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COVID-19 infection is still a mystery in terms of its long-term effect on health and its consequences on hematological disorders. Prior studies including ours have shown the abnormal changes in hematopoietic cells in COVID-19 patients. In this article, we are presenting 2 cases of pediatric B-lymphoblastic leukemia (B-ALL) with a previous history of COVID-19 infection. The first case describes a 22-month-old boy presenting with lymphadenopathy, neutropenia, and anemia with concurrent COVID-19 infection without any evidence of a hematolymphoid neoplasm as per bone marrow and lymph node biopsy. However, he presented after 2 months with bone marrow biopsy confirming B-ALL. The second case is that of a 4-year-old girl presenting with B-ALL who has had asymptomatic COVID-19 infection 5 months before this current presentation. Both the cases had complete resolution of COVID-19 infection during the time of presentation with acute leukemia. There were notably 2 rare findings along the course of the patients illnesses. First, the unusual plasmacytosis in the marrow during active COVID-19 infection in the first patient and the second, is predilection of development of B-ALL following COVID-19. In both the cases the fluorescence in situ hybridization (FISH) studies showed pathologic alteration of the RUNX1 gene. Overall, there are no literature to support a causal association between acute B-ALL and COVID-19. The diagnosis of B-ALL in these patients after COVID-19 infection may be totally unrelated. However, if we consider Greaves proposed 2-hit model for childhood acute leukemia, that an infectious agent can precipitate development of B-ALL in a genetically susceptible individual. Alteration of the RUNX1 gene in both the patients, opens a door for further exploration of the second-hit hypothesis regarding an infectious agent precipitating development of B-ALL in a genetically susceptible individual.

In the treatment of diseases such as acute childhood leukaemia (ALL) and inflammatory bowel disease (IBD), the thiopurines azathioprine, 6-mercaptopurine, and 6-thioguanine are used. Thiopurines are antimetabolites and immunomodulators used to maintain remission in patients. They are all prodrugs and must be converted into the competing antimetabolites thioguanosine triphosphate and deoxythioguanosine triphosphate for final incorporation into RNA or DNA. The current therapeutic drug monitoring (TDM) method measures the sum of the formed metabolites in the sample, after acidic hydrolysis at high temperature. In this work, the goal is to measure these drugs closer to their pharmacological endpoints, once incorporated into DNA. After extracting DNA from whole blood, followed by DNA hydrolysis, 2′-deoxythioguanosine (dTG) and the complementary natural nucleobase 2′-deoxycytidine (dC) were measured. Chromatographic separation on a HSS T3 column followed by mass spectrometric detection was performed in multi-reaction monitoring (MRM) mode on a Xevo TQ-XS with ESI in positive mode, within 5 min. The concentration range for dTG was 0.04–5 nmol/L, and for dC, 0.1–12.5 µmol/L. The lower limit of detection was determined to a concentration of 0.003 nmol/L for dTG and 0.019 µmol/L for dC. The intra- and inter-assay imprecision for the quality controls ranged between 3.0 and 5.1% and between 8.4 and 10.9%, respectively. Sample stability for up to 4 years is shown. In summary, a sensitive method to quantify the thiopurines incorporated into DNA as dTG has been developed and will be used in further clinical studies for a better understanding of the mode of action of the thiopurines and the use of this method in TDM. [ABSTRACT FROM AUTHOR]

The diagnosis of acute lymphoblastic leukemia (ALL), which is the most common type of cancer in children, has become more accurate with the use of flow cytometry. Here, this technology was used to immunophenotype leukemic cells in peripheral blood samples from Libyan pediatric ALL patients. We recruited 152 newly diagnosed patients at Tripoli Medical Center (Tripoli, Libya) by morphological examination of blood and bone marrow. Twenty-three surface and cytoplasmic antigen markers were used to characterize B and T cells in circulating blood cells by four-color flow cytometry. Six children (3.9%) turned out to have biphenotypic acute leukemia, 88 (57.9%) had B ALL, and 58 (38.1%) had T ALL. There were 68 cases of pro-B ALL CD10-positive (44.7%), 8 cases of pro-B ALL CD10-negative (5.2%), 6 cases of pre-B ALL (3.9%), and 6 of mature-B ALL (3.9%). CD13 was the most commonly expressed myeloid antigen in ALL. We present immunophenotypic data for the first time describing ALL cases in Libya. The reported results indicate that the most common subtype was pro-B ALL, and the frequency of T-ALL subtype was higher compared to previous studies. Six cases were positive for both myeloid and B lymphoid markers. Our findings may provide the basis for future studies to correlate immunophenotypic profile and genetic characteristics with treatment response among ALL patients. [ABSTRACT FROM AUTHOR]

Background: Methotrexate (MTX) is the primary drug used in the treatment of pediatric acute lymphoblastic leukemia (ALL). However, some patients exhibit delayed clearance of high-dose (HD) MTX, which induces severe nephrotoxicity, mucositis, hepatotoxicity, and neurotoxicity. We sought to identify relevant variants associated with delayed clearance of HD-MTX in pediatric patients with ALL. Methods: Whole-exome sequencing of germline DNA was performed in 51 Korean pediatric patients with ALL. A total of 341 HD-MTX infusion data points from 51 patients were analyzed. MTX levels and laboratory measurements reflecting toxicity outcomes were obtained. Correlations between peak serum MTX levels at 24 h and toxicity outcomes were assessed. Analyses were performed to identify variants affecting delayed MTX clearance. Results: The 24 h MTX level strongly correlated with the subsequent creatinine (Cr) level. Moreover, rs2229866 in contactin 2 (CNTN2), rs200687372 in myotubularin Related Protein 9 (MTMR9), rs777260512 in polymerase iota (POLI), rs16954698 in polycystic kidney disease 1-like 2 (PKD1L2), rs117765468 in NSE1 Homolog, SMC5-SMC6 Complex Component (NSMCE1) , and rs1800956 in endoglin (ENG) were identified as candidate variants associated with delayed MTX clearance. In particular, ENG rs1800956 was significantly associated with delayed MTX clearance in all analyses and PKD1L2 rs16954698 was replicated in an external dataset (phs000637.v1.p1) from the Database of Genotypes and Phenotypes (dbGaP). Conclusion: This is the first whole-exome sequencing-based analysis of delayed MTX clearance in pediatric patients with ALL. ENG rs1800956 and PKD1L2 rs16954698 were found to be potentially influential variants associated with delayed MTX clearance. These findings provide insights into HD-MTX-induced nephrotoxicity and may contribute to reducing adverse reactions through treatment modification. [ABSTRACT FROM AUTHOR]

Background: The introduction of antibody–drug conjugates represents a significant advancement in targeted therapy of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Our study aims to investigate the role of the DNA damage response pathway and the impact of PARP1 inhibition, utilizing talazoparib, on the response of AML and ALL cells to Gemtuzumab ozogamicin (GO) and Inotuzumab ozogamicin (INO), respectively. Methods: AML and ALL cells were treated with GO, INO and γ-calicheamicin in order to induce severe DNA damage and activate the G2/M cell-cycle checkpoint in a dose- and time-dependent manner. The efficacy of PARP1 inhibitors and, in particular, talazoparib in enhancing INO or GO against ALL or AML cells was assessed through measurements of cell viability, cell death, cell cycle progression, DNA damage repair, accumulation of mitotic DNA damage and inhibition of clonogenic capacity. Results: We observed that both ALL and AML cell lines activate the G2/M cell-cycle checkpoint in response to γ-calicheamicin-induced DNA damage, highlighting a shared cellular response mechanism. Talazoparib significantly enhanced the efficacy of INO against ALL cell lines, resulting in reduced cell viability, increased cell death, G2/M cell-cycle checkpoint override, accumulation of mitotic DNA damage and inhibition of clonogenic capacity. Strong synergism was observed in primary ALL cells treated with the combination. In contrast, AML cells exhibited a heterogeneous response to talazoparib in combination with GO. Our findings suggest a potential link between the differential responses of ALL and AML cells to the drug combinations and the ability of talazoparibto override G2/M cell-cycle arrest induced by antibody–drug conjugates. Conclusion: PARP1 emerges as a key player in the response of ALL cells to INO and represents a promising target for therapeutic intervention in this leukemia setting. Our study sheds light on the intricate interplay between the DNA damage response pathway, PARP1 inhibition, and response of γ-calicheamicin-induced DNA damages in AML and ALL. These findings underscore the importance of targeted therapeutic strategies and pave the way for future research aimed at optimizing leukemia treatment approaches. [ABSTRACT FROM AUTHOR]

