Myeloproliferative and lymphoproliferative disorders: State of the art

Medicinal chemistry perspective of JAK inhibitors: synthesis, biological profile, selectivity, and structure activity relationship

JAK-STAT signalling pathway was discovered more than quarter century ago. The JAK-STAT pathway protein is considered as one of the crucial hubs for cytokine secretion which mediates activation of different inflammatory, cellular responses and hence involved in different etiological factors. The various etiological factors involved are haematopoiesis, immune fitness, tissue repair, inflammation, apoptosis, and adipogenesis. The presence of the active mutation V617K plays a significant role in the progression of the JAK-STAT pathway-related disease. Consequently, targeting the JAK-STAT pathway could be a promising therapeutic approach for addressing a range of causative factors. In this current review, we provided a comprehensive discussion for the in-detail study of anatomy and physiology of the JAK-STAT pathway which contributes structural domain rearrangement, activation, and negative regulation associated with the downstream signaling pathway, relationship between different cytokines and diseases. This review also discussed the recent development of clinical trial entities. Additionally, this review also provides updates on FDA-approved drugs. In the current investigation, we have classified recently developed small molecule inhibitors of JAK-STAT pathway according to different chemical classes and we emphasized their synthetic routes, biological evaluation, selectivity, and structure-activity relationship.

The Role of Erythrocyte Sedimentation Rate (ESR) in Myeloproliferative and Lymphoproliferative Diseases: Comparison between DIESSE CUBE 30 TOUCH and Alifax Test 1

(1) Background: The erythrocyte sedimentation rate (ESR) is widely diffused in hematology laboratories to monitor inflammatory statuses, response to therapies (such as antibiotics), and oncologic diseases. However, ESR is not a specific diagnostic marker but needs to be contextualized and compared with clinical and other laboratory findings. This study aimed to investigate the performance of two automated instruments, namely the DIESSE CUBE 30 TOUCH (DIESSE, Siena, Italy) and the Alifax Test 1 (Alifax Srl, Polverara, Italy), in comparison with the gold standard, the Westergren method, in lymphoproliferative and myeloproliferative patients. (2) Methods: 97 EDTA samples were selected from the hematology department of Roma Tor Vergata Hospital and analyzed. Statistical analysis was applied. (3) A good correlation between CUBE 30 TOUCH and the gold standard was observed in the overall sample (R2 = 0.90), as well as in patients with lymphoproliferative diseases (R2 = 0.90) and myeloproliferative diseases (R2 = 0.90). The correlation between Test 1 and the gold standard was observed in the overall sample (R2 = 0.68), as well as in patients with lymphoproliferative diseases (R2 = 0.79) and myeloproliferative diseases (R2 = 0.53). (4) Conclusions: The CUBE 30 TOUCH appears to be a more trustworthy tool for evaluating ESR in these pathologies.

Genetic and immunohistochemical profiling of NK/T-cell lymphomas reveals prognostically relevant BCOR-MYC association

Extranodal NK/T-cell lymphoma, nasal type (ENKTL) is an Epstein-Barr virus-positive, aggressive lymphoma with a heterogeneous cell of origin and variable clinical course. Several clinical prognostic indices have been proposed for ENKTL; however, there are few pathological biomarkers. This multi-institutional study sought to identify histologically assessable prognostic factors. We investigated mutation profiles by targeted next-generation sequencing (NGS) and immunohistochemical assessments of expression of MYC, Tyr705-phosphorylated (p-)STAT3, and CD30 in 71 ENKTL samples. The median age of the patients was 66 years (range, 6-100). The most frequent mutations were in STAT3 (27%), JAK3 (4%), KMT2D (19%), TP53 (13%), BCOR (10%), and DDX3X (7%). Immunohistochemistry (IHC) revealed that ENKTLs with STAT3 mutations exhibited higher expression of pSTAT3 and CD30. BCOR mutations were associated with increased MYC expression. Univariate analysis in the entire cohort showed that stage (II, III, or IV), BCOR mutations, TP53 mutations, and high MYC expression (defined as ≥40% positive neoplastic cells) were associated with reduced overall survival (OS). Multivariate modeling identified stage (II, III, or IV) and high MYC expression as independent adverse prognostic factors. In a subgroup analysis of patients treated with anthracycline (AC)-free chemotherapy and/or radiotherapy (RT) with curative intent, BCOR but not high MYC expression was an independent adverse prognostic factor. In conclusion, activating STAT3 mutations are common in ENKTLs and are associated with increased CD30 expression. MYC overexpression is, at least in part, associated with deleterious BCOR mutations, and this BCOR-MYC linkage may have prognostic significance, underscoring the potential utility of IHC for MYC in risk stratification of patients with ENKTL.

