Pathogenesis Of Myeloid Leukemia Research Articles

Study of the effect of sFRP1 protein on molecules involved in the regulation of DNA methylation in CML cell line.

Wnt-signaling pathway plays a crucial role in the pathogenesis and progression of Chronic Myeloid Leukemia (CML). sFRP1 is involved in the suppression ofthe Wnt-signaling pathway and has been shown to be epigenetically silenced by promoter hypermethylation during CML progression. DNMT3A plays a crucial role in promoter hypermethylation andis responsible for establishing methylation patterns. We aimed to analyze the relationship between sFRP1 expression and DNMT3A, TET1, TET2 and TET3 proteins that are responsible for maintaining cellular methylation patterns; along with miRNAs miR144-3p and miR-767-5p that are known to be associated with these proteins. CML cell lines K562 and K562S which stably expresses sFRP1, were used to compare the changes in miR144-3p and miR-767-5p expression. DNMT3A, TET1, TET2 and TET3 protein levels were analyzed by Western blot. In K562S cells the expression of miR-144-3p and miR-767-5p were decreased along with DNMT3A and TET1 protein levels. On the contrary, TET2 protein was increased. Our results support other reports involving sFRP1 and methylation dynamics; as well as opening new avenues of exploration. Our data supports the conclusion that re-expression of sFRP1 protein alters the expression of factors that play important roles in the overall methylation patterns in the leukemic cell line K562.

Prognostic impact of inhibitors of DNA binding proteins1 and inhibitors of DNA binding proteins4 genes expression on adult Egyptian patients with acute myeloid leukemia

Background Acute myeloid leukemia (AML) pathogenesis and treatment are currently being better understood at an accelerated rate. Determining genetic and epigenetic changes that can identify patients who are at risk of poor outcomes is therefore desired to optimize treatment options. Many solid tumors have been reported to overexpress Inhibitors of DNA binding proteins (ID1), but few research has looked at the clinical significance of ID1 expression in AML. Additionally, little research has been focused on the direct role of ID4 in myeloid malignancies, as well as its expression and methylation patterns. The aim of the current study was to assess ID1 and ID4 gene expression in bone marrow (BM) aspiration specimens of 91 AML patients, compared with 14 control donors of bone marrow transplantation (BMT), using real-time polymerase chain reaction (RT-PCR). Data were correlated with patients’ clinicopathological features, response to treatment, disease-free survival (DFS), and overall survival (OS) rates. Results ID1 transcript level was significantly increased in AML bone marrow samples compared with normal controls (P = 0.002), while ID4 gene expression showed a nonsignificant difference (P = 0.717). In addition, there was a significant increase in ID1 gene expression in fms-like tyrosine kinase 3 (FLT3) mutant group than fms-like tyrosine kinase 3 wild group (P = 0.010). The total leukocytic count (TLC) was significantly higher in patients with high ID1 expression (P = 0.038) and patients with undetected ID4 expression (P = 0.025). No significant associations were detected between ID1 and ID4 expression levels and patients’ clinicopathological characteristics and OS rates. Conclusion In contrast to ID4, overexpressed ID1 can be adopted as a genetic biomarker for diagnosing AML. ID1 and ID4 expressions did not affect the patients’ OS or DFS.

Enhanced MAPK signaling induced by CSF3R mutants confers dependence to DUSP1 for leukemic transformation

AbstractElevated MAPK and the JAK-STAT signaling play pivotal roles in the pathogenesis of chronic neutrophilic leukemia and atypical chronic myeloid leukemia. Although inhibitors targeting these pathways effectively suppress the diseases, they fall short in providing enduring remission, largely attributed to the cytostatic nature of these drugs. Even combinations of these drugs are ineffective in achieving sustained remission. Enhanced MAPK signaling besides promoting proliferation and survival triggers a proapoptotic response. Consequently, malignancies reliant on elevated MAPK signaling use MAPK feedback regulators to intricately modulate the signaling output, prioritizing proliferation and survival while dampening the apoptotic stimuli. Herein, we demonstrate that enhanced MAPK signaling in granulocyte colony-stimulating factor 3 receptor (CSF3R)–driven leukemia upregulates the expression of dual specificity phosphatase 1 (DUSP1) to suppress the apoptotic stimuli crucial for leukemogenesis. Consequently, genetic deletion of Dusp1 in mice conferred synthetic lethality to CSF3R-induced leukemia. Mechanistically, DUSP1 depletion in leukemic context causes activation of JNK1/2 that results in induced expression of BIM and P53 while suppressing the expression of BCL2 that selectively triggers apoptotic response in leukemic cells. Pharmacological inhibition of DUSP1 by BCI (a DUSP1 inhibitor) alone lacked antileukemic activity due to ERK1/2 rebound caused by off-target inhibition of DUSP6. Consequently, a combination of BCI with a MEK inhibitor successfully cured CSF3R-induced leukemia in a preclinical mouse model. Our findings underscore the pivotal role of DUSP1 in leukemic transformation driven by enhanced MAPK signaling and advocate for the development of a selective DUSP1 inhibitor for curative treatment outcomes.

