Acute Leukemia Cells Research Articles

THE SYSTEMATIC REVIEW OF ADIPOCYTES IN ACUTE LEUKEMIA

Background: Adipose tissue, a major cell type in the bone marrow microenvironment, plays a crucial role in the development and progression of cancer. Adipocytes, which make up the majority of cells in adipose tissue, exhibit distinct metabolic roles, replication and development abilities, cytokine production, and reactions to external stimuli. Adipocytes are abundant in bone marrow, a key site of metastasis for solid tumors and a crucial microenvironment for hematological malignancies. The aim: This study aims to determine the association of adipocytes in acute leukemia. Methods: By comparing itself to the standards set by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020, this study was able to show that it met all of the requirements. So, the experts were able to make sure that the study was as up-to-date as it was possible to be. For this search approach, publications that came out between 2014 and 2024 were taken into account. Several different online reference sources, like PubMed and ScienceDirect, were used to do this. It was decided not to take into account review pieces, works that had already been published, or works that were only half done. Results: In the PubMed database, the results of our search brought up 27 articles, whereas the results of our search on ScienceDirect brought up 281 articles. The results of the search conducted by title screening yielded a total 14 articles for PubMed and 3 articles for ScienceDirect. We compiled a total of 12 papers, 10 of which came from PubMed and 2 of which came from ScienceDirect. We excluded 4 review articles, 2 articles having ineligible subjects, and 1 article having insufficient outcomes. In the end, we included five research that met the criteria. Conclusion: Acute leukemia cells have various effects on adipocytes which alter adipogenic differentiation capacities or adipocyte lipolysis and promote bone marrow adipocyte remodeling. Adipocytes play a crucial role in acute leukemia cell survival and their treatment.

RNA-binding protein RBM5 plays an essential role in acute myeloid leukemia by activating the oncogenic protein HOXA9

BackgroundThe oncogenic protein HOXA9 plays a critical role in leukemia transformation and maintenance, and its aberrant expression is a hallmark of most aggressive acute leukemia. Although inhibiting the upstream regulators of HOXA9 has been proven as a significant therapeutic intervention, the comprehensive regulation network controlling HOXA9 expression in leukemia has not been systematically investigated.ResultsHere, we perform genome-wide CRISPR/Cas9 screening in the HOXA9-driven reporter acute leukemia cells. We identify a poorly characterized RNA-binding protein, RBM5, as the top candidate gene required to maintain leukemia cell fitness. RBM5 is highly overexpressed in acute myeloid leukemia (AML) patients compared to healthy individuals. RBM5 loss triggered by CRISPR knockout and shRNA knockdown significantly impairs leukemia maintenance in vitro and in vivo. Through domain CRISPR screening, we reveal that RBM5 functions through a noncanonical transcriptional regulation circuitry rather than RNA splicing, such an effect depending on DNA-binding domains. By integrative analysis and functional assays, we identify HOXA9 as the downstream target of RBM5. Ectopic expression of HOXA9 rescues impaired leukemia cell proliferation upon RBM5 loss. Importantly, acute protein degradation of RBM5 through auxin-inducible degron system immediately reduces HOXA9 transcription.ConclusionsWe identify RBM5 as a new upstream regulator of HOXA9 and reveal its essential role in controlling the survival of AML. These functional and molecular mechanisms further support RBM5 as a promising therapeutic target for myeloid leukemia treatment.

Differentiation of Acute Leukemia Cells Including Cells with MLL-AF4 Rearrangements Induced by Jiyuan Oridonin A.

Chromosomal rearrangements involving the Mixed lineage leukemia (MLL) gene are observed in acute leukemia (AL) patients, which have poor prognosis, especially in infants. Hence, there is still a challenge to develop other effective agents to treat AL with MLL rearrangements (MLLr). MLL has been shown to rearrange with partner genes, of which the most frequently observed are AF4 and AF9. Moreover, AL is characterized by a differentiation blockage resulting in the accumulation of immature cells. An ent-kaurene diterpenoid compound, Jiyuan Oridonin A (JOA), has been shown to reduce the viability of AML cells by differentiation. We aimed to evaluate the effect of JOA on the growth and differentiation of AL cells (SEM, JURKAT and MV4-11) including cells with MLLr-AF4 by cell proliferation assay, colony formation assay, cell cycle analysis, cell apoptosis analysis, measurement of cell surface antigens, cell morphology, mRNA-sequencing analysis, quantitative Real-time PCR and Western blotting analysis. Our findings demonstrated that the proliferation of AL cells including cells with MLLr-AF4 was significantly suppressed by JOA, which induced cell differentiation followed by G0/G1 cell cycle withdrawal. Moreover, JOA-mediated cell differentiation was likely due to activation of G-CSFR in MV4-11 cells. Our results suggest that JOA may be considered a promising anti-leukemia compound to develop to surmount the differentiation block in AL patients.

