scholarly journals Hematopoietic fitness of JAK2V617F Myeloproliferative Neoplasms is linked to clinical outcome

Author(s):  
Ghaith Abu-Zeinah ◽  
Silvana Di Giandomenico ◽  
Tatiana Cruz ◽  
Elwood Taylor ◽  
Ellen K Ritchie ◽  
...  

AbstractMyeloproliferative Neoplasms (MPN) harbor highly recurrent driver mutations affecting targetable kinases yet treatment options for these phenotypically diverse diseases are limited, and patients experience significant morbidity and shortened survival. The most important disease-related complications—thrombosis, transformation and death—are not used as clinical trial endpoints due to the long follow-up required to assess such disease modifying activity. A reliable monitoring biomarker linking MPN biology with these important clinical outcomes is missing. MPN driver mutation allele frequency (MAF) from whole blood or marrow (WB) does not faithfully predict MPN phenotype, clinical progression or response. This is likely because WB MAF is a composite measure of alleles from a heterogenous and variable mixture of mature leukocytes and, as such, does not report any information about the critical MPN stem and progenitor cells (MPN-SPCs). Driver mutations allow MPN cells to outcompete their normal hematopoietic counterparts and this competitive advantage—increased “fitness”—underlies core biology of MPN pathogenesis. We developed an approach to directly measure MPN fitness from samples. We measured fitness in 115 samples from 84 patients with JAK2V617F MPNs by quantifying MAF of 11 well-defined and strictly validated hematopoietic stem, progenitor and mature cell populations purified from routinely collected blood and marrow specimens. Unsupervised, hierarchical clustering of MPN fitness revealed 4 major fitness levels: F1, F2, F3, and F4 with significantly different but overlapping clinical features and diagnoses. Notably, these four fitness levels were associated with significantly different event-free survival (EFS): 95% (F1), 81% (F2), 73% (F3), 50% (F4) at 24 months (log-rank p=0.017). In contrast, WB MAF quartile failed to predict EFS. Multivariable models showed that fitness was associated with event risk independent of age, sex, duration of disease, MPN diagnosis and WB MAF. Principal component analysis allowed convenient projection of the 11-component MAF fitness measures to reduce dimensionality and develop a model for relative risk (RR) of event that could be used to assess individual or serial samples. Serial samples with more than a year of follow-up was available for 13 patients. We found that a reduction of this RR score was associated with a therapeutic response (p=0.045). In contrast, increasing RR overtime portended a disease-related event (p=0.045). Changes in WB MAF did not correlate with RR (r2=0.022) possibly explaining why WB MAF failed to predict events. These data demonstrate that fitness dynamics from serial blood samples can be used as a monitoring biomarker to assess changes in RR over time. Thus, fitness risk is a promising endpoint alongside corresponding clinical parameters such as blood counts, spleen size and marrow fibrosis grade. Our study offers a feasible approach to monitor the MPN biology central to disease progression and can be used in clinical trials to efficiently identify disease-modifying, potentially life-prolonging treatments.

Blood ◽  
2021 ◽  
Author(s):  
Matthieu Mosca ◽  
Gurvan Hermange ◽  
Amandine Tisserand ◽  
Robert John Noble ◽  
Christophe Marzac ◽  
...  

Classical BCR-ABL-negative myeloproliferative neoplasms (MPN) are clonal disorders of hematopoietic stem cells (HSC) caused mainly by recurrent mutations in genes encoding JAK2 (JAK2), calreticulin (CALR), or the thrombopoietin receptor (MPL). Interferon alpha (IFNα) has demonstrated some efficacy in inducing molecular remission in MPN. In order to determine factors that influence molecular response rate, we evaluated the long-term molecular efficacy of IFNα in MPN patients by monitoring the fate of cells carrying driver mutations in a prospective observational and longitudinal study of 48 patients over more than 5 years. We measured several times per year the clonal architecture of early and late hematopoietic progenitors (84,845 measurements) and the global variant allele frequency in mature cells (409 measurements). Using mathematical modeling and hierarchical Bayesian inference, we further inferred the dynamics of IFNα-targeted mutated HSC. Our data support the hypothesis that IFNα targets JAK2V617F HSC by inducing their exit from quiescence and differentiation into progenitors. Our observations indicate that treatment efficacy is higher in homozygous than heterozygous JAK2V617F HSC and increases with high IFNα dosage in heterozygous JAK2V617F HSC. Besides, we found that the molecular responses of CALRm HSC to IFNα were heterogeneous, varying between type 1 and type 2 CALRm, and high dosage of IFNα correlates with worse outcomes. Together, our work indicates that the long-term molecular efficacy of IFNα implies an HSC exhaustion mechanism and depends on both the driver mutation type and IFNα dosage.


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3296
Author(s):  
Ioannis Chanias ◽  
Kristina Stojkov ◽  
Gregor Stehle ◽  
Michael Daskalakis ◽  
Helena Simeunovic ◽  
...  

