scholarly journals Influence of JAK2V617F allele burden on clinical phenotype of polycythemia vera patients: A study from India

2019 ◽  
Vol 08 (02) ◽  
pp. 127-129
Author(s):  
Sudha Sazawal ◽  
Kanwaljeet Singh ◽  
Sunita Chhikara ◽  
Rekha Chaubey ◽  
Manoranjan Mahapatra ◽  
...  
Keyword(s):  
Target Genes ◽  
Clinical Phenotype ◽  
Myeloproliferative Neoplasms ◽  
Treatment Protocol ◽  
Allele Burden ◽  
Downstream Target ◽  
Chronic Myeloproliferative Neoplasms ◽  
Enhanced Expression ◽  
The Impact ◽  
Jak2v617f Allele Burden

Abstract Background: Elevated JAK2V617F allele burden is associated with enhanced expression of downstream target genes in Philadelphia negative chronic myeloproliferative neoplasms (CMPNs) which include PV, ET & PMF. Previous studies have shown the impact of JAK2V617F allele burden on clinical phenotype of CMPNs. However, there is no data from India regarding the association between JAK2V617F allele burden and clinical phenotype in PV. Aims/Settings and Design: We aimed to investigate the effect of allele burden on clinical phenotype in 90 JAK2V617F positive PV patients and to see its influence on disease related complications. Material and Methods: Allele burden of 90 JAK2V617F positive PV patients was quantified by Real-time polymerase chain reaction (RQ-PCR). Results: 74/90 (82.22%) were males and 16/90 (17.78%) were females (median 45 years, range 35-78). Patients with age >50 years had significantly higher JAK2V617F allele burden (median 40.15%, range 0.49–91.62 %) than patients with ≤ 50 years age (median 48.59 %, range 0.56–86.74 %; P < 0.032). Patients with splenomegaly had significantly higher JAK2V617F allele burden (mean 50.24%, range 6.91–84.17%) than patients without splenomegaly (mean 33.82 %, range 0.49–71.83 %; P < 0.017). Patients with higher allele burden (median 57.20, range 43.4–72.03%) had significantly raised thrombotic events than the patients with lower allele burden (median 37.38, range 0.49–84.17% P < 0.043). 49/90 (54%) were homozygous and 41/90 (46%) were heterozygous. Conclusions: Higher JAK2V617F allele burden showed association with increased age, splenomegaly and thrombotic events. Thus, it may be considered for prognostication and setting up the treatment protocol in PV patients.

Clinical Implications for Patients with Low JAK2V617F Allele Burden

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1745-1745
Author(s):  
Marguerite Vignon ◽  
Dorota Jeziorowska ◽  
Pierre Hirsch ◽  
Ollivier Legrand ◽  
Nicole Casadevall ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Clinical Phenotype ◽  
Myeloproliferative Neoplasms ◽  
Kinase Domain ◽  
Jak2 Mutation ◽  
Allele Burden ◽  
Vein Thrombosis ◽  
Myeloid Neoplasms ◽  
Exon 10 ◽  
Jak2v617f Allele Burden

