Prefibrotic Myelofibrosis Presenting with Multiple Cerebral Embolic Infarcts and the Rare MPL W515S Mutation

Acquired, activating mutations of MPL W515 are recognised driver mutations of the myeloproliferative neoplasms (MPN), namely, essential thrombocythemia and primary myelofibrosis. The most common mutation at this codon is W515L with several other mutations also described at a lower frequency. Of these less common mutations, MPL W515S has only been reported sporadically with limited information on clinicopathological associations. We describe the case of an elderly man with persistent thrombocytosis presenting with an ischemic cerebral event. Bone marrow biopsy showed evidence of prefibrotic myelofibrosis with targeted sequencing demonstrating the presence of the rare MPL W515S mutation. Thrombolytic and cytoreductive therapies resulted in a favorable outcome and follow-up. This case provides additional, necessary, and phenotypic data for the rare MPN-associated MPL W515S mutation.

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Diagnostic and Therapeutic MicroRNAs in Primary Myelofibrosis

Proceedings of the Singapore National Academy of Science ◽

10.1142/s2591722620400074 ◽

2020 ◽

Vol 14 (02) ◽

pp. 91-109

Author(s):

Roxana Manaila ◽

Vlad Moisoiu ◽

Erik Knutsen ◽

Mihnea P. Dragomir ◽

George A. Calin

Keyword(s):

Bone Marrow ◽

Myeloproliferative Neoplasms ◽

Symptom Control ◽

Laboratory Data ◽

Primary Myelofibrosis ◽

In Vivo Studies ◽

Driver Mutations ◽

Transcriptional Level ◽

Hematopoietic Stem ◽

Medical Needs

Primary myelofibrosis (PMF) is a pluripotent hematopoietic stem cell-derived malignancy, included in the heterogeneous group of myeloproliferative neoplasms (MPNs). PMF diagnosis is based on a composite assessment of clinical and laboratory data. The three major diagnostic criteria are: screening for driver mutations, exclusion of other conditions that can cause myelofibrosis, and bone marrow biopsy displaying megakaryocyte changes and fibrosis. PMF treatment options are only partially disease-modifying and consist mainly of symptom control. Recently, a new targeted therapy was introduced for PMF patients, JAK-STAT inhibitors (i.e. ruxolitinib). However, specific subgroups of patients do not benefit from the JAK-STAT inhibitors: (1) those who are carrying JAK2 mutations, but ruxolitinib does not reduce the spleen size; (2) triple negative patients (no JAK2, CALR, or MPL mutations); and (3) those who discontinue JAK-STAT therapy because of side effects. These subgroups are in need of new therapeutic approaches. Mature microRNAs (miRNAs) range from 16 to 28 nucleotides (nt) in length and regulate specific messenger RNAs at the post-transcriptional level. Numerous in vitro and in vivo studies have reported specific miRNAs, as well as complex miRNA networks, to be dysregulated in PMF. Several of these miRNAs were shown to be implicated in essential events of PMF pathophysiology: increase of bone marrow fibrosis, progression to acute myeloid leukemia, resistance to JAK-STAT inhibitors, and activation of differentiation of hematopoietic stem/progenitor cells into megakaryocytes. Hence, we propose miRNAs as a potential minimally invasive diagnostic tool for PMF and as therapeutic targets that could address the unmet medical needs of these patients.

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Autoimmune Myelofibrosis: Clinical Features, Course, and Outcome

Acta Haematologica ◽

10.1159/000479103 ◽

2017 ◽

Vol 138 (3) ◽

pp. 129-137 ◽

Cited By ~ 10

Author(s):

Caroline I. Piatek ◽

Maria E. Vergara-Lluri ◽

Vinod Pullarkat ◽

Imran N. Siddiqi ◽

Casey O'Connell ◽

...

