Molecular genetics of chronic neutrophilic leukemia, chronic myelomonocytic leukemia and atypical chronic myeloid leukemia

The clinical regimens and cell membrane camouflaged nanodrug delivery systems in hematologic malignancies treatment

Hematologic malignancies (HMs), also referred to as hematological or blood cancers, pose significant threats to patients as they impact the blood, bone marrow, and lymphatic system. Despite significant clinical strategies using chemotherapy, radiotherapy, stem cell transplantation, targeted molecular therapy, or immunotherapy, the five-year overall survival of patients with HMs is still low. Fortunately, recent studies demonstrate that the nanodrug delivery system holds the potential to address these challenges and foster effective anti-HMs with precise treatment. In particular, cell membrane camouflaged nanodrug offers enhanced drug targeting, reduced toxicity and side effects, and/or improved immune response to HMs. This review firstly introduces the merits and demerits of clinical strategies in HMs treatment, and then summarizes the types, advantages, and disadvantages of current nanocarriers helping drug delivery in HMs treatment. Furthermore, the types, functions, and mechanisms of cell membrane fragments that help nanodrugs specifically targeted to and accumulate in HM lesions are introduced in detail. Finally, suggestions are given about their clinical translation and future designs on the surface of nanodrugs with multiple functions to improve therapeutic efficiency for cancers.

Eighty-year-old man with rare chronic neutrophilic leukemia caused by CSF3R T618I mutation: A case report and review of literature

BACKGROUND

Chronic neutrophilic leukemia (CNL) is a rare bone marrow proliferative tumor and a heterogeneous disorder. In 2016, the World Health Organization included activating mutations in the CSF3R gene as one of the diagnostic criteria, with CSF3R T618I being the most common mutation. The disease is often accompanied by splenomegaly, but no developmental abnormalities and significant reticular fibrosis, and no Ph chromosome and BCR-ABL fusion gene. So, it is difficult to diagnose at the first presentation in the absence of classical symptoms. Herein we describe a rare CNL patient without splenomegaly whose initial diagnostic clue was neutrophilic hyperactivity.

CASE SUMMARY

The patient is an 80-year-old Han Chinese man who presented with one month of fatigue and fatigue aggravation in the last half of the month. He had no splenomegaly, but had persistent hypofibrinogenemia, obvious skin bleeding, and hemoptysis, and required repeated infusion of fibrinogen therapy. After many relevant laboratory examinations, histopathological examination, and sequencing analysis, the patient was finally diagnosed with CNL [CSF3R T618I positive: c.1853C>T (p.T618I) and c.2514T>A (p.C838)].

CONCLUSION

The physical examination and blood test for tumor-related genes are insufficient to establish a diagnosis of CNL. Splenomegaly is not that important, but hyperplasia of interstitial neutrophil system and activating mutations in CSF3R are important clues to CNL diagnosis.

Severe hyperlipemia-induced pseudoerythrocytosis - Implication for misdiagnosis and blood transfusion: A case report and literature review

BACKGROUND

Severe hyperlipemia (SHLE) has an impact on the results of many kinds of laboratory tests. Complete blood count (CBC) examination by automated blood cell counter (ABCC) is a quick and convenient measurement for screening abnormalities of blood cells that are triggered by various pathogenic insults in disease diagnosis and for monitoring changes in the treatment of existing hematological conditions. However, CBC results are frequently affected by many intrinsic and extrinsic factors from blood samples, such as in the setting of hypergammaglobulinemia and certain anticoagulants. SHLE could also affect CBC results.