RNA modification is the critical mechanism for regulating post-transcriptional processes. There are more than 150 RNA modifications reported so far, among which N6-Methyladenosine is the most prevalent one. M6A RNA modification complex consists of 'writers', 'readers' and 'erasers' which together in a group catalyze, recognize and regulate the methylation process of RNA and thereby regulate the stability and translation of mRNA. The discovery of erasers also known as demethylases, revolutionized the research on RNA modifications as it revealed that this modification is reversible. Since then, various studies have focused on discovering the role of m6A modification in various diseases especially cancers. Aberrant expression of these 'readers', 'writers', and 'erasers' is found to be altered in various cancers resulting in disturbance of cellular homeostasis. Acute leukemias are the most common cancer found in pediatric patients and account for 20% of adult cases. Dysregulation of the RNA modifying complex have been reported in development and progression of hematopoietic malignancies. Further, targeting m6A modification is the new approach for cancer immunotherapy and is being explored extensively. This review provides detailed information about current information on the role of m6A RNA modification in acute leukemia and their therapeutic potential. M6A RNA modifications: emerging drivers of leukemia growth and progression. [ABSTRACT FROM AUTHOR]

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory disorder that occurs as a consequence of immune dysregulation. HLH can be primary (familial or non-familial) or secondary to infection, autoimmune disease or malignancy. Malignancy-associated HLH is often accompanied by hematologic and lymphoid neoplasms. This report describes the case of a 3-year-old girl with an initial diagnosis of acute lymphoblastic leukemia who subsequently developed HLH during primary chemotherapy. She was admitted with a pulmonary infection, and initial blood tests showed thrombocytopenia and anemia. Whole-exome sequencing of gene and whole transcriptome RNA sequencing data indicated mutations of UNC13D. The hospital course was complicated by multiple infections, altered mental status and acute respiratory distress syndrome. HLH secondary to multiple infections that achieved remission following targeted therapy with ruxolitinib, in conjunction with corticosteroids and other complementary treatments. This report provides a synopsis of the diagnostic and treatment procedures implemented in this case. [ABSTRACT FROM AUTHOR]

Acute lymphoblastic leukemia (ALL) with granular blasts was historically referred to as "granular ALL", but this is not recognized as a distinct entity in the current WHO classification. This rare morphological feature is predominantly associated with a B-cell immunophenotype, while T-ALL with prominent cytoplasmic granules is extremely rare, with limited available genetic, molecular, and prognostic data. Here, we report a unique case of ALL in a 9-year-old girl. Initial blood tests revealed leukocytosis, and both peripheral blood and bone marrow morphology showed a high number of blasts with granular cytoplasm and bilobed nuclei. Immunophenotyping confirmed T-cell origin. The patient tested positive for KMT2A::AFDN, with WT1 overexpression, and NRAS and EZH2 mutations were detected by next-generation sequencing (NGS). Remarkably, the patient achieved complete remission after treatment and has shown no signs of relapse for nearly four years. Her favorable response to conventional therapy underscores the importance of molecular phenotyping in the treatment of this disease. The continued use of NGS to gather relevant molecular data is crucial for further understanding the molecular phenotype and prognosis of such atypical ALL cases. [ABSTRACT FROM AUTHOR]

This narrative review seeks to summarize chemotherapeutic regimens commonly used for patients with newly diagnosed Philadelphia (Ph) chromosome–negative B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in the frontline setting and to describe the latest clinical research using the bispecific T-cell–engaging immunotherapy blinatumomab in the first-line treatment setting. Current standard-of-care chemotherapeutic backbones for newly diagnosed Ph-negative BCP-ALL are based on the same overarching treatment principle: to reduce disease burden to undetectable levels and maintain lasting remission. The adult treatment landscape has progressively evolved following the adoption of pediatric-inspired regimens. However, these intense regimens are not tolerated by all, and high-risk patients still have inferior outcomes. Therefore, designing more effective and less toxic strategies remains key to further improving efficacy and safety outcomes. Overall, the treatment landscape is evolving in the frontline, and integration of blinatumomab into different standard frontline regimens may improve overall outcomes with a favorable safety profile. [ABSTRACT FROM AUTHOR]

The ability of flow cytometry to identify and quantify the presence of cell populations defined by their expression profile of specific markers has made this technique a powerful and routinary tool in clinical diagnostic practice. Specifically in the field of hematological malignancies, flow cytometry allows the identification of the correct type and lineage of each patient's disease and also sensitively quantifies the presence of the disease at precise moments during treatment, that is, levels of measurable residual disease (MRD). The quantification of MRD by flow cytometry has allowed the adaptation of tailored therapies to patients, contributing to the improvement of the results of the different protocols in recent decades. In this context, our objective in the present work was to evaluate the potential impact that spectral flow cytometry can provide compared to conventional cytometry, which is the one usually used in clinics. We present here a comparative study of both technologies, spectral versus conventional flow cytometry, in primary samples corresponding to the diagnosis and follow-up of children and adolescents with acute lymphoblastic leukemia. Our initial experience demonstrates the feasibility of incorporating spectral flow cytometry into the routine workflow of a reference laboratory. [ABSTRACT FROM AUTHOR]

Efficient gene transduction and cell viability are critical factors in genetic manipulation for research and therapeutic purposes. In this study, we explored the challenges associated with transducing the NB-4 cell line, a well-established model for acute promyelocytic leukemia (APL), using lentiviral vectors. While the initial transduction efficiency in NB-4 cells reached approximately 30%, we observed a significant decrease in cell viability, a phenomenon not observed in other acute leukemia cell lines such as THP-1 cells. We identified that this toxicity could be mitigated by purifying viral particles through ultracentrifugation or polyethylene glycol (PEG) precipitation, indicating that toxic substances, potentially secondary metabolites released by HEK293, could be responsible for the cell death. Nevertheless, cell selection by puromycin was still ineffective; crucially, we discovered that the human phosphoglycerate kinase (hPGK) promoter, commonly used in the PLKO1 vector, may become silenced in NB-4 cells, preventing effective selection with puromycin. By replacing the hPGK promoter with the elongation factor-1 alpha (EF1α) promoter, we successfully achieved high transduction efficiency and robust selection, demonstrating the potential for this modified vector system to facilitate genetic studies in APL models. These findings provide important insights into optimizing gene transduction protocols not only for NB-4 cells but also for other challenging cell lines, offering a refined approach for gene delivery and selection in cell models. [ABSTRACT FROM AUTHOR]

Myeloproliferative neoplasms, polycythemia vera, essential thrombocytosis, and primary myelofibrosis are a unique group of clonal hematopoietic stem cell neoplasms that share somatic, gain-in-function driver mutations in JAK2, CALR, and MPL. As a consequence, these disorders exhibit similar phenotypic features, the most common of which are the ceaseless production of normal erythrocytes, myeloid cells, platelets alone or in combination, extramedullary hematopoiesis, myelofibrosis, and a potential for leukemic transformation. In the case of polycythemia vera and essential thrombocytosis, however, prolonged survival is possible. With an incidence value in the range of 0.5–2.0/100,000, myeloproliferative neoplasms are rare disorders, but they are not new disorders, and after a century of scrutiny, their clinical features and natural histories are well-defined, though their individual management continues to be controversial. With respect to polycythemia vera, there has been a long-standing dispute between those who believe that the suppression of red blood cell production by chemotherapy is superior to phlebotomy to prevent thrombosis, and those who do not. With respect to essential thrombocytosis, there is a similar dispute about the role of platelets in veinous thrombosis, and the role of chemotherapy in preventing thrombosis by suppressing platelet production. Linked to these disputes is another: whether therapy with hydroxyurea promotes acute leukemia in disorders with a substantial possibility of longevity. The 21st century revealed new insights into myeloproliferative neoplasms with the discovery of their three somatic, gain-of-function driver mutations. Almost immediately, this triggered changes in the diagnostic criteria for myeloproliferative neoplasms and their therapy. Most of these changes, however, conflicted with prior well-validated, phenotypically driven diagnostic criteria and the management of these disorders. The aim of this review is to examine these conflicts and demonstrate how genomic discoveries in myeloproliferative neoplasms can be used to effectively complement the known phenotypic features of these disorders for their diagnosis and management. [ABSTRACT FROM AUTHOR]