Molecular Pathogenesis and Treatment Strategies of Chronic Myeloid Leukemia (CML)

Chronic Myeloid Leukemia (CML) is a myeloproliferative disease diagnosed in bone marrow, arising from a chromosomal translocation between chromosomes 9 and 22, resulting in the formation of fusion oncogene BCR–ABL. The product of this fusion oncogene is a new oncoprotein bcr–abl which possesses abnormal tyrosine kinase activity. In response to this, abnormal signaling pathway activation occurs, leading to cell transformation. BCR–ABL oncogene could be targeted by tyrosine kinase inhibitors (TKIs) to delay or inhibit the disease progression. Imatinib is the first drug designed against CML but resistance to this has led to the development of the second- and third generations of inhibitors that are active against many types of BCR–ABL gene mutations. However, somehow, due to disease progression, TKIs do not remain as effective. There are three well-characterized phases of CML: The chronic phase (CP), the accelerated phase, and the terminal stage which is the blast crisis (BC) stage. In the CP of CML, mature granulocytes and myeloid precursors become aggregated majorly in the bone marrow and peripheral blood. The accelerated phase is marked by increased disease severity and an increase in progenitor/precursor cell number. In the BC stage, undifferentiated blast cells grow in number. Many patients with CML are diagnosed during the CP of the disease, so the survival rate of CML is high. However, 20% of CML patients proceed to advanced stages that result in drug resistance, intolerance, and mortality. So, for proper CML treatment, drugs are needed to target multiple BCR– ABL mutations, delay or stop disease progression, and overcome resistance caused by BCR–ABL independent mechanisms, especially during advanced phases of CML. Moreover, drugs could be developed to eradicate the stem cells of CML. These targets could be achieved by understanding mechanisms of disease progression, disease relapse, and drug resistance by utilizing high throughput molecular genetics, cell biology and immunology techniques.

G Protein-Coupled Receptor 183 Plays a Prognostic Factor in Acute Myeloid Leukemia By Regulating Immune Regulation

CONCLUSION G protein-coupled receptor 183 (GPR183) is a critical oligoheptameric transmembrane receptor that regulates cellular immune responses. Its malfunction causes a variety of immunological and inflammatory disorders. GPR183 overexpression enhances B cell migration from the germinal center and plays a significant role in the pathogenesis of Chronic myeloid leukemia. However, its prognostic value and regulatory role in AML are not clear. This study aimed to reveal the prognostic significance of GPR183 in AML and the mechanism of its regulatory role in AML. The expression level of GPR183 in 300 deno AML patients was analyzed by RT-qPCR. Combined with the clinical characteristics and treatment response of patients, the expression characteristics and clinical prognostic significance of GPR183 in AML were analyzed. The regulatory function of GPR183 in AML was investigated using shRNA-targeted knockdown or over expression of GPR183 in AML, and the impact of knockdown of GPR183 on tumor burden and survival of AML mice was further confirmed in vivo using an AML mouse model. By using bioinformatics techniques, the potential regulatory mechanisms of GPR183's effects on AML cells were further examined and verified. The expression level of GPR183 in AML cells was higher than that in normal samples, and its expression was significantly higher in older AML patients than in younger ones. By univariate and multivariate analyses, it was found that the high expression of GPR183 was an independent poor prognostic factor in AML patients for overall survival(OS) and eventfree survival(EFS), and the knockdown of GPR183 in AML cells could inhibit the proliferation of AML cells, promote apoptosis, and inhibit the migration of AML cells, and the in vivo model of AML mice showed that the knockdown of GPR183 could reduce the tumor load and prolong the survival of AML mice. Overexpression of GPR183 in AML cells promoted the growth and increased the drug resistance of AML drug. Single-gene GESA revealed that AML patients with high GPR183 expression had HALLMARK_ALLOGRAFT_REJECTION, HALLMARK_TNFA_SIGNALING_VIA_NFKB, HALLMARK_INFLAMMATORY_RESPONSE, HALLMARK_COMPLEMENT, and HALLMARK_CLEARING_VIA_NFKB, and HALLMARK_INFLAMMATORY_RESPONSE. COMPLEMENT, HALLMARK_IL6_JAK_STAT3_SIGNALING, and HALLMARK_IL2_STAT5_SIGNALING pathways were activated, and all of these top 5 activated pathways were associated with immune regulation. GPR183 plays a prognostic factor in Acute Myeloid Leukemia by regulating immune regulation

Insights into the New Molecular Updates in Acute Myeloid Leukemia Pathogenesis.