CASE SUMMARY

A 33-year-old Chinese male presented with painful foot numbness and abdominal pain. He was initially misdiagnosed as having a myeloproliferative neoplasm (MPN) because of the marked abnormalities in CBC examination by the ABCC. Morphological evaluation of the bone marrow smears and biopsy showed no evidence of MPN. Gene mutations in Breakpoint cluster regions-Abelson murine leukemia viral oncogene homologue 1 (BCR-ABL1), Janus kinase 2 (JAK2), calreticulin (CALR), myeloproliferative leukemia virus (MPL), and colony-stimulating factor 3 receptor (CSF3R) were negative. Having noticed the thick chylomicron layer on blood samples and the dramatically fluctuating CBC results, we speculated that the fat droplets formed by shaking the blood samples in the setting of SHLE were mistakenly identified as blood cells due to the limited parameters of ABCC. Therefore, we removed a large part of the chylomicron layer and then reexamined the CBC, and the CBC results, as we expected, differed significantly from that of the sample before the chylomicron layer was removed. These significant differences had been validated by the subsequently repeated laboratory tests by measuring dual blood samples that the chylomicron layer was removed in one sample and was not in another, and comparing the CBC results. Computerized tomography reexamination of the upper abdomen revealed an exudative lesion surrounding his pancreas. After intensive consultation, definitive diagnosis was made as recurrent pancreatitis, hyperlipemia and pseudoerythrocytosis.

CONCLUSION

SHLE may become a potential cause of misdiagnosis of hyperlipemia-related diseases as MPNs and the resultant mistreatment. It may also lead to the misinterpretation of transfusion indications in patients with hematological disorders who critically need blood transfusion for supportive treatment.

Leukemia incidence trends at the global, regional, and national level between 1990 and 2017

Background

Leukemias are a group of life-threatening malignant disorders of the blood and bone marrow. The incidence of leukemia varies by pathological types and among different populations.

Methods

We retrieved the incidence data for leukemia by sex, age, location, calendar year, and type from the Global Burden of Disease online database. The estimated average percentage change (EAPC) was used to quantify the trends of the age-standardized incidence rate (ASIR) of leukemia from 1990 to 2017.

Results

Globally, while the number of newly diagnosed leukemia cases increased from 354.5 thousand in 1990 to 518.5 thousand in 2017, the ASIR decreased by 0.43% per year. The number of acute lymphoblastic leukemia (ALL) cases worldwide increased from 49.1 thousand in 1990 to 64.2 thousand in 2017, whereas the ASIR experienced a decrease (EAPC = - 0.08, 95% CI - 0.15, - 0.02). Between 1990 and 2017, there were 55, 29, and 111 countries or territories that experienced a significant increase, remained stable, and experienced a significant decrease in ASIR of ALL, respectively. The case of chronic lymphocytic leukemia (CLL) has increased more than twice between 1990 and 2017. The ASIR of CLL increased by 0.46% per year from 1990 to 2017. More than 85% of all countries saw an increase in ASIR of CLL. In 1990, acute myeloid leukemia (AML) accounted for 18.0% of the total leukemia cases worldwide. This proportion increased to 23.1% in 2017. The ASIR of AML increased from 1.35/100,000 to 1.54/100,000, with an EAPC of 0.56 (95% CI 0.49, 0.62). A total of 127 countries or territories experienced a significant increase in the ASIR of AML. The number of chronic myeloid leukemia (CML) cases increased from 31.8 thousand in 1990 to 34.2 thousand in 2017. The ASIR of CML decreased from 0.75/100,000 to 0.43/100,000. A total of 141 countries or territories saw a decrease in ASIR of CML.

Conclusions

A significant decrease in leukemia incidence was observed between 1990 and 2017. However, in the same period, the incidence rates of AML and CLL significantly increased in most countries, suggesting that both types of leukemia might become a major global public health concern.

SRSF2 mutations in myelodysplasia/myeloproliferative neoplasms

Recurrent gene mutations have been described with varying frequencies in myelodysplasia (MDS) /myeloproliferative neoplasm (MPN) overlap syndromes (MMOS). Recent work has placed significant focus on understanding the role of gene lesions involving the spliceosomal machinery in leukemogeneis. SRSF2 is a gene encoding critical spliceosomal proteins. SRSF2 mutations appear to play an important role in pathogenesis of MMOS, particularly in chronic myelomonocytic leukemia. Inhibition of splicing may be a new therapeutic approach. E7107, a spliceosome inhibitor, has been shown to differentially inhibit splicing more in SRSF2-mutant cells leading to decreased leukemia burden in mice. H3B-8800 is a small molecule modulator of spliceosome complex and has been shown to lower leukemia burden in SRSF2-P95H mutant mice. This review focuses on the incidence of mutant SRSF2 across various MMOS as well as recent clinical development of spliceosome inhibitors.