Co-Occurrence of Myeloid and Lymphoid Neoplasms: Clinical Characterization and Impact on Outcome. A Single-Center Cohort Study

The co-occurrence of myeloid neoplasms and lymphoproliferative diseases (LPDs) has been epidemiologically described, particularly in myeloproliferative neoplasms (MPNs). However, the clinical features of these patients are poorly known. In this study, we evaluated a single-center cohort of 44 patients with a diagnosis of myeloid and LPD focusing on clinical features, therapy requirement, and outcome. The two diagnoses were concomitant in 32% of patients, while myeloid disease preceded LPD in 52% of cases (after a median of 37 months, 6-318), and LPD preceded myeloid neoplasm in 16% (after a median of 41 months, 5-242). The most prevalent LPD was non-Hodgkin lymphoma (50%), particularly lymphoplasmacytic lymphoma (54.5%), followed by chronic lymphocytic leukemia (27%), plasma cell dyscrasias (18.2%), and rarer associations such as Hodgkin lymphoma and Erdheim-Chester disease. Overall, 80% of BCR-ABL1-negative MPN patients required a myeloid-specific treatment and LPD received therapy in 45.5% of cases. Seven subjects experienced vascular events, 13 a grade >/= 3 infectious episode (9 pneumonias, 3 urinary tract infection, and 1 sepsis), and 9 developed a solid tumor. Finally, nine patients died due to solid tumor (four), leukemic progression (two), infectious complications (two), and brain bleeding (one). Longer survival was observed in younger patients (p = 0.001), with better performance status (p = 0.02) and in the presence of driver mutations (p = 0.003). Contrarily, a worse survival was significantly associated with the occurrence of infections (p < 0.0001). These data suggest that in subjects with co-occurrence of myeloid and lymphoid neoplasms, high medical surveillance for infectious complications is needed, along with patient education, since they may negatively impact outcome.

Proteomic Profiling Differentiates Lymphoma Patients with and without Concurrent Myeloproliferative Neoplasia

Simple Summary

Patients are diagnosed with myeloproliferative neoplasia (MPN) and lymphoma more frequently in the population than expected, which has led to the hypothesis that the two malignancies may, in some cases, be pathogenetically related. In this study, lymphoma patients with and without MPN show subtle but important differences in the protein expression that enables the clustering of the lymphomas, thus indicating the differences at the molecular level between the lymphoma malignancies with and without MPN, and strengthening the hypothesis that the lymphoma and MPN may be biologically related.

Abstract

Myeloproliferative neoplasia (MPN) and lymphoma are regarded as distinct diseases with different pathogeneses. However, patients that are diagnosed with both malignancies occur more frequently in the population than expected. This has led to the hypothesis that the two malignancies may, in some cases, be pathogenetically related. Using a mass spectrometry-based proteomic approach, we show that pre-treatment lymphoma samples from patients with both MPN and lymphoma, either angioimmunoblastic T-cell lymphoma (MPN-AITL) or diffuse large B-cell lymphoma (MPN-DLBCL), show differences in protein expression compared with reference AITL or DLBCL samples from patients without MPN. A distinct clustering of samples from patients with and without MPN was evident for both AITL and DLBCL. Regarding MPN-AITL, a pathway analysis revealed disturbances of cellular respiration as well as oxidative metabolism, and an immunohistochemical evaluation further demonstrated the differential expression of citrate synthase and DNAJA2 protein (p = 0.007 and p = 0.015). Interestingly, IDH2 protein also showed differential expression in the MPN-AITL patients, which contributes to the growing evidence of this protein’s role in both myeloid neoplasia and AITL. In MPN-DLBCL, the disturbed pathways included a significant downregulation of protein synthesis as well as a perturbation of signal transduction. These results imply an underlying disturbance of tumor molecular biology, and in turn an alternative pathogenesis for tumors in these patients with both myeloid and lymphoid malignancies.

Polycythemia Vera Associated with Pulmonary Hypertension and Diffuse Large B-Cell Lymphoma: A Case Report