As our understanding of the biologic basis of acute myeloid leukemia evolves, so do the classification systems used to describe this group of cancers. Early classification systems focused on the morphologic features of blasts and other cell populations; however, the explosion in genomic technologies has led to rapid growth in our understanding of these diseases and thus the refinement of classification systems. Recently, two new systems, the International Consensus Classification system and the 5th edition of the World Health Organization classification of tumors of hematopoietic and lymphoid tissues, were published to incorporate the latest genomic advances in blood cancer. This article reviews the major updates in acute myeloid leukemia in both systems and highlights the biologic insights that have driven these changes.

Contribution of metabolic abnormalities to acute myeloid leukemia pathogenesis.

Acute myeloid leukemia (AML) is a malignant disease of myeloid precursors. Somatic mutations have long been accepted as drivers of this malignancy. Over the past decade, unique mitochondrial and metabolic dependencies of AML and AML stem cells have been identified, including a reliance on oxidative phosphorylation. More recently, metabolic enzymes have demonstrated noncanonical roles in regulating gene expression in AML, controlling cell differentiation and stemness. These mitochondrial and metabolic adaptations occur independent of underlying genomic abnormalities and contribute to chemoresistance and relapse. In this opinion article, we discuss the current understanding of AML pathogenesis and whether mitochondrial and metabolic abnormalities drive leukemogenesis or are a non-contributory phenotype.

LEP promoter methylation in the initiation and progression of clonal cytopenia of undetermined significance and myelodysplastic syndrome

BackgroundIdiopathic non-clonal cytopenia (ICUS) and clonal cytopenia (CCUS) are common in the elderly population. While these entities have similar clinical presentations with peripheral blood cytopenia and less than 10% bone marrow dysplasia, their malignant potential is different and the biological relationship between these disorders and myeloid neoplasms such as myelodysplastic syndrome (MDS) is not fully understood. Aberrant DNA methylation has previously been described to play a vital role in MDS and acute myeloid leukemia (AML) pathogenesis. In addition, obesity confers a poorer prognosis in MDS with inferior overall survival and a higher rate of AML transformation. In this study, we measured DNA methylation of the promoter for the obesity-regulated gene LEP, encoding leptin, in hematopoietic cells from ICUS, CCUS and MDS patients and healthy controls. We investigated whether LEP promoter methylation is an early event in the development of myeloid neoplasms and whether it is associated with clinical outcome.ResultsWe found that blood cells of patients with ICUS, CCUS and MDS all have a significantly hypermethylated LEP promoter compared to healthy controls and that LEP hypermethylation is associated with anemia, increased bone marrow blast percentage, and lower plasma leptin levels. MDS patients with a high LEP promoter methylation have a higher risk of progression, shorter progression-free survival, and inferior overall survival. Furthermore, LEP promoter methylation was an independent risk factor for the progression of MDS in a multivariate Cox regression analysis.ConclusionIn conclusion, hypermethylation of the LEP promoter is an early and frequent event in myeloid neoplasms and is associated with a worse prognosis.

Novel Tools for Diagnosis and Monitoring of AML.

In recent years, major advances in the understanding of acute myeloid leukemia (AML) pathogenesis, together with technological progress, have led us into a new era in the diagnosis and follow-up of patients with AML. A combination of immunophenotyping, cytogenetic and molecular studies are required for AML diagnosis, including the use of next-generation sequencing (NGS) gene panels to screen all genetic alterations with diagnostic, prognostic and/or therapeutic value. Regarding AML monitoring, multiparametric flow cytometry and quantitative PCR/RT-PCR are currently the most implemented methodologies for measurable residual disease (MRD) evaluation. Given the limitations of these techniques, there is an urgent need to incorporate new tools for MRD monitoring, such as NGS and digital PCR. This review aims to provide an overview of the different technologies used for AML diagnosis and MRD monitoring and to highlight the limitations and challenges of current versus emerging tools.