Discovery and Optimization of WDR5 Inhibitors via Cascade Deoxyribonucleic Acid-Encoded Library Selection Approach.

The DNA-encoded library (DEL) is a powerful hit generation tool for chemical biology and drug discovery; however, the optimization of DEL hits remained a daunting challenge for the medicinal chemistry community. In this study, hit compounds targeting the WIN binding domain of WDR5 were discovered by the initial three-cycle linear DEL selection, and their potency was further enhanced by a cascade DEL selection from the focused DEL designed based on the original first run DEL hits. As expected, these new compounds from the second run of focused DEL were more potent WDR5 inhibitors in the protein binding assay confirmed by the off-DNA synthesis. Interestingly, selected inhibitors exhibited good antiproliferative activity in two human acute leukemia cell lines. Taken together, this new cascade DEL selection strategy may have tremendous potential for finding high-affinity leads against WDR5 and provide opportunities to explore and optimize inhibitors for other targets.

The role of PKC and PKD in CXCL12 and CXCL13 directed malignant melanoma and acute monocytic leukemic cancer cell migration.

Cancer metastasis is the leading cause of cancer related mortality. Chemokine receptors and proteins in their downstream signalling axis represent desirable therapeutic targets for the prevention of metastasis. Despite this, current therapeutics have experienced limited success in clinical trials due to a lack of insight into the downstream signalling pathway of specific chemokine receptor cascades in different tumours. In this study, we investigated the role of protein kinase C (PKC) and protein kinase D (PKD) in CXCL12 and CXCL13 stimulated SK-MEL-28 (malignant melanoma) and THP-1 (acute monocytic leukaemia) cell migration. While PKC and PKD had no active role in CXCL12 or CXCL13 stimulated THP-1 cell migration, PKC and PKD inhibition reduced CXCL12 stimulated migration and caused profound effects upon the cytoskeleton of SK-MEL-28 cells. Furthermore, only PKC and not PKD inhibition reduced CXCL13 stimulated migration in SK-MEL-28 cells however PKC inhibition failed to stimulate any changes to the actin cytoskeleton. These findings indicate that PKC inhibitors would be a useful therapeutic for the prevention of both CXCL12 and CXCL13 stimulated migration and PKD inhibitors for CXCL12 stimulated migration in malignant melanoma.

Streptolysin S induces proinflammatory cytokine expression in calcium ion-influx-dependent manner

Anginosus group streptococci (AGS) are opportunistic pathogens that reside in the human oral cavity. The β-hemolytic strains of Streptococcus anginosus subsp. anginosus (SAA) produce streptolysin S (SLS), a streptococcal peptide hemolysin. In recent clinical scenarios, AGS, including this species, have frequently been isolated from infections and disorders beyond those in the oral cavity. Consequently, investigating this situation will reveal the potential pathogenicity of AGS to ectopic infections in humans. However, the precise mechanism underlying the cellular response induced by secreted SLS and its relevance to the pathogenicity of AGS strains remain largely unknown. This study aims to elucidate the mechanism underlying the host cellular response of the human acute monocytic leukemia cell line THP-1 to secreted SLS. In THP-1 cells incubated with the culture supernatant of β-hemolytic SAA containing SLS as the sole cytotoxic factor, increased Ca2+ influx and elevated expression of proinflammatory cytokines were observed. Significantly reduced expression of SLS-dependent upregulated cytokine genes under Ca2+-chelating conditions suggests that Ca2+ influx triggers SLS-dependent cellular responses. Furthermore, SLS-dependent enhanced expression of IL-8 was also implicated in the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways. The findings presented in this study are crucial for a comprehensive understanding of the real pathogenicity of SLS-producing β-hemolytic AGS in the latest clinical situations.

Allostreptopyrroles A-E, β-alkylpyrrole derivatives from an actinomycete Allostreptomyces sp. RD068384.

Five new β-alkylpyrrole derivatives, allostreptopyrroles A-E (1-5), were isolated from the culture broth of Allostreptomyces RD068384. Their structures were elucidated by 1D and 2D NMR spectroscopic analyses, HRESIMS, and chemical derivatization. The absolute configurations of compounds 2 and 3 were predicted by comparison of experimental and calculated specific rotation data. Compounds 1-5 are the first examples of natural pyrroles substituted by formyl and carboxyl functionalities. Compounds 1, 4, and 5 showed cytotoxicity against Kasumi-1 human acute myeloblastic leukemia cells with IC50 values of 103, 105, and 105 μM, respectively, which are less active than the anticancer agent cisplatin, with an IC50 value of 70 μM.

Rapid cellular uptake of citrate-coated iron oxide nanoparticles unaffected by cell-surface glycosaminoglycans.