BACKGROUND Myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), are associated with pulmonary hypertension (PH) and malignant lymphomas. Although the underlying mechanisms have not been completely clarified, it has been suggested that the Janus kinase 2 (JAK2) mutation, which is frequently identified in PV, can be involved in the development and/or progression of these distinct diseases in patients with MPNs. However, no reports have described the coexistence of PH and malignant lymphoma in patients with MPNs. CASE REPORT A 79-year-old man being treated for PV for 27 years and PH for 5 years was hospitalized due to severe dyspnea at rest. His soluble interleukin-2 receptor levels gradually increased and the chest computed tomography showed remarkable progression of the lung lesions and an enlargement of the mediastinal and axillary lymph nodes. A lymph node biopsy was performed and the patient was diagnosed with diffuse large B-cell lymphoma (DLBCL). Owing to his poor condition, chemotherapy was not initiated, and he died on the 89th day of hospitalization. The pathological autopsy revealed the destruction of alveolar structures with neoplastic space-occupying lesions of DLBCL. Multifactorial features of PH associated with MPNs, including the intimal thickening of pulmonary arteries accompanied by megakaryocytes and obstructed pulmonary arteries with organized thrombi in the lung tissue specimens, were observed. We found a JAK2 mutation based on a genetic analysis of the patient's bone marrow. CONCLUSIONS We present the rare case of a patient who had PV with a JAK2 mutation, which coexisted with PH and DLBCL, and he developed severe refractory respiratory failure.

The JAK-STAT pathway: an emerging target for cardiovascular disease in rheumatoid arthritis and myeloproliferative neoplasms

Inflammation contributes centrally to cardiovascular diseases, and anti-inflammatory treatments can reduce cardiovascular events. The JAK-STAT pathway is an emerging target in inflammation, mainly in rheumatoid arthritis (RA) and chronic myeloproliferative neoplasms (MPNs), disorders that heighten cardiovascular risk. The aim of this study was to review the international literature on the relationship between dysregulation of the JAK-STAT pathway in RA/MPNs and cardiovascular risk and on the potential cardiovascular effects of JAK-STAT inhibitors. The JAK-STAT pathway sustains inflammatory and thrombotic events in autoimmune disorders such as RA and MPNs. Here, an imbalance exists between pro- and anti-inflammatory cytokines [increased levels of interleukin (IL)-6, IL-1-β, tumour necrosis factor-α, decreased levels of IL-10] and the over-expression of some prothrombotic proteins, such as protein kinase Cε, on the surface of activated platelets. This pathway also operates in atherosclerotic cardiovascular disease. JAK-STAT inhibitors may reduce cardiovascular events and related deaths in such conditions, but the potential of these agents requires more studies, especially with regard to cardiovascular safety, and particularly for potential prothrombotic effects. JAK-STAT inhibitors merit consideration to curb heightened cardiovascular risk in patients with RA and MPNs, with rigorous assessment of the potential benefits and risks.

Burkitt leukemia with precursor B-cell features that developed after ruxolitinib treatment in a patient with hydroxyurea-refractory JAK2V617F-myeloproliferative neoplasm

A 62-year-old woman, who had a 16-year history of JAK2^V617F-mutated myeloproliferative neoplasm (MPN), developed Burkitt leukemia (BL) 16 months after treatment with ruxolitinib to control hydroxyurea-refractory conditions. BL cells were CD10⁺, CD19⁺, CD20⁻, CD34⁻, cytoplasmic CD79a⁺, and TdT⁺, and lacked surface immunoglobulins but expressed the cytoplasmic μ heavy chain. In the bone marrow, nuclear MYC⁺ BL cells displaced the MPN tissues. t(8;14)(q24;q32) occurred at a CG dinucleotide within MYC exon 1 and at the IGHJ3 segment, and an N-like segment was inserted at the junction. The V-D-J sequence of the non-translocated IGH allele had the unmutated configuration. DNA from peripheral blood at a time of the course of MPN exhibited homozygous JAK2^V617F mutation, while that at BL development included both JAK2^V617F and wild-type DNAs. Although the association between JAK1/2 inhibitor therapy for MPN and secondary development of aggressive B-cell neoplasm remains controversial, this report suggests that, in selected patients, close monitoring of clonal B-cells in the BM is required before and during treatment with JAK1/2 inhibitors.

Clinicopathological characterisation of myeloproliferative neoplasm-unclassifiable (MPN-U): a retrospective analysis from a large UK tertiary referral centre

Myeloproliferative neoplasm-unclassifiable (MPN-U) presents an MPN-type phenotype that fails to meet diagnostic criteria for other MPN variants. Variability in the clinicopathological phenotypes presents many challenges. Amongst a registry cohort of 1512 patients with MPN, 82 with MPN-U were included, with a median (range) age of 49·7 (13-79) years. Albeit heterogeneous, common presentation features included raised lactate dehydrogenase, thrombocytosis and clustered/pleomorphic megakaryocytes on trephine biopsy. Thrombosis was common (21%), necessitating vigilance. The median event-free survival was 11·25 years (95% confidence interval 9·3-not reached), significantly shortened in cases with lower platelet counts (<500 × 10⁹ /l) and a leucocytosis (≥12 × 10⁹ /l) at presentation. Generation of potential MPN-U prognostic scores is required.

