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Journal ArticleDOI

Evaluation of the association between the JAK2 46/1 haplotype and chronic myeloproliferative neoplasms in a Brazilian population

01 Jan 2013-Clinics (Faculdade de Medicina / USP)-Vol. 68, Iss: 1, pp 5-9

TL;DR: The JAK2 46/1 haplotype, represented in this study by the presence of the G allele, is an important predisposing factor in the oncogenetic development of these neoplasms in the studied population.

AbstractOBJECTIVE: The JAK2 46/1 haplotype has recently been described as a major contributing factor to the development of myeloproliferative neoplasm, whether positive or negative forthe JAK2 V617F mutation. The G allele, identified by a single-nucleotide polymorphism known as JAK2 rs10974944, is part of the JAK2 46/1 haplotype. The aim of this study was to verify the association between the presence of the G allele and the development of BCR-ABL-negative chronic myeloproliferative neoplasms in our population. METHODS: Blood and oral mucosa swab samples were obtained from 56 patients of two local Brazilian hospitals who had previously been diagnosed with BCR-ABL-negative chronic myeloproliferative neoplasms. Blood samples from 90 local blood donors were used as controls. The presence of the G allele was assessed using a PCR-RFLP assay after extracting DNA from the samples. RESULTS: The presence of the G allele was strongly associated with the presence of BCR-ABL-negative chronic myeloproliferative neoplasms (p = 0.0001; OR = 2.674; 95% CI = 1.630-4.385) in the studied population. CONCLUSION: In agreement with previous reports, the JAK2 46/1 haplotype, represented in this study by the presence of the G allele, is an important predisposing factor in the oncogenetic development of these neoplasms in our population.

Topics: Myeloproliferative neoplasm (63%), Population (54%), Haplotype (52%), Allele (51%)

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Citations
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Journal ArticleDOI
TL;DR: Three basic types of paternal effect are distinguished and key questions that can serve as a road map for research on the proximate basis and evolutionary implications of paternal effects are outlined.
Abstract: Maternal effects are now universally recognised as a form of nongenetic parental influence on offspring but, until recently, paternal effects were regarded as an anomaly. Although it is now clear that paternal effects are both widespread and important, their proximate basis and evolutionary consequences have received little attention and remain poorly understood. In particular, because many paternal effects are mediated by maternal responses such as differential allocation, the boundary between paternal and maternal effects is sometimes blurred. We distinguish here three basic types of paternal effect and clarify the role of maternal responses in these effects. We also outline key questions that can serve as a road map for research on the proximate basis and evolutionary implications of paternal effects.

137 citations


Journal ArticleDOI
TL;DR: Existing evidence does not support ICSI in preference over in vitro fertilization (IVF) in the general non-male factor ART population; however, in couples with unexplained infertility, I CSI is associated with lower fertilization failure rates than IVF.
Abstract: Intracytoplasmic sperm injection (ICSI) has become the most commonly used method of fertilization in assisted reproductive technology. The primary reasons for its popularity stem from its effectiveness, the standardization of the procedure, which means that it can easily be incorporated into the routine practice of fertility centres worldwide, and the fact that it can be used to treat virtually all forms of infertility. ICSI is the clear method of choice for overcoming untreatable severe male factor infertility, but its (over)use in other male and non-male factor infertility scenarios is not evidence-based. Despite all efforts to increase ICSI efficacy and safety through the application of advanced sperm retrieval and cryopreservation techniques, as well as methods for selecting sperm with better chromatin integrity, the overall pregnancy rates from infertile men remain suboptimal. Treating the underlying male infertility factor before ICSI seems to be a promising way to improve ICSI outcomes, but data remain limited. Information regarding the health of ICSI offspring has accumulated over the past 25 years, and there are reasons for concern as risks of congenital malformations, epigenetic disorders, chromosomal abnormalities, subfertility, cancer, delayed psychological and neurological development, and impaired cardiometabolic profile have been observed to be greater in infants born as a result of ICSI than in naturally conceived children. However, as subfertility probably influences the risk estimates, it remains to be determined to what extent the observed adverse outcomes are related to parental factors or associated with ICSI.