Keyword(s):

Bone Marrow ◽

Immunosuppressive Therapy ◽

Myeloproliferative Neoplasms ◽

Retrospective Chart Review ◽

Primary Myelofibrosis ◽

Complete Response ◽

Bone Marrow Examination ◽

Autoimmune Disorders ◽

Systemic Autoimmune Disease

Background: Autoimmune myelofibrosis (AIMF) is an underrecognized cause of nonmalignant bone marrow fibrosis which occurs in the presence or absence of a defined systemic autoimmune disease. Patients with AIMF present with cytopenias and autoantibodies, and have a distinctive nonclonal myelofibrosis on bone marrow examination. AIMF is distinguished from primary myelofibrosis by the absence of splenomegaly, eosinophilia, or basophilia, and the absence of abnormal myeloid, erythroid, or megakaryocytic morphology. Objectives: The objective of the study was to describe the clinical presentation and outcomes of patients with AIMF. Methods: We conducted a single-institution, retrospective chart review of patients diagnosed with AIMF to investigate clinical presentations, therapies, and outcomes. Results: Twelve patients with AIMF were identified with a mean follow-up of 5.8 years. All patients had detectable autoantibodies and the majority had concomitant autoimmune disorders. Four patients experienced a complete response of cytopenias and 3 patients experienced a partial response (PR) of cytopenias with immunosuppressive therapy. One patient achieved a PR following splenectomy. No patients were diagnosed with myeloproliferative neoplasms during the follow-up period. Conclusions: AIMF contributes to cytopenias in the subset of patients with various autoimmune disorders. The majority of patients with AIMF experience an improvement in cytopenias with immunosuppressive therapy.

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Incidence and Impact of Activating Mutations of the RAS-RAF-MEK-ERK Pathway in Patients with Philadelphia-Negative (Ph-negative) Myeloproliferative Neoplasms (MPNs) and Myelodysplastic/Myeloproliferative Disorders–Unclassified (MDS/MPD-U)

Blood ◽

10.1182/blood.v124.21.3172.3172 ◽

2014 ◽

Vol 124 (21) ◽

pp. 3172-3172

Author(s):

Fabio PS Santos ◽

Bianca Lisboa ◽

Tarcila S Datoguia ◽

Ricardo Helman ◽

Welbert Oliveira Pereira ◽

...

Keyword(s):