TSPAN32 suppresses chronic myeloid leukemia pathogenesis and progression by stabilizing PTEN

We report herein that TSPAN32 is a key node factor for Philadelphia (Ph+) leukemia pathogenesis. We found that TSPAN32 expression was repressed by BCR-ABL and ectopic TSPAN32 expression upon Imatinib treatment inhibited the proliferation of Ph+ cell lines. Tspan32 overexpression significantly prevented BCR-ABL induced leukemia progression in a murine model and impaired leukemia stem cell (LSC) proliferation. LSCs represent an obstacle for chronic myeloid leukemia (CML) elimination, which continually replenish leukemia cells and are associated with disease relapse. Therefore, the identification of essential targets that contribute to the survival and self-renewal of LSCs is important for novel curative CML. Mechanistically, TSPAN32 was shown to interact with PTEN, increased its protein level and caused a reduction in PI3K-AKT signaling activity. We also found that TSPAN32 was repressed by BCR-ABL via the suppression of an important transcription factor, TAL1. Ectopic expression of TAL1 significantly increased TSPAN32 mRNA and protein level, which indicated that BCR-ABL repressed TSPAN32 transcription by decreasing TAL1 expression. Overall, we identified a new signaling axis composed of “BCR-ABL-TAL1-TSPAN32-PTEN-PI3K-AKT”. Our findings further complement the known mechanisms underlying the transformation potential of BCR-ABL in CML pathogenesis. This new signaling axis also provides a potential means to target PI3K-AKT for CML treatment.

Mutant NPM1 maintains RASGRP3 protein stability via interaction with MID1 to promote acute myeloid leukemia cell proliferation and autophagy.

Acute myeloid leukemia is a heterogeneous hematologic malignancy with high mortality in the world. NPM1 gene mutations are a frequent occurrence in acute myeloid leukemia, leading to abnormal autophagy, while the mechanism of NPM1 mutation-driven acute myeloid leukemia pathogenesis remains to be fully elucidated. GEO microarrays were used to screen for dysregulated autophagy-related genes in NPM1-mutant acute myeloid leukemia and analysis of RASGRP3 expression and prognosis. Next, we explored the potential molecular mechanisms relationship between RASGRP3 and NPM1 through utilizing immunoprecipitation, Western blot, and cycloheximide assay. Further, CCK8, EdU staining, immunofluorescence, and Western blot were performed to explore the effect of RASGRP3 on cell proliferation and apoptosis in NPM1-mutated acute myeloid leukemia. Finally, Western blot was used to study the mechanism of action of RASGRP3. RASGRP3 expression was upregulated in NPM1-mutated acute myeloid leukemia. Mislocalized NPM1-mA in the cytoplasm could bind to E3 ubiquitin-protein ligase MID1 to block degradation of the RASGRP3 protein. RASGRP3 could also activate the EGFR-STAT3 axis to promote proliferation and autophagy in acute myeloid leukemia. In conclusion, our results identified RASGRP3 as a proto-oncogene in NPM1-mutated acute myeloid leukemia. The RASGRP3-EGFR/STAT3 axis may be a promising therapeutic target for this unique leukemic subtype.

MYC Influences mRNA Processing and Nuclear Export to Initiate Acute Myeloid Leukemia