Citrate-coated iron oxide nanoparticles, specifically Synomag®-COOH (SynC), are promising tracers in magnetic particle imaging (MPI) due to their high magnetic moments and rapid cellular uptake. The mechanisms driving efficient SynC uptake remain unclear. Previous observations suggest a role of the extracellular glycocalyx during nanoparticle uptake. Here, we ascertain whether the cell-surface glycosaminoglycans (GAGs) regulate the uptake of SynC. Using transmission electron microscopy (TEM), we visualized SynC uptake by THP-1 cells, a human acute monocytic leukemia cell line. We investigated the interaction of SynC with GAGs in living cells using click-chemistry-based labeling. Upon treating THP-1 cells with chondroitinase or hyaluronidase and with a xylosyltransferase-deficient cell line, we quantified SynC uptake and measured interactions of SynC with cells in real time using magnetic particle spectroscopy (MPS). The THP-1 cell membrane engulfed or formed extensions around SynC, indicating uptake through pinocytosis and phagocytosis. We measured an increased MPS signal of SynC within seconds of cell contact, suggesting an interaction with extracellular components like the glycocalyx. Upon adding SynC to THP-1 cells, we could not observe disruption of fluorescently labeled GAGs or an enhanced intracellular fluorescence, implying that SynC does not accelerate the turnover of GAGs by binding. Lack of chondroitin sulfate, heparan sulfate, and hyaluronic acid did not affect the rapid magnetic behavior increase of SynC upon cell contact. Accordingly, we measured no significant differences in SynC uptake between wild type cells and our GAG-deficient models. These findings suggest that GAGs act as a permeable bandpass for SynC nanoparticles with a minor negative surface charge of -13.8 mV. This finding has significant implications for MPI-based cell tracking because it facilitates efficient tracking of cell types that lack a strong repulsion by cell-surface GAGs. It will be crucial to investigate whether the rapid uptake of SynC is cell-type specific and influenced by different extracellular matrix compositions.

Evaluation of mRNA Expressions of TOX and NR4As in CD8+ T cells in Acute Leukemia.

Thymocyte selection-associated high mobility group box protein (TOX) and members of the nuclear receptor 4A (NR4A) are known as transcription factors involved in T cell exhaustion. To evaluate the mRNA expression of TOX and NR4A1-3 in CD8+ T cells in acute leukemia. Blood samples were obtained from 21 ALL and 6 AML patients as well as 20 control subjects. CD8+ T cells were isolated using MACS. Relative gene expression of TOX and NR4A1-3 was then evaluated using qRT-PCR. Comparison of mRNA expression of TOX in CD8+ T cells showed no significant difference among the study groups (p>0.05), while the expression of NR4A1 was significantly lower in AML patients than in the control group (p=0.0006). Also, the expression of NR4A2 and NR4A3 was significantly lower in both ALL (p=0.0049 and p=0.0005, respectively) and AML (p=0.0019 and p=0.0055, respectively) patients. NR4As expressions were found to be lower in CD8+ T cells from patients with AML and ALL compared to controls, whereas the mRNA expression of TOX showed no significant difference. Although TOX and NR4As are associated with CD8+ T cell exhaustion in solid tumors, they might play different roles in acute leukemia, which requires further investigation.

Acute Kidney Injury in Methotrexate treated Leukemia

Background: The study was performed to know the incidence of acute kidney injury within 48 hours following High dose Methotrexate administration in children with high-risk B cell Acute Lymphoblastic Leukemia along with its risk factors and toxicities. Most studies have been conducted in adults and have included non-Hodgkin lymphoma along with leukemia. There is a paucity of data regarding the burden of Acute kidney injury with Methotrexate use in the pediatric age group with B cell Acute Lymphoblastic Leukemia. Methods: It was a prospective observational study conducted at the pediatric ward of All India Institute of Medical Sciences, New Delhi between 2019 September to 2021 June. Children between 1 to 18 years with high-risk B lineage Acute Lymphoblastic Leukemia planned for high-dose Methotrexate at 3gm/m² were enrolled. The measurement of serum creatinine was done at baseline, 24 and 42 hours while serum methotrexate at 24 and 42 hours, adverse reactions were assessed till day 14 of methotrexate administration. Results: The incidence of Acute Kidney Injury and severe Acute Kidney Injury (stages 2 and 3) at 42 hours of High dose Methotrexate infusion was 24.3% and 12.8% respectively. Low serum albumin was associated with an increased risk of Acute Kidney Injury (p=0.004). Transaminitis and thrombocytopenia were common toxicities. Conclusions: Acute Kidney Injury is common following High dose Methotrexate administration in B cell Acute Leukemic Leukemia. Low serum albumin level increases renal toxicity following methotrexate infusion. The measures to prevent renal toxicity should be instituted promptly in high-risk groups.