Targeting few to help hundreds: JAK, MAPK and ROCK pathways as druggable targets in atypical chronic myeloid leukemia

Atypical Chronic Myeloid Leukemia (aCML) is a myeloproliferative neoplasm characterized by neutrophilic leukocytosis and dysgranulopoiesis. From a genetic point of view, aCML shows a heterogeneous mutational landscape with mutations affecting signal transduction proteins but also broad genetic modifiers and chromatin remodelers, making difficult to understand the molecular mechanisms causing the onset of the disease. The JAK-STAT, MAPK and ROCK pathways are known to be responsible for myeloproliferation in physiological conditions and to be aberrantly activated in myeloproliferative diseases. Furthermore, experimental evidences suggest the efficacy of inhibitors targeting these pathways in repressing myeloproliferation, opening the way to deep clinical investigations. However, the activation status of these pathways is rarely analyzed when genetic mutations do not occur in a component of the signaling cascade. Given that mutations in functionally unrelated genes give rise to the same pathology, it is tempting to speculate that alteration in the few signaling pathways mentioned above might be a common feature of pathological myeloproliferation. If so, targeted therapy would be an option to be considered for aCML patients.

Allogeneic stem cell transplantation in patients with atypical chronic myeloid leukaemia: a retrospective study from the Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplantation

Atypical chronic myeloid leukaemia (aCML) is an aggressive malignancy for which allogeneic haematopoietic stem cell transplantation (allo-HSCT) represents the only curative option. We describe transplant outcomes in 42 patients reported to the European Society for Blood and Marrow Transplantation (EBMT) registry who underwent allo-HSCT for aCML between 1997 and 2006. Median age was 46 years. Median time from diagnosis to transplant was 7 months. Disease status was first chronic phase in 69%. Donors were human leucocyte antigen (HLA)-identical siblings in 64% and matched unrelated (MUD) in 36%. A reduced intensity conditioning was employed in 24% of patients. T-cell depletion was applied in 87% and 26% of transplants from MUD and HLA-identical siblings, respectively. According to the EBMT risk-score, 45% of patients were 'low-risk', 31% 'intermediate-risk' and 24% 'high-risk'. Following allo-HSCT, 87% of patients achieved complete remission. At 5 years, relapse-free survival was 36% and non-relapse mortality (NRM) was 24%, while relapse occurred in 40%. Patient age and the EBMT score had an impact on overall survival. Relapse-free survival was higher in MUD than in HLA-identical sibling HSCT, with no difference in NRM. In conclusion, this study confirmed that allo-HSCT represents a valid strategy to achieve cure in a reasonable proportion of patients with aCML, with young patients with low EBMT risk score being the best candidates.

[The clinical characteristics, gene mutations and prognosis of chronic neutrophilic leukemia]

Objective: To investigate the clinical manifestation, cytogenetics, gene mutations and prognostic factors of chronic neutrophilic leukemia (CNL) . Methods: 16 CNL cases, according to WHO (2016) -definition, were reviewed retrospectively. Identifications of the CSF3R, ASXL1, SETBP1, CALR and MPL mutations were performed by direct sequencing. JAK2 V617F mutation was detected by AS-PCR. Results: Of the 16 CNL patients, the median age was 64 (43-80) years with a male predominance of 75% (12/16) . The median hemoglobin was 114 (81-154) g/L, with median WBC of 41.20 (26.05-167.70) (10(9)/L and median PLT of 238 (91-394) ×10(9)/L.The median level of marrow fibrosis (MF) was 1 (0-3) degree. There was no other cytogenetic abnormalities except t (1;7) (p32;q11) , +21 and 14ps+ for each. All the 16 CNL patients harbored CSF3R T618I mutation. ASXL1 mutations were identified in 81% (13/16) , while SETBP1 mutations were confirmed in 63% (10/16) . The CALR K385fs*47 mutation was found. There was no mutation in JAK2 V617F or MPL in the above 16 patients. The median overall survival (OS) of patients presented with WBC≥50×10(9)/L at diagnosis (11 months) was significantly shorter than of WBC<50×10(9)/L (39 months, P=0.005) . Conclusion: CSF3R T618I mutation was specific for CNL. The median OS of CNL patients was 24 months, and WBC≥50×10(9)/L at diagnosis was an unfavorable prognostic factor.

