Enhanced Molecular Response in Myeloproliferative Neoplasms with Complete JAK2V617F Inhibition.

SUMMARY: Dunbar, Bowman, and colleagues present here a novel genetic mouse model with inducible and reversible expression of the JAK2V617F mutation in the endogenous locus. Results from this study clearly demonstrate an absolute requirement for myeloproliferative neoplasm-initiating cells for this mutation in their survival and imply that more efficacious inhibitors could be curative for these patients even in the setting of additional cooperating mutations. See related article by Dunbar et al., p. 737 (8).

Real-world status of treatment for lymphoid neoplasms developed during the course of myeloproliferative neoplasms in Japan.

OBJECTIVES: Patients with myeloproliferative neoplasms (MPNs) are at higher risk of developing secondary malignancies. In this study, we focused on patients with MPNs that complicated lymphoid neoplasms. To analyze the real-world status of lymphoid neoplasm treatment in patients with pre-existing MPNs in Japan, we conducted a multicenter retrospective study. METHODS: Questionnaires were sent to collect the data on patients who were first diagnosed with either polycythemia vera, essential thrombocythemia or myelofibrosis and who later were complicated with lymphoid neoplasms defined as malignant lymphoma, multiple myeloma, or chronic lymphocytic leukemia/small cell lymphoma. RESULTS: Twenty-four patients with MPNs complicated by lymphoid neoplasms were enrolled (polycythemia vera, n = 8; essential thrombocythemia, n = 14; and primary myelofibrosis, n = 2). Among these, diffuse large B-cell lymphoma (DLBCL) was the most frequently observed (n = 13, 54.1%). Twelve (92.3%) of the patients with DLBCL received conventional chemotherapy. Among these 12 patients, regarding cytoreductive therapy for MPNs, 8 patients stopped treatment, one continued treatment, and two received a reduced dose. Consequently, most patients were able to receive conventional chemotherapy for DLBCL with a slightly higher dose of granulocyte colony-stimulating factor support than usual without worse outcomes. All 3 patients with multiple myeloma received a standard dose of chemotherapy. CONCLUSION: Our data indicate that if aggressive lymphoid neoplasms develop during the course of treatment in patients with MPNs, it is acceptable to prioritize chemotherapy for lymphoma.

[Analysis of the factors influencing the severity of coronavirus disease 2019 in patients with myeloproliferative neoplasms based on an online questionnaire].

Objective: To explore the variables associated with the severity of coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 omicron variant during the epidemic in patients with myeloproliferative neoplasms (MPN). Methods: A cross-sectional study. During the SARS-CoV-2 omicron variant pandemic from December 15, 2022, to March 15, 2023, COVID-19 related data for patients with MPN who were treated at Peking University People's Hospital were collected through an online questionnaire-based survey. All questionnaires and clinical data were checked by medical assistants. Logistic multivariate analysis was used to explore the prevalence and variables associated with the severity of COVID-19 in patients with MPN. Results: A total of 239 patients with MPN, including 90 (37.7%) presenting with essential thrombocythemia (ET), 50 (20.9%) with polycythemia vera (PV), and 99 (41.4%) with myelofibrosis (MF), were enrolled in the study. The 99 patients with MF included 87 (87.9%) with primary MF, 5 (5.1%) with post-PV MF, and 7 (7.1%) with post-ET MF. Overall, 239 (100%) patients reported that they experienced COVID-19 during the pandemic. Of these, 226 (94.6%) had mild disease, 4 (1.7%) had moderate disease, 7 (2.9%) had severe disease, and 2 (0.8%) had critical disease. Two (0.8%) patients with severe COVID-19 died, one of which suffered from MT and the other from PV. Multivariate analysis showed that older age (OR=2.36, 95%CI 1.24-4.49), MF (OR=10.22, 95%CI 1.13-92.80), or comorbidity (OR=5.25, 95%CI 1.25-22.03) were associated with a significantly higher risk of developing moderate, severe, or critical COVID-19. Among patients with MF, higher risk stratification reflected an increased risk of developing moderate, severe, or critical COVID-19 (P=0.034). Conclusion: During the omicron pandemic, older age, MF (especially higher-risk categories), and comorbidity were associated with a higher risk of developing moderate, severe, or critical COVID-19.