70 citations


Journal ArticleDOI
TL;DR: Level of JAK2V617F mutation burden was associated with myeloproliferative neoplasm progression rate, consistent with a biological continuum of increasing JAK 2V617f mutation burden across increasing severity of myeloplasm from no disease to primary myelofibrosis.
Abstract: Clinical significance of the JAK2V617F mutation in patients with a myeloproliferative neoplasm has been the target of intensive research in recent years. However, there is considerably uncertainty about prognosis in JAK2V617F positive individuals without overt signs of myeloproliferative disease. In this study, we tested the hypothesis that increased JAK2V617F somatic mutation burden is associated with myeloproliferative neoplasm progression rate in the general population. Among 49,488 individuals from the Copenhagen General Population Study, 63 (0.1%) tested positive for the JAK2V617F mutation in the time period 2003-2008. Of these, 48 were available for re-examination in 2012. Level of JAK2V617F mutation burden was associated with myeloproliferative neoplasm progression rate, consistent with a biological continuum of increasing JAK2V617F mutation burden across increasing severity of myeloproliferative neoplasm from no disease (n=8 at re-examination) through essential thrombocythemia (n=20) and polycythemia vera (n=13) to primary myelofibrosis (n=7). Among those diagnosed with a myeloproliferative neoplasm only at re-examination in 2012, in the preceding years JAK2V617F mutation burden increased by 0.55% per year, erythrocyte volume fraction increased by 1.19% per year, and erythrocyte mean corpuscular volume increased by 1.25% per year, while there was no change in platelet count or erythropoietin levels. Furthermore, we established a JAK2V617F mutation burden cut-off point of 2% indicative of disease versus no disease; however, individuals with a mutation burden below 2% may suffer from a latent form of myeloproliferative disease revealed by a slightly larger spleen and/or slightly higher lactic acid dehydrogenase concentration compared to controls. Of all 63 JAK2V617F positive individuals, 48 were eventually diagnosed with a myeloproliferative neoplasm.

57 citations


Additional excerpts

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Journal ArticleDOI
TL;DR: It is proposed that careful assessment of spermatozoal parameters is essential to achieve embryo development and a healthy live birth and the need for more research and the development of standardized protocols to assess the role of sperm factors affecting embryo quality.
Abstract: Advancing maternal and paternal age leads to a decrease in fertility, and hence, many infertile couples opt for assisted reproductive technologies [ART] to achieve biological parenthood. One of the key determinants of achieving a live outcome of ART, embryo quality, depends on both the quality of the oocyte and sperm that have created the embryo. Several studies have explored the effect of oocyte parameters on embryo quality, but the effects of sperm quality on the embryo have not been comprehensively evaluated. In this review, we assess the effect of various genetic factors of paternal origin on the quality and development of the embryo. The effects of sperm aneuploidy, sperm chromatin structure, deoxyribonucleic acid [DNA] fragmentation, role of protamines and histones, sperm epigenetic profile, and Y chromosome microdeletions were explored and found to negatively affect embryo quality. We propose that careful assessment of spermatozoal parameters is essential to achieve embryo development and a healthy live birth. However, the heterogeneity in test results and the different approaches of assessing a single sperm parameter highlight the need for more research and the development of standardized protocols to assess the role of sperm factors affecting embryo quality.