Disease Progression ◽

Clinical Features ◽

Double Mutant ◽

Myeloproliferative Neoplasms ◽

Primary Myelofibrosis ◽

Allogeneic Transplantation ◽

Driver Mutations ◽

Erk Pathway ◽

Braf Mutations ◽

Activating Mutations

Abstract Introduction: Mutations that activate the RAS-RAF-MEK-ERK pathway have long been known to occur in patients with solid tumors and hematological malignancies. The most common mutations occur in the Ras family of GTPases (HRAS, NRAS, KRAS) and the Raf family of serine-threonine kinases (ARAF, BRAF, CRAF). In myeloid malignancies, RAS mutations have mainly been described in patients with acute myeloid leukemia, chronic myelomonocytic leukemia (CMML) and myelodysplastic syndrome. There are few studies describing the incidence of mutations of the RAS-RAF-MEK-ERK pathway in patients with MPNs other than CMML. Objective: To describe the incidence, clinical features and prognostic impact of Ras and Raf mutations in patients with Ph-negative MPNs and MPN/MDS-U Methods: Paired DNA (sorted CD66b-granulocytes/skin biopsy) from patients with MPNs or MPN/MDS was subjected to whole exome sequencing on a Illumina HiSeq 2000 platform using Agilent SureSelect kit (see our abstract “Whole Exome Sequencing of Myeloproliferative Neoplasms and Myelodysplastic/Myeloproliferative Disorders”). Tumor coverage was 150x and germline coverage was 60x. Somatic variants calls were generated by combining the output of Somatic Sniper (Washington University), Mutect (Broad Institute) and Pindel (Washington University), followed by in-house filters to reduce false positive calls. Statistical calculations were done in Stata, v11.0. Results: We found clonal activating mutations of the RAS-RAF-MEK-ERK pathway in 8 patients (6.7% of cases). Diagnosis included primary myelofibrosis (PMF; N=5), MDS/MPD-U (N=2) and essential thrombocythemia (ET; N=1). Their clinical features are summarized in Table 1 (three of these patients [UPIs #11, #13, #99] are also described in the abstract “Genomic Profile of Patients with Triple Negative (JAK2, CALR and MPL) Essential Thrombocythemia and Primary Myelofibrosis”). There were 7 NRAS mutations and 1 BRAF mutation. In 5 cases the variant allele fraction (VAF) of reads in the tumor sample indicated that the mutation was present in a subclone at the time of sequencing. We next compared the clinical features of these 8 patients with 79 patients (MF=43, ET=35, MDS/MPD=1) who did not harbor these mutations. Patients with NRAS/BRAF mutations had lower hemoglobin (8.3 vs. 11.8 g/dL, p=0.001), higher white blood cell counts (28.37 vs. 7.7 x109/L, p=0.008) and had higher lactate dehydrogenase (1041 vs. 685 IU/L, p=0.02). They also had worse overall survival compared to unmutated cases (Hazard ratio [HR]=11.57; p=0.001). Most patients with NRAS/BRAF mutations had a high number of concomitant driver mutatons (median 5 vs. 1; p<0.0001). When the number of driver mutations was analyzed together with NRAS/BRAF mutations in a Cox model, NRAS/BRAF mutations were no longer independent predictors of survival (HR=1.48; p=0.61). Conclusions: Activating mutations of the RAS-RAF-MEK-ERK pathway occur in 6-7% of patients with Ph-negative MPNs, and they tend to co-occur with a high number of concomitant driver mutations. In most cases the mutation was present in a subclone, suggesting that they are late occurring. Patients with NRAS/BRAF mutations had a trend for worse outcome, but that was mainly dependent on the total number of driver mutations. The activity of MEK and BRAF inhibitors needs to be explored in patients with Ph-negative MPNs who harbor activating mutations of the RAS-RAF-MEK-ERK pathway. Table 1. Clinical features of patients with NRAS/BRAF mutations UPI Diagnosis Mutation VAF Concomitant driver genes and Chromosomal abnormalities Outcomes 7 MF NRAS p.G12S 47% ASXL1, CALR, STAG2, U2AF1 Died from disease progression 11 MF NRAS p.G12R 5% ASXL1, CBL, CUX1 (double mutant), EZH2 Died from disease progression 13 MF NRAS p.G12D 48% ASXL1, DNMT3A, ETV6 (double mutant) JARID2, U2AF1 Died from disease progression 18 MF NRAS p.G13D 25% JAK2, Del(5q) Underwent allogeneic transplantation; disease relapsed day+80; alive 29 MDS/MPD-U BRAF p.D594G 25% JAK2, Del(5q) Transformed to AML; entered CR with induction chemotherapy; underwent allogeneic transplantation; disease relapsed day+35; alive 99 ET NRAS p.G12D 43% ASXL1, CSF3R, STAG2 Alive 109 MF NRAS p.Q61R 19% CALR, DNMT3A, ZRSR2 Alive 122 MDS/MPD-U NRAS p.G12S 7% ASXL1, EZH2 (double mutant), PTPN11, TET2 (double mutant) Transformed to AML; underwent allogeneic transplantation; died on day+58 Disclosures No relevant conflicts of interest to declare.

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A Case Report on Coexisting JAK2 V617F and Calr exon 9 Mutation in Essential Thrombocythemia

Blood ◽

10.1182/blood.v126.23.5215.5215 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5215-5215

Author(s):

Munazza Rashid ◽

Rifat Zubair Ahmed ◽

Shariq Ahmed ◽

Muhammad Nadeem ◽

Nuzhat Ahmed ◽

...

Keyword(s):