Background: Although MYC is a potent oncogene that is frequently associated with poor outcomes in many solid tumors, its precise role in Acute Myeloid Leukemia (AML) pathogenesis and outcomes are not clear. We recently discovered that intermediate-risk AML patients with long first remissions with standard chemotherapy have an unexpectedly high frequency of pathogenic MYC mutations in the dominant leukemia clone at diagnosis (6 of 26 [23%] cases, versus 1.8% of all AML patients, p=0.002). An analysis of all MYC mutations reported in AML, revealed that they are nearly always single base substitutions that localize to a hotspot in the MYC Box I domain (MBI - AAs hotspot 73-74); this stands in distinct contrast to other hematopoietic malignancies, where MYC mutations are scattered throughout the entire gene. In this study, we engineered mouse hematopoietic stem and progenitor cells (HSPCs) to express AML-associated MYC missense mutations and characterized their in-vitro and in-vivo cellular and molecular phenotypes. Results: We observed that constitutive expression of MYC MBI mutant proteins in mouse HSPCs significantly prolonged Myc half-life and conferred different degrees of growth advantage over both wild type MYC overexpression and overexpression of non-MBI mutant proteins. To determine whether these mutations are AML drivers, HSPCs expressing MYCWT or the MBI mutants MYCP74Q and MYCT73N were transplanted into lethally irradiated syngeneic recipient mice, which were then evaluated for the development of leukemia. Primary recipient mice transplanted with MYCWT-expressing cells developed leukemia with a median survival of 58 days for whereas mice transplanted with MYCP74Q- or MYCT73N-expressing cells displayed a median survival of 42 and 41.5 days, respectively (p<0.001). Furthermore, secondary recipient mice transplanted with MYCWT-, MYCP74Q- or MYCT73N-expressing AML cells from primary recipient mice also developed AML, indicating that expression of WT and MBI-MUT Myc leads to the development of frank leukemia in mice. Next, we investigated the impact of these point mutations on the transcriptional targets of Myc by comparing single-cell RNA-seq profiles of murine HSPCs expressing wild type, P74Q, or T73N Myc versus an empty vector control. From these analyses, we found that while each of these mutants retain many of the transcriptional activities of wild type Myc, they also display unique transcriptional signatures. To better understand how these mutations affect the transcriptional output of MYC, we performed ChIP-seq analysis of primary murine HSPCs expressing MYCWT-, MYCcP74Q- or MYCT73N. Despite MBI mutations causing persistent MYC protein expression (due to prolonged half-life), we detected an overall decrease in chromatin binding of MBI-MUT MYC, with preserved binding to transcriptional start sites of a core sets of genes involved in splicing and translation. Importantly, MBI mutations did not affect the canonical E-box Myc binding site, nor create novel binding sites, indicating that these mutations lead to an overall decrease in Myc occupancy at target promoters. Immunofluorescent staining for WT vs. MBI mutant MYC showed that despite their overall decrease in chromatin binding, Myc mutant proteins localized predominantly to the nucleus. However, a substantial number of nuclei showed a ring-like morphology of MBI-MUT MYC, suggesting that MBI mutations might enrich protein localization at the nuclear periphery. To determine whether the changes in staining pattern observed for MBI-MUT were associated with alterations in the ability of MYC to interact with its regulatory proteins, we employed a modified BioID proximity labeling system, "TurboID", to screen for differential protein interactions in murine HSPCs. This analysis showed that MBI mutations resulted in several gained interactions over WT MYC - most prominently with components of the nuclear pore complex (NUP98, NUP107, NUP133, XPOT, RAE1) supporting the idea that MBI-MUT might accelerate transformation by controlling translation and mRNA nuclear export. Conclusions: Collectively, these data indicate that AML-associated MYC mutations support leukemogenesis through non-canonical (transcription-independent) MYC proprieties. More broadly, these data suggest that aberrant mRNA processing and nuclear export might play an important role in the initiation of AML by MYC mutations.

CML-401 Case Report of NGS Results in the Chronic Myeloid Leukemia Patient With Multiple Resistance to Tyrosine Kinase Inhibitors

The significance of BCR::ABL in pathogenesis of chronic myeloid leukemia (CML) is studied quite well and tyrosine kinase inhibitors (TKI) are really efficient in CML treatment. Nevertheless, there are still patients with TKI-resistance. This fact could be explained by BCR::ABL-independent pathways of disease maintenance and progression. A female (1959 year of birth) was diagnosed with CML in chronic phase (EUTOS-low risk, Sokal-high risk) according to CBC (leukocytosis, thrombocytosis, shift to blasts); presence of the Ph-chromosome; detecting of BCR::ABL(p210,b3a2,b2a2)-43.395% in 12/2018. The patient had tried multiple TKIs. Imatinib 600 mg/day since 12/2018 to 03/2019. Complete hematologic response (CHR) was achieved, but the treatment required dose reduction (150-300 mg/day) due to hematological toxicity (neutropenia grade 3). Therapy was discontinued after 3 months due to loss of CHR. No mutations of BCR::ABL gene were detected. Dasatinib 100 mg/day since 04/2019 to 07/2019. The reason for interruption was hematological toxicity (neutropenia, anemia grade 2-3 required G-CSF and epoetin). At 3 months there was a lack of cytogenetic response (100% Ph-positive metaphases), BCR::ABL-43.3% by IS. Nilotinib 800 mg/day started on 07/2019 but it was ceased on 08/2019 because of the non-hematologic intolerance (vomiting, nausea, amylase elevation). Bosutinib 500 mg/day since 09/2019. Treatment was stopped on 12/2019 due to severe neutropenia which persisted for 28 days. Ponatinib (7.5 mg/day - maximum tolerated dose) since 12/2019 up to date. BCR::ABL on 25-Dec-2019 - 31%. Given the multiple resistance to TKIs, next-generation sequencing (NGS) was performed. 32 mutations in 24 genes were detected: 16 were favorable, 9-possible favorable, 7-with unclear significance. Mutations with highest allelic burden were in genes EZH2, CIITA, CDKN2A, IKZF1, ATM, SETBP1, TET2. NGS results could be considered as one of the possible reasons of multiple resistance. Ponatinib treatment is still ongoing. Major molecular response (MMR) is not achieved (BCR::ABL(01/2022)- 17%). Neutropenia grade 3-4 persists throughout treatment but therapy is continued due to lack of alternatives. The discovery of mutated genes by NGS in this patient on multiple lines of TKI-therapy gives the evidence of non-BCR::ABL resistance mechanisms. The use of NGS could find the additional targets for treatment of CML resistant patients besides TKI.