46 citations


Journal ArticleDOI
TL;DR: Overall results showed that BDMC-A induced apoptosis more effectively compared to curcumin and the activity can be attributed to the presence of hydroxyl group in the ortho position in its structure.
Abstract: In developing countries, survival rates for breast cancer are poor and it accounts for 22.9% of all cancers in women. Curcumin, a major constituent from turmeric, is one of the well-known chemopreventive agents. Reports have shown that curcumin induces apoptosis in breast cancer cells. We synthesized an ortho-hydroxy substituted analog of curcumin (BDMC-A) and analyzed its cytotoxicity. The BDMC-A inhibited MCF-7 at a dose equivalent to that of curcumin (30 μM). The present study was aimed at delineating the apoptotic mechanism of BDMC-A in comparison to that of curcumin. In our study, BDMC-A exerted more potent effect on the modulation of selective apoptotic markers (intrinsic pathway: p53, Bcl-2, Bax, cyt c, Apaf-1, caspase-9, 3, PARP; extrinsic pathway: FasL, caspase 8) compared to curcumin. mRNA expression studies for Bcl2/Bax also supported the increased efficacy of BDMC-A. An in silico molecular docking study with PI3K revealed that the docking of BDMC-A was more potent compared to curcumin. Increased apoptotic induction by BDMC-A compared to curcumin was also demonstrated by Annexin V, Rh123 (ΔΨm), PI, Hoechst 33258, AO/EB fluorescent staining studies which showed characteristic apoptotic features like nuclear fragmentation and chromatin condensation. Moreover, BDMC-A treated cells effectively induced apoptosis through ROS intermediates compared to curcumin, as measured by 2'-7'-Dichlorodihydrofluorescein diacetate (DCFH-DA). Hence our overall results showed that BDMC-A induced apoptosis more effectively compared to curcumin and the activity can be attributed to the presence of hydroxyl group in the ortho position in its structure. Further researches are going on to delineate its molecular targets to evaluate its effect as a potent anticancer agent.

45 citations


References
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Book
29 Sep 2017
TL;DR: Thank you very much for reading who classification of tumours of haematopoietic and lymphoid tissues, and maybe you have knowledge that, people have look hundreds of times for their chosen readings like this, but end up in malicious downloads.
Abstract: WHO CLASSIFICATION OF TUMOURS OF HAEMATOPOIETIC AND LYMPHOID TISSUES , WHO CLASSIFICATION OF TUMOURS OF HAEMATOPOIETIC AND LYMPHOID TISSUES , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

12,924 citations


Journal ArticleDOI
TL;DR: A single acquired mutation of JAK2 was noted in more than half of patients with a myeloproliferative disorder and its presence in all erythropoietin-independent erythroid colonies demonstrates a link with growth factor hypersensitivity, a key biological feature of these disorders.
Abstract: Summary Background Human myeloproliferative disorders form a range of clonal haematological malignant diseases, the main members of which are polycythaemia vera, essential thrombocythaemia, and idiopathic myelofibrosis. The molecular pathogenesis of these disorders is unknown, but tyrosine kinases have been implicated in several related disorders. We investigated the role of the cytoplasmic tyrosine kinase JAK2 in patients with a myeloproliferative disorder. Methods We obtained DNA samples from patients with polycythaemia vera, essential thrombocythaemia, or idiopathic myelofibrosis. The coding exons of JAK2 were bidirectionally sequenced from peripheral-blood granulocytes, T cells, or both. Allele-specific PCR, molecular cytogenetic studies, microsatellite PCR, Affymetrix single nucleotide polymorphism array analyses, and colony assays were undertaken on subgroups of patients. Findings A single point mutation (Val617Phe) was identified in JAK2 in 71 (97%) of 73 patients with polycythaemia vera, 29 (57%) of 51 with essential thrombocythaemia, and eight (50%) of 16 with idiopathic myelofibrosis. The mutation is acquired, is present in a variable proportion of granulocytes, alters a highly conserved valine present in the negative regulatory JH2 domain, and is predicted to dysregulate kinase activity. It was heterozygous in most patients, homozygous in a subset as a result of mitotic recombination, and arose in a multipotent progenitor capable of giving rise to erythroid and myeloid cells. The mutation was present in all erythropoietin-independent erythroid colonies. Interpretation A single acquired mutation of JAK2 was noted in more than half of patients with a myeloproliferative disorder. Its presence in all erythropoietin-independent erythroid colonies demonstrates a link with growth factor hypersensitivity, a key biological feature of these disorders. Relevance to practice Identification of the Val617Phe JAK2 mutation lays the foundation for new approaches to the diagnosis, classification, and treatment of myeloproliferative disorders.

