bluuebunny/crossref_metadata_2025_split huggingface dataset:
JAK2
V617F Mutational Load in Patients with Polycythemia Vera (PV) Measured by Peripheral Blood DNA Is Associated with Disease Severity.
Authors: Silver Richard T. , Vandris Katherine , Wang Y. Lynn , Christos Paul J. , Adriano Fernando , Jones Amy V. , Cross Nicholas C.P. 
Published: April 2020

Abstract
Different methods using peripheral blood RNA (Vannucchi AM, et al. Leukemia. 2007,1–8), or archival bone marrow DNA (Tefferi A, et al. Leukemia. 2007,1–2) have yielded varied results correlating allele burden with severity and duration of disease. We therefore aimed to determine whether JAK2V617F allele burden correlated with certain parameters of disease. At our institution, 105 patients were diagnosed according to the criteria of the Polycythemia Vera Study Group. We grouped their JAK2V617F allele burdens into quintiles. DNA from peripheral blood was analyzed using pyrosequencing. For those patients whose allele burden was &lt;5%, a sensitive ARMS (amplification refractory mutation system) assay was performed to demonstrate the presence of the JAK2V617F allele. Duration of disease was assessed from onset of symptoms. Spleen size was measured in cm below the midpoint of the left costal margin in the midclavicular line and categorized as not enlarged, slightly (1–3 cm), moderately (4–9 cm), or grossly enlarged (&gt;9 cm). Thrombotic events were recorded within 5 years of JAK2V617F determination. There were 52 men and 53 women. The patients ranged in age from 35 to 88 years, median 60 years. The median duration of disease was 7.4 years (range: 0.2 - 36.6 years), and the median duration of follow-up after JAK2V617F determination was 12 months year (range: 1 - 43 months). The mean mutant allele burden was 46.0% (s.d. ± 29.7%). The fifth, and highest quintile had a mean mutant allele burden of 90.2% (s.d. ± 5.8%); the lowest quintile had a mean mutant allele burden of 9.9% (s.d. ± 6.3%). JAK2V617F did not correlate with age, gender, hematocrit and platelet count at diagnosis, or rate of phlebotomy prior to cytoreductive therapy. Increasing JAK2V617F burden did correlate with higher WBC at diagnosis (P=0.02), degree of splenomegaly (P&lt;0.0001), presence of marrow fibrosis (P=0.03), and longer duration of disease (P=0.001). There was a trend for a higher JAK2V617F allele burden among patients with venous compared to arterial thrombosis. When the subset of patients who had JAK2V617F testing performed within 5 years of diagnosis (N=35) was examined, trends similar to those we had reported for all 105 patients were found, but no definitive statement can be made because of the small sample size. We noted a JAK2V617F allele burden of more than 80% during the course of the illness was associated with a significant disease phenotype. This is the first report of increased marrow fibrosis associated with high JAK2V617F burden. The importance of using quantitative JAK2V617F for assessing allele burden is stressed because patients with an increased allele burden may be candidates for anti-JAK therapy.
Frequency of JAK2 Exon 12 Mutations in JAK2 Exon 14 V617F-Negative Patients: High Frequency in ET Patients.
Authors: Duke Veronique M. , Gurunlian Nicole , Yogashangari Bi , Colley Tom , McNamara Christopher , Hoffbrand A. Victor , Foroni Letizia 
Published: April 2020

Abstract
The identification of the G to T point (V617F) mutation in exon 14 of the JH2 domain of the Janus kinase 2 gene (JAK2) has recently simplified the diagnosis of many patients affected with a variety of myeloproliferative disorders (MPDs). More recently JAK2 exon 12 mutations have been described in these disorders; although the role of these mutations is as yet unclear. There have been only two investigations which have identified the presence of exon 12 mutations in clinical diagnosis among polycythaemia vera (PV) (Scott et al NEJM 2007, Pardanani et al Leukaemia 2007). A total of 725 patients diagnosed clinically with a variety of MPDs were investigated for both the frequently occurring exon 14 V617F and for the rarer exon 12 mutations.