Addressing Genetic Tumor Heterogeneity, Post-Therapy Metastatic Spread, Cancer Repopulation, and Development of Acquired Tumor Cell Resistance.

The concept of post-therapy metastatic spread, cancer repopulation and acquired tumor cell resistance (M-CRAC) rationalizes tumor progression because of tumor cell heterogeneity arising from post-therapy genetic damage and subsequent tissue repair mechanisms. Therapeutic strategies designed to specifically address M-CRAC involve tissue editing approaches, such as low-dose metronomic chemotherapy and the use of transcriptional modulators with or without targeted therapies. Notably, tumor tissue editing holds the potential to treat patients, who are refractory to or relapsing (r/r) after conventional chemotherapy, which is usually based on administering a maximum tolerable dose of a cytostatic drugs. Clinical trials enrolling patients with r/r malignancies, e.g., non-small cell lung cancer, Hodgkin's lymphoma, Langerhans cell histiocytosis and acute myelocytic leukemia, indicate that tissue editing approaches could yield tangible clinical benefit. In contrast to conventional chemotherapy or state-of-the-art precision medicine, tissue editing employs a multi-pronged approach targeting important drivers of M-CRAC across various tumor entities, thereby, simultaneously engaging tumor cell differentiation, immunomodulation, and inflammation control. In this review, we highlight the M-CRAC concept as a major factor in resistance to conventional cancer therapies and discusses tissue editing as a potential treatment.

Photothermal Prussian blue nanoparticles generate potent multi-targeted tumor-specific T cells as an adoptive cell therapy.

Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) is an effective tumor treatment capable of eliciting an antitumor immune response. Motivated by the ability of PBNP-PTT to potentiate endogenous immune responses, we recently demonstrated that PBNP-PTT could be used ex vivo to generate tumor-specific T cells against glioblastoma (GBM) cell lines as an adoptive T cell therapy (ATCT). In this study, we further developed this promising T cell development platform. First, we assessed the phenotype and function of T cells generated using PBNP-PTT. We observed that PBNP-PTT facilitated CD8+ T cell expansion from healthy donor PBMCs that secreted IFNγ and TNFα and upregulated CD107a in response to engagement with target U87 cells, suggesting specific antitumor T cell activation and degranulation. Further, CD8+ effector and effector memory T cell populations significantly expanded after co-culture with U87 cells, consistent with tumor-specific effector responses. In orthotopically implanted U87 GBM tumors in vivo, PBNP-PTT-derived T cells effectively reduced U87 tumor growth and generated long-term survival in >80% of tumor-bearing mice by Day 100, compared to 0% of mice treated with PBS, non-specific T cells, or T cells expanded from lysed U87 cells, demonstrating an enhanced antitumor efficacy of this ATCT platform. Finally, we tested the generalizability of our approach by generating T cells targeting medulloblastoma (D556), breast cancer (MDA-MB-231), neuroblastoma (SH-SY5Y), and acute monocytic leukemia (THP-1) cell lines. The resulting T cells secreted IFNγ and exerted increased tumor-specific cytolytic function relative to controls, demonstrating the versatility of PBNP-PTT in generating tumor-specific T cells for ATCT.

Evaluating the cost-effectiveness of [18F]FDG-PET/CT for investigation of persistent or recurrent neutropenic fever in high-risk haematology patients

BackgroundA recent randomised trial demonstrated [18F]fluorodeoxyglucose positron-emission tomography in combination with low-dose CT (FDG-PET/CT), compared to standard of care computed tomography (CT) imaging, positively impacted antimicrobial management and outcomes of acute leukaemia and haematopoietic stem cell transplant recipients with persistent and recurrent neutropenic fever. We conducted an economic evaluation from a healthcare perspective alongside the clinical trial.MethodsUnit costs in Australian dollars were applied to all resources used (antimicrobials, diagnostic tests, ICU and hospital bed days). Effectiveness was measured as number of patients with antimicrobial rationalisation, 6-month mortality and quality-adjusted life years (QALYs) derived from patient-reported trial-based health-related quality-of-life. Generalised linear models were used to analyse costs and outcomes. Incremental cost-effectiveness ratios (ICERs) for all outcomes and net monetary benefit (NMB) for QALYs were calculated. We performed bootstrapping with 1000 replications using the recycled predictions method.ResultsThe adjusted healthcare costs were lower for FDG-PET/CT (mean $49,563; 95%CI 36,867, 65,133) compared to CT (mean $57,574; 95% CI 44,837, 73,347). The difference in QALYs between the two groups was small (0.001; 95% CI -0.001, 0.004). When simulated 1000 times, FDG-PET/CT was the dominant strategy as it was cheaper with better outcomes than the standard CT group in 74% of simulations. The estimated NMBs at willingness-to-pay thresholds of $50,000 and $100,000 per QALY were positive, thus FDG-PET/CT remained cost-effective at these thresholds.ConclusionsFDG-PET/CT is cost effective when compared to CT for investigation of persistent/recurrent neutropenic fever in high-risk patients, providing further support for incorporation of FDG-PET/CT into clinical guidelines and funding.Trial registrationThis trial is registered with ClinicalTrials.gov, NCT03429387.