Essential Thrombocythemia ◽

Conflicts Of Interest ◽

Myeloproliferative Neoplasms ◽

Diagnostic Algorithm ◽

Jak2 V617f ◽

Primary Myelofibrosis ◽

Common Mutation ◽

Hypochondriac Region ◽

Exon 9 ◽

Calr Mutations

Abstract Myeloproliferative Neoplasms (MPNs) are a heterogeneous group of clonal disorders derived from multipotent hematopoietic myeloid progenitors. Classic "BCR-ABL1-negative" MPNs is an operational sub-category of MPNs that includes polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). These three disorders are characterized by stem cell-derived clonal myeloproliferation. The most common mutation in the MPNs PV, ET and PMF is JAK2 V617F. JAK2 V617F can be detected in about 95% of patients with PV while remaining 5% of PV patients carry a somatic mutation of JAK2 exon 12. Approximately one third of patients with ET or PMF do not carryany mutation in JAK2 or MPL. In December 2013 mutations were described in calreticulin (CALR) gene in 67-71% and 56-88% of JAK2 V617F and MPL negative patients with ET and PMF, respectively. Since this discovery, CALR mutations have not only been recommended to be included in the diagnostic algorithm for MPNs, but also CALR exon 9 mutations have been recognised to have clinical utility as mutated patients have a better outcome than JAK2 V617F positive patients.CALR mutations have also been reported to be mutually exclusive with JAK2 V617F or MPL mutations. According to our knowledge so farthere have been only six reports published,which described patients harbouring concurrent JAK2 V617F and CALR exon 9 mutations; seven ET, three PMF, one PV and one MPN-U. In the present study we are reporting ET patient with coexisting JAK2 V617F and CALR exon 9 mutations from our center. In July 2011, 55-years-old female patient was referred to our hospital with a history of gradual elevation of platelet counts accompanied with pain in right hypochondriac region and feet. Bone Marrow aspirate consisted of 'Stag-horn' appearance Megakarocytes. Multiple platelets aggregates and islands were seen throughout the aspirate smear. ARMS-PCR for JAK2 V617F mutation was positive whereas bidirectional Sanger sequencing for CALR exon 9 exhibited c.1214_1225del12 (p.E405_D408del) mutation pattern. Disclosures No relevant conflicts of interest to declare.

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A Heterogeneous Response Pattern to Interferon-alpha2 with Induction of a Significant Decrease in the Calreticulin Mutant Allele Burden in a Subset of Patients with Essential Thrombocythemia and Primary Myelofibrosis

Blood ◽

10.1182/blood.v126.23.4057.4057 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4057-4057

Author(s):

Sabrina Cordua ◽

Lasse Kjaer ◽

Morten Orebo Holmström ◽

Niels Pallisgaard ◽

Vibe Skov ◽

...

Keyword(s):