Expression of deubiquitinase genes and inflammatory response in myeloid leukemia

Myeloid leukemia (ML) is a cancer of the blood that begins when cells of the myeloid lineage uncontrollably change and grow. Acute myeloid leukemia (AML) is a disorder of rapid, uncontrolled growth of immature myeloid cells in the blood and bone marrow. Chronic myeloid leukemia (CML) is characterized by the aberrant proliferation of myeloid cells and driven by the translocation of regions of the BCR and ABL genes to form the Philadelphia (Ph) chromosome. The deubiquitinase enzymes (DUBs) including A20, OTUB1, OTUB2, and Cezanne play important roles in inhibiting NF-κB activation in response to various stimuli. Cytokines including tumor necrosis factor-alpha (TNF-α), IL-6, and IL-1β are released from immune cell activation triggered by antigenic stimulation. To this end, blood samples of 20 AML and 62 CML patients and the control group consisting of 37 healthy individuals were used to examine the mRNA expression of A20, OTUB1, OTUB2 and Cezanne genes by using quantitative RT-PCR and determine IL-6, TNF-α and IL-1β concentrations by using ELISA. As a result, the mRNA level of OTUB1 was significantly decreased in both AML and CML patients compared to that in healthy individuals, however, no difference in the transcriptional expression of OTUB2 among AML and CML patients and control group was detected. Unlike the levels of OTUB1 and OTUB2, the expressions of A20 and Cezanne in CML, but not in AML patients were significantly lower than healthy individuals. For serum cytokine analysis of the study groups, in AML and CML samples, IL-6 and TNF-α concentrations significantly increased in comparison with the control group, however, IL-1β level was similar among CML, AML patients and healthy individuals. In conclusion, this study revealed the different DUB involvement in the pathogenesis of ML, suggesting further investigations on gene polymorphisms and their functions linked to biological properties of leukemia cells.

P494: MYELOID LEUKEMIA IN PATIENTS WITH INFLAMMATORY BOWEL DISEASES: A RETROSPECTIVE COHORT STUDY

Background: Inflammatory bowel diseases include ulcerative colitis and Crohn’s disease and affect around 3.1 million adults in the United States (US). The data on the risk of myeloid leukemia among patients with IBD are limited and there has been only a couple of studies that evaluated the incidence of myeloid leukemia in this patient population. Aims: This study aimed to estimate the prevalence of myeloid leukemia in patients with IBD. Secondary outcomes included mortality, length of stay, all-cause 30-day non-elective readmission rate, and total cost of hospitalization. Methods: This is a retrospective cohort study for patients with IBD in the US. We queried the Nationwide Readmission Databases 2016-2018 using ICD-10-CM codes to identify all adult patients admitted for IBD. Patients with a comorbid diagnosis of myeloid leukemia including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), Myeloid sarcoma, and Unspecified Myeloid leukemia were identified. Figure 1 summarizes the case selection process. Median and IQR were used to describe Continuous variables, and proportions were used with categorical variables. Comparison between groups was performed by Mann Whitney test for continuous variables and Chi-Square test for Categorical variables. Multivariate regression analysis was performed to study the impact of comorbid myeloid leukemia on inpatient mortality and non-elective readmissions. Statistical analyses were performed using SPSS Version 25 (IBM Corporation, Armonk, NY, USA). Results: We extracted 365,152 index hospitalization records for IBD, 1052 (0.3%) had myeloid leukemia. Six hundred sixteen patients had acute myeloid leukemia (AML), 341 patients had chronic myeloid leukemia, 10 patients had myeloid sarcoma and 104 had unspecified myeloid leukemia. IBD patients with myeloid leukemia were older (64; Interquartile Range (IQR): 52-73 vs. 56; IQR: 38-70, P <0.001), more common to be males (50.8% vs. 49.2%, P <0.001) compared to IBD patients without myeloid leukemia. Having myeloid leukemia was associated with increased length of stays in days (7; Interquartile Range (IQR): 3-23 vs. 3; IQR: 2-6, P <0.001), increased median total charges ($74,413; IQR: $31,700 - $259,676 vs. $32,586; IQR: $17,827 - $62,260, P <0.001). On multivariate analysis; having myeloid leukemia was associated with increased mortality (Odds ratio (OR): 6.544; 95% confidence interval (CI): 5.318-8.052, P <0.001) and higher odds of all-cause 30-day non-elective readmission (OR: 1.4; 95% CI: 1.155-1.697, P= 0.001). Image:Summary/Conclusion: In our nationwide cohort of IBD patients, 0.3% had myeloid leukemia. Given the associated mortality and morbidity, we recommend considering a hematological consult for IBD patients with leukocytosis or leukopenia for further evaluation and appropriate management. More research studies are needed to investigate the pathogenesis of myeloid leukemia in IBD patients.