The phosphatidylinositol 3‐kinase/Protein Kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway is pivotal in various cancers, including T‐cell acute lymphoblastic leukaemia (T‐ALL), a particularly aggressive type of leukaemia. This study investigates the effects of Neosetophomone B (NSP‐B), a meroterpenoid fungal metabolite, on T‐ALL cell lines, focusing on its anti‐cancer mechanisms and therapeutic potential. NSP‐B significantly inhibited the proliferation of T‐ALL cells by inducing G0/G1 cell cycle arrest and promoting caspase‐dependent apoptosis. Additionally, NSP‐B led to the dephosphorylation and subsequent inactivation of the PI3K/AKT/mTOR signalling pathway, a critical pathway in cell survival and growth. Molecular docking studies revealed a strong binding affinity of NSP‐B to the active site of AKT, primarily involving key residues crucial for its activity. Interestingly, NSP‐B treatment also induced apoptosis and significantly reduced proliferation in phytohemagglutinin‐activated primary human CD3+ T cells, accompanied by a G0/G1 cell cycle arrest. Importantly, NSP‐B did not affect normal primary T cells, indicating a degree of selectivity in its action, targeting only T‐ALL cells and activated T cells. In conclusion, our findings highlight the potential of NSP‐B as a novel therapeutic agent for T‐ALL, specifically targeting the aberrantly activated PI3K/AKT/mTOR pathway and being selective in action. These results provide a strong basis for further investigation into NSP‐B's anti‐cancer properties and potential application in T‐ALL clinical therapies. [ABSTRACT FROM AUTHOR]

The development of cerebral cavernous malformations (CCMs) is a well-recognized sequela of irradiation to the brain in pediatric tumors, particularly in medulloblastoma, glioma, and acute lymphoblastic leukaemia. So far, only one case of cerebral cavernoma after chemotherapy with autologous hematopoietic stem cell transplantation (HSCT) has been described. We describe a case of a patient with medulloblastoma aged 18 months at the time of oncological diagnosis who was treated with high-dose chemotherapy followed by HSCT and who developed CCM two years later. The patient was not treated for vascular malformation since he remained asymptomatic until now and is regularly followed with neuro-radiological check-ups. This represents the second case of acquired cavernoma developed in a patient who has not received radiation therapy. [ABSTRACT FROM AUTHOR]

Acute leukemia has rapid onset and severe complications. Anticancer peptides from natural sources have demonstrated efficacy in eliminating various cancers through apoptosis signaling pathways. Additionally, extracellular vesicles containing microRNAs play pivotal roles in promoting tumorigenesis. Therefore, this study aimed to investigate the impact of PG2, a pomegranate peptide that regulates extracellular vesicles, on the induction of acute leukemia cell apoptosis. NB4 and MOLT-4 leukemia cell lines were treated with PG2 alone or in combination with daunorubicin to assess cell viability using the MTT assay. Extracellular vesicles were extracted from PG2-treated NB4 and MOLT-4 cells. Bioinformatic tools were utilized to predict target proteins and microRNAs, following which mRNA and protein expression were determined by using RT‒qPCR and western blotting, respectively. PG2 significantly reduced the viability of NB4 and MOLT-4 cells. Furthermore, the combination of PG2 with daunorubicin had a synergistic effect on NB4 and MOLT-4 cells. Subsequent treatment with PG2 or PG2-treated extracellular vesicles decreased CDK2 expression while increasing microRNA-339-5p and caspase-3 expression in NB4 and MOLT-4 cells. Our findings revealed that the anticancer activity of PG2 through the CDK2/miR-339-5p/caspase-3 pathway is mediated by extracellular vesicles, ultimately inducing apoptosis. PG2 holds promise as a potential antileukemic drug. [ABSTRACT FROM AUTHOR]

Despite the initial success of single‐targeted chimeric‐antigen receptor (CAR) T‐cell therapy in hematological malignancies, its long‐term effectiveness is often hindered by antigen heterogeneity and escape. As a result, there is a growing interest in cell therapies targeting multiple antigens (≥2). However, the dose–exposure–response relationship and specific factors influencing the pharmacology of dual‐targeted CAR‐T‐cell therapy remain unclear. In this study, we have developed a multiscale cellular kinetic–pharmacodynamic (CK–PD) model using case studies from CD19/CD22 and GPRC5D/BCMA autologous CAR‐Ts. Initially, an in vitro tumor‐killing model characterized the impact of individual binder affinities and their contribution to overall potency across varying (1) effector: target (ET) ratios and (2) tumor‐associated antigen (TAA) expressing cell lines. Subsequently, an integrated CK–PD model was developed in pediatric acute lymphoblastic leukemia (ALL) patients, which accounted for CAR‐T‐cell product composition and relative antigen abundance in patients' tumor burden to characterize patient‐level multiphasic cellular kinetics using multiple bioanalytical assays (e.g., flow and qPCR‐based readouts). Global sensitivity analysis highlighted relative antigen expression, maximum killing rate constant, and CAR‐T expansion rate constant as major determinants for observed exposure of dual‐targeted CAR‐T‐cell therapy. This modeling framework could facilitate dose‐optimization and construct refinement for dual‐targeted bicistronic CAR‐T‐cell therapies, serving as a valuable tool for both forward and reverse translation in drug development. [ABSTRACT FROM AUTHOR]

Introduction: L-Asparaginase (L-Asp) is a key drug in the treatment of acute lymphoblastic leukemia (ALL); however, it is commonly associated with the occurrence of adverse events (AE). Risk factors such as age, sex, nutritional status, and some single nucleotide variants (SNVs) in specific genes could be related to hypersensitivity reactions to L-Asp. The objective of this study was to identify the influence of individual characteristics and three SNVs in the GRIA1 and NFATC2 genes on the occurrence of the most significant adverse events caused by the use of L-Asp in Mexican children with ALL. Methods: Eighty-five children from ages 0–17 years old diagnosed with ALL were included. The patients were treated at two hospital centers in Mexico. The SNV genotypes of the GRI1A and NFATC2 genes studied were examined using real-time qPCR. The evaluation of AE was carried out according to the Common Terminology Criteria for adverse events, and the determination of anti-L-Asp antibodies was conducted using Western blot immunoassay. Results: Homozygosity (AA) of the GRIA1 rs4958351 SNV was significantly associated with the occurrence of AE with the use of L-Asp (OR = 4.05; 95% CI = 1.06 to 15.40, p = 0.04) and was strongly associated with the development of anti-L-Asp antibodies (OR = 3.4375, 95% CI = 1.04 to 11.25, p = 0.04). With this, we found a significant risk association for the SNV rs4958351 of the GRIA1 gene. On the other hand, we did not find significant risk associations for the GRIA1 rs6889909 and NFATC2 rs6021191 SNVs, although other populations have shown a significant risk. Discussion: Our study has some limitations, such as the small sample size, the heterogeneity in adverse events due to the patients' different regions of origin, and the limited ability to conduct a more detailed follow-up on pancreatitis. Additionally, since no significant associations were found between the NFATC2 rs6021191 and GRIA1 rs6889909 SNVs and the development of adverse events or the presence of antibodies due to the use of L-Asp, it is necessary to investigate new specific SNVs that may improve the efficacy and safety of treatment in Mexican children with ALL. [ABSTRACT FROM AUTHOR]

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy that expresses high levels of the enzyme aldo-keto reductase family 1 member C3 (AKR1C3). To exploit this finding, we developed a novel prodrug, ACHM-025, which is selectively activated by AKR1C3 to a nitrogen mustard DNA alkylating agent. We show that ACHM-025 has potent in vivo efficacy against T-ALL patient-derived xenografts (PDXs) and eradicated the disease in 7 PDXs. ACHM-025 was significantly more effective than cyclophosphamide both as a single agent and when used in combination with cytarabine/6-mercaptopurine. Notably, ACHM-025 in combination with nelarabine was curative when used to treat a chemoresistant T-ALL PDX in vivo. The in vivo efficacy of ACHM-025 directly correlated with AKR1C3 expression levels, providing a predictive biomarker for response. Together, our work provides strong preclinical evidence highlighting the potential of ACHM-025 as a targeted and effective therapy for aggressive forms of T-ALL. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to identify the impact of the COVID-19 pandemic on the frequency, clinical characteristics and outcomes of patients with acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL). Methods: This retrospective cohort study included all patients treated at Sultan Qaboos University Hospital in Muscat, Oman with AML or ALL from January 2017 to December 2021. Data were obtained from the electronic medical record, and patients diagnosed before the start of the COVID-19 pandemic were compared with those diagnosed during the pandemic using appropriate statistical tests. Results: A total of 151 patients with ALL (n = 58) and AML (n = 93) were included, of whom 78 were diagnosed before the COVID-19 pandemic and 73 during the pandemic. The rate of acute leukaemia increased during the pandemic (P = 0.039). The clinical characteristics and molecular profiles were similar between the 2 periods, except for platelet count which was higher during the pandemic compared to before the pandemic (median platelet count: 55 × 109/L versus 47 × 109/L; P = 0.02). No significant difference was found in the number of FLT3-positive AML; however, the number of NPM1-mutated AML cases was higher during the pandemic (P = 0.02). The number of Philadelphia-positive ALL cases remained consistent between the 2 time periods. The complete remission (P = 0.48) and the overall survival rates were similar (P >0.05). Conclusion: Except for an increased rate of acute leukaemia and a lower platelet count, the COVID-19 pandemic did not impact the presentation and outcomes of acute leukaemia. [ABSTRACT FROM AUTHOR]