Essential Thrombocythemia ◽

Mutant Allele ◽

Myeloproliferative Neoplasms ◽

Primary Myelofibrosis ◽

Allele Burden ◽

Travel Grant ◽

Ifn Treatment

Abstract Introduction The discovery of mutations in the calreticulin (CALR) gene in the majority of JAK2 -V617F negative patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF) (Klampfl et al., 2013; Nangalia et al., 2013) has improved the diagnostic accuracy considerably, and most recently distinct clinical and hematological characteristics according to mutational status have been described (Park et al., 2015). The perspective is to personalize and optimize treatment according to the molecular and clinical landscape. This may be achieved by obtaining more information on responses in myeloproliferative neoplasms (MPN) to existing treatment strategies as assessed by the allele burden. Mutations in the CALR gene have proven to play a major role in oncogenic and immunologic processes (Lu, Weng, & Lee, 2015). In this context, it is highly relevant to explore the effectiveness of interferon-alpha2 (IFN) in reducing the CALR -mutated clone. Until now, only one paper has reported a decrease in allele burden in two patients during IFN treatment (Cassinat, Verger, & Kiladijan, 2014). The objective of this report is to expand current knowledge on this important topic by describing the mutant CALR allele burden over time in a larger group of IFN-treated patients. Method Clinical data were collected retrospectively from a single institution on all IFN-treated CALR positive MPN patients with sequential determinations of the mutant allele burden. Type 1 and type 2 mutations were initially identified by a previously published fragment analysis (Klampfl et al 2013). We have developed a Taqman qPCR assay for precise determination of the mutant allele burden of type 1 and type 2 mutations. Stored DNA was subsequently analysed to increase follow-up time. Results Twenty-one patients were included. Fifteen patients had a diagnosis of PMF; 7 of these were diagnosed with prefibrotic myelofibrosis. Six patients had ET. The type 1 and 2 mutations were found in 15 and 6 patients, respectively. Median age was 60 years (range 42-79) and the sex ratio (M/F) was 8/13. Fifteen patients (71%) were in ongoing treatment with IFN, whereas treatment was discontinued in 6 (29%) because of side effects. Median time of IFN treatment was 756 days (range 42-3927). The IFN prescribed was either subcutaneous injection of Pegasys® (median: 45 microgram (ug) per week), PegIntron® 25-50 ug per week, or Multiferon® 3 x 3 million IU per week. Median follow up time since the first CALR measurement was 756 days (range 294-2108). Fourteen patients (67%) maintained an unchanged allele burden during follow up; 1 patient (5%) presented a temporary decrease (from 39% to 27% in allele burden) but increased to the initial level within months while still on IFN treatment (presumably due to low compliance); 1 patient (5%) displayed an increase in allele burden during transformation to acute myelogenous leukemia (Figure 1); and 5 patients (24%) exhibited a marked decrease in allele burden (median decrease: 32%, range 18-45) during treatment with IFN (Figure 2). All 5 patients with decreasing allele burden (Table 1) normalized their platelet counts within a median time of 5 weeks (range 4-20) after initiating treatment with IFN. Conclusion Using a novel sensitive assay for the CALR mutant allele burden, we have demonstrated and substantiated the effectiveness of IFN to reduce the allele burden in a larger series of CALR positive patients with PMF and ET. Importantly, we report for the first time on highly heterogeneous response patterns. Our observation of one fourth of the CALR positive patients responding to treatment with IFN strongly suggests that IFN significantly influences the CALR mutational load. Further clinical and molecular studies are urgently needed to explore the mechanisms behind the heterogeneous response patterns and the clinical implications in regard to clonal evolution and disease progression in non-responding patients. We are currently analysing these issues to assess the definite role of IFN in future treatment strategies in CALR positive MPN patients. Table 1. Patients responding to interferon-alpha2 Characteristics Number/median (range) Patients 5 Age, years 53 (42-62) Sex (M/F) 1/4 Diagnosis- Essential thrombocythemia- Primary myelofibrosis- Prefibrotic myelofibrosis 221 Calreticulin mutation type- type 1- type 2 50 Duration of interferon-alpha2 treatment, days 960 (177-2790) Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Cordua: Janssen-Cilag: Other: travel grant. Off Label Use: interferon alpha2 for myeloproliferative neoplasms. Holmström:La Roche Ltd: Other: travel grant. Pallisgaard:Qiagen: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel grant, Speakers Bureau; Bristol Meyer Squibb: Speakers Bureau; Novartis: Other: travel grant, Research Funding, Speakers Bureau; Roche: Other: travel grant. Hasselbalch:Novartis: Research Funding.

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Next-Generation Sequencing Mutational Landscape and Clinical Features of Chinese Adults with Myeloproliferative Neoplasms

Blood ◽

10.1182/blood-2021-145837 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4641-4641

Author(s):

Lan Zhang ◽

Xingnong Ye ◽

Shengjie Wang ◽

Keyi Jin ◽

Shuna Luo ◽

...

Keyword(s):