Exploring Thiazolopyridine AV25R: Unraveling of Biological Activities, Selective Anti-Cancer Properties and In Silico Target and Binding Prediction in Hematological Neoplasms.

Thiazolopyridines are a highly relevant class of small molecules, which have previously shown a wide range of biological activities. Besides their anti-tubercular, anti-microbial and anti-viral activities, they also show anti-cancerogenic properties, and play a role as inhibitors of cancer-related proteins. Herein, the biological effects of the thiazolopyridine AV25R, a novel small molecule with unknown biological effects, were characterized. Screening of a set of lymphoma (SUP-T1, SU-DHL-4) and B- acute leukemia cell lines (RS4;11, SEM) revealed highly selective effects of AV25R. The selective anti-proliferative and metabolism-modulating effects were observed in vitro for the B-ALL cell line RS4;11. Further, we were able to detect severe morphological changes and the induction of apoptosis. Gene expression analysis identified a large number of differentially expressed genes after AV25R exposure and significant differentially regulated cancer-related signaling pathways, such as VEGFA-VEGFR2 signaling and the EGF/EGFR pathway. Structure-based pharmacophore screening approaches using in silico modeling identified potential biological AV25R targets. Our results indicate that AV25R binds with several proteins known to regulate cell proliferation and tumor progression, such as FECH, MAP11, EGFR, TGFBR1 and MDM2. The molecular docking analyses indicates that AV25R has a higher binding affinity compared to many of the experimentally validated small molecule inhibitors of these targets. Thus, here we present in vitro and in silico analyses which characterize, for the first time, the molecular acting mechanism of AV25R, including cellular and molecular biologic effects. Additionally, this predicted the target binding of the molecule, revealing a high affinity to cancer-related proteins and, thus, classified AVR25 for targeted intervention approaches.

Rational engineering and insight for a L-glutaminase activity reduced type II L-asparaginase from Bacillus licheniformis and its antileukemic activity in vitro

Type II L-asparaginase (ASNase) has been approved by the FDA for treating acute lymphoid leukemia (ALL), but its therapeutic effect is limited by low catalytic efficiency and L-glutaminase (L-Gln) activity. This study utilized free energy based molecular dynamics calculations to identify residues associated with substrate binding in Bacillus licheniformis L-asparaginase II (BLASNase) with high catalytical activity. After saturation and combination mutagenesis, the mutant LGT (74 L/75G/111 T) with intensively reduced l-glutamine catalytic activity was generated. The l-glutamine/L-asparagine activity (L-Gln/L-Asn) of LGT was only 6.6 % of parent BLASNase, whereas the L-asparagine (L-Asn) activity was preserved >90 %. Furthermore, structural comparison and molecular dynamics calculations indicated that the mutant LGT had reduced binding ability and affinity towards l-glutamine. To evaluate its effect on acute leukemic cells, LGT was supplied in treating MOLT-4 cells. The experimental results demonstrated that LGT was more cytotoxic and promoted apoptosis compared with commercial Escherichia coli ASNase. Overall, our findings firstly provide insights into reducing l-glutamine activity without impacting L-asparagine activity for BLASNase to possess remarkable potential for anti-leukemia therapy.

Interleukin-8 Rs4073 Genotypes as Prognostic Predictors for Childhood Acute Lymphocytic Leukemia.

Interleukin 8 (IL-8) is highly expressed in refractory acute lymphocytic leukemia (ALL) cells. This study aimed to investigate the contribution of IL-8 polymorphisms to the risk of childhood ALL. The genotypes of IL-8 rs4073, rs2227306, rs2227543, and rs1126647 were determined in 266 childhood ALL cases and 266 controls using the PCR-RFLP method. Additionally, we assessed whether the interactions of these genotypes with age and sex contributed to childhood ALL risk. The distributions of genotypic and allelic frequencies of IL-8 rs4073, rs2227306, rs2227543, and rs1126647 were not significantly different between childhood ALL cases and controls (all p>0.05). However, carriers of the variant AA genotype at IL-8 rs4073 had a significantly higher risk of childhood ALL among those aged ≤3.5 years and among girls (OR=2.39 and 3.32, 95%CI=1.21-4.73 and 1.51-7.30, p=0.0182 and 0.0042, respectively). In the stratification analysis, IL-8 rs4073 AT and AA genotypes were associated with higher childhood ALL risk classification and shorter survival time (OR=2.21 and 4.13, 95%CI=1.29-3.78 and 1.87-9.10, p=0.0054 and 0.0002, respectively). There was no positive association for rs2227306, rs2227543, or rs1126647 (all p>0.05). The A allele of IL-8 rs4073 can serve as a diagnostic predictor for childhood ALL, but only in girls and patients younger than or equal to 3.5 years old. More importantly, it can serve as a prognostic marker for high-risk classification and shorter survival time. Further validation studies can help extend the use of this prognostic predictor in clinical practice.