3,204 citations


"Evaluation of the association betwe..." refers background or methods or result in this paper

  • ...Blood samples were also collected from 90 healthy individuals (blood donors from the Hemocentro Regional de Maringá) and used as controls, as the JAK2 V617F mutation is not found in healthy individuals (3-6,13,14)....

    [...]

  • ...The JAK2 V617F mutation was identified in more than 95% of PV patients and in approximately half of the patients with ET and MF but was not observed in healthy individuals (2-6)....

    [...]

  • ...As shown in Table 1, the characteristics of the studied patients are very similar to those observed in the literature (2-5), which indicates the comparability of our data and supports the assertion that the presence of the G allele is a pivotal factor in the development of cMPN in our population....

    [...]

  • ...It was observed that the JAK2 V617F mutation could occur in a homozygous or heterozygous fashion in the affected hematopoietic cells (2-5)....

    [...]


Journal ArticleDOI
TL;DR: Genetic evidence and in vitro functional studies indicate that V617F gives hematopoietic precursors proliferative and survival advantages and a high proportion of patients with myeloproliferative disorders carry a dominant gain-of-function mutation of JAK2.
Abstract: background Polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis are clonal myeloproliferative disorders arising from a multipotent progenitor. The loss of heterozygosity (LOH) on the short arm of chromosome 9 (9pLOH) in myeloproliferative disorders suggests that 9p harbors a mutation that contributes to the cause of clonal expansion of hematopoietic cells in these diseases. methods We performed microsatellite mapping of the 9pLOH region and DNA sequencing in 244 patients with myeloproliferative disorders (128 with polycythemia vera, 93 with essential thrombocythemia, and 23 with idiopathic myelofibrosis). results Microsatellite mapping identified a 9pLOH region that included the Janus kinase 2 ( JAK2 )

3,179 citations


"Evaluation of the association betwe..." refers background or methods or result in this paper

  • ...Blood samples were also collected from 90 healthy individuals (blood donors from the Hemocentro Regional de Maringá) and used as controls, as the JAK2 V617F mutation is not found in healthy individuals (3-6,13,14)....

    [...]

  • ...The JAK2 V617F mutation was identified in more than 95% of PV patients and in approximately half of the patients with ET and MF but was not observed in healthy individuals (2-6)....

    [...]

  • ...As shown in Table 1, the characteristics of the studied patients are very similar to those observed in the literature (2-5), which indicates the comparability of our data and supports the assertion that the presence of the G allele is a pivotal factor in the development of cMPN in our population....

    [...]

  • ...It was observed that the JAK2 V617F mutation could occur in a homozygous or heterozygous fashion in the affected hematopoietic cells (2-5)....

    [...]


Journal ArticleDOI
28 Apr 2005-Nature
TL;DR: A clonal and recurrent mutation in the JH2 pseudo-kinase domain of the Janus kinase 2 (JAK2) gene in most (> 80%) polycythaemia vera patients leads to constitutive tyrosine phosphorylation activity that promotes cytokine hypersensitivity and induces erythrocytosis in a mouse model.
Abstract: Myeloproliferative disorders are clonal haematopoietic stem cell malignancies characterized by independency or hypersensitivity of haematopoietic progenitors to numerous cytokines(1,2). The molecular basis of most myeloproliferative disorders is unknown. On the basis of the model of chronic myeloid leukaemia, it is expected that a constitutive tyrosine kinase activity could be at the origin of these diseases. Polycythaemia vera is an acquired myeloproliferative disorder, characterized by the presence of polycythaemia diversely associated with thrombocytosis, leukocytosis and splenomegaly(3). Polycythaemia vera progenitors are hypersensitive to erythropoietin and other cytokines(4,5). Here, we describe a clonal and recurrent mutation in the JH2 pseudo-kinase domain of the Janus kinase 2 (JAK2) gene in most (>80%) polycythaemia vera patients. The mutation, a valine-to-phenylalanine substitution at amino acid position 617, leads to constitutive tyrosine phosphorylation activity that promotes cytokine hypersensitivity and induces erythrocytosis in a mouse model. As this mutation is also found in other myeloproliferative disorders, this unique mutation will permit a new molecular classification of these disorders and novel therapeutical approaches.