Abstract Abstract 1745 In classical Philadelphia-negative myeloproliferative neoplasms (MPN), JAK2V617F is considered as a driver mutation when the threshold of 1% JAK2V617F/JAK2total allele burden is reached. However a lower ratio is sometimes detected with highly sensitive assays. We investigated the clinical significance of such minor clones by describing the characteristics of 27 patients with a low JAK2V617F allele burden ranging from 0.1% to 0.99%. Material and Methods A commercially available quantitative ASO-PCR assay of 0.1% sensitivity (MutaQuant® kit, Ipsogen) was used. Two thousand five hundred consecutive blood samples were sent to our lab for JAK2V617F mutation between 2009 and 2012. Total blood DNA was extracted by an automated standardized procedure (Qiasymphony®, Qiagen). All samples were tested in duplicate. The 27 samples of our cohort were controlled using a second assay of 0.01% sensitivity (Larsen et al, BJH 2007). Thirty samples from healthy donors were also tested. High resolution melting curve (HRM) analysis of JAK2 exon 14 ruled out the possibility of an additional mutation hampering the annealing of a primer. Patients with a known classical MPN clinical phenotype were also tested for JAK2 exons 12–17 (entire pseudo-kinase domain) or for MPL exon 10 depending on the context. Results Laboratory Findings Among the 2500 samples, 735 (29.4%) were positive above 1%, 27 (1.1%) had low JAK2V617F allele burden ranging from 0.12 to 0.99%. The patient with the lowest ratio (0.12%) was not confirmed by the second assay and therefore was excluded from the study. This allowed the median to settle at 0.40%. No associated mutations were found in the JAK2 pseudo-kinase domain in patients with polycythemia vera (PV) and in MPL exon 10 in patients with essential thrombocytosis (ET) and primary myelofibrosis (PMF). Healthy patients were all tested JAK2V617F negative. Clinical Aspects The cohort included 19 men and 7 women ranging from 28 to 95 years of age (median 63 years old). Two patients had secondary acute myeloid leukaemia following JAK2V617F positive MPN indicating the presence of residual JAK2V617F cells and the negativity of the myeloblastic population. Thirteen patients (50%) had a classical MPN with a median ratio of 0.36%: 7 ET, 5 PV and 1 PMF according to WHO 2008 criteria. However a bone marrow biopsy was available for only two patients (1 ET, 1 PMF). None of them had received pegylated interferon alpha-2a. Four patients had a prior history of thrombosis: two strokes, one pulmonary embolism, two portal vein thrombosis (PVT). For one PV patient, a 6 months follow-up blood and bone marrow sample confirmed a low allele burden in the same range (0.4%) and in vitro Epo-independant erythroid colonies were observed. Five patients had other chronic myeloid neoplasms (two myelodysplastic/myeloproliferative neoplasms, one chronic eosinophilic leukaemia, one chronic myeloid leukaemia, one refractory anaemia with ring sideroblasts). Among these five, four had an abnormal karyotype. We did not observe any thrombotic event in these patients. We cannot conclude on hematological diagnosis for the last six patients: four patients were screened for JAK2 mutation because of PVT. One patient had chronic polycythemia in a context of alcohol and tobacco abuse. One patient had homozygous hemochromatosis with a normal haemoglobin level in spite of repeated phlebotomies. Discussion In this single centre study low JAK2V617F allele burden represented 1% of all samples sent for JAK2V617F study and 3.5% of JAK2V617F positive patients. Seventeen patients (65%) had classical MPN or splanchnic vein thrombosis. To our knowledge PV patients with such low JAK2V617F allele burden have not been reported in the absence of associated JAK2 pseudo-kinase domain mutation. A larger screen for cooperating mutations responsible for the PV phenotype is under process. In the context of other chronic myeloid neoplasms, the JAK2V617F mutation is thought to belong to a more complex clonal architecture mostly implicating chromatin remodeling genes. Here, the presence of a JAK2 mutation could argue in favour of clonal haematopoiesis. In conclusion the clinical phenotype of low JAK2V617F patients overlaps with classical JAK2V617F MPN. The technical implications might be challenging for molecular diagnostic platforms. More data are needed to further characterize these patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Up-regulation of miR-24-1-5p is involved in the chemoprevention of colorectal cancer by black raspberry anthocyanins

2018 ◽  
Vol 122 (5) ◽  
pp. 518-526 ◽  
Author(s):  
He Zhang ◽  
Jun Guo ◽  
Liping Mao ◽  
Qianqian Li ◽  
Mengnan Guo ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Target Genes ◽  
Black Raspberry ◽  
Differential Analysis ◽  
Human Colorectal Cancer ◽  
Colon Tissue ◽  
Downstream Target ◽  
Enhanced Expression ◽  
Regulate Protein ◽  
Regulatory Loop

AbstractAs important epigenetic regulators, microRNA regulate protein expression by triggering the degradation of target mRNA and/or by inhibiting their translation. Dysregulation of microRNA expression has been reported in several cancers, including colorectal cancer. In this study, microRNA-array differential analysis revealed strongly enhanced expression of miR-24-1-5p in the colon tissue of azoxymethane/dextran sulphate sodium-induced mice that were fed with black raspberry anthocyanins for 9 weeks. Overexpression of miR-24-1-5p in human colorectal cancer cells significantly repressed β-catenin expression, and simultaneously decreased cell proliferation, migration and survival. Furthermore, miR-24-1-5p could target β-catenin and trigger a negative regulatory loop for β-catenin and its downstream target genes. β-Catenin signalling is vital to the formation and progression of human colorectal cancer. The current findings therefore identified miR-24-1-5p as a potent regulator of β-catenin, and this may provide a novel chemopreventive and therapeutic strategy for β-catenin signalling-driven colorectal cancer.