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal disorders caused by sequential accumulation of somatic driver mutations in hematopoietic stem and progenitor cells (HSPCs). MDS is characterized by ineffective hematopoiesis with cytopenia, dysplasia, inflammation, and a variable risk of transformation into secondary acute myeloid leukemia. The advent of next-generation sequencing has revolutionized our understanding of the genetic basis of the disease. Nevertheless, the biology of clonal evolution remains poorly understood, and the stochastic genetic drift with sequential accumulation of genetic hits in HSPCs is individual, highly dynamic and hardly predictable. These continuously moving genetic targets pose substantial challenges for the implementation of precision medicine, which aims to maximize efficacy with minimal toxicity of treatments. In the current postgenomic era, allogeneic hematopoietic stem cell transplantation remains the only curative option for younger and fit MDS patients. For all unfit patients, regeneration of HSPCs stays out of reach and all available therapies remain palliative, which will eventually lead to refractoriness and progression. In this review, we summarize the recent advances in our understanding of MDS pathophysiology and its impact on diagnosis, risk-assessment and disease monitoring. Moreover, we present ongoing clinical trials with targeting compounds and highlight future perspectives for precision medicine.


2021 ◽  
Vol 41 (03) ◽  
pp. 197-205
Author(s):  
Franziska C. Zeeh ◽  
Sara C. Meyer

AbstractPhiladelphia chromosome-negative myeloproliferative neoplasms are hematopoietic stem cell disorders characterized by dysregulated proliferation of mature myeloid blood cells. They can present as polycythemia vera, essential thrombocythemia, or myelofibrosis and are characterized by constitutive activation of JAK2 signaling. They share a propensity for thrombo-hemorrhagic complications and the risk of progression to acute myeloid leukemia. Attention has also been drawn to JAK2 mutant clonal hematopoiesis of indeterminate potential as a possible precursor state of MPN. Insight into the pathogenesis as well as options for the treatment of MPN has increased in the last years thanks to modern sequencing technologies and functional studies. Mutational analysis provides information on the oncogenic driver mutations in JAK2, CALR, or MPL in the majority of MPN patients. In addition, molecular markers enable more detailed prognostication and provide guidance for therapeutic decisions. While JAK2 inhibitors represent a standard of care for MF and resistant/refractory PV, allogeneic hematopoietic stem cell transplantation remains the only therapy with a curative potential in MPN so far but is reserved to a subset of patients. Thus, novel concepts for therapy are an important need, particularly in MF. Novel JAK2 inhibitors, combination therapy approaches with ruxolitinib, as well as therapeutic approaches addressing new molecular targets are in development. Current standards and recent advantages are discussed in this review.


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1037
Author(s):  
Alessandro Allegra ◽  
Giovanni Pioggia ◽  
Alessandro Tonacci ◽  
Marco Casciaro ◽  
Caterina Musolino ◽  
...  

Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) have recently been revealed to be related to chronic inflammation, oxidative stress, and the accumulation of reactive oxygen species. It has been proposed that MPNs represent a human inflammation model for tumor advancement, in which long-lasting inflammation serves as the driving element from early tumor stage (over polycythemia vera) to the later myelofibrotic cancer stage. It has been theorized that the starting event for acquired stem cell alteration may occur after a chronic inflammation stimulus with consequent myelopoietic drive, producing a genetic stem cell insult. When this occurs, the clone itself constantly produces inflammatory components in the bone marrow; these elements further cause clonal expansion. In BCR–ABL1-negative MPNs, the driver mutations include JAK 2, MPL, and CALR. Transcriptomic studies of hematopoietic stem cells from subjects with driver mutations have demonstrated the upregulation of inflammation-related genes capable of provoking the development of an inflammatory state. The possibility of acting on the inflammatory state as a therapeutic approach in MPNs appears promising, in which an intervention operating on the pathways that control the synthesis of cytokines and oxidative stress could be effective in reducing the possibility of leukemic progression and onset of complications.


2020 ◽  
Vol 4 (21) ◽  
pp. 5540-5546
Author(s):  
Laurent Schmied ◽  
Patricia A. Olofsen ◽  
Pontus Lundberg ◽  
Alexandar Tzankov ◽  
Martina Kleber ◽  
...  

Abstract Acquired aplastic anemia and severe congenital neutropenia (SCN) are bone marrow (BM) failure syndromes of different origin, however, they share a common risk for secondary leukemic transformation. Here, we present a patient with severe aplastic anemia (SAA) evolving to secondary chronic neutrophilic leukemia (CNL; SAA-CNL). We show that SAA-CNL shares multiple somatic driver mutations in CSF3R, RUNX1, and EZH2/SUZ12 with cases of SCN that transformed to myelodysplastic syndrome or acute myeloid leukemia (AML). This molecular connection between SAA-CNL and SCN progressing to AML (SCN-AML) prompted us to perform a comparative transcriptome analysis on nonleukemic CD34high hematopoietic stem and progenitor cells, which showed transcriptional profiles that resemble indicative of interferon-driven proinflammatory responses. These findings provide further insights in the mechanisms underlying leukemic transformation in BM failure syndromes.