CHD4 Promotes Tumor Formation, Survival, and Resistance to Genotoxic Therapeutics in TP53 Mutant T-Cell Acute Lymphoblastic Leukemia Cells through the NuRD Chromatin Remodeling Complex

T-Cell acute leukemia(T-ALL) though generally responsive to current chemotherapy remains incurable in over 50% of adult patients. Importantly, the survival for patients with TP53 mutant T-ALL disease is less than 10%. We have previously shown the role of the Methyl Binding Domain protein 2-Nucleosome Remodeling and Deacetylase (MBD2-NURD) chromatin remodeling complex in triple negative breast cancer cell growth and the role of the NuRD component, Chromatin-helicase-binding protein 4(CHD4), in tumor colony formation and genotoxic resistance in acute myeloid leukemia. In the present study, we have examined the role of specific NuRD complexes and CHD4 in T-cell acute leukemia cells with mutant TP53. The prototypical NuRD complex possesses both a histone deacetylase (HDCC) sub-complex and an ATPase chromatin remodeling sub-complex containing CHD4 linked to MBD2 or MBD3 of the HDCC. CHD4 is linked to the MBD2/3 anchors of the NuRD complex, via GATAD2A or GATAD2B. Depletion of CHD4 was found to increase the rate of apoptosis in several TP53 mutant T-ALL cell lines including Jurkat, MOLT4, RPMI and CCRF by up to 5 to 10-fold. Likewise, depletion of both MBD2 and MBD3 also increased apoptosis and sensitization to the standard genotoxic chemotherapeutic agent, cytosine arabinoside (Ara-C) but had only minimal effects in normal human CD34+ hematopoietic progenitor cells. Depletion of GATAD2B and GATAD2A by shRNA also resulted in a significantly increased survival of 60 days compared to 20 days in Scramble shRNA controls, in a xenogeneic mouse model of T-ALL. Depletion of CHD4 resulted in a profound (10 to 100-fold) decrease in colony formation of the TP53 mutant T-ALL cell lines in methylcellulose. RNA seq analyses identified the apoptosis, ferroptosis and mitophagy pathways as potential mechanisms for the striking effect of NURD disruption on colony formation. In summary, CHD4, through the NuRD complex, promotes tumor cell formation, survival and therapeutic resistance of TP53 mutant T-ALL cells. Current efforts are aimed at validating these findings in primary T-ALL cells and structure-function studies to advance development of tool compounds for disrupting the NuRD complex, with the long-term goal of developing improved small molecule therapeutics for treatment resistant acute leukemia.

Preclinical Characterization of the Anti-Leukemia Activity of the CD33/CD16/NKG2D Immune Modulating TriNKET ® BMS-986357 (CC-96191)