Methods: Peripheral blood samples from all patients were screened for the V617F mutation by gene-scaning on an ABI 3130 fragment analyser. 478 of these patients were further screened for the exon 12 mutant allele by denaturing high performance liquid chromatography (Transgenomic WAVE®) and direct sequencing.
Results: Of 725 patients screened for the V617F mutation 204 (28%) were found to be heterozygous (HET) and 30 (4%) homozygously (HM) mutated while 491 (68%) were wildtype (WT). 478 were further tested for the exon 12 mutation and eight were found to carry mutations. Two of the patients had previously described mutations while three novel mutations were described in the remaining six patients. Only one of these was in the PV group while the majority of exon 12 mutations clustered in the essential thrombocythemia (ET) (4/8) and Budd Chiari patients (2/8). All exon 12 mutations were identified at very low level.
Conclusions: Combined rapid gene-scanning and WAVE analysis allows for the characterisation of a large cohort of patients diagnosed clinically to have a variety of MPDs. This helps with the correct diagnosis of a frequently difficult group of patients. Detection of exon 12 mutations should be used in patients who are WT for V617F, including patients in the ET and the Budd Chiari syndrome groups. Both V617F and exon 12 mutation analysis tests should be included in primary screening in the routine management of MPD patients.
Diagnosis Total WT for V617F (mutant exon 12) HET for V617F (mutant exon 12) HM for V617F (mutant exon 12) Results of Exon 14 V617F and exon 12 mutation screening Budd Chiari/PVT 60 42 (2) 16 (0) 2 (0) Polycythemia Vera (PV) 187 112 (1) 63 (0) 12 (0) Reactive PV 28 28 (0) 0 (none tested) 0 (none tested) ET 198 123 (4) 71 (none tested) 4 (none tested) MPD 123 87 (1) 29 (none tested) 7 (none tested) Inspecified diagnosis 129 99 (none tested) 25 (none tested) 5 (none tested) TOTAL 725 491 (8) 204 (0) 30 (0)
Targeting CDK4/6 and the Cell Cycle in Combination with Bortezomib in the 5T33MM Myeloma Model.
Authors: Menu Eline , Garcia Josefina , Huang Xiangao , Di Liberto Maurizio , Toogood Peter , Chen Isan , Vanderkerken Karin , Chen-Kiang Selina 
Published: April 2020

Abstract
Multiple myeloma (MM) is ultimately fatal in part because no effective cell cycle-based therapy has been available to control tumor cell proliferation. Loss of cell cycle control in MM cells stems from coordinated deregulation of Cdk4-cyclin D1 or Cdk6 (Cdk4)-cyclin D2. PD 0332991 is the first orally bioactive small molecule that potently and specifically inhibits Cdk4 and Cdk6. It represents a promising cell cycle-based therapy for myeloma owing to its ability to potently inhibit Cdk4/6 and induce G1 cell cycle arrest in primary human myeloma cells in BM stromal cell co-cultures and to control tumor progression in a xenograft model. However, the efficacy of PD 0332991 in the presence of an intact immune system is unknown. To optimize therapeutic targeting of Cdk4/6 with PD 0332991, we investigated the effectiveness of PD 0332991 in inhibiting Cdk4/6 and controlling myeloma tumor progression in the immunocompetent, bone migrating 5T33MM model. By quantitative real-time PCR analysis, we found that these myeloma cells express a normal plasma cell transcription program such as upregulated Blimp-1 and loss of Bcl-6 expression. However, they proliferate aggressively due to Cdk4 overexpression and impaired p27Kip1 expression, thereby mimicking relapse disease in human myeloma. PD 0332991 potently inhibits Cdk4/6 phosphorylation of Rb in primary 5T33MM cells and induces G1 cell cycle arrest, both in vivo and ex vivo. Accordingly, treatment with PD 0332991 significantly prolongs the survival of tumor-induced 5T33MM mice; a mean of 35 days in the PD 0332991-treated group (N=9) versus 25 days in the vehicle-treated group (N=9, p&lt; 0.003). These findings demonstrate for the first time that PD 0332991 targets Cdk4/6 and controls tumor expansion in the presence of an intact immune system. To further optimize Cdk4/6 targeting in MM, we combined PD 0332991 with bortezomib, a cytotoxic drug widely used in MM treatment. Pretreatment of 5T33MMvt cells with PD 0332991 for 48 hours markedly augmented bortezomib killing, to the same level of twice the dose of bortezomib when it was used alone. These studies of PD 0332991 in the immunocompetent 5T33MM model demonstrate that, as a consequence of Cdk4/6 inhibition and induction of G1 arrest, PD 0332991 sensitizes MM cells to killing by a cytotoxic agent. Targeting Cdk4/6 in combination therapy, therefore, represents a novel and promising strategy for myeloma treatment.