3,136 citations


"Evaluation of the association betwe..." refers background or methods or result in this paper

  • ...Blood samples were also collected from 90 healthy individuals (blood donors from the Hemocentro Regional de Maringá) and used as controls, as the JAK2 V617F mutation is not found in healthy individuals (3-6,13,14)....

    [...]

  • ...The JAK2 V617F mutation was identified in more than 95% of PV patients and in approximately half of the patients with ET and MF but was not observed in healthy individuals (2-6)....

    [...]

  • ...As shown in Table 1, the characteristics of the studied patients are very similar to those observed in the literature (2-5), which indicates the comparability of our data and supports the assertion that the presence of the G allele is a pivotal factor in the development of cMPN in our population....

    [...]

  • ...It was observed that the JAK2 V617F mutation could occur in a homozygous or heterozygous fashion in the affected hematopoietic cells (2-5)....

    [...]


Journal ArticleDOI
15 Sep 2005-Blood
TL;DR: It is concluded that V617F is widespread in MPDs and detection of this acquired mutation is likely to have a major impact on the way patients with MPD are diagnosed, as well as serving as an obvious target for signal transduction therapy.
Abstract: The analysis of rare chromosomal translocations in myeloproliferative disorders has highlighted the importance of aberrant tyrosine kinase signaling in the pathogenesis of these diseases. Here we have investigated samples from 679 patients and controls for the nonreceptor tyrosine kinase JAK2 V617F mutation. Of the 480 myeloproliferative disorder (MPD) samples, the proportion of positive cases per disease subtype was 30 (20%) of 152 for atypical or unclassified MPD, 2 of 134 (2%) for idiopathic hypereosinophilic syndrome, 58 of 72 (81%) for polycythemia vera, 24 of 59 (41%) essential thrombocythemia (ET), and 15 of 35 (43%) for idiopathic myelofibrosis. V617F was not identified in patients with systemic mastocytosis (n = 28), chronic or acute myeloid leukemia (n = 35), secondary erythrocytosis (n = 4), or healthy controls (n = 160). Homozygosity for V617F was seen in 43% of mutant samples and was closely correlated with chromosome 9p uniparental disomy. Homozygosity was significantly less common in ET compared with other MPD subtypes. In 53 cases analyzed, the median level of PRV1 expression was significantly higher in V617F-positive cases compared with cases without the mutation. We conclude that V617F is widespread in MPDs. Detection of this acquired mutation is likely to have a major impact on the way patients with MPD are diagnosed, as well as serving as an obvious target for signal transduction therapy.

823 citations


"Evaluation of the association betwe..." refers background or result in this paper

  • ...The JAK2 V617F mutation was identified in more than 95% of PV patients and in approximately half of the patients with ET and MF but was not observed in healthy individuals (2-6)....

    [...]

  • ...As shown in Table 1, the characteristics of the studied patients are very similar to those observed in the literature (2-5), which indicates the comparability of our data and supports the assertion that the presence of the G allele is a pivotal factor in the development of cMPN in our population....

    [...]

  • ...Homozygosity frequently occurs for a specific allele through duplication of the mutated allele and consequent loss of the non-mutated allele (2)....

    [...]

  • ...It was observed that the JAK2 V617F mutation could occur in a homozygous or heterozygous fashion in the affected hematopoietic cells (2-5)....

    [...]