Background: Although BRAF V600E mutations are common in solid tumors and select hematologic neoplasms, they are reported less frequently in myeloid malignancies. Of the cases of BRAF V600E-mutant acute myeloid leukemia (AML) that have been described, most display monocytic morphology and concurrent KMT2A rearrangement. Strikingly, all cases have been associated with poor survival. Case Presentation: Here, we report two cases of AML, one diagnosed in an elderly male with metastatic lung adenocarcinoma and hepatocellular carcinoma and the other diagnosed in a young boy previously treated for B-cell acute lymphoblastic leukemia. Peripheral blood NGS revealed oncogenic mutations in BRAF p.V600E (VAF = 33%), TET2 p.M508Cfs*25 (VAF = 48%), TET2 p.C211* (VAF = 49%), ZRSR2 p.R295* (VAF = 71%), BRAF p.N581S (VAF = 6%), and EZH2 c.118-2A>G, p.? (VAF = 4%) in case 1 and BRAF p.V600E (VAF = 1%) and KRAS p.G12A (VAF = 28%) in case 2. Cytogenetic workup revealed a complex karyotype in case 1 and an abnormal karyotype with non-clonal aberrations and KMT2A (MLL) rearrangement in case 2. Morphologically, both patients were found to have AML with monocytic features. The post-mortem examination of case 2 also revealed extensive solid organ infiltration, consistent with a monocytic leukemia. Both patients died within days of diagnosis, demonstrating the lethality of this molecular subgroup of AML. Conclusions: Our cases add to the literature, highlighting the poor prognosis of patients diagnosed with BRAF-mutant AML. Although it is uncertain whether the complex karyotype and somatic mutations observed in case 1 and KMT2A rearrangement and variants identified in case 2 may have either independently or cooperatively conferred a poor prognosis, we contend that additional comprehensive studies are needed to further understand the pathophysiology and prognosis of BRAF mutations in AML. We further posit whether patients with BRAF V600E-mutant AML may benefit from the combined use of BRAF inhibitors and/or RAS-pathway-targeting regimens, which are currently FDA-approved for the treatment of BRAF V600-mutant solid tumors and BRAF-mutant histiocytic neoplasms. [ABSTRACT FROM AUTHOR]

Background/Objectives: Infections remain the leading cause of mortality among neutropenic patients with haematologic malignancies, making effective infection management crucial. Achieving a sufficient neutrophil count is essential for the elimination of pathogens. Granulocyte concentrate (GC) can be a treatment option for neutropenic patients with severe infections. This study aimed to evaluate the efficacy, safety, and impact on survival of GC transfusions in neutropenic children with severe infections treated over the past 13 years in a single centre. Methods: The retrospective study analysed clinical data from 60 children (median age 9.5 years) who received GC transfusions at our centre. Granulocytes were collected by apheresis from donors stimulated with granulocyte colony-stimulating factor. The majority of the patients (70%) were diagnosed with acute leukaemia. The main indications for GC were severe pneumonia (45%) and bacterial sepsis (38.33%). Results: The patients received 1 to 29 GC transfusions for 1 to 70 days, with a median time of administration of 3 days. Neutrophil counts increased to >1000/µL within a median of 5 days. GCs were well tolerated by most patients. One patient presented symptoms of anaphylaxis, the other acute lung injury related to transfusions, and alloimmunisation was reported in one patient. Of the patients analysed, 78.33% survived the infection that justified GC administration. We did not observe significant differences in survival depending on the aetiology of the infection. Conclusions: Based on our research, GC appears to be a beneficiary for neutropenic children with severe infections and reduces infection mortality rates. However, further well-designed randomised trials are needed to define its role in this setting. [ABSTRACT FROM AUTHOR]

CD99, a type I transmembrane protein, emerges as a promising therapeutic target due to its heightened expression in T cell acute lymphoblastic leukemia (T-ALL). This characteristic renders it a potential marker for minimal residual disease detection and an appealing target for antibody-based treatments. Previous studies have revealed that a mouse monoclonal antibody, mAb MT99/3, selectively binds to CD99, triggering apoptosis in T-ALL/T-LBL cells while preserving the integrity of healthy cells. By targeting CD99, mAb MT99/3 suppresses antigen presentation and disrupts T cell functions, offering promise for addressing hyperresponsive T cell conditions. To facilitate clinical translation, we developed a humanized ScFv variant of mAb MT99/3, termed HuScFvMT99/3 in "ScFvkh" design. Structural analysis confirms its resemblance to the original antibody, and the immunoreactivity of HuScFvMT99/3 against CD99 is preserved. The fully humanized version of antibody HuMT99/3 was further engineered, exhibiting similar binding affinity at the 10−10 M level and specificity to the CD99 epitope without antigenic shift. HuMT99/3 demonstrates remarkable selectivity, recognizing both malignant and normal T cells but inducing apoptosis only in T-ALL/T-LBL cells, highlighting its potential for safe and targeted therapy. [ABSTRACT FROM AUTHOR]

ABSTRACT: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by damage to organs and cells, initially mediated by tissue-binding autoantibodies and immune complexes. Lymphomas have been frequently reported, but the association of SLE with acute leukemia is rare and likely coincidental. We report a case of a 40-year-old female admitted for an etiological diagnosis of fever and dyspnea with peripheral edema. She had a history of SLE diagnosed 2 years prior and had been on immunosuppressive therapy since then. Hematological investigations showed leukocytosis, anemia, and thrombocytopenia. Further diagnostic testing could not be done as she passed away 3 days after acute leukemia was diagnosed. This case highlights the challenges of diagnosing hematological malignancies in immunosuppressed SLE patients where symptoms may be obscured. [ABSTRACT FROM AUTHOR]

Acute lymphoblastic leukemia (ALL) is a hematopoietic disorder that mainly affects the child population, and it is characterized by the presence of lymphoid progenitor or precursor cells with different genetic alterations. The origin of this disease is controversial, since some authors assumed that leukemic transformation occurs in a lymphoid progenitor, and there is also evidence that suggests the existence of leukemic initiating cells (LIC). PTL, DMAPT, and PU-H71 are agents that have been shown to eliminate bulk and stem cells from myeloid leukemias, but this effect has not been analyzed in lymphoblastic leukemias. In this study, we evaluated the effect of these compounds in different populations from pediatric B-ALL. For this, bone marrow samples from pediatric patients without treatment were obtained and cultured in the presence or absence of PTL, DMAPT, and PU-H71. The viability and apoptosis index were analyzed by flow cytometry in different hematopoietic subpopulations. These observations indicate that PTL and DMAPT are able to reduce B-ALL cells with a minimum effect in normal hematopoietic and non-hematopoietic cells. In contrast, PU-H71 was able to reduce the leukemic population and had a minimal effect in normal cells. These results present evidence that PTL and DMAPT are able to abrogate in vitro different populations of B-ALL and could represent a possibility of treatment, as well as prevent disease progression or relapse. [ABSTRACT FROM AUTHOR]

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy. Current intensified therapeutic protocols coincide with severe side effects, and no salvage therapy is available for primary therapy-resistant or relapsed patients. This highlights the need to identify new therapeutic targets in T-ALL. PSIP1, dispensable for normal hematopoiesis, is a dependency factor in KMT2A-rearranged myeloid leukemia. Nonetheless, loss-of-function mutations suggest a tumor suppressor role for PSIP1 in T-ALL. Here, we demonstrate that the loss of Psip1 accelerates T-ALL initiation in mice which we correlated with reduced H3K27me3 binding. Contrastingly, loss of PSIP1 impaired cell proliferation in several T-ALL cell lines. In cell lines, PSIP1 down-regulation leads to a reduction of COX20, an assembly factor of the cytochrome c oxidase in the mitochondria, and to a reduction in mitochondrial respiration. This indicates that PSIP1 can exert a dual role in the context of T-ALL, either as a tumor suppressor gene during tumor initiation or as a dependency factor in tumor maintenance. [ABSTRACT FROM AUTHOR]