Analysis of Mutant cMPL in Philadelphia Chromosome-Negative Myeloproliferative Disorders (Ph−MPDs) Using a Novel High-Sensitivity Assay.
Authors: Samuelson Scott J. , Swierczek Sabina , Parker Charles J. , Boucher Kenneth , Jelinek Jaroslav , Prchal Josef 
Published: April 2020

Abstract
cMPL is a gene encoding for the thrombopoietin receptor that is essential for thrombopoiesis and contributes to pluripotent hematopoietic stem cell expansion. A gain of function cMPL mutation, MPLW515L, was identified in myeloid cells from patients with primary myelofibrosis (PMF). Subsequent studies identified a second gain of function mutation, MPLW515K, in PMF and essential thrombocytosis (ET). The prevalence of MPLW515L and MPLW515K mutations was 5% in PMF and 1% in ET. No mutant cMPL was detected in Polycythemia Vera (PV). The methods utilized in these assays were sensitive to mutant frequencies of &gt;3–5%. We developed a rapid, sensitive, quantitative real time PCR assay based on a unique primer design wherein allelic discrimination was enhanced by the synergistic effect of a mismatch in the −1 position, and a locked nucleic acid nucleoside at the −2 position of the allele-specific primers. An assay of similar design can detect G1849T mutation of JAK2 in &lt;0.1% mutant allele in peripheral blood granulocyte (Nussenzveig Exp Hematol20073:32). We hypothesized that a similar high sensitivity assay would increase detection of mutant cMPL in Ph−MPDs. We analyzed genomic DNA from peripheral blood granulocytes of 197 MPD patients and found that 10/197 (5.1%) carried one of the two cMPL mutations. Further, 5 of these patients were also JAK2V617F positive. cMPL mutations were detected in 1/78 (1.3%) PV patients, 3/56 (5.4%) ET patients, 4/49 (8.2%) PMF patients, and 2/11 (18%) MPD-Unspecified patients. W515L accounted for 9/10 cases, with W515K accounting for only 1. Of the ten positive samples, five (including the patient with PV) had ≤1% mutant alleles. To confirm the validity of our assay, we tested DNA from 96 normal controls. Neither W515L nor W515K was detected (p=0.03 compared to samples from the Ph−MPD patients). Additionally, when DNA from megakaryocytic colonies from a patient with 0.70% mutant alleles was analyzed, 12.5% of colonies were found to be heterozygous for cMPLW515L. These studies demonstrate the sensitivity and accuracy of our assay and show that cMPL activating mutations are more common in ET than previously reported. Mutant allele frequency appears greater in megakaryocytic cultures perhaps indicating a proliferative advantage for the cMPL-mutant clone. That mutant cMPL and JAK2V617F can be found in the same patient demonstrates the molecular heterogeneity of Ph−MPDs and emphasizes the need for prospective studies designed to determine the relationship between genotype and clinical phenotype. Scott J. Samuelson and Sabina Swierczek contributed equally to this project.