Next Generation Sequencing ◽

Comprehensive Evaluation ◽

Myeloproliferative Neoplasms ◽

Primary Myelofibrosis ◽

Clinical Parameters ◽

Next Generation ◽

School Of Medicine ◽

Medical Discipline ◽

Generation Sequencing

Abstract Myeloproliferative neoplasms (MPNs) include three classical subtypes: polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). Since prefibrotic primary myelofibrosis (pre-PMF) was recognized as a separate entity in the 2016 revised classification of MPN, it has been a subject of debate among experts due to its indefinite diagnosis. However, pre-PMF usually has a distinct outcome compared with either ET or overt PMF. We conducted a retrospective study of MPN patients from October 2014 to June 2020 in the Fourth Affiliated Hospital of Zhejiang University. Patients who were diagnosed with ET, pre-PMF or overt-MF according to the 2016 WHO Classification were included. We reviewed the clinical parameters, haematologic information, and genetic mutations of patients using next-generation sequencing (NGS). Mutation screening was performed in 44 patients by next-generation sequencing techniques, 84 genes and 258 mutations were detected. JAK2 was the most frequently mutated gene (25/44, 56.82%), followed by TET2 (14/44, 31.82%), KMT2C (13/44, 29.55%), and ASXL1 (10/44, 23.73%) in MPN (Figure 1-A). The VAFs of all studied genes with mutation frequencies >10% are shown in Figure 1-B. Of the 20 patients with ET, 9 (45%) were positive for the JAK2 mutation, 5 (25%) carried FAT1, 5 (25%) carried KMT2C, and 4 (20%) carried CALR. Of the 5 patients with pre-PMF, 4 (80%) carried JAK2, 3 (60%) carried EP300, and 2 (40%) carried TET2. Of the 19 patients with overt PMF, 12 (63%) carried JAK2, 10 (53%) carried TET2, 7 (37%) carried ASXL1, and 6 (32%) carried KMT2C, as reported in Figure 2. The median follow-up was 36 months for ET, 42 months for pre-PMF, and 53 months for overt PMF. Overall survival between pre-PMF, overt PMF, and ET was significantly different (P<0.001), as shown in Figure 3. During the follow-up time, only one death of ET was registered, so we analysed the impact of clinical parameters and mutational status at diagnosis on outcome in PMF, including pre-PMF and overt PMF. We performed Kaplan-Meier curves to examine the relationships between the clinical parameters and patient survival. We found that male sex (P=0.0107), MPN10 symptoms (P=0.0354), anaemia (haemoglobin<120g/L, P=0.0239), and thrombocytopenia (platelet count <100 ×10 9/L, P=0.0002) were significantly related to inferior OS (Figure 4). Pre-PMF patients exhibited higher leukocyte counts, higher LDH values, a higher frequency of splenomegaly, and a higher incidence of hypertension than ET patients. On the other hand, pre-PMF patients had higher platelet counts and haemoglobin levels than overt PMF patients. Molecular analysis revealed that the frequency of EP300 mutations was significantly increased in pre-PMF patients compared with ET and overt PMF patients. In terms of outcome, male sex, along with symptoms including MPN10, anaemia, thrombocytopenia, and KMT2A and CUX1 mutations, indicated a poor prognosis for PMF patients. In conclusion, we identified differences in the clinical, haematologic, and molecular presentations of ET, pre-PMF, and overt PMF patients, indicating that comprehensive evaluation of not only BM features but also clinical, haematologic, and molecular profiles is needed for accurate diagnosis and treatment of these three disease entities. The molecular analysis revealed that pre-PMF might be relevant to EP300 mutation, demonstrating the value of molecular examination. The results of this study indicated that comprehensive evaluation of BM features, clinical phenotypes, haematologic parameters, and molecular profiles is needed for the accurate diagnosis and treatment of ET, pre-PMF, and overt PMF patients. Acknowledgment:The research was supported by the Public Technology Application Research Program of Zhejiang, China (LGF21H080003), the Key Project of Jinhua Science and Technology Plan, China (2020XG-29 and 2020-3-011), the Academician Workstation of the Fourth Affiliated Hospital of the Zhejiang University School of Medicine (2019-2024), the Key Medical Discipline of Yiwu, China (Hematology, 2018-2020) and the Key Medical Discipline of Jinhua, China (Hematology, 2019-2021). Correspondence to: Dr Jian Huang, Department of Hematology, The Fourth Affiliated Hospital of Zhejiang University School of Medicine. N1 Shangcheng Road. Yiwu, Zhejiang, Peoples R China. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

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MPL W515 L/K mutations in myeloproliferative neoplasms

Egyptian Journal of Medical Human Genetics ◽

10.1186/s43042-019-0039-9 ◽

2019 ◽

Vol 20 (1) ◽

Author(s):

Sohaila Eldeweny ◽

Hosny Ibrahim ◽

Ghada Elsayed ◽

Mohamed Samra

Keyword(s):