Aberrant EVI1 splicing contributes to EVI1-rearranged leukemia

AbstractDetailed genomic and epigenomic analyses of MECOM (the MDS1 and EVI1 complex locus) have revealed that inversion or translocation of chromosome 3 drives inv(3)/t(3;3) myeloid leukemias via structural rearrangement of an enhancer that upregulates transcription of EVI1. Here, we identify a novel, previously unannotated oncogenic RNA-splicing derived isoform of EVI1 that is frequently present in inv(3)/t(3;3) acute myeloid leukemia (AML) and directly contributes to leukemic transformation. This EVI1 isoform is generated by oncogenic mutations in the core RNA splicing factor SF3B1, which is mutated in >30% of inv(3)/t(3;3) myeloid neoplasm patients and thereby represents the single most commonly cooccurring genomic alteration in inv(3)/t(3;3) patients. SF3B1 mutations are statistically uniquely enriched in inv(3)/t(3;3) myeloid neoplasm patients and patient-derived cell lines compared with other forms of AML and promote mis-splicing of EVI1 generating an in-frame insertion of 6 amino acids at the 3′ end of the second zinc finger domain of EVI1. Expression of this EVI1 splice variant enhanced the self-renewal of hematopoietic stem cells, and introduction of mutant SF3B1 in mice bearing the humanized inv(3)(q21q26) allele resulted in generation of this novel EVI1 isoform in mice and hastened leukemogenesis in vivo. The mutant SF3B1 spliceosome depends upon an exonic splicing enhancer within EVI1 exon 13 to promote usage of a cryptic branch point and aberrant 3′ splice site within intron 12 resulting in the generation of this isoform. These data provide a mechanistic basis for the frequent cooccurrence of SF3B1 mutations as well as new insights into the pathogenesis of myeloid leukemias harboring inv(3)/t(3;3).

In silico design and computational evaluation of novel 2-arylaminopyrimidine-based compounds as potential multi-targeted protein kinase inhibitors: application for the native and mutant (T315I) Bcr-Abl tyrosine kinase

An integrated computational approach to drug discovery was used to identify novel potential inhibitors of the native and mutant (T315I) Bcr-Abl tyrosine kinase, the enzyme playing a key role in the pathogenesis of chronic myeloid leukemia (CML). This approach included i) design of chimeric molecules based on the 2-arylaminopyrimidine fragment, the main pharmacophore of the Abl kinase inhibitors imatinib and nilotinib used in the clinic for the CML treatment, ii) molecular docking of these compounds with the ATP-binding site of the native and mutant Abl kinase, iii) refinement of the ligand-binding poses by the quantum chemical method PM7, iv) molecular dynamics simulations of the ligand/Abl complexes, and v) prediction of the ligand/Abl binding affinity in terms of scoring functions of molecular docking, machine learning, quantum chemistry, and molecular dynamics. As a result, five top-ranking compounds able to effectively block the enzyme catalytic site were identified. According to the data obtained, these compounds exhibit close modes of binding to the Abl kinase active site that are mainly provided by hydrogen bonds and multiple van der Waals contacts. The identified compounds show high binding affinity to the native and mutant Abl kinase comparable with the one calculated for the FDA-approved kinase-targeted inhibitors imatinib, nilotinib, and ponatinib used in the calculations as a positive control. The results obtained testify to the predicted drug candidates against CML may serve as good scaffolds for the design of novel anticancer agents able to target the ATP-binding pocket of the native and mutant Abl kinase. Communicated by Ramaswamy H. Sarma

Multistep pathogenesis of chronic myelomonocytic leukemia in patients.