Summary: Olverembatinib is a novel orally administered third-generation tyrosine kinase inhibitor (TKI) with definitive responses in T315I-mutant chronic myeloid leukemia (CML) patients. However, its value in newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) remained unclarified. In this multiple-center study, 20 patients with de novo Ph + ALL were treated with olverembatinib-based regimens as frontline therapy. All patients acquired complete remission (CR) after induction. 85% of patients achieved complete molecular response (CMR) within three months, contributed mainly by the addition of blinatumomab. A total of 45% of patients experienced mild hematological treatment-related adverse events (TRAEs). Olverembatinib-based treatment led to promising outcomes in de novo Ph + ALL patients but warranted further studies to investigate the best-combined strategy. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia presenting de novo in the blast phase (CML-BP) is a rare diagnosis among pediatric malignancies. We report on a 16-year-old male who presented with CML-BP lymphoid at diagnosis. He was treated with shortened acute lymphoblastic leukemia induction plus the tyrosine kinase inhibitor (TKI) imatinib followed by dasatinib. After achieving molecular remission (MR), hematopoietic stem cell transplantation (HSCT) was performed early after diagnosis. Despite prophylactic dasatinib, he relapsed 3 months later with the kinase domain mutation T315I. Multiple therapeutic approaches including ponatinib, blinatumomab, a 2nd HSCT from a different donor, donor lymphocyte infusions, and high-dose asciminib all resulted in subsequent relapse. Another molecular response was achieved by combining ponatinib plus asciminib with chemotherapy. In this situation, CD19-directed CAR-T cells (Kymriah®) were administered for compassionate use and tolerated without adverse events. Compared to all prior therapies, CAR T-cells maintained remission. After 12 months of follow-up, complete B-cell aplasia and low numbers of CAR-T cells are detectable in the peripheral blood, potentially mediating long-term disease control. [ABSTRACT FROM AUTHOR]

The association between cytokine receptor-like factor 2 (CRLF2) and clinical outcomes in acute lymphoblastic leukemia (ALL) has been a topic of ongoing debate, with divergent findings. This article intended to investigate the influence of CRLF2 alterations on ALL prognosis. Following the PRISMA 2020 guidelines, this meta-analysis was conducted. Hazard ratio (HR) values and confidence intervals (CIs) were the primary statistical measures used. Data heterogeneity was judged using the chi-square test and I2 statistic. Publication bias was appraised with funnel plots, Begg's test, and Egger's test. 16 studies with 6771 patients were finally screened out. CRLF2 over-expression (CRLF2 OE) was associated with poorer event-free survival (EFS) (HR = 1.70, 95% CI = 1.18–2.44, P = 0.004) and relapse-free survival (RFS) (HR = 1.70, 95% CI = 1.28–2.24, P = 0.000) in pediatric ALL. Patients with CRLF2-deregulation (CRLF2-d), also known as CRLF2 rearrangement, exhibited shorter overall survival (OS) (HR = 2.22, 95% CI = 1.49–3.32, P = 0.000), EFS (HR = 1.93, 95% CI = 1.43–2.60, P = 0.000), and RFS (HR = 2.2, 95% CI = 1.53–3.18, P = 0.000) compared to those without CRLF2-d. Subgroup analysis of multivariate HRs and corresponding CIs indicated that childhood with CRLF2 OE had a shorter RFS (HR = 1.70, 95% CI = 1.28–2.24, P = 0.006), and CRLF2-d was identified as an independent prognostic biomarker for OS (HR = 2.22, 95% CI = 1.49–3.32, P = 0.000), EFS (HR = 1.95, 95% CI = 1.44–2.64, P = 0.000), and RFS (HR = 2.2, 95% CI = 1.53–3.18, P = 0.000) in pediatric ALL patients. Both CRLF2 OE and CRLF2-d are associated with poor prognosis in ALL patients. [ABSTRACT FROM AUTHOR]

In children with acute leukemia (AL), the mortality rate from Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae bloodstream infection (KPC-KpBSI) exceeds 50%, highest when active treatment is delayed. Neutropenic KPC-K. pneumoniae carriers are at high risk of KPC-KpBSI, and preemptive empiric antibiotic treatment (EAT) of febrile neutropenic episodes (FNEs) active against KPC-K. pneumoniae may reduce this mortality. We conducted an 8-year (2014–2021) retrospective observational study of 112 febrile neutropenic episodes (FNEs) in 32 children with AL who were KPC-K. pneumoniae carriers: standard EAT for 39 FNEs and active EAT for 73 FNEs (52 ceftazidime/avibactam (CAZAVI)-based and 21 colistin-based combinations, and 5 CAZAVI monotherapy). Successful outcomes (survival from FNE) were observed in 94%; seven were fatal, with four due to infectious causes. KPC-KpBSIs caused 10/112 FNEs, 10/20 g-negative BSIs, and 3 deaths. The mortality rate of KPC-KpBSI was 30%. Active EAT was successful in 97% of the FNEs, compared to 87% with standard EAT. All deaths from KPC-KpBSI occurred in patients who received standard EAT, while none occurred with active EAT. KPC-KpBSI mortality rate with initial inactive treatment was 60%. CAZAVI-based EAT was successful in all FNEs, with a higher success rate without any modification compared to colistin-based EAT, where nephrotoxicity occurred in 14%. Therefore, active EAT, mainly a CAZAVI-based combination, was effective, safe, and associated with low overall and KPC-KpBSI-related mortality. [ABSTRACT FROM AUTHOR]

Background: Hematopoietic cell transplantation (HCT) increases survival for acute leukemia. Outpatient allogeneic HCT reduces costs and increases transplant rates in developing countries. We report outcomes of outpatient HLA-identical and haploidentical HCT in acute leukemia. Methods: This single-center retrospective cohort study analyzed 121 adult patients with acute myeloblastic (AML) and acute lymphoblastic leukemia (ALL) receiving an outpatient allogeneic HCT with peripheral blood allografts after reduced-intensity conditioning (RIC) from 2012-2022. Results: There were 81 (67%) haploidentical and 40 (33%) HLA-identical transplants. Complete chimerism (CC) at day +100 was not different in HLA-identical compared to haploidentical HCT (32.5% and 38.2%, P=0.054). Post-HCT complications, including neutropenic fever (59.3% vs. 40%), acute graft-versus-host-disease (aGVHD) (46.9% vs. 25%), cytokine release syndrome (CRS) (18.5% vs. 2.5%), and hospitalization (71.6% vs 42.5%) were significantly more frequent in haploidentical HCT. Two-year overall survival (OS) was 60.6% vs. 46.9%, (P=0.464) for HLA-identical and haplo-HCT, respectively. There was no difference in the 2-year disease-free-survival (DFS) (33.3% vs. 35%, P=0.924) between transplant types. In multivariate analysis, positive measurable residual disease (MRD) at 30 days (HR 8.8, P=0.018) and 100 days (HR 28.5, P=0.022) was associated with lower OS, but not with non-relapse mortality (NRM) (P=0.252 and P=0.123, univariate). In univariate analysis, both 30-day and 100-day MRD were associated with lower DFS rates (P=0.026 and P=0.006), but only day 30 MRD was significant in multivariate analysis (P=0.050). In the case of relapse, only MRD at day 100 was associated with increased risk in the univariate and multivariate analyses (HR 4.48, P=0.003 and HR 4.67, P=0.008). Chronic graft-versus-host-disease (cGVHD) was protective for NRM (HR 0.38, P=0.015). There was no difference in cumulative incidence of relapse (CIR) between transplant types (P=0.126). Forty-four (36.4%) patients died, with no difference between HCT type (P=0.307). Septic shock was the most frequent cause of death with 17 cases, with no difference between transplant types Conclusions: Outpatient peripheral blood allogenic HCT after RIC is a valid and effective alternative for adult patients suffering acute myeloblastic or lymphoblastic leukemia in low-income populations. [ABSTRACT FROM AUTHOR]

Background: Cancer is the leading cause of disease-related mortality in children. Causes of leukemia, the most common form, are largely unknown. Growing evidence points to an origin in-utero, when global redistribution of DNA methylation occurs driving tissue differentiation. Methods: Epigenome-wide DNA methylation was profiled in surrogate (blood) and target (bone marrow) tissues at birth, diagnosis, remission and relapse of pediatric pre-B acute lymphoblastic leukemia (pre-B ALL) patients. Double-blinded analyses was performed between prospective cohorts extending from birth to diagnosis and retrospective studies backtracking from clinical disease to birth. Validation was carried out using independent technologies and populations. Results: The imprinted and immuno-modulating VTRNA2-1 was hypermethylated (FDR<0.05) at birth in nested cases relative to controls in all tested populations (totaling 317 cases and 483 controls), including European and Hispanic ancestries. VTRNA2-1 methylation was stable over follow-up years after birth and across surrogate, target and other tissues (n=5,023 tissues; 30 types). When profiled in leukemic tissues from two clinical cohorts (totaling 644 cases), VTRNA2-1 methylation exhibited higher levels at diagnosis relative to controls, it reset back to normal levels at remission, and then re-increased to above control levels at relapse. Hypermethylation was significantly associated with worse pre-B ALL patient survival and with reduced VTRNA2-1 expression (n=2,294 tissues; 26 types), supporting a functional and translational role for VTRNA2-1 methylation. Conclusion: This study provides proof-of-concept to detect at birth epigenetic precursors of pediatric pre-B ALL. These alterations were reproducible with different technologies, in three continents and in two ethnicities, and can offer biomarkers for early detection and prognosis as well as actionable targets for therapy. Key points: • Precursors of pediatric acute lymphoblastic leukemia may be of epigenetic origin, detectable since birth and affecting patient prognosis. • These epigenetic precursors can be robust over several years and across several populations, ethnicities and surrogate and target tissues. [ABSTRACT FROM AUTHOR]