Bone Marrow ◽

Polycythemia Vera ◽

Ethnic Groups ◽

Essential Thrombocythemia ◽

Myeloproliferative Neoplasms ◽

Primary Myelofibrosis ◽

Myelogenous Leukemia ◽

Egyptian Population ◽

Ph Chromosome ◽

Pathological Variant

Abstract Background Myeloproliferative neoplasms (MPNs) describe a group of diseases involving the bone marrow (BM). Classical MPNs are classified into chronic myelogenous leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). This classification is based on the presence of Philadelphia (Ph) chromosome (BCR/ABL1). CML is BCR/ABL1-positive while PV, ET, and PMF are negative. JAK2 p. Val617Phe pathological variant is the most associated mutation in BCR/ABL1-negative MPNs. The frequency of JAK2 p. Val617Phe is 90–95% in PV patients, 50–60% in ET, and 40–50% in patients with PMF. Studies on MPL gene led to the revelation of a gain of function pathological variants in JAK2 p. Val617Phe-negative myeloproliferative neoplasms (MPNs). MPL p. W515 L/K pathological variants are the most common across all mutations in MPL gene. The prevalence of these pathological variants over the Egyptian population is not clear enough. In the present study, we aimed to investigate the prevalence of MPL p. W515 L/K pathological variants in the Philadelphia (Ph)-negative MPNs over the Egyptian population. Results We have tested 60 patients with Ph-negative MPNs for MPL p. W515 L/K pathological variants. Median age was 51 (22–73) years. No MPL p. W515 L/K pathological variants were detected among our patients. JAK2 p. Val617Phe in PV and PMF patients showed significantly lower frequency than other studies. Splenomegaly was significantly higher in ET patients compared to other studies. Conclusion MPL p. W515 L/K pathological variants are rare across the Egyptian Ph-negative MPNs, and further studies on a large number are recommended. MPN patients in Egypt are younger compared to different ethnic groups.

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Hippo Pathway-related Genes Expression Is Deregulated in Myeloproliferative Neoplasms

10.21203/rs.3.rs-1107475/v1 ◽

2021 ◽

Author(s):

Maira da Costa Cacemiro ◽

Juçara Gastaldi Cominal ◽

Luiz Miguel Pereira ◽

Maria Gabriela Berzoti-Coelho ◽

Giovana Michelassi Berbel ◽

...

Keyword(s):

Cell Proliferation ◽

Tumor Suppressor ◽

Molecular Mechanisms ◽

Myeloproliferative Neoplasms ◽

Hippo Pathway ◽

Primary Myelofibrosis ◽

Driver Mutations ◽

Hippo Signaling ◽

Apoptosis Resistance ◽

Hematological Disorders

Abstract Myeloproliferative neoplasms (MPN) are hematological disorders characterized by increased proliferation of precursor and mature myeloid cells. MPN patients may present driver mutations in JAK2, MPL, and CALR genes, which are essential to describe the molecular mechanisms of MPN pathogenesis. Despite all the new knowledge on MPN pathogenesis, many questions remain to be answered to develop effective therapies to cure MPN or impair its progression to acute myeloid leukemia. The present study examined the expression levels of the Hippo signaling pathway members in patients with polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), as well as the role that they play in disease pathogenesis. The Hippo pathway is a tumor suppressor pathway that participates in the regulation of cell proliferation, differentiation, and death. Our main findings were: (i) expression of tumor suppressor genes from Hippo pathway were downregulated and seemed to be associated with cell resistance to apoptosis and increased proliferation rate; and (ii) Hippo pathway-related gene expression was associated with mutation status in ET and PMF patients. Therefore, the decreased expression of Hippo pathway-related genes may contribute to the malignant phenotype, apoptosis resistance, and cell proliferation in MPN pathogenesis.

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Advanced forms of MPNs are accompanied by chromosomal abnormalities that lead to dysregulation of TP53

Blood Advances ◽

10.1182/bloodadvances.2018024018 ◽

2018 ◽

Vol 2 (24) ◽

pp. 3581-3589 ◽

Cited By ~ 11

Author(s):

Bridget K. Marcellino ◽

Ronald Hoffman ◽

Joseph Tripodi ◽

Min Lu ◽

Heidi Kosiorek ◽

...