Treatment outcome and germline predictive factors of ropeginterferon alpha-2b in myeloproliferative neoplasm patients.

BACKGROUND: Studies have shown that some single nucleotide polymorphisms (SNPs) could serve as excellent markers in foretelling the treatment outcome of interferon (IFN) in myeloproliferative neoplasms (MPN). However, most work originated from western countries, and data from different ethnic populations have been lacking. METHODS: To gain insights, targeted sequencing was performed to detect myeloid-associated mutations and SNPs in eight loci across three genes (IFNL4, IFN-γ, and inosine triphosphate pyrophosphatase [ITPA]) to explore their predictive roles in our cohort of 21 ropeginterferon alpha-2b (ROPEG)-treated MPN patients, among whom real-time quantitative PCR was also performed periodically to monitor the JAK2V617F allele burden in 19 JAK2V617F-mutated cases. RESULTS: ELN response criteria were adopted to designate patients as good responders if they achieved complete hematological responses (CHR) within 1 year (CHR1) or attained major molecular responses (MMR), which occurred in 70% and 45% of the patients, respectively. IFNL4 and IFN-γ gene SNPs were infrequent in our population and were thus excluded from further analysis. Two ITPA SNPs rs6051702 A>C and rs1127354 C>A were associated with an inferior CHR1 rate and MMR rate, respectively. The former seemed to be linked to grade 2 or worse hepatotoxicity as well, although the comparison was of borderline significance only (50%, vs. 6.7% in those with common haplotype, p = 0.053). Twelve patients harbored 19 additional somatic mutations in 12 genes, but the trajectory of these mutations varied considerably and was not predictive of any response. CONCLUSIONS: Overall, this study provided valuable information on the ethnics- and genetics-based algorithm in the treatment of MPN.

Associations of the circulating levels of cytokines with the risk of myeloproliferative neoplasms: a bidirectional mendelian-randomization study.

OBJECTIVE: In the pathogenesis of myeloproliferative neoplasms (MPN), inflammation plays an important role. However, it is unclear whether there is a causal link between inflammation and MPNs. We used a bidirectional, two-sample Mendelian randomization (MR) approach to investigate the causal relationship between systemic inflammatory cytokines and myeloproliferative neoplasms. METHODS: A genome-wide association study (GWAS) of 8293 European participants identified genetic instrumental variables for circulating cytokines and growth factors. Summary statistics of MPN were obtained from a GWAS including 1086 cases and 407,155 controls of European ancestry. The inverse-variance-weighted method was mainly used to compute odds ratios (OR) and 95% confidence intervals (Cl). RESULTS: Our results showed that higher Interleukin-2 receptor, alpha subunit (IL-2rα) levels, and higher Interferon gamma-induced protein 10 (IP-10) levels were associated with an increased risk of MPN (OR = 1.36,95%CI = 1.03-1.81, P = 0.032; OR = 1.55,95%CI = 1.09-2.22, P = 0.015; respectively).In addition, Genetically predicted MPN promotes expression of the inflammatory cytokines interleukin-10 (IL-10) (BETA = 0.033, 95% CI = 0.003 ~ 0.064, P = 0.032) and monokine induced by interferon-gamma (MIG) (BETA = 0.052, 95% CI = 0.002-0.102, P = 0.043) and, on activation, normal T cells express and secrete RANTES (BETA = 0.055, 95% CI = 0.0090.1, P = 0.018). CONCLUSION: Our findings suggest that cytokines are essential to the pathophysiology of MPN. More research is required if these biomarkers can be used to prevent and treat MPN.

Role of the STING pathway in myeloid neoplasms: a prospero-registered systematic review of principal hurdles of STING on the road to the clinical practice.