Background: Porphyromonase gingivalis (P. gingivalis) is a type of bacteria that causes periodontitis, which is strongly correlated with systemic diseases such as diabetes. However, the effect of hyperglycemia on periodontitis are unclear. The present study examined the effects of high glucose levels on the response to P. gingivalis infection. Results: The expression of P. gingivalis-induced interleukin-1β (IL-1β) and inflammasomes increased as the glucose concentration increased. High glucose conditions suppressed P. gingivalis–induced autophagy in human acute monocytic leukemia cell line (THP-1) macrophages. Zingerone increased autophagy and alleviated P. gingivalis-induced inflammatory response in THP-1 macrophages under high glucose conditions. In addition, P. gingivalis- induced inflammation in bone marrow-derived macrophages of diabetic mice was higher than in wild-type mice, but a zingerone treatment decreased the levels. Alveolar bone loss due to a P. gingivalis infection was significantly higher in diabetic mice than in wild-type mice. Conclusions: High-glucose conditions aggravated the inflammatory response to P. gingivalis infection by suppressing of autophagy, suggesting that autophagy induction could potentially to treat periodontitis in diabetes. Zingerone has potential use as a treatment for periodontal inflammation induced by P. gingivalis in diabetes patients. [ABSTRACT FROM AUTHOR]

Introduction: Despite the improvement in survival in acute lymphoblastic leukemia (ALL), there are still cases with evasion of chemotherapy-induced apoptosis. The IKK/ NF-kB signaling pathway contributes to antiapoptotic gene expression. Pentoxifylline (PTX) inhibits IkB phosphorylation, blocking NF-kB and antiapoptotic activity. Methods: We conducted a randomized, double-blind clinical trial on pediatric ALL patients undergoing induction therapy, assigning them to PTX or placebo group. Bone marrow aspirates were obtained on days 1, 8, 15, and 22. Apoptosis was assessed using Annexin-V/propidium iodide. Results: Results indicated that the PTX group exhibited higher apoptosis on day- 8 (41.3% vs. 19.4%, p =0.029) and day-15 (35.0% vs. 14.2%, p <0.01). On day-8, the PTX group displayed an MRD of 0.25% vs. 18.2% (p <0.01) in placebo group; on day-15, the PTX group demonstrated an MRD of 0.09% vs. 1.4% (p =0.02). Patients achieving an MRD <0.01% on day-8 demonstrated a 3-year Overall Survival (OS) of 81.6% vs. 58.3% (p =0.03); on day-15, patients with MRD <0.01% had a 3-year OS of 77.9% vs. 54.5% (p =0.03). The PTX group achieved an MRD of <0.01% earlier on days-8 and 15, along with a higher apoptosis rate, indicating a more favorable therapeutic response. In the entire cohort, patients achieving MRD <0.01% on day-8 or 15 displayed superior OS. Conclusion: Our study demonstrates that PTX enhances apoptosis and reduces MRD in pediatric acute lymphoblastic leukemia patients. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT02451774. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to explore the development process of psychological resilience among adult patients with de novo acute leukemia. Methods: This study utilized a descriptive qualitative approach, employing a purposeful sampling method to select a sample of 15 newly diagnosed patients with acute leukemia (AL) who underwent their initial induction chemotherapy treatment at the Hematology Department of the First Affiliated Hospital of Zhejiang University School of Medicine, China. Semi‐structured interviews were conducted with the selected patients. Content analysis methodology was used to analyze, summarize, and extract themes from the collected data. Results: Three categories emerged—namely, (1) negative period, (2) adaptive response phase, and (3) growth transformation period. The negative period occurs during the initial diagnosis and throughout the treatment cycle. However, influenced by both internal and external protective factors, including personal characteristics and social support, individuals enhance their psychological resilience through emotional regulation, mental adjustment, and adaptive strategies vis‐à‐vis healthcare decision‐making and disease management. Overall, psychological resilience development follows an upward spiral trajectory. Conclusions: This study identified that negative emotions and symptom clusters impede the development of patients' psychological resilience. Moreover, it revealed a substantial need for disease‐related information among patients. Therefore, healthcare professionals should prioritize addressing the negative emotions of patients, early identification of protective factors, dynamic monitoring of symptom clusters, effective management, and provision of psychological counseling and interventions. Simultaneously, providing personalized, professional, and systematic disease‐related information is vital for promoting psychological resilience development. [ABSTRACT FROM AUTHOR]

Background: Rearrangements of the histone‐lysine‐N‐methyltransferase (KMT2A), previously referred to as mixed‐lineage leukemia (MLL), are among the most common chromosomal abnormalities in patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), involving numerous different fusion partners. KMT2A‐rearranged (KMT2A‐r) leukemia is characterized by a rapid onset, aggressive progression, and significantly worse prognosis compared to non‐KMT2A‐r leukemias. Even with contemporary chemotherapeutic treatments and hematopoietic stem cell transplantations (HSCT), patients with KMT2A‐r leukemia typically experience poor outcomes and limited responses to these therapies. Objectives: This review aims to consolidate recent studies on the general gene characteristics and associated mechanisms of KMT2A‐r acute leukemia, as well as the cytogenetics, immunophenotype, clinical presentation, and risk stratification of both KMT2A‐r‐AML and KMT2A‐r‐ALL. Particularly, the treatment targets in KMT2A‐r acute leukemia are examined. Methods: A comprehensive review was carried out by systematically synthesizing existing literature on PubMed, using the combination of the keywords 'KMT2A‐rearranged acute leukemia', 'lymphoblastic leukemia', 'myeloid leukemia', and 'therapy'. The available studies were screened for selection based on quality and relevance. Conclusions: Studies indicate that KMT2A rearrangements are present in over 70% of infant leukemia cases, approximately 10% of adult AML cases, and numerous instances of secondary acute leukemias, making it a disease of critical concern to clinicians and researchers alike. The future of KMT2A‐r acute leukemia research is characterized by an expanding knowledge of the disease's biology, with an emphasis on personalized therapies, immunotherapies, genomic advancements, and innovative therapeutic combinations. The overarching aim is to enhance patient outcomes, lessen the disease burden, and elevate the quality of life for those affected. Ongoing research and clinical trials in this area continue to offer promising opportunities for refining treatment strategies and improving patient prognosis. [ABSTRACT FROM AUTHOR]

Background: Since the development of the first‐generation Tyrosine Kinase Inhibitor (TKI), it has played a crucial role in the treatment of BCR::ABL1‐positive acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML). However, ABL1 kinase domain (ABL1 KD) mutations confer resistance to several TKIs. These mutations have been extensively studied in chronic myeloid leukemia (CML) but less so in BCR::ABL1‐positive acute lymphoblastic leukemia (ALL). Methods: Our study aimed to analyze the the ABL1 KD mutations in 97 consecutive newly‐diagnosed adults with BCR::ABL1‐positive ALL before therapy, in cytogenetic complete remission and at relapse with next generation sequencing (NGS). The relationship between ABL1 KD mutations and TKI selection was also analyzed. Results: Previously unreported ABL1 KD mutations R239G, F401V/L, R516L and K262T were the most prevalent in pre‐therapy and cytogenetic remission samples, whereas T315I/P and P‐loop mutations were most prevalent in relapse samples. R239G, F401V/L, R516L and K262T are related to the BCR::ABL1 structure, whereas T315I/P and P‐loop mutations directly alter kinase activity. BaF3 cells transfected with ABL1 KD F401V, K262T, R239G, or R516L mutations were resistant to imatinib but strongly inhibited by olverembatinib with IC50 values of 0.73 to 1.52nM. Meanwhile, olverembatinib had advantages in increasing complete molecular response (CMR) and good prognosis. Conclusion: Overall, our findings indicate the prevalence and impact of new ABL1 KD mutations in BCR::ABL1‐positive ALL patients, highlighting the necessity for effective therapies targetingthese mutations. [ABSTRACT FROM AUTHOR]