scholarly journals Bcor insufficiency promotes initiation and progression of myelodysplastic syndrome

Blood ◽  
2018 ◽  
Vol 132 (23) ◽  
pp. 2470-2483 ◽  
Author(s):  
Shiro Tara ◽  
Yusuke Isshiki ◽  
Yaeko Nakajima-Takagi ◽  
Motohiko Oshima ◽  
Kazumasa Aoyama ◽  
...  
Keyword(s):  
Myelodysplastic Syndrome ◽  
Target Genes ◽  
Myeloproliferative Neoplasms ◽  
Lymphoblastic Leukemia ◽  
Transcriptional Profiling ◽  
Hoxa Cluster ◽  
Carboxyl Terminal ◽  
Regulator Genes ◽  
The Impact ◽  
P53 Target Genes

Abstract BCOR, encoding BCL-6 corepressor (BCOR), is X-linked and targeted by somatic mutations in various hematological malignancies including myelodysplastic syndrome (MDS). We previously reported that mice lacking Bcor exon 4 (BcorΔE4/y) in the hematopoietic compartment developed NOTCH-dependent acute T-cell lymphoblastic leukemia (T-ALL). Here, we analyzed mice lacking Bcor exons 9 and 10 (BcorΔE9-10/y), which express a carboxyl-terminal truncated BCOR that fails to interact with core effector components of polycomb repressive complex 1.1. BcorΔE9-10/y mice developed lethal T-ALL in a similar manner to BcorΔE4/y mice, whereas BcorΔE9-10/y hematopoietic cells showed a growth advantage in the myeloid compartment that was further enhanced by the concurrent deletion of Tet2. Tet2Δ/ΔBcorΔE9-10/y mice developed lethal MDS with progressive anemia and leukocytopenia, inefficient hematopoiesis, and the morphological dysplasia of blood cells. Tet2Δ/ΔBcorΔE9-10/y MDS cells reproduced MDS or evolved into lethal MDS/myeloproliferative neoplasms in secondary recipients. Transcriptional profiling revealed the derepression of myeloid regulator genes of the Cebp family and Hoxa cluster genes in BcorΔE9-10/y progenitor cells and the activation of p53 target genes specifically in MDS erythroblasts where massive apoptosis occurred. Our results reveal a tumor suppressor function of BCOR in myeloid malignancies and highlight the impact of Bcor insufficiency on the initiation and progression of MDS.

Influence of JAK2 46/1 haplotype in the natural evolution of JAK2V617F allele burden in patients with myeloproliferative neoplasms

2012 ◽  
Vol 36 (3) ◽  
pp. 324-326 ◽  
Author(s):  
Alberto Alvarez-Larrán ◽  
Anna Angona ◽  
Luz Martínez-Avilés ◽  
Beatriz Bellosillo ◽  
Carlos Besses
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Natural Evolution ◽  
Allele Burden ◽  
Jak2v617f Allele Burden

The Role Of Deregulated HMGA2 Expression With Promoter Methylation Of p16 In Myeloproliferative Neoplasms

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1606-1606
Author(s):  
Kayo Shirado Harada ◽  
Kazuhiko Ikeda ◽  
Kazuei Ogawa ◽  
Hideyoshi Noji ◽  
Hideo Kimura ◽  
...  
Keyword(s):  
Promoter Methylation ◽  
Blood Cells ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Expression Levels ◽  
Allele Burden ◽  
Polycomb Group Genes ◽  
Micro Rnas ◽  
Jak2v617f Allele Burden