Haematologica ◽  
2021 ◽  
Author(s):  
Mirko Farina ◽  
Domenico Russo ◽  
Ronald Hoffman

Myeloproliferative neoplasms (MPN) are chronic, clonal hematologic malignancies characterized by myeloproliferation and a high incidence of vascular complications (thrombotic and bleeding). Although MPN-specific driver mutations have been identified, the underlying events that culminate in these clinical manifestations require further clarification. We reviewed the numerous studies performed during the last decade identifying endothelial cell (EC) dysregulation as a factor contributing to MPN disease development. The JAK2V617F MPN mutation and other myeloid-associated mutations have been detected not only in hematopoietic cells but also in EC and their precursors in MPN patients, suggesting a link between mutated EC and the high incidence of vascular events. To date, however, the role of EC in MPN continues to be questioned by some investigators. In order to further clarify the role of EC in MPN, we first describe the experimental strategies used to study EC biology and then analyze the available evidence generated using these assays which implicate mutated EC in MPN-associated abnormalities. Mutated EC have been reported to possess a pro-adhesive phenotype as a result of increased endothelial Pselectin exposure, secondary to degranulation of Weibel-Palade bodies, which is further accentuated by exposure to pro-inflammatory cytokines. Additional evidence indicates that MPN myeloproliferation requires JAK2V617F expression by both hematopoietic stem cells and EC. Furthermore, the reports of JAK2V617F and other myeloid malignancy- associated mutations in both hematopoietic cells and EC in MPN patients support the hypothesis that MPN driver mutations may first appear in a common precursor cell for both EC and hematopoietic cells.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kelly L. Bolton ◽  
Youngil Koh ◽  
Michael B. Foote ◽  
Hogune Im ◽  
Justin Jee ◽  
...  

AbstractAcquired somatic mutations in hematopoietic stem and progenitor cells (clonal hematopoiesis or CH) are associated with advanced age, increased risk of cardiovascular and malignant diseases, and decreased overall survival. These adverse sequelae may be mediated by altered inflammatory profiles observed in patients with CH. A pro-inflammatory immunologic profile is also associated with worse outcomes of certain infections, including SARS-CoV-2 and its associated disease Covid-19. Whether CH predisposes to severe Covid-19 or other infections is unknown. Among 525 individuals with Covid-19 from Memorial Sloan Kettering (MSK) and the Korean Clonal Hematopoiesis (KoCH) consortia, we show that CH is associated with severe Covid-19 outcomes (OR = 1.85, 95%=1.15–2.99, p = 0.01), in particular CH characterized by non-cancer driver mutations (OR = 2.01, 95% CI = 1.15–3.50, p = 0.01). We further explore the relationship between CH and risk of other infections in 14,211 solid tumor patients at MSK. CH is significantly associated with risk of Clostridium Difficile (HR = 2.01, 95% CI: 1.22–3.30, p = 6×10−3) and Streptococcus/Enterococcus infections (HR = 1.56, 95% CI = 1.15–2.13, p = 5×10−3). These findings suggest a relationship between CH and risk of severe infections that warrants further investigation.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Elad Jacoby ◽  
Moriya Ben Yakir-Blumkin ◽  
Shiri Blumenfeld-Kan ◽  
Yehuda Brody ◽  
Amilia Meir ◽  
...  

AbstractMitochondria are cellular organelles critical for numerous cellular processes and harboring their own circular mitochondrial DNA (mtDNA). Most mtDNA associated disorders (either deletions, mutations, or depletion) lead to multisystemic disease, often severe at a young age, with no disease-modifying therapies. Mitochondria have a capacity to enter eukaryotic cells and to be transported between cells. We describe a method of ex vivo augmentation of hematopoietic stem and progenitor cells (HSPCs) with normal exogenous mitochondria, termed mitochondrial augmentation therapy (MAT). Here, we show that MAT is feasible and dose dependent, and improves mitochondrial content and oxygen consumption of healthy and diseased HSPCs. Ex vivo mitochondrial augmentation of HSPCs from a patient with a mtDNA disorder leads to superior human engraftment in a non-conditioned NSGS mouse model. Using a syngeneic mouse model of accumulating mitochondrial dysfunction (Polg), we show durable engraftment in non-conditioned animals, with in vivo transfer of mitochondria to recipient hematopoietic cells. Taken together, this study supports MAT as a potential disease-modifying therapy for mtDNA disorders.


PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0197233 ◽  
Author(s):  
Richard K. Lubberich ◽  
Thomas Walenda ◽  
Tamme W. Goecke ◽  
Klaus Strathmann ◽  
Susanne Isfort ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-4
Author(s):  
Stephen E. Langabeer ◽  
Lisa Lee Tokar ◽  
Laura Kearney ◽  
Cathal O’Brien ◽  
Kowshika Thavarajah ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document