MRD). The main advantages are the high precision, the very reliable quantification, the absolute quantification without the need for a standard curve, and the excellent reproducibility. Nowadays the main disadvantages of this strategy are the costs that are still higher than standard qPCR, the lack of standardized methods, and the limited number of laboratories that are equipped with instruments for dPCR. Several studies describing the possibility and advantages of using digital PCR for the detection of specific leukemic transcripts or mutations have already been published. In this review we summarize the available data on the use of dPCR in acute myeloid leukemia and myeloproliferative disorders
A human model of platelet-leucocyte adhesive interactions during controlled ischaemia in patients with peripheral vascular disease.
No full textAIMS:
In humans, little is known about the effects of platelet-leucocyte interactions on blood viscosity and microvascular perfusion. This study tested the hypotheses that (1) activation and interactions between platelets and leucocytes may have an impact on microvascular blood viscosity and perfusion in patients with stage II peripheral arterial occlusive disease, and (2) a powerful antiplatelet drug such as Clopidogrel might help to improve microvascular perfusion by reducing platelet-leucocyte activation and blood viscosity.
METHODS:
Plasma concentrations of certain markers of leucocyte and platelet activation, in addition to low and high shear rate blood viscosity, were measured before and after a repeated exercise treadmill test. Functional parameters including maximum walking time, transcutaneous oxygen pressure, and half recovery time were also measured.
RESULTS:
Blocking platelet activation only with a single dose of Clopidogrel (300 mg) did not improve microvascular blood viscosity and perfusion after repeated exercise, but a significant improvement in microvascular perfusion during controlled ischaemia and a lack of post exercise increase in low shear rate blood viscosity was achieved when both platelet and leucocyte activation were suppressed by a relatively longer treatment with Clopidogrel (four days).
CONCLUSIONS:
Clopidogrel, by inhibiting platelet activation and aggregation, might also block the vicious cycle of leucocyte-platelet activation, thus improving the functioning of the microcirculation
Reduced Expression of Sprouty1 Contributes to the Aberrant Proliferation and Impaired Apoptosis of Acute Myeloid Leukemia Cells
No full textIn most of the acute myeloid leukemia patients there is an aberrant tyrosine kinase activity. The prototype of Sprouty proteins was originally identified in Drosophila melanogaster as antagonists of Breathless, the mammalian ortholog of fibroblast growth factor receptor. Usually, SPRY family members are inhibitors of RAS signaling induced by tyrosine kinases receptors and they are implicated in negative feedback processes regulating several intracellular pathways. The present study aims to investigate the role of a member of the Sprouty family, Sprouty1, as a regulator of cell proliferation and growth in patients affected by acute myeloid leukemia. Sprouty1 mRNA and protein were both significantly down-regulated in acute myeloid leukemia cells compared to the normal counterpart, but they were restored when remission is achieved after chemotherapy. Ectopic expression of Sprouty1 revealed that it plays a key role in the proliferation and apoptotic defect that represent a landmark of the leukemic cells. Our study identified Sprouty1 as negative regulator involved in the aberrant signals of adult acute myeloid leukemia. Furthermore, we found a correlation between Sprouty1 and FoxO3a delocalization in acute myeloid leukemia (AML) patients at diagnosis, suggesting a multistep regulation of RAS signaling in human cancers
Promoter polymorphisms and transcript levels of nicotinic receptor CHRNA5
No full textChromosomal locus 15q25, implicated in lung cancer risk and nicotine dependence, shows extensive linkage disequilibrium that complicates identification of causal variation. Cholinergic receptor nicotinic α5 (CHRNA5) has been identified as a lung cancer risk factor. We identified by sequence analysis three haplotypes (delTTC, insATC, and insTGG) in the 5′ promoter region and three at the 3′-untranslated region of CHRNA5. Linkage disequilibrium analysis of the 5′ variants showed that the insTGG haplotype is associated with three tightly linked risk alleles (nicotine dependence, lung cancer, and chronic obstructive pulmonary disease). The three CHRNA5 promoter haplotypes were statistically significantly associated with lung CHRNA5 transcript levels, determined by real-time polymerase chain reaction. In nontumor lung parenchyma from 68 patients who underwent lung lobectomy, the delTTC haplotype was associated with the highest CHRNA5 transcript levels (relative quantification units = 1.82), whereas the insTGG haplotype was associated with the lowest (0.88 units, Pdiff <. 001, Welch t test; all statistical tests were two-sided). Luciferase reporter assays in human lung cancer cell lines A549, H460, H520, and H596 also showed that the 5′ region haplotypes were statistically significantly associated with changes in CHRNA5 promoter activity, whereas the 3′-untranslated region variants were not. © 2010 The Author
Comprehensive Molecular Profiling of NPM1-Mutated Acute Myeloid Leukemia Using RNAseq Approach
No full textAcute myeloid leukemia (AML) is a complex hematologic malignancy with high morbidity and mortality. Nucleophosmin 1 (NPM1) mutations occur in approximately 30% of AML cases, and NPM1-mutated AML is classified as a distinct entity. NPM1-mutated AML patients without additional genetic abnormalities have a favorable prognosis. Despite this, 30–50% of them experience relapse. This study aimed to investigate the potential of total RNAseq in improving the characterization of NPM1-mutated AML patients. We explored genetic variations independently of myeloid stratification, revealing a complex molecular scenario. We showed that total RNAseq enables the uncovering of different genetic alterations and clonal subtypes, allowing for a comprehensive evaluation of the real expression of exome transcripts in leukemic clones and the identification of aberrant fusion transcripts. This characterization may enhance understanding and guide improved treatment strategies for NPM1mut AML patients, contributing to better outcomes. Our findings underscore the complexity of NPM1-mutated AML, supporting the incorporation of advanced technologies for precise risk stratification and personalized therapeutic strategies. The study provides a foundation for future investigations into the clinical implications of identified genetic variations and highlights the importance of evolving diagnostic approaches in leukemia management
Genome-wide association study in discordant sibships identifies multiple inherited susceptibility alleles linked to lung cancer
No full textWe analyzed a series of young (median age = 52 years) nonsmoker lung cancer patients and their unaffected siblings as controls, using a genome-wide 620 901 single-nucleotide polymorphism (SNP) array analysis and a case-control DNA pooling approach. We identified 82 putatively associated SNPs that were retested by individual genotyping followed by use of the sib transmission disequilibrium test, pointing to 36 SNPs associated with lung cancer risk in the discordant sibs series. Analysis of these 36 SNPs in a polygenic model characterized by additive and interchangeable effects of rare alleles revealed a highly statistically significant dosage-dependent association between risk allele carrier status and proportion of cancer cases. Replication of the same 36 SNPs in a population-based series confirmed the association with lung cancer for three SNPs, suggesting that phenocopies and genetic heterogeneity can play a major role in the complex genetics of lung cancer risk in the general population. © The Author 2009. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected]
Treatment-free remission in Chronic Myeloid Leukemia harboring atypical BCR-ABL1 transcripts.
No full textDiscontinuation of tyrosine kinase inhibitors (TKI) is the main goal today in the field of Philadelphia positive chronic myeloid leukemia (Ph + CML) and the criteria to attempt the interruption of therapy are well defined and rely on the possibility to regularly monitor the BCR-ABL1 transcript. Patients harboring atypical transcripts are automatically excluded from protocols due to the absence of a standardized method of quantification of their minimal residual disease (MRD). We report here the outcome of 6 patients with atypical transcripts with a long follow up whose MRD was followed in three cases with digital PCR during their treatment free remission (TFR)
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