Pruritus in Polycythemia Vera Is More Prevalent in Non-Smokers and Is Independently Associated with a Lower Risk of Arterial Thrombosis.
Authors: Gangat Naseema , Strand Jacob J. , Lasho Terra L. , Li Chin-Yang , Pardanani Animesh , Tefferi Ayalew 
Published: April 2020

Abstract
Background: Pruritus in polycythemia vera (PV) has been associated with a high JAK2V617F allele burden (Tefferi et al. Cancer. 2006;106:631, Vannucchi et al, Leukemia2007, in press). However, there is limited information regarding clinical correlates of pruritus per se in PV. Accordingly, we conducted a large (n=418) retrospective study in PV to accurately assess the prevalence and severity of pruritus as well as its relationship with presenting clinical features, bone marrow JAK2V617F allele burden, and prognosis.
Methods: The study cohort consisted of a consecutive group of patients with PV who fulfilled the World Health Organization (WHO) diagnostic criteria and in whom information regarding the presence or absence of pruritus at diagnosis was fully documented. Pruritus was graded as being mild, moderate, or severe based on careful review of patient history.
Results:
Prevalence and severity of pruritus: A total of 418 patients fulfilled the above stipulated criteria for study inclusion (median age of 60 years; 56% males; median follow-up of 73 months). Of these, 131 (31%) experienced pruritus at time of initial diagnosis: mild in 97 patients (74%), moderate in 22 (17%), and severe in 12 (9%). Most patients with mild pruritus (n=92) received no specific therapy for pruritus whereas all 12 patients with severe pruritus required treatment; all 7 patients who received treatment with paroxetine responded. Pruritus and JAK2V617F allele burden: Quantitative measurement of JAK2V617F was performed in 64 patients using genomic DNA from archived bone marrow obtained at the time of PV diagnosis. Mutational frequency was 97%; median mutant allele burden was 25.4% (range 0.2 - 93.3%). Among the 62 V617F-positive patients, 24 (39%) had pruritus; the proportion of patients in the upper and lower quartile allele burden ranges were 50% and 0% in the presence of pruritus and 18% and 34% in its absence (p=0.002). Clinical correlates of pruritus: Pruritus was more prevalent in non-smokers (35% vs. 19%; p=0.004) and non-diabetics (33% vs. 16%; p=0.04) and was associated with a lower rate of arterial thrombosis at diagnosis (8% vs. 17%; p=0.01) as well as during follow-up (16% vs. 30%; p=0.003).
These significant associations remained intact during multivariable analysis. Pruritus did not have an impact on the rate of leukemic or fibrotic transformation.
Conclusions: Pruritus in PV is independently associated with a lower risk of arterial thrombosis despite high JAK2V617F allele burden and is also more prevalent in non-smokers. These observations suggest that pruritus might be a surrogate for an underlying platelet pathology with functional relevance.
A Phase 2 Study of Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA) in Relapsed or Refractory Indolent Non Hodgkin Lymphoma. A California Cancer Consortium Study.
Authors: Kirschbaum Mark H. , Zain Jasmine M. , Popplewell Leslie , Pullarkat Vinod , Nademanee Auayporn P. , Delioukina Maria L. , Pulone Bernadette , Matsuoka Deron , Frankel Paul , James Zwiebel A. , Forman Stephen J. , Newman Edward , Gandara David 
Published: April 2020

Abstract
Background: The indolent (follicular, marginal zone and mantle cell) lymphomas tend to recur with decreasing intervals of remission after standard chemotherapy. New modalities of treatment are necessary. Vorinostat (SAHA), an orally administered hydroxamic acid histone deacetylase inhibitor with activity against class I and II deactylases with preclinical and clinical activity against various forms of lymphoma, is being studied in patients with relapsed or refractory indolent lymphoma. We report the results at the first interim analysis, after accrual of the first 17 evaluable patients according to the two-stage trial design.