Acute promyelocytic leukemia co-existing with JAK2 V617F positive myeloproliferative neoplasm: a case report

The V617F mutation of Janus-associated kinase 2 (JAK2) is commonly seen in myeloproliferative neoplasms (MPN). Transformation of JAK2 positive MPNs to acute leukemia has been reported. We here report a case of acute promyelocytic leukemia which was later confirmed to have a co-existing JAK2 V617F positive MPN. In addition, the patient was found to have FLT3-TKD mutation, which, together with PML/RARa, could play a role in the MPN transformation to APL.

Bleeding, thrombosis, and anticoagulation in myeloproliferative neoplasms (MPN): analysis from the German SAL-MPN-registry

BACKGROUND

Patients with Ph-negative myeloproliferative neoplasms (MPN), such as polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are at increased risk for thrombosis/thromboembolism and major bleeding. Due to the morbidity and mortality of these events, antiplatelet and/or anticoagulant agents are commonly employed as primary and/or secondary prophylaxis. On the other hand, disease-related bleeding complications (i.e., from esophageal varices) are common in patients with MPN. This analysis was performed to define the frequency of such events, identify risk factors, and assess antiplatelet/anticoagulant therapy in a cohort of patients with MPN.

METHODS

The MPN registry of the Study Alliance Leukemia is a non-interventional prospective study including adult patients with an MPN according to WHO criteria (2008). For statistical analysis, descriptive methods and tests for significant differences as well as contingency tables were used to identify the odds of potential risk factors for vascular events.

RESULTS

MPN subgroups significantly differed in sex distribution, age at diagnosis, blood counts, LDH levels, JAK2V617F positivity, and spleen size (length). While most thromboembolic events occurred around the time of MPN diagnosis, one third of these events occurred after that date. Splanchnic vein thrombosis was most frequent in post-PV-MF and MPN-U patients. The chance of developing a thromboembolic event was significantly elevated if patients suffered from post-PV-MF (OR 3.43; 95% CI = 1.39-8.48) and splenomegaly (OR 1.76; 95% CI = 1.15-2.71). Significant odds for major bleeding were previous thromboembolic events (OR = 2.71; 95% CI = 1.36-5.40), splenomegaly (OR = 2.22; 95% CI 1.01-4.89), and the administration of heparin (OR = 5.64; 95% CI = 1.84-17.34). Major bleeding episodes were significantly less frequent in ET patients compared to other MPN subgroups.

CONCLUSIONS

Together, this report on an unselected "real-world" cohort of German MPN patients reveals important data on the prevalence, diagnosis, and treatment of thromboembolic and major bleeding complications of MPN.

Bone marrow fibrosis in primary myelofibrosis: pathogenic mechanisms and the role of TGF-β

Primary myelofibrosis (PMF) is a Philadelphia chromosome negative myeloproliferative neoplasm (MPN) with adverse prognosis and is associated with bone marrow fibrosis and extramedullary hematopoiesis. Even though the discovery of the Janus kinase 2 (JAK2), thrombopoietin receptor (MPL) and calreticulin (CALR) mutations have brought new insights into the complex pathogenesis of MPNs, the etiology of fibrosis is not well understood. Furthermore, since JAK2 inhibitors do not lead to reversal of fibrosis further understanding of the biology of fibrotic process is needed for future therapeutic discovery. Transforming growth factor beta (TGF-β) is implicated as an important cytokine in pathogenesis of bone marrow fibrosis. Various mouse models have been developed and have established the role of TGF-β in the pathogenesis of fibrosis. Understanding the molecular alterations that lead to TGF-β mediated effects on bone marrow microenvironment can uncover newer therapeutic targets against myelofibrosis. Inhibition of the TGF-β pathway in conjunction with other therapies might prove useful in the reversal of bone marrow fibrosis in PMF.

Identification of AIM2 as a downstream target of JAK2V617F

Background

The gain-of-function mutation JAK2V617F is frequently found in Philadelphia-chromosome-negative myeloproliferative neoplasm (MPN) patients. However, the tumorigenic properties of JAK2V617F have mostly been characterized in in vivo and in vitro murine models due to the lack of appropriate human cell lines.