Keyword(s):

Disease Progression ◽

Chromosomal Abnormalities ◽

Myeloproliferative Neoplasms ◽

Philadelphia Chromosome ◽

Primary Myelofibrosis ◽

Chromosome 17 ◽

Transcript Levels ◽

History Of ◽

Tumor Protein P53

Abstract The Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and the prefibrotic form of primary myelofibrosis (PMF), frequently progress to more overt forms of MF and a type of acute leukemia termed MPN-accelerated phase/blast phase (MPN-AP/BP). Recent evidence indicates that dysregulation of the tumor suppressor tumor protein p53 (TP53) commonly occurs in the MPNs. The proteins MDM2 and MDM4 alter the cellular levels of TP53. We investigated in 1,294 patients whether abnormalities involving chromosomes 1 and 12, which harbor the genes for MDM4 and MDM2, respectively, and chromosome 17, where the gene for TP53 is located, are associated with MPN disease progression. Gain of 1q occurred not only in individuals with MPN-BP but also in patients with PV and ET, who, with further follow-up, eventually evolve to either MF and/or MPN-BP. These gains of 1q were most prevalent in patients with a history of PV and those who possessed the JAK2V617F driver mutation. The gains of 1q were accompanied by increased transcript levels of MDM4. In contrast, 12q chromosomal abnormalities were exclusively detected in patients who presented with MF or MPN-BP, but were not accompanied by further increases in MDM2/MDM4 transcript levels. Furthermore, all patients with a loss of 17p13, which leads to a deletion of TP53, had either MF or MPN-AP/BP. These findings suggest that gain of 1q, as well as deletions of 17p, are associated with perturbations of the TP53 pathway, which contribute to MPN disease progression.

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Prognostic and therapeutic impact of cytogenetic abnormalities in patients with myelodysplastic/myeloproliferative neoplasms, unclassifiable.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.7058 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. 7058-7058

Author(s):

Abhishek Avinash Mangaonkar ◽

Hassan Alkhateeb ◽

Aref Al-Kali ◽

Naseema Gangat ◽

Kebede Begna ◽

...

Keyword(s):

Bone Marrow ◽

High Risk ◽

Treatment Guidelines ◽

Myeloproliferative Neoplasms ◽

Univariate Analysis ◽

Prognostic Impact ◽

Trisomy 8 ◽

Abnormal Karyotype ◽

Immature Myeloid Cells

7058 Background: The 2016 WHO classification includes myelodysplastic/myeloproliferative neoplasms, unclassifiable (MDS/MPN-U), as an MDS/MPN overlap syndrome not meeting criteria for well-defined entities such as CMML. No standard prognostication or treatment guidelines exist for such patients. Methods: We retrospectively identified MDS/MPN-U cases from 1990-2016 through our myeloid malignancies database. All bone marrow reports were reviewed to ensure compliance with 2016 WHO criteria. Clinical & cytogenetic parameters at diagnosis were assessed & compared with treatment outcomes. Results: Eighty nine patients met study criteria, with a median age of 69 years (range: 37-93); 58 (65%) males. Median follow-up was 22.2 months (range: 0-172), with 41 (46%) deaths & 13 (15%) leukemic transformations. Median OS was 24.8 months (range: 0-172). 43 (53%) patients had an abnormal karyotype, with common abnormalities being trisomy 8 (12%), complex karyotype (9%) & del (20q) (6%). Given the fewer types of abnormalities identified, the IPSS cytogenetic stratification was more effective than IPSS-R, with risk categorization including; 45 good (55%), 20 intermediate (25%) & 16 high risk (20%) respectively (8 unavailable). On univariate analysis, increased age (p = 0.05), decreased hemoglobin (p = 0.02), higher ANC (p = 0.03), circulating immature myeloid cells (p = 0.02), higher LDH (p = 0.009), absence of bone marrow ring sideroblasts (p = 0.001) & higher risk (intermediate & high) IPSS cytogenetic categories (p = 0.01) adversely impacted OS. In a multivariate model that included the aforementioned variables, higher risk IPSS cytogenetics retained a negative prognostic impact (p = 0.04). 28 patients received a median of 6 cycles (range: 1-21) of hypomethylating agent therapy (HMA), with an overall response rate of 18% (CR-3, PR-2). All responders had an abnormal karyotype (p = 0.01). However, HMA did not affect either OS or LFS. Conclusions: Intermediate & high risk IPSS cytogenetic categories independently & adversely impact survival in WHO defined MDS/MPN-U patients. HMA use did not impact OS; however, patients with abnormal karyotypes were more likely to respond.

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