Methods: Patients with relapsed or refractory follicular, marginal zone, or mantle cell lymphoma are eligible. Vorinostat is dosed at 200 mg po twice daily for 14 consecutive days on a 21 day cycle. CT scanning is performed after every three cycles, as is marrow biopsy for those with marrow involvement at time of entry into study. Patients may have received up to four prior chemotherapy regimens including Zevalin or Bexxar; previous transplant is allowed.
Results: 17 eligible patients (8 female, 9 male) were accrued prior to interim analysis (1 ineligible patient due to wrong histology is excluded from the analysis). The median age at diagnosis was 61 (34–78) years. All patients had progressed or failed to respond to chemotherapy and/or rituximab. Five patients were taken off study due to progression, two came off study due to toxicities (one for fatigue and diarrhea after 10 cycles and the other for diarrhea and dizziness after 2 cycles). One patient stopped therapy due to intercurrent illness, one came off for alternate therapy, 1 completed the treatment per protocol with a CR, and 7 patients remain on treatment. One patient had grade 4 ANC and thrombocytopenia, and one patient had grade 4 thrombocytopenia. Both patients were able to get subsequent cycles. Grade 3 toxicities attributable to study drug were thrombocytopenia, neutropenia, anemia, and fatigue. By the current Cheson criteria, there were 4 patients who achieved complete remission (CR), and 2 patients who achieved partial remission (PR). The two patients with PR as best response subsequently progressed (one at 189 days, one after 462 days). Four other patients are on therapy with stable disease, one patient with stable disease now for over 420 days.
Conclusions: The histone deacetylase inhibitor vorinostat shows promising activity against follicular and marginal zone lymphoma, refractory to chemotherapy and rituximab. The target response for stage 1 (4/17) was met and stage 2 is open for accrual.
Identification of Vacuolar H+- ATPase as a Target for Myeloma Therapeutics.
Authors: Zhu Yuan Xiao , Xin Chung , Ben Liang Lian Sheng , Chng Wee-Joo , Trudel Suzanne , Stewart Keith 
Published: April 2020

Abstract
From a high throughput RNAi screen of the human druggable genome targeting the KMS11 cell line, we identified the suppression of the vacuolar H+- ATPase (V-ATPase) family as cytotoxic to myeloma cells. In the screen, two oligos against each gene for the V-ATPase subunits ATP6V1A and ATP6V1B1 resulted in suppression of cell growth (50% and 60% inhibition of cell viability respectively). We further confirmed this result using both lentiviral shRNA knockdown and two small molecule inhibitors specific for V-ATPase. Silencing of ATP6V1A by lentiviral shRNA knock-down in KMS11 and in OPM1 myeloma cell lines caused 75–80% reduction of cell viability at 5 days post infection (measured by MTT assay). Consistent with this result, the V-ATPase specific inhibitors, bafilomycin A1 and REATA 203, both inhibited the growth of a genetically heterogeneous and standardized panel of 14 human myeloma cell lines in vitro with an IC50 ranging from 2.2 – 8.9 nM (mean 5.25 nM) for bafilomycin A1 and 46–1594 nM (mean 542.5 nM)) for REATA 203. We further demonstrated that patient samples (n=10) were sensitive to 20nM bafilomycin A1 which induced a mean of 58% of MM cells to undergo apoptosis (range 10% to 93%) after 24 hours of treatment. Similar to bafilomycin A1, treatment of primary patient-derived MM cells with 500 nM REATA 203 for 72 hours resulted in a mean 69% apoptosis (range 24% to 97%). In contrast, non-myeloma cells (the CD138- fractions of the bone marrow samples) were less sensitive - mean 9% apoptosis (range from 0% to 34%) under the same treatment conditions. Of high interest, however, unlike most drugs we have studied in pre-clinical myeloma models, the cytotoxicity induced by bafilomycin A1 in MM cell lines is abrogated by co-culture with patient bone marrow stromal cells but is not affected by IL-6 or IGF-1 treatment. Dexamethasone- or melphalan-resistant MM cell lines were also highly sensitive to both bafilomycin A1 and REATA 203. In a xenographic JJN3 mouse model, bafilomycin A1 suppresses and delays growth of tumor in a dose-dependent fashion. Gene expression analysis of normal-donor bone marrow plasma cells (n=19), primary tumor samples from MM patients (n=107) and normal somatic tissues demonstrates ubiquitous expression of most subunits of V-ATPase, however, some subunits are preferentially expressed in myeloma cells compared with normal plasma cells, including ATP6V1F (84% vs. 11%), ATP6V1E1 (29% vs. 5%), ATP6V1G2 (17% vs. 0%) and ATP6V0E 2 (36% vs. 16%). In conclusion, our data indicate that vacuolar H+-ATPase inhibitors are of interest as potential therapeutics for MM.