Methods

Using the multipotent hematologic cell line UT-7/GM, we established D9, a novel human cell line that expresses JAK2V617F upon tetracycline addition. We assessed cellular differentiation in UT-7/GM cells when JAK2V617F was induced, and we used microarrays to analyze changes in mRNA expression caused by JAK2V617F.

Results

Using the human D9 cell line, we demonstrated that the induction of JAK2V617F leads to cytokine-independent cell growth with increased STAT activation and erythroid differentiation, mimicking the characteristics observed in polycythemia vera, making it a suitable in vitro model for studying this disorder. Interestingly, JAK2V617F-dependent erythroid cell differentiation was blocked when GM-CSF was added to the culture, suggesting that the GM-CSF pathway antagonizes JAK2V617F-induced erythroid cell differentiation. Our microarray analysis identified several genes involved in inflammasome activation, such as AIM2, IL1B, and CASP1, which were significantly up-regulated in JAK2V617F-induced cells.

Conclusions

The observed inflammasome activation following JAK2V617F induction is consistent with a recent report demonstrating the involvement of IL1B in myelofibrosis development in a JAK2V617F model mouse. These results indicate that the D9 cell line should be useful for characterizing the signaling pathways downstream of JAK2V617F, allowing for the identification of effector molecules that contribute to the development of MPN.

Electronic supplementary material

The online version of this article (doi:10.1186/s40164-016-0032-7) contains supplementary material, which is available to authorized users.

Establishment and genetic characterization of a novel mixed-phenotype acute leukemia cell line with EP300-ZNF384 fusion

Herein, we describe the establishment and characterization of the first mixed-phenotype acute leukemia cell line (JIH-5). The JIH-5 cell line was established from leukemia cells with B lymphoid/myeloid phenotype from a female mixed-phenotype acute leukemia patient. JIH-5 cells exhibit an immunophenotype comprised of myeloid and B lymphoid antigens. Whole-exome sequencing revealed somatic mutations in nine genes in JIH-5 cells. Transcriptional sequencing of JIH-5 cells identified EP300-ZNF384 fusion transcript, which is a recurrent alteration in B cell acute lymphoblastic leukemia. Our results suggest that the JIH-5 cell line may serve as a tool for the study of mixed-phenotype acute leukemia or EP300-ZNF384.

Impact of TET2, SRSF2, ASXL1 and SETBP1 mutations on survival of patients with chronic myelomonocytic leukemia

BACKGROUND

Chronic myelomonocytic leukemia (CMML) is a myeloid neoplasm classified in the myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) category. Molecular abnormalities are reported in about 90 % of patients with CMML. ASXL1 and SETBP1 mutations, but not TET2 or SFRS2 mutations are reported to be associated with prognosis.

METHODS

We studied frequency of TET2, SRSF2, ASXL1 and SETBP1 mutations in 145 patients with CMML using Sanger sequencing, and determined the prognostic factors for OS. We also identified the predictive value of ASXL1 mutations (frameshift and nonsense mutations) through comparing the Mayo Prognostic Model with the Mayo Molecular Model.

RESULTS

Forty-seven (32 %) had a mutation in TET2, 42 (29 %), a mutation in SRSF2, 65 (45 %), a mutation (nonsense and frame-shift) in ASXL1 and 26 (18 %), a mutation in SETBP1. Significant variables in multivariable analysis of survival included ASXL1 (HR = 1.99 [1.20-3.28]; P = 0.007), hemoglobin <100 g/L (HR = 2.42 [1.40-4.19]; P = 0.002) and blood immature myeloid cells (IMCs) (HR = 2.08 [1.25-3.46]; P = 0.005). When our patients were analyzed using the Mayo Prognostic Model median OS were not reached, 26 months and 15 months (P = 0.014). An analysis using the Mayo Molecular Model identified 4 cohorts with median OS of not reached, 70 months, 26 months and 11 months (P < 0.001). Data fitting using our patients suggest the Molecular Mayo Model has significantly higher survival predictive power compared with Mayo Prognostic Model (P < 0.001, -2 log-likelihood ratios of 538.070 and 552.260).

CONCLUSIONS

There were high frequencies of mutations in TET2, SRSF2, ASXL1 and SETBP1 in patients with CMML. With the addition of ASXL1 frameshift and nonsense mutations, the Mayo Molecular Model fitted better than Mayo Prognostic Model of our patients.