BackgroundA multistep pathogenesis of myeloid leukemia including mutations in epigenetic, spliceosome, and signaling genes has been recently demonstrated in a preclinical model but is poorly validated in patients.MethodsClinical, phenotypic, and biologic features were compared between three distinct molecularly defined CMML cohorts including TET2 monomutated patients (T, n = 10), TET2/SRSF2 bimutated patients (TS, n = 19), and patients who had NRAS mutations in addition to TET2/SRSF2 comutations (TSN, n = 14).ResultsMedian survival was 90, 45, and 9 months, respectively (p = .001). Whereas no patient in the T and TS group transformed into acute myeloid leukemia (AML), 6/14 patients in the TSN group had AML at study entry or transformed during follow‐up. Leukocyte counts, blast cell counts, and LDH levels were significantly higher in TSN vs. TS and T, respectively, whereas hemoglobin and platelet values were not significantly different. Increased growth factor‐independent myeloid colony formation was restricted to TSN but not found in T and TS, respectively. The proportion of patients showing in vitro myelomonocytic skewing in T, TS, and TSN was 0%, 56%, and 100%, respectively (p = .010).ConclusionOur results demonstrate that the model of multistep pathogenesis in CMML can be recapitulated in patients regarding clinical, phenotypic, and biologic features.

Association of TP53 P72R and MDM2 SNP309 variants with susceptibil-ity to chronic myeloid leukaemia development in Algerian population: TP53 P72R C allele is a strong risk marker and MDM2 SNP309 G allele has a protective effect

Chronic myeloid leukaemia is a monoclonal myeloproliferative syndrome, whose development is related to disturbance of growth, survival, and apop-totic pathways, such as MDM2-p53 pathway, mainly due to the abnormal kinase activity of BCR-ABL. A lot of work has to be done to understand chron-ic myeloid leukaemia genetic predisposition. This is a pilot study that search-es for association between TP53 P72R variant (rs1042522); and MDM2 T309G variant (rs2279744), and the risk of chronic myeloid leukaemia occur-rence in the Algerian population. It is a case-control study using DNA sam-ples of 74 Algerian chronic myeloid leukaemia patients and 104 healthy con-trol individuals. Our results attested that TP53 P72R C allele (Pro) was strong-ly associated with increased risk of chronic myeloid leukaemia, and that TP53 P72R homozygous CC genotype should be a genetic susceptibility factor in the pathogenesis of chronic myeloid leukaemia independently of age and of gender. Furthermore, MDM2 SNP309 TT genotype was moderately associat-ed with a risk of chronic myeloid leukaemia occurrence. In conclusion, our data suggest that, in Algerian population, TP53 P72R C allele (Pro) could be a possible biomarker of chronic myeloid leukaemia susceptibility, and that MDM2 SNP309 TT genotype seems to be a low penetrance risk factor of chronic myeloid leukaemia susceptibility.

The Inhibitory Effect of Sulforaphane on The Proliferation of Acute Myeloid Leukemia Cell Lines through Controlling miR-181a.

Objective The present study investigated the role of miR-181a as a small non-coding RNA molecule in acute myeloid leukemia (AML) pathogenesis and reflected on the effects of Sulforaphane (SFN) on AML progression. Materials and Methods This experimental study had two parts. In vivo study, the miR-181a levels was measured in patients with symptoms of AML and compared to healthy controls (HCs) to investigate its role in AML pathogenesis. Afterward, an in vitro study was performed to examine the effects of SFN on the growth, apoptosis and proliferation rate of AML cell lines. Finally, the effect of SFN on miR-181a was evaluated as a major miRNA involved in hematopoiesis. Results The results of this study showed an increasing trend (2.9-fold, P=0.0019) in miR-181a expression levels in AML patients as compared with HCs. The data associated with MTT assay and flow cytometry (FCM) additionally demonstrated the anti-proliferative effects of SFN against AML cell lines, with a reduction in miR-181a levels. As well, no significant difference was noted between 24 hours and 48 hours treatments by SFN. It was deduced that modulation of miR-181a expression levels could be one of the mechanisms associated with the anti-proliferative effects of SFN against AML. ConclusionMiR-181a levels contribute to AML pathogenesis and thus they can be considered as a strategy in controlling AML progression in patients. Accordingly, SFN can arrest cell proliferation and induce apoptosis in AML cell lines through retardation expression of miR-181a and affecting miR-181a pathway, which already clarified its role in the differentiation of hematopoietic stem cells and indicates another mode of anti-cancer action of sulforaphane.