Abstract Myeloproliferative Neoplasms (MPNs) are characterized by clonal proliferative hematopoiesis with increased mature blood cells. The signal-activating mutations such as JAK2V617F increase blood cells, but it remains uncertain how an abnormal hematopoietic cell clone expands in MPNs. We have recently showed that overexpression of the high mobility group AT-hook 2 (HMGA2) causes proliferative hematopoiesis with providing a clonal growth advantage to hematopoietic cells in mice (Ikeda et al, Blood, 2011), suggesting the possibility that HMGA2 contributes to the pathogenesis of MPNs. However, since only a few studies have evaluated expression of HMGA2 mRNA in patients with MPNs, the role of HMGA2 in the pathogenesis of MPNs is yet unclear. MPNs also show mutations in epigenetic modifiers involving DNA methylation such as polycomb group genes (PcG) and aberrant expressions of micro RNAs (miRNA) that negatively regulate expressions of targeted genes. Interestingly, deficiency in either PcG-related BMI1 (Oguro et al, J Exp Med, 2012) or let-7-family miRNA (Mayr et al, Science, 2007) causes deregulation of HMGA2 expression, leading to its oncogenic activity in part by negatively regulating tumor suppressor p16. Thus, in this study, to clarify the role of HMGA2 in MPNs, we investigated expression of HMGA2 mRNA in peripheral granulocytes of 56 patients with MPNs including 23 polycythemia vera (PV), 26 essential thrombocythemia (ET) and 7 primary myelofibrosis (PMF) along with clinical findings, JAK2V617F allele burden, expressions of BMI1 mRNA and let-7-family miRNAs, and promoter methylation of p16. Quantitative RT-PCR (qPCR) showed significantly higher expression of HMGA2 mRNA relative to internal control HPRT1 mRNA in PMF (mean ± SD; 31.7 ± 42.8, p<0.01), but not PV (15.7 ± 53.2) or ET (2.14 ± 7.70), compared with 12 healthy volunteers (HV; 0.431 ± 0.366). In addition, deregulated HMGA2 expression (>1.2), which was determined as relative expression level above mean + 2SD of HMGA2 mRNA in 12 HV, was most frequently detected in patients with PMF [7/7 (100%)] (p<0.01), compared with PV [5/23 (21.7%)] and ET [6/26 (23.1%)]. We also found a significant positive correlation in expression levels of HMGA2 mRNA with serum LDH values (r=0.531, p<0.01) rather than JAK2V617F allele burden (r=0.25, p=0.08). These data suggested that expression of HMGA2 mRNA independently correlated with disease phenotype and status in MPNs. We next explored the cause of deregulated expression of HMGA2 mRNA and found lower expression of let-7a (0.19 ± 0.13 vs. 0.42 ± 0.39, p=0.04) and -7c (0.57 ± 0.60 vs. 1.14 ± 0.94, p=0.06) rather than -7b (p=0.2) by qPCR, in patients with deregulated expression of HMGA2 mRNA compared with other patients. However, HMGA2-involved chromosomal abnormality in 12q13-15 was not detected in any patient, and there was no difference in expression of BMI1 mRNA between patients with deregulated expression of HMGA2 mRNA and other patients. Thus, decreased expression of let-7 miRNAs might contribute to deregulated expression of HMGA2 mRNA in MPNs. Finally, we investigated correlation of deregulated expression of HMGA2 mRNA with promoter methylation of p16. Methylation-specific PCR assay detected promoter methylation of p16 in 17/56 (30.4%) patients with MPNs. Strikingly, patients with deregulated expression of HMGA2 mRNA significantly more often showed promoter methylation of p16 compared with other patients [10/18 (55.6%) vs. 7/38 (18.4%), p<0.01]. Furthermore, patients with promoter methylation of p16 showed higher expression levels of HMGA2 mRNA than patients without the methylation, especially in patients with PMF (2.33 ± 0.90 vs. 70.9 ± 38.3, p=0.01). In conclusion, deregulated expression of HMGA2 in association with decreased expression of let-7 miRNAs may play a crucial role in the pathogenesis of MPNs possibly through p16. Disclosures: No relevant conflicts of interest to declare.

JAK2V617F allele burden in patients with myeloproliferative neoplasms

2013 ◽  
Vol 93 (5) ◽  
pp. 791-796 ◽  
Author(s):  
Salem H. Alshemmari ◽  
Reshmi Rajaan ◽  
Reem Ameen ◽  
Mohammad A. Al-Drees ◽  
Marwa R. Almosailleakh
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Allele Burden ◽  
Jak2v617f Allele Burden

scholarly journals Significantly Upregulated Thrombo-Inflammatory Genes Are Normoregulated or Significantly Downregulated during Treatment with Interferon-Alpha2 in Patients with Philadelphia-Negative Chronic Myeloproliferative Neoplasms