CD33 is widely expressed by myeloid cells and is a validated drug target in acute myeloid leukemia (AML), as shown by the benefit of some patients from the CD33 antibody-drug conjugate gemtuzumab ozogamicin (GO). However, GO is often ineffective and toxic, prompting interest in more potent CD33-directed therapies. Success of T cell-engaging bispecific antibodies in lymphoid malignancies has raised enthusiasm for similar agents targeting CD33, but toxicities from activated T cells cause significant challenges for their use and provide a strong rationale to explore drugs engaging natural killer (NK) cells. Here, we investigated BMS-986357, a TriNKET ® that activates NK cells via CD16 and NKG2D receptors while targeting CD33. This format was chosen because simultaneous engagement of multiple activating NK cell receptors yields greater cytotoxic activity against neoplastic cells than engagement via a single activating receptor. Surface plasmon resonance analyses showed BMS-986357 simultaneously binds CD33, NKG2D, and CD16a, and co-engagement of NKG2D and CD16a increases the avidity. In the presence of primary human NK cells from healthy donors or a human NK cell line, the TriNKET ® demonstrated broad cytolytic anti-leukemia activity in a strictly CD33-dependent manner using a panel of CD33-expressing or CD33-deficient/deleted acute leukemia cells. Consistent with this, removing the CD33 binding domain rendered BMS-986357 ineffective against CD33+ AML cells. Drug-induced cytotoxicity was greater with BMS-986357 than with monoclonal CD33 antibodies, including lintuzumab and an afucosylated antibody with enhanced NK function, demonstrating the benefit of the TriNKET ® format. Compared to BMS-986357, substantially less cytotoxicity was observed with an Fc-mutant variant of BMS-986357 that abrogates binding to CD16a or an NKG2D dead-arm TriNKET ®, and cytolytic effects were reduced with a CD16-deficient NK cell line vs. a CD16-expressing subline, indicating maximal efficacy of BMS-986357 required co-engagement of CD16a and NKG2D. Using sublines of OCI-AML3 and KG-1 cells (both cell lines with low endogenous CD33 expression) to overexpress wild-type CD33 at increasing levels, we found low abundance of CD33 curtailed BMS-986357-induced cytotoxicity. Flow cytometric binding studies identified BMS-986357 to recognize the membrane-distal V-set domain of CD33. Unlike GO, BMS-986357-mediated cytolysis was not affected by over-expression of ABC transporter proteins by AML cells. The potency but not maximal activity of BMS-986357 was reduced by super-physiologic concentrations of soluble CD33; in contrast, the soluble form of the NKG2D ligand MICA did not impact TriNKET ® activity. In the presence of CD33+ AML cells, BMS-986357 activated NK cells but not T cells from healthy donor peripheral blood mononuclear cells and produced similar levels of maximum cytolysis as a CD33/CD3 bispecific antibody. Despite this, BMS-986357 elicited 10 to >100-fold lower soluble cytokine levels including IFN-γ, TNF, IL-6, and GM-CSF than a CD33/CD3 bispecific antibody, suggesting BMS-986357 has the potential for CD33/CD3 bispecific-like efficacy without the associated risk of cytokine release syndrome. Finally, in bone marrow specimens from patients with AML, BMS-986357 killed AML cells but not normal monocytes, suggesting selectivity of drug-induced cytotoxicity toward neoplastic cells, consistent with the notion NK cells are capable to differentiate between healthy and leukemic CD33+ cells. This selectivity suggests BMS-986357 may produce less myelosuppressive toxicity than what has been observed with CD33 targeting antibody-drug conjugates. In summary, our findings demonstrate that BMS-986357 TriNKET ® has potent CD33-dependent cytolytic activity in vitro against human AML cells, supporting the drug's exploration in early phase clinical trials. One such trial (NCT04789655) has opened accrual for adults with relapsed/refractory AML.

Consecutive Inpatient Hematology Consultation Service Utilization across 11 Years in the Medical Intensive Care Unit

INTRODUCTION The current understanding of hematology consultation service utilization is limited to four studies in the outpatient setting and zero in the inpatient setting. While training programs in non-hematology specialties (i.e., cardiology, infectious diseases, nephrology) invest in dual-trained specialty-intensivists, investments into dual-trained hematologist-intensivists are systematically underdeveloped. Despite the high clinical volume of hematology patients admitted to the Medical Intensive Care Unit (MICU), there is currently no characterization of hematology MICU service needs. We sought to begin to fill this gap by examining the volume of consecutive consultations, time to consultation, consult patient characteristics, type, and number of consult question per patient and consult categories originating in the MICU at the largest hospital in the United States (2023 Becker's Hospital Review). METHODS We conducted a retrospective observational study of consecutive patients 18 years of age or older who had an incident (i.e., de novo) hematology consultation while admitted to the MICU from February 2013 through March 2023 at a single academic center. Inclusion criteria included (1) age of ≥ 18, and (2) initial consultation generated during MICU admission. To ensure only incident hematology consultations originating in the MICU were examined, patients with consultation placed on the medical floor with subsequent transfer to the MICU, and re-consultations in the MICU for the same patient, were excluded. Each consult note was manually reviewed to determine the exact consultation query. Descriptive statistics collected for each patient included (1) baseline demographics, (2) labs from day of consultation, (3) time to consultation, (4) binary hospital discharge status (alive or dead), and (5) number and type of consult queries within each consult. For the latter, number of queries per each consult were also recorded (i.e., anemia and thrombocytopenia would be two independent queries), and each query was further adjudicated as pertaining to either classical or malignant hematology. Descriptive statistics were tabulated using Microsoft Excel and GraphPad 9.4.1. RESULTS Across 11 years of consecutive, incident consultations requested from the MICU, there were a total of 594 hematology consults with 776 total consultation queries. At time of consultation request, the median age of patients was 60 years, 47% were of female sex, and mean time to hematology consultation was 30 hours after initial MICU admission (Table 1). Of the queries, 75% pertained to classical and 25% to malignant hematology. Of the 776 consult queries, the top three overall hematology consultation queries were for thrombocytopenia (n=105), coagulopathy (n = 86), and lymphoproliferative disorders (n=77). The top three classical hematology queries were for thrombocytopenia (n=105), coagulopathy (n=86), and thrombosis (n = 76). The top three malignant hematology queries were for lymphoproliferative disorders (n=77), acute leukemia (n=48), and plasma cell dyscrasias (n=25) (Table 1). CONCLUSIONS To our knowledge, our study is the first to describe the volume of incident inpatient hematology consultations originating from the MICU. We found that classical hematology queries constitute three quarters of consultation volume, yet the existing literature on hematologic critical care focus only on quality improvement metrics for hematologic malignancies in the ICU. The development of quality metrics for classical hematology critical care management and identification of research are needed, particularly in the context of the identified national workforce shortage in classical hematology. Future work to examine intensivists' consultation queries originating from other intensive care units (i.e., surgical, cardiac, and neurological), would allow a data-driven evaluation of the service need for dual-trained hematologist-intensivists in the United States. The volume and complexity of classical hematology consults that arise in the ICU, as demonstrated in this study, in addition to frequent ICU consultations and admission for hematologic malignancies, highlights an area of both research and clinical practice that could support developing dual trained hematologist-intensivist to help protocolize and deliver safe and expedient care for all consult queries.