Myeloid neoplasms are a group of bone marrow diseases distinguished by disruptions in the molecular pathways that regulate the balance between hematopoietic stem cell (HSC) self-renewal and the generation of specialized cells. Cytokines and chemokines, two important components of the inflammatory process, also influence hematological differentiation. In this scenario, immunological dysregulation plays a pivotal role in the pathogenesis of bone marrow neoplasms. The STING pathway recognizes DNA fragments in the cell cytoplasm and triggers an immune response by type I interferons. The role of STING in cancer has not yet been established; however, both actions, as an oncogene or tumor suppressor, have been documented in other types of cancer. Therefore, we performed a systematic review (registered in PROSPERO database #CRD42023407512) to discuss the role of STING pathway in the advancement of pathogenesis and/or prognosis for different myeloid neoplasms. In brief, scientific evidence supports investigations that primarily use cell lines from myeloid neoplasms, such as leukemia. More high-quality research and clinical trials are needed to understand the role of the STING pathway in the pathology of hematological malignancies. Finally, the STING pathway suggests being a promising therapeutic molecular target, particularly when combined with current drug therapies.

Gadd45g insufficiency drives the pathogenesis of myeloproliferative neoplasms.

Despite the identification of driver mutations leading to the initiation of myeloproliferative neoplasms (MPNs), the molecular pathogenesis of MPNs remains incompletely understood. Here, we demonstrate that growth arrest and DNA damage inducible gamma (GADD45g) is expressed at significantly lower levels in patients with MPNs, and JAK2V617F mutation and histone deacetylation contribute to its reduced expression. Downregulation of GADD45g plays a tumor-promoting role in human MPN cells. Gadd45g insufficiency in the murine hematopoietic system alone leads to significantly enhanced growth and self-renewal capacity of myeloid-biased hematopoietic stem cells, and the development of phenotypes resembling MPNs. Mechanistically, the pathogenic role of GADD45g insufficiency is mediated through a cascade of activations of RAC2, PAK1 and PI3K-AKT signaling pathways. These data characterize GADD45g deficiency as a novel pathogenic factor in MPNs.

RAS mutations in myeloid malignancies: revisiting old questions with novel insights and therapeutic perspectives.

NRAS and KRAS activating point mutations are present in 10-30% of myeloid malignancies and are often associated with a proliferative phenotype. RAS mutations harbor allele-specific structural and biochemical properties depending on the hotspot mutation, contributing to variable biological consequences. Given their subclonal nature in most myeloid malignancies, their clonal architecture, and patterns of cooperativity with other driver genetic alterations may potentially have a direct, causal influence on the prognosis and treatment of myeloid malignancies. RAS mutations overall tend to be associated with poor clinical outcome in both chronic and acute myeloid malignancies. Several recent prognostic scoring systems have incorporated RAS mutational status. While RAS mutations do not always act as independent prognostic factors, they significantly influence disease progression and survival. However, their clinical significance depends on the type of mutation, disease context, and treatment administered. Recent evidence also indicates that RAS mutations drive resistance to targeted therapies, particularly FLT3, IDH1/2, or JAK2 inhibitors, as well as the venetoclax-azacitidine combination. The investigation of novel therapeutic strategies and combinations that target multiple axes within the RAS pathway, encompassing both upstream and downstream components, is an active field of research. The success of direct RAS inhibitors in patients with solid tumors has brought renewed optimism that this progress will be translated to patients with hematologic malignancies. In this review, we highlight key insights on RAS mutations across myeloid malignancies from the past decade, including their prevalence and distribution, cooperative genetic events, clonal architecture and dynamics, prognostic implications, and therapeutic targeting.

Exploring hematological alterations and genetics linked to SNV rs10974944 in myeloproliferative neoplasms among Amazon patients.

BCR::ABL1-negative myeloproliferative neoplasms are hematopoietic disorders characterized by panmyelosis. JAK2 V617F is a frequent variant in these diseases and often occurs in the 46/1 haplotype. The G allele of rs10974944 has been shown to be associated with this variant, specifically its acquisition, correlations with familial cases, and laboratory alterations. This study evaluated the association between the 46/1 haplotype and JAK2 V617F in patients with myeloproliferative neoplasms in a population from the Brazilian Amazon. Clinical, laboratory and molecular sequencing analyses were considered. Carriers of the G allele of rs10974944 with polycythemia vera showed an increase in mean corpuscular volume and mean corpuscular hemoglobin, while in those with essential thrombocythemia, there was an elevation in red blood cells, hematocrit, and hemoglobin. Associations were observed between rs10974944 and the JAK2 V617F, in which the G allele (OR 3.4; p < 0.0001) and GG genotype (OR 4.9; p = 0.0016) were associated with JAK2 V617F + and an increase in variant allele frequency (GG: OR 15.8; p = < 0.0001; G: OR 6.0; p = 0.0002). These results suggest an association between rs10974944 (G) and a status for JAK2 V617F, JAK2 V617F + _VAF ≥ 50%, and laboratory alterations in the erythroid lineage.