Protein arginine methyltransferase 3 (PRMT3) plays an important role in gene regulation and a variety of cellular functions, thus, being a long sought‐after therapeutic target for human cancers. Although a few PRMT3 inhibitors are developed to prevent the catalytic activity of PRMT3, there is little success in removing the cellular levels of PRMT3‐deposited ω‐NG,NG‐asymmetric dimethylarginine (ADMA) with small molecules. Moreover, the non‐enzymatic functions of PRMT3 remain required to be clarified. Here, the development of a first‐in‐class MDM2‐based PRMT3‐targeted Proteolysis Targeting Chimeras (PROTACs) 11 that selectively reduced both PRMT3 protein and ADMA is reported. Importantly, 11 inhibited acute leukemia cell growth and is more effective than PRMT3 inhibitor SGC707. Mechanism study shows that 11 induced global gene expression changes, including the activation of intrinsic apoptosis and endoplasmic reticulum stress signaling pathways, and the downregulation of E2F, MYC, oxidative phosphorylation pathways. Significantly, the combination of 11 and glycolysis inhibitor 2‐DG has a notable synergistic antiproliferative effect by further reducing ATP production and inducing intrinsic apoptosis, thus further highlighting the potential therapeutic value of targeted PRMT3 degradation. These data clearly demonstrated that degrader 11 is a powerful chemical tool for investigating PRMT3 protein functions. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) are common hematological malignancies in adults. Despite considerable research advances, the development of standard therapies, supportive care, and prognosis for the majority of AML and ALL patients remains poor and the development of new effective therapy is urgently needed. Here, it is reported that activation of thermogenic adipose tissues (TATs) by cold exposure or β3‐adrenergic receptor agonists markedly alleviated the development and progression of AML and ALL in mouse leukemia models. TAT activation (TATA) monotherapy substantially reduces leukemic cells in bone marrow and peripheral blood, and suppresses leukemic cell invasion, including hepatomegaly and splenomegaly. Notably, TATA therapy prolongs the survivals of AML‐ and ALL‐bearing mice. Surgical removal of thermogenic brown adipose tissue (BAT) or genetic deletion of uncoupling protein 1 (UCP1) largely abolishes the TATA‐mediated anti‐leukemia effects. Metabolomic pathway analysis demonstrates that glycolytic metabolism, which is essential for anabolic leukemic cell growth, is severely impaired in TATA‐treated leukemic cells. Moreover, a combination of TATA therapy with chemotherapy produces enhanced anti‐leukemic effects and reduces chemotoxicity. These data provide a new TATA‐based therapeutic paradigm for the effective treatment of AML, ALL, and likely other types of hematological malignancies. [ABSTRACT FROM AUTHOR]

Purpose: The current study aims to investigate the significance of N6-methyladenosine (m6A) methylationrelated genes in the clinical prognosis of childhood relapsed B-cell acute lymphoblastic leukemia (B-ALLL) patient. Methods: Transcriptome data and corresponding clinical data on m6A methylation-related genes (including 20 genes) were obtained from the Therapeutically Applicable Research To Generate Effective Treatments (TARGET) database. Results: The bone marrow (BM) samples of 134 newly diagnosed (naive) and 116 relapsed B-ALL from TARGET were enrolled in the current study. Three genes (FTO, HNRNPC, RBM15B) showed significant up-regulation in relapsed B-ALL compared with that in naive B-ALL.The three genes had a significantly worse survival (P < 0.05). The LASSO Cox regression model was used to select the most predictive genes as prognostic indicators, and YTHDC1 and FTO were identified as prognostic factors for relapsed B-ALL. Finally, the results of multivariate regression analysis showed that the risk score of m6A methylation-related genes was an independent prognostic factor in relapsed B-ALL (P < 0.05). Conclusion: We found that the expression levels of m6A methylation-related genes were different in naive and relapsed patients with B-ALL and correlated with survival and prognosis.This implies that m6A methylation-related genes may be promising prognostic indicators or therapeutic targets for relapsed B-ALL. [ABSTRACT FROM AUTHOR]

KMT2A-rearranged acute lymphoblastic leukemia (ALL) is characterized by deregulation of the epigenome and shows susceptibility towards histone deacetylase (HDAC) inhibition. Most broad-spectrum HDAC inhibitors simultaneously target multiple human HDAC isoforms. Consequently, they often induce toxicity and especially in combination with other therapeutic agents. Therefore, more specifically targeting HDAC isoforms may represent a safer therapeutic strategy. Here we show that shRNA-mediated knock-down of the class IIA HDAC isoforms HDAC4, HDAC5, and HDAC7 results in apoptosis induction and cell cycle arrest in KMT2A-rearranged ALL cells. In concordance, the HDAC4/5 selective small molecule inhibitor LMK-235 effectively eradicates KMT2A-rearranged ALL cell lines as well as primary patient samples in vitro. However, using a xenograft mouse model of KMT2A-rearranged ALL we found that the maximum achievable dose of LMK-235 was insufficient to induce anti-leukemic effects in vivo. Similar results were obtained for the specific class IIA HDAC inhibitors MC1568 and TMP195. Finally, LMK-235 appeared to exert minimal anti-leukemic effects in vivo in combination with the BCL-2 inhibitor venetoclax, but not enough to prolong survival in treated mice. In conclusion, class IIA HDAC isoforms represent attractive therapeutic target in KMT2A-rearranged ALL, although clinical applications require the development of more stable and efficient specific HDAC inhibitors. Class IIA isoform specific inhibition represents an attractive therapeutic target in KMT2A-rearranged infant acute lymphoblastic leukemia. [ABSTRACT FROM AUTHOR]

Invasive fungal infections in patients with leukemia carry a high mortality rate, but early diagnosis has the potential to modify this natural history. A novel screening method using Aspergillus droplet-digital polymerase chain reaction in exhaled breath condensate may have a similar performance to serum galactomannan screening. Larger studies, including other molds, are necessary. [ABSTRACT FROM AUTHOR]

Menin is an essential oncogenic cofactor of MLL1 fusion proteins in acute leukemias and inhibitors of the menin-MLL1 interaction are under evaluation in clinical trials. Recent studies found emerging resistance to menin inhibitor treatment in patients with leukemia as a result of somatic mutations in menin. To understand how patient mutations in menin affect the interaction with MLL1, we performed systematic characterization of the binding affinity of these menin mutants (T349M, M327I, G331R and G331D) and the N-terminal fragment of MLL1. We also determined the crystal structures of menin patient mutants and their complexes with MLL1- derived peptides. We found that drug-resistant mutations in menin occur at a site adjacent to the MLL1 binding site, but they do not affect MLL1 binding to menin. On the contrary, our structural analysis shows that all these point mutations in menin generate steric clash with menin inhibitors. We also found that mutation G331D results in a very slow dissociation of MLL1 from menin and this mutant might be particularly difficult to inhibit with small molecule drugs. This work provides structural information to support the development of a new generation of small molecule inhibitors that overcome resistance caused by menin mutations. [ABSTRACT FROM AUTHOR]

T-cell acute lymphoblastic leukemia (T-ALL) is a challenging childhood cancer to treat, with limited therapeutic options and high relapse rates. This study explores deamidated triosephosphate isomerase (dTPI) as a novel therapeutic target. We hypothesized that selectively inhibiting dTPI could reduce T-ALL cell viability without affecting normal T lymphocytes. Computational modeling and recombinant enzyme assays revealed that disulfiram (DS) and curcumin (CU) selectively bind and inhibit dTPI activity without affecting the non-deamidated enzyme. At the cellular level, treatment with DS and CU significantly reduced Jurkat T-ALL cell viability and endogenous TPI enzymatic activity, with no effect on normal T lymphocytes, whereas the combination of sodium dichloroacetate (DCA) with DS or CU showed synergistic effects. Furthermore, we demonstrated that dTPI was present and accumulated only in Jurkat cells, confirming our hypothesis. Finally, flow cytometry confirmed apoptosis in Jurkat cells after treatment with DS and CU or their combination with DCA. These findings strongly suggest that targeting dTPI represents a promising and selective target for T-ALL therapy. [ABSTRACT FROM AUTHOR]

The document discusses the importance of antiviral prophylaxis to prevent herpes simplex virus (HSV) and varicella zoster virus (VZV) reactivation in adult patients with newly diagnosed acute leukemia. It highlights the efficacy of antiviral medications like acyclovir in reducing the incidence of symptomatic HSV reactivation during intensive chemotherapy. The study conducted in Italian centers belonging to SEIFEM group revealed a heterogeneous scenario in antiviral prophylaxis policies, with some centers not adhering to current international guidelines. The authors suggest the need for harmonization in applying antiviral prevention approaches and further prospective studies to optimize the schedule and duration of antiviral prophylaxis in different acute leukemia subgroups. [Extracted from the article]