Preliminary Safety, Pharmacological and Efficacy Data from Patients with Relapsed or Refractory B-Cell Malignancies Treated with the ICP-248, a Next Generation BCL2 Inhibitor

Background: BCL2, a key protein regulator of the apoptotic pathway, is constitutively expressed in various malignancies, which is a hallmark of cancer cell. BCL2 inhibitors have been shown to be safe and effective and are approved for the treatment of patients with chronic lymphocytic leukemia/small cell lymphoma (CLL/SLL) or acute myeloid leukemia (AML). Venetoclax, the first and only approved BCL2 inhibitor, is associated with gastrointestinal toxicities and tumor lysis syndrome (TLS). Therefore, ICP-248 was developed as a potent and highly selective inhibitor of BCL2 and has shown antitumor activity superior to venetoclax in preclinical studies. Preclinical studies of ICP-248 have demonstrated favorable pharmacokinetics profile, broad safety window and excellent safety profile, as well as synergistic effect in anti-tumor activity in combination with Orelabrutinib, a novel and highly selective BTK inhibitor. Methods: ICP-CL-1201 is a phase I study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of ICP-248 in patients with relapsed or refractory B-cell malignancies ( ClinicalTrials.gov ID: NCT05728658). The study will be conducted in 2 parts. Part 1 will evaluate ICP-248 as monotherapy at the target dose of 100mg, 200mg, 300mg, 400mg, 500mg and 600mg (once daily and 28 days per cycle) and will explore different ramp-up dosing strategies. Part 2 will evaluate ICP-248 in selected and proposed indications. The dose escalation in Part 1 will follow the 3+3 design with dose-limiting toxicity (DLT) observation window with 49 days. Eligible patients include those with CLL/SLL and B-cell non-Hodgkin lymphomas (NHLs) who failed on available therapy. Key exclusion criteria include CNS involvement, prior exposure to BCL2 inhibitors and clinically significant cardiovascular disease. Adverse events (AEs) are reported per common terminology criteria for AEs (CTCAE) v5.0. Efficacy was evaluated according to the Lugano 2014 or International Workshop on Chronic Lymphocytic Leukemia (iwCLL) 2018 criteria. Minimal residual disease was evaluated with flow or next generation sequencing. Results: As of 30 th July, 2023 (data cutoff date) 3 patents (mantle cell lymphoma [MCL], SLL and CLL) had been enrolled at the dose level of 100 mg QD; age ranging from 53 to 68; follow-up ranging from 1.9 to 4.7 months); median of prior regimen numbers was 3 (range, 1-3; 2 out 3 patients failed on zanubrutinib or pirtobrutinib). ICP-248 demonstrated a favorable PK profile, approximate dose proportionality was observed across the ramp-up stage. No DLTs and SAEs were observed. All the AEs were grade 1 to 2 (mainly neutropenia) without dose interruption and modifications. No TLS including laboratory TLS was observed. Two patients with MCL and SLL were assessed as complete response (CR) at the end of cycle 2, and the CLL patient was assessed as stable disease without sign and symptom of disease and recovering hematology. Undetectable MRD was confirmed in the patient with SLL and MCL. Conclusions: Preliminary results suggest that ICP-248 is safe and well tolerated in relapsed or refractory B-cell malignancies. The favorable clinical pharmacological and safety profiles support current dose ramp up strategy. Preliminary efficacy data demonstrated good response with deep remission. Further assessment of safety and efficacy with additional dose levels and dosing strategies will be pursued in expanded patient population and in the combination with orelabrutinib.