[SFCE harmonization workshops: Neonatal acute myeloid leukemia]. / Orientation et prise en charge de la leucémie aiguë myéloïde néonatale : recommandations du comité leucémies de la SFCE.

Neonatal acute myeloid leukemias (AML) occurred within the first 28 days of life and constitute only a small proportion of all AL. They are distinguished from leukemias of older children by their clinical presentation, which frequently includes cutaneous localizations ("blueberry muffin rash syndrome") and a leukocytosis above 50 ×109/L. This proliferation may be transient, causing a transient leukemoid reaction in a background of constitutional trisomy 21 ("Transient Abnormal Myelopoieseis" or TAM) or Infantile Myeloproliferative Disease in the absence of constitutional trisomy 21 ("Infantile Myeloproliferative Disease" or IMD). In cases of true neonatal AML, the prognosis of patients is poor. Overall survival is around 35 % in the largest historical series. This poor prognosis is mainly due to the period of onset of this pathology making the use of chemotherapy more limited and involving many considerations, both ethical and therapeutic. The objective of this work is to review this rare pathology by addressing the clinical, biological, therapeutic and ethical particularities of patients with true neonatal AML or transient leukemoid reactions occurring in a constitutional trisomy 21 (true TAM) or somatic background (IMD).

SHP2 inhibition displays efficacy as a monotherapy and in combination with JAK2 inhibition in preclinical models of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocytosis, and primary myelofibrosis, are clonal hematopoietic neoplasms driven by mutationally activated signaling by the JAK2 tyrosine kinase. Although JAK2 inhibitors can improve MPN patients' quality of life, they do not induce complete remission as disease-driving cells persistently survive therapy. ERK activation has been highlighted as contributing to JAK2 inhibitor persistent cell survival. As ERK is a component of signaling by activated RAS proteins and by JAK2 activation, we sought to inhibit RAS activation to enhance responses to JAK2 inhibition in preclinical MPN models. We found the SHP2 inhibitor RMC-4550 significantly enhanced growth inhibition of MPN cell lines in combination with the JAK2 inhibitor ruxolitinib, effectively preventing ruxolitinib persistent growth, and the growth and viability of established ruxolitinib persistent cells remained sensitive to SHP2 inhibition. Both SHP2 and JAK2 inhibition diminished cellular RAS-GTP levels, and their concomitant inhibition enhanced ERK inactivation and increased apoptosis. Inhibition of SHP2 inhibited the neoplastic growth of MPN patient hematopoietic progenitor cells and exhibited synergy with ruxolitinib. RMC-4550 antagonized MPN phenotypes and increased survival of an MPN mouse model driven by MPL-W515L. The combination of RMC-4550 and ruxolitinib, which was safe and tolerated in healthy mice, further inhibited disease compared to ruxolitinib monotherapy, including extending survival. Given SHP2 inhibitors are undergoing clinical evaluation in patients with solid tumors, our preclinical findings suggest that SHP2 is a candidate therapeutic target with potential for rapid translation to clinical assessment to improve current targeted therapies for MPN patients.

Activating mutations in JAK2 and CALR differentially affect intracellular calcium flux in store operated calcium entry.