Ruxolitinib Inhibits IFNγ Licensing of Human Bone Marrow Derived Mesenchymal Stromal Cells

Ruxolitinib is a JAK2/JAK1 inhibitor that blocks the inflammatory JAK-STAT signaling pathway. Ruxolitinib has been demonstrated to be effective in the treatment of steroid-resistant acute graft-versus-host disease (GVHD). Ruxolitinib's effect on inflammatory cells of hematopoietic origin is known. However, its effect on nonhematopoietic cell types with immune-modulating and antigen-presenting cell competency plausibly involved in pathogenesis of GVHD has not been explored. Mesenchymal stromal cells (MSCs) are CD45^- nonhematopoietic cells of the bone marrow with immune modulatory functions in vivo. MSCs' immunobiology largely depends on their responsiveness to IFNγ. We aimed to define the effect of ruxolitinib on the immunobiology of MSCs that are modulated by IFNγ. Human bone marrow derived MSCs, peripheral blood mononuclear cells (PBMCs), and primary bone marrow aspirates were analyzed for their sensitivity to ruxolitinib-mediated blocking of IFNγ-induced STAT-1 phosphorylation and downstream effector molecules, utilizing Western blot, flow cytometry, secretome analysis, and phosflow techniques. IFNγ-induced cytostatic effects on MSCs are reversed by ruxolitinib. Ruxolitinib inhibits IFNγ and secretome of activated peripheral PBMC-induced STAT-1 phosphorylation on human bone marrow derived MSCs. In addition, ruxolitinib inhibits IFNγ-induced pro-GVHD pathways on MSCs, which includes HLAABC(MHCI), HLADR(MHCII), CX3CL1, and CCL2. IFNγ-induced immunosuppressive molecules IDO and PDL-1 were also inhibited by ruxolitinib on MSCs. Comparative analysis with PBMCs has demonstrated that MSCs are as equal as to HLADR⁺ PBMC populations in responding to ruxolitinib-mediated inhibition of IFNγ-induced STAT-1 phosphorylation. Ex vivo analysis of human marrow aspirates has demonstrated that ruxolitinib blocks IFNγ-induced STAT-1 phosphorylation in CD45^+/-HLADR^+/- populations at different levels, which is depending on their sensitivity to IFNγ responsiveness. These results inform the hypothesis that ruxolitinib's immune-modulatory effects in vivo may pharmacologically involve marrow and tissue-resident MSCs. Ruxolitinib affects the immunobiology of MSCs equivalent to professional HLADR⁺ antigen presenting cells, which collectively mitigate GVHD.

JAK-Inhibitoren für die Behandlung hämatoonkologischer Erkrankungen

Die konstitutive Aktivierung des JAK-STAT-Signalwegs ist charakteristisch für die Pathogenese der myeloproliferativen Neoplasien, speziell der primären Myelofibrose, der Polycythaemia vera und der essentiellen Thrombozythämie. Die Einführung von oral verfügbaren JAK-Inhibitoren in die Klinik brachte einen entscheidenden Fortschritt für die pharmakologische Behandlung der Myelofibrose und der Polycythaemia vera, wenngleich damit noch keine Heilung verbunden ist. Im Vordergrund steht die Verbesserung der Lebensqualität der meist älteren Patienten durch Kontrolle krankheitsbedingter konstitutioneller Symptome, Reduktion einer bestehenden Splenomegalie und Vermeidung insbesondere von thromboembolischen Folgekomplikationen. Darüber hinaus kann die Therapie von Myelofibrose-Patienten mit JAK-Inhibitoren jedoch auch deren Krankheitsverlauf verlangsamen und ihr Gesamtüberleben verlängern. Der bislang einzige in Europa zugelassene JAK-Inhibitor Ruxolitinib hemmt die Isoformen JAK1 und JAK2 und besitzt sowohl antiinflammatorisches als auch antiproliferatives Potenzial. Damit zeigt dieser Inhibitor überdies eine gute Wirkung in der Therapie der Graft-versus-Host-Erkrankung nach allogener hämatopoetischer Stammzelltransplantation. Mit Fedratinib, Pacritinib und Momelatinib befinden sich derzeit 3 weitere vielversprechende JAK-Inhibitoren mit etwas unterschiedlichen Wirkprofilen in der klinischen Phase III-Testung. Diese zeigen auch bei Patienten mit unwirksamer oder unverträglicher Vorbehandlung mit Ruxolitinib Wirksamkeit, sodass eine kontinuierliche Weiterentwicklung der entsprechenden Therapiestrategien abzusehen ist.