Imatinib Mesylate (Gleevec®) Produces Responses in Patients with Relapsed/Refractory Waldenstrom’s Macroglobulinemia.
Authors: Soumerai Jacob D. , O’Connor Kelly E. , Ioakimidis Leukothea M. , Patterson Christopher J. , Ciccarelli Bryan T. , Leduc Renee , Hunter Zachary R. , Nelson Marybeth , Roccaro Aldo M. , Leleu Xavier , Hatjiharissi Evdoxia , Adamia Sophia , Xu Lian , Ghobrial Irene M. , Treon Steven P. 
Published: April 2020

Abstract
Waldenstrom’s macroglobulinemia is a B-cell disorder characterized by the infiltration of lymphoplasmacytic cells (LPC) in the bone marrow (BM), along with an IgM monoclonal gammopathy. Characteristic of WM is an increased number of mast cells (MC) which are found in association with LPC, and stimulate LPC growth through several TNF-family members including CD40L, APRIL and BLYS (Ann Oncol17:1275; Blood104:917A). As such, we have targeted MC in WM. One important growth and survival factor for MC is stem cell factor (SCF), which signals through CD117. Imatinib mesylate blocks SCF signaling through CD117, and induces apoptosis of WM BM MC and LPC, both of which highly express CD117 (Blood2004; 104:314b). As such, we performed this Phase II study of imatinib mesylate in patients with relapsed and refractory WM. Intended therapy consisted of imatinib mesylate which was initiated at 400 mg po qD over the first month, and subsequently dose escalated to 600 mg po qD for up to 2 years. Dose de-escalation to 300 mg po qD was permitted for toxicity. Twenty-eight patients were enrolled, 27 of whom are eligible for evaluation at final analysis. Median age was 61 (range 33–80 years), and median prior therapies was 2 (range 1–5). Twenty-four and four patients had relapsed and refractory disease, respectively. With a median follow-up of 6.3 months for all evaluable patients, median serum IgM levels declined from 3,110 to 2,530 mg/dL at best response (p=0.002). On an evaluable basis, 7/27 (26%) and 2/27 (7%) of patients attained a ≥25% and ≥50% decrease in serum IgM, respectively. Responses were prompt, and occurred at a median of 2.1 months. The median time to progression for responding patients was 8.4 (range 2–15 months). Hematological toxicities were the most common feature and ≥grade 2 toxicities included anemia (n=12), leucopenia (n=5), edema (n=3), thrombocytopenia (n=2) and neutropenia (n=1). Tryptase levels, which measure mast cell burden, declined in all patients for whom pre- and post-serum was available from 6.7 (range 2.2–10 ng/ml) to 3 (range 1–5.5 ng/ml) (p&lt;0.001) though did not predict response to therapy.The results of this study demonstrate that imatinib mesylate is an active salvage therapy for WM and is associated with decreases in mast cell burden in patients with WM.