Relapsed/refractory acute leukemia (R/R-AL) is associated with a low remission rate, short survival rate, and poor prognosis. Treating R/R-AL remains challenging as there is no standardized effective regimen; hence, there is a need for efficient therapies. CD38 expression has been observed in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Daratumumab is a humanized anti-CD38 monoclonal antibody used to treat multiple myeloma and has been reported to treat R/R-AL safely and effectively. The clinical data of 10 adult patients with R/R-AL who were treated with a daratumumab-based salvage regimen between July 2018 and May 2023 at our center were analyzed retrospectively. Seven AML and three ALL cases were included in the analysis. Seven (70%) patients showed responses to the treatments (complete response [CR], 60%; partial response [PR], 10%). Of the seven responders, three underwent allogenic stem cell transplantation (ASCT), including one who underwent a second ASCT. Among the five patients with R/R AML who had prior exposure to venetoclax, three achieved a therapeutic response (two CR and one PR) when re-treated with venetoclax in combination with daratumumab. The median follow-up time was 6.15 months (0.9–21 months). Overall survival and event-free survival rates at 12 months were 68.6% and 40.0%, respectively. The main adverse events included grade 3 febrile neutropenia (20%) and grade 3 hematological toxicities (60%). The daratumumab-based salvage regimen offers patients with R/R-AL the opportunity of remission with acceptable tolerability, creating the possibility of bridging ASCT. [ABSTRACT FROM AUTHOR]

Background Acute leukemia is a heterogeneous group of malignancies characterized by the rapid proliferation of immature blood cells. This study aims to compare the efficacy and safety of two different regimens of combination chemotherapy in patients diagnosed with acute leukemia. Materials and Methods A total of 120 patients with acute leukemia were randomly assigned to two treatment groups: Regimen A (cytarabine and daunorubicin) and Regimen B (cytarabine, daunorubicin, and etoposide). Patients were evaluated based on complete remission rates, overall survival, and adverse effects over a 12-month period. Results The results indicated that Regimen A achieved a complete remission rate of 70% (42 out of 60 patients), while Regimen B showed a higher rate of 80% (48 out of 60 patients). The median overall survival was 14 months for Regimen A and 18 months for Regimen B. Adverse effects were comparable, with Grade 3 or higher toxicities observed in 30% of patients in Regimen A and 25% in Regimen B. Conclusion Both regimens demonstrated significant efficacy in treating acute leukemia, with Regimen B showing superior remission rates and overall survival. Further studies are needed to confirm these findings and optimize treatment protocols. [ABSTRACT FROM AUTHOR]

Assessment of minimal residual disease (MRD) is the most powerful predictor of outcome in B-type acute lymphoblastic leukemia (B-ALL). MRD, defined as the presence of leukemic cells in the blood or bone marrow, is used for the evaluation of therapy efficacy. We report on a microfluidic-based MRD (MF-MRD) assay that allows for frequent evaluation of blood for the presence of circulating leukemia cells (CLCs). The microfluidic chip affinity selects B-lineage cells, including CLCs using anti-CD19 antibodies poised on the wall of the microfluidic chip. Affinity-selected cells are released from the capture surface and can be subjected to immunophenotyping to enumerate the CLCs, perform fluorescence in situ hybridization (FISH), and/or molecular analysis of the CLCs' mRNA/gDNA. During longitudinal testing of 20 patients throughout induction and consolidation therapy, the MF-MRD performed 116 tests, while only 41 were completed with multiparameter flow cytometry (MFC-MRD) using a bone marrow aspirate, as standard-of-care. Overall, 57% MF-MRD tests were MRD(+) as defined by CLC numbers exceeding a threshold of 5 × 10−4%, which was determined to be the limit of quantitation. Above a threshold of 0.01%, MFC-MRD was positive in 34% of patients. The MF offered the advantage of the opportunity for efficiently processing small volumes of blood (2 mL), which is important in the care of pediatric patients, especially infants. The minimally invasive means of blood collection are of high value when treating patients whose MRD is typically tested using an invasive bone marrow biopsy. MF-MRD detection can be useful for stratification of patients into risk groups and monitoring of patient well-being after completion of treatment for early recognition of potential impending disease recurrence. [ABSTRACT FROM AUTHOR]

Tumor cells of acute lymphoblastic leukemia (ALL) may have various genetic abnormalities. Some of them lead to a complete loss of certain genes. Our aim was to reveal biallelic deletions of genes in Ph–negative T-ALL. Chromosomal microarray analysis (CMA) was performed for 47 patients with de novo Ph–negative T-ALL, who received treatment according to RALL-2016m clinical protocol at the National Medical Research Center for Hematology (Moscow, Russia) from 2017 to 2023. Out of forty-seven patients, only three had normal molecular karyotype. The other 44 patients had multiple gains, losses, and copy neutral losses of heterozygosity. Biallelic losses were found in 14 patients (30%). In ten patients (21%), a biallelic deletion of 9p21.3 involved a different number of genes, however CDKN2A gene loss was noted in all ten cases. For seven patients (15%), a biallelic deletion of 7q34 was found, including two genes—PRSS1, PRSS2 located within the T-cell receptor beta (TRB) locus. A clonal rearrangement of the TRB gene was revealed in 6 out of 7 cases with 7q34 biallelic loss. Both biallelic deletions can be considered favorable prognostic factors, with an association with 9p21 being statistically significant (p = 0.01) and a trend for 7q34 (p = 0.12) being observed. [ABSTRACT FROM AUTHOR]

Transcription factors control genes to maintain normal hemopoiesis, and dysregulation of some factors can lead to acute lymphoblastic leukemia (ALL). Mycoviruses are known to alter the genetics of their fungal host. The present study evaluates the effects of the products of a mycovirus-containing Aspergillus flavus (MCAF), isolated from the home of a patient with ALL, on certain transcription factors of normal and ALL cell lines. Our published studies have shown that ALL patients have antibodies to MCAF, and that exposure of the mononuclear leukocytes of patients in complete remission to its products, unlike controls, results in the re-development of genetic and cell surface phenotypes characteristic of ALL. For the present study, normal, pre-B, and B-cell leukemia cell lines were exposed to the culture of MCAF. Pre- and post-exposure levels of PAX5, Ikaros, and NF-κB were assessed. Exposure to MCAF resulted in apoptosis, cell cycle changes, and complete downregulation of all transcription factors in normal cell lines. In acute leukemia cell lines, cellular apoptosis and alterations in the cell cycle were also noted; however, while there was downregulation of all tested transcription factors, residual levels were retained. The noted alterations in the transcription factors caused by MCAF are novel findings. The possible role of MCAF in leukemogenesis needs to be further investigated. Mycovirus-containing Aspergillus flavus was initially isolated from a leukemia patient's home. Our prior published studies have illuminated intriguing associations of this organism with leukemia. Unlike controls, patients diagnosed with acute lymphoblastic leukemia (ALL) harbor antibodies to this organism. Furthermore, the exposure of mononuclear cells from patients with ALL in complete remission to the products of this organism reproduced genetic and cell phenotypes characteristic of ALL. These findings underscore the potential role of environmental factors in leukemogenesis and hint at novel avenues for therapeutic intervention and preventive strategies. [ABSTRACT FROM AUTHOR]

Purpose: Leukaemia remains a major contributor to global mortality, representing a significant health risk for a substantial number of cancer patients. Despite notable advancements in the field, existing treatments frequently exhibit limited efficacy or recurrence. Here, we explored the potential of abolishing HVEM (herpes virus entry mediator, TNFRSF14) expression in tumours as an effective approach to treat acute lymphoblastic leukaemia (ALL) and prevent its recurrence. Methods: The clinical correlations between HVEM and leukaemia were revealed by public data analysis. HVEM knockout (KO) murine T cell lymphoblastic leukaemia cell line EL4 were generated using CRISPR-Cas9 technology, and syngeneic subcutaneous tumour models were established to investigate the in vivo function of HVEM. Immunohistochemistry (IHC), RNA-seq and flow cytometry were used to analyse the tumour immune microenvironment (TIME) and tumour draining lymph nodes (dLNs). Immune functions were investigated by depletion of immune subsets in vivo and T cell functional assays in vitro. The HVEM mutant EL4 cell lines were constructed to investigate the functional domain responsible for immune escape. Results: According to public databases, HVEM is highly expressed in patients with ALL and acute myeloid leukemia (AML) and is negatively correlated with patient prognosis. Genetic deletion of HVEM in EL4 cells markedly inhibited tumour progression and prolonged the survival of tumour-bearing mice. Our experiments proved that HVEM exerted its immunosuppressive effect by inhibiting antitumour function of CD8+ T cell through CRD1 domain both in vivo and in vitro. Additionally, we identified a combination therapy capable of completely eradicating ALL tumours, which induces immune memory toward tumour protection. Conclusions: Our study reveals the potential mechanisms by which HVEM facilitates ALL progression, and highlights HVEM as a promising target for clinical applications in relapsed ALL therapy. [ABSTRACT FROM AUTHOR]