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2978-2978 ◽  
Author(s):  
Vibe Skov ◽  
Caroline Riley ◽  
Mads Thomassen ◽  
Lasse Kjær ◽  
Thomas Stauffer Larsen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Whole Blood ◽  
Myeloproliferative Neoplasms ◽  
Inflammatory Genes ◽  
Chronic Myeloproliferative Neoplasms ◽  
Cell Counts ◽  
Increased Risk ◽  
Long Term Treatment ◽  
The Impact ◽  
First Time

Introduction: The Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are associated with a high risk of arterial and venous thrombosis, which are attributed to several mechanisms, including elevated blood cell counts per se, in vivo leukocyte and platelet activation with increased adhesion of granulocytes, monocytes and platelets to each other and to a dysfunctional endothelium. In recent years, evidence has accumulated that chronic inflammation is an important pathogenetic mechanism for MPN-disease development and disease progression, inducing increasing genomic instability in hematopoietic cells and thereby emergence of additional mutations of significance for myelofibrotic and leukemic transformation. Recent studies have shown several thrombo-inflammatory genes to be upregulated in patients with MPNs, likely contributing to the increased risk of thrombosis. Several studies have documented that long term treatment with interferon-alpha2 (IFN) is able to normalize elevated cell counts in concert with induction of a remarkable decrease in the JAK2V617F allele burden and accordingly impacting important thrombosis promoting factors in MPNs. Herein, using whole blood gene expression profiling we for the first time report that treatment with IFN is able to normoregulate or significantly downregulate upregulated thrombo-inflammatory genes in patients with MPNs. Methods: Eight patients with ET, 21 patients with PV, and 4 patients with PMF participated in the study. All patients received treatment with IFN, in the large majority in a dosage ranging from 45-90 ug x 1 sc/week. Gene expression microarray analysis of whole blood was performed before and after 3 months of treatment. Total RNA was purified from whole blood, amplified to biotin-labeled RNA, and hybridized to Affymetrix HG-U133 2.0 Plus chips. Results: We identified 6261, 10,008, and 2828 probe sets to be significantly differentially expressed in ET, PV, and PMF, respectively, in response to treatment with IFN (pvalue < 0.05). Six thrombo-inflammatory genes were investigated: F3, PADI4, SELP, SERPINE1, SLC2A1, and THBS1. In all patients groups, the 6 genes were significantly upregulated at baseline and either normoregulated or significantly downregulated during treatment with IFN (Figure 1). Discussion and Conclusions: Thrombosis contributes significantly to morbidity and mortality in MPNs. Despite treatment with conventional drugs (hydroxyurea, anagrelide) - the most used cytoreductive therapies worldwide - patients with MPNs are still suffering potentially life-threatening or life-invalidating thrombotic complications in the brain, heart, lungs and elsewhere. Therefore, there is an urgent need for studies that explore the pathogenetic mechanisms eliciting the thrombotic state and the impact of novel therapies, such as IFN, upon the thrombogenic factors which might be operative. Herein, we have for the first time shown that IFN significantly downregulates several thrombo-inflammatory genes, known to be the upregulated in patients with concurrent or previous thrombosis. Highly intriguing, we found that IFN significantly downregulated the PADI4 gene, which is required for neutrophil extracellular trap (NET) formation and thrombosis development. A most recent study has shown neutrophils from patients with MPNs to be associated with an increase in NET formation, which was blunted by ruxolitinib. This study also showed that JAK2V617F-driven MPN mouse models have a NET-rich, prothrombotic phenotype, highlighting NETosis to be yet another important thrombosis mechanism in MPNs. In conclusion, we have for the first time shown 3 months IFN-treatment to be associated with a significant downregulation of upregulated thrombo-inflammatory genes, including significant downregulation of the NETosis associated gene - PADI4. In the context of a significantly increased risk of thrombosis after the MPN-diagnosis with a particular increased risk at 3 months, our results of significant downregulation of these thrombo-inflammatory genes during IFN-therapy are of paramount importance and may signal an advantage of IFN over conventional cytoreductive therapies. Further studies are required to decipher the impact of IFN upon upregulated thrombo-inflammatory genes and if combination therapy with ruxolitinib may be even more efficacious. Figure 1 Disclosures Hasselbalch: Novartis: Research Funding; AOP Orphan Pharmaceuticals: Other: Data monitoring board. OffLabel Disclosure: Interferon-alpha for treatment of myeloproliferative neoplasms

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