BACKGROUND: Calcium (Ca2+) signaling regulates various vital cellular functions, including integrin activation and cell migration. Store-operated calcium entry (SOCE) via calcium release-activated calcium (CRAC) channels represents a major pathway for Ca2+ influx from the extracellular space in multiple cell types. The impact of JAK2-V617F and CALR mutations which are disease initiating in myeloproliferative neoplasms (MPN) on SOCE, calcium flux from the endoplasmic reticulum (ER) to the cytosol, and related key signaling pathways in the presence or absence of erythropoietin (EPO) or thrombopoietin (TPO) is poorly understood. Thus, this study aimed to elucidate the effects of these mutations on the aforementioned calcium dynamics, in cellular models of MPN. METHODS: Intracellular Ca2+ levels were measured over a time frame of 0-1080 s in Fura-2 AM labeled myeloid progenitor 32D cells expressing various mutations (JAK2-WT/EpoR, JAK2-V617F/EpoR; CALR-WT/MPL, CALR-ins5/MPL, and del52/MPL). Basal Ca2+ concentrations were assessed from 0-108 s. Subsequently, cells were stimulated with EPO/TPO in Ca2+-free Ringer solution, measuring Ca2+ levels from 109-594 s (store depletion). Then, 2 mM of Ca2+ buffer resembling physiological concentrations was added to induce SOCE, and Ca2+ levels were measured from 595-1080 s. Fura-2 AM emission ratios (F340/380) were used to quantify the integrated Ca2+ signal. Statistical significance was assessed by unpaired Student's t-test or Mann-Whitney-U-test, one-way or two-way ANOVA followed by Tukey's multiple comparison test. RESULTS: Following EPO stimulation, the area under the curve (AUC) representing SOCE significantly increased in 32D-JAK2-V617F cells compared to JAK2-WT cells. In TPO-stimulated CALR cells, we observed elevated Ca2+ levels during store depletion and SOCE in CALR-WT cells compared to CALR-ins5 and del52 cells. Notably, upon stimulation, key components of the Ca2+ signaling pathways, including PLCγ-1 and IP3R, were differentially affected in these cell lines. Hyper-activated PLCγ-1 and IP3R were observed in JAK2-V617F but not in CALR mutated cells. Inhibition of calcium regulatory mechanisms suppressed cellular growth and induced apoptosis in JAK2-V617F cells. CONCLUSIONS: This report highlights the impact of JAK2 and CALR mutations on Ca2+ flux (store depletion and SOCE) in response to stimulation with EPO and TPO. The study shows that the JAK2-V617F mutation strongly alters the regulatory mechanism of EpoR/JAK2-dependent intracellular calcium balance, affecting baseline calcium levels, EPO-induced calcium entry, and PLCγ-1 signaling pathways. Our results reveal an important role of calcium flux in the homeostasis of JAK2-V617F positive cells.

[Blastic plasmacytoid dendritic cell tumor treated with DVT regimen: a case report and literature review].

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressive hematological malignancy, there is no standard treatment and the prognosis is very poor. Affiliated Zhongshan Hospital of Dalian University report a case of 85-year-old BPDCN male patient treated with DVT regimen (decitabine combined with Venetoclax and thalidomide) and achieved complete remission. The patient with skin nodules and the pathology diagnosed BPDCN, the next generation sequencing of skin nodules showed mutations of IDH2 and ASXL1. DVT (decitabine combined with Venetoclax and thalidomide) has significant efficacy with rapid and deep remission for BPDCN, and the adverse effects is less, especially suitable for elderly patients who cannot tolerate intense chemotherapy.

Comparative Analyses of Targeted Myeloid Cancer Next-Generation Sequencing Panel in Fresh Blood, Bone Marrow and FFPE Material.

Next-generation sequencing is a vital tool for personalized diagnostics and therapies in cancer. Despite numerous advantages, the method depends on multiple parameters regarding the sample material, e.g., sample fixation. A panel's ability to ensure balanced pre-amplification of the regions of interest is challenging, especially in targeted sequencing approaches, but of significant importance to its applicability across hematological malignancies and solid tumors. This study comparatively evaluated the technical performance of the commercially available OncomineTM Myeloid Panel in fresh and Formalin-fixed paraffin-embedded (FFPE) material by using an Ion Torrent™ Personal Genome Machine™ System and Ion GeneStudio S5 System platform. In total, 114 samples were analyzed, including 55 fresh materials and 59 FFPE samples. Samples were sequenced with a minimum of one million reads. Amplicons with coverage below 400 reads were classified as underperforming. In fresh material, 49/526 amplicons were identified as performing insufficiently, corresponding with 18 genes. Using FFPE material, 103/526 amplicons underperformed. Independent of input material, regions in 27 genes, including ASXL1, BCOR and BRAF, did not match quality parameters. Subsequently, exemplary mutations were extracted from the Catalogue of Somatic Mutations in Cancer database. This technical evaluation of the OncomineTM Myeloid Panel identified amplicons that do not achieve adequate coverage levels and which need to be considered when interpreting sequencing.