Involvement Value of FLT-3, c-Myc, STAT3, p27, and HOTAIR Gene Expression in Acute Myeloid Leukemia Patients: A Molecular Perspective to a Novel Leukemogenesis Mechanism

Background: The identification of long non-coding RNAs (lncRNAs) in the pathogenesis of acute myeloid leukemia (AML) has marked a new era in the molecular understating of the disease. This study investigated the correlation between the changes in the expression of lncRNAs, including HOTAIR, PVT-1, and CRNDE, and the alteration in the expression profile of FLT-3, c-Myc, STAT3, STAT5, and p27 in AML patients. Materials and Methods: Blood samples were collected from forty-one newly diagnosed AML patients and ten healthy individuals to evaluate the expression levels of the study genes using qRT-PCR analysis. The probable correlation between the gene expressions was determined using Pearson's correlation test. Results: The results showed that while there was a significant elevation in the expression of FLT3, c-Myc, STAT3, and HOTAIR, p27 expression remarkably diminished in AML patients compared to the control group. Also, a correlation was found between the expression of FLT-3 and p27 and the expression of HOTAIR and STAT3. It was assumed that FLT-3 had a role in increasing the proliferative and survival capacity of AML cells, at least partly, through c-Myc-mediated suppression of p27. Moreover, lncRNA HOTAIR showed to be involved in leukemia proliferation assumably by enhancing the expression of STAT3. Conclusion: Overall, the results of gene profile analysis suggested that studying the expression of HOTAIR, FLT-3, c-Myc, STAT3, and p27 could be helpful to AML patients, and each of these genes could be a valuable target for pharmaceutic intervention.

PCW-A1001, AI-assisted de novo design approach to design a selective inhibitor for FLT-3(D835Y) in acute myeloid leukemia

Treating acute myeloid leukemia (AML) by targeting FMS-like tyrosine kinase 3 (FLT-3) is considered an effective treatment strategy. By using AI-assisted hit optimization, we discovered a novel and highly selective compound with desired drug-like properties with which to target the FLT-3 (D835Y) mutant. In the current study, we applied an AI-assisted de novo design approach to identify a novel inhibitor of FLT-3 (D835Y). A recurrent neural network containing long short-term memory cells (LSTM) was implemented to generate potential candidates related to our in-house hit compound (PCW-1001). Approximately 10,416 hits were generated from 20 epochs, and the generated hits were further filtered using various toxicity and synthetic feasibility filters. Based on the docking and free energy ranking, the top compound was selected for synthesis and screening. Of these three compounds, PCW-A1001 proved to be highly selective for the FLT-3 (D835Y) mutant, with an IC₅₀ of 764 nM, whereas the IC₅₀ of FLT-3 WT was 2.54 μM.

Co-Treatments of Edible Curcumin from Turmeric Rhizomes and Chemotherapeutic Drugs on Cytotoxicity and FLT3 Protein Expression in Leukemic Stem Cells

This study aims to enhance efficacy and reduce toxicity of the combination treatment of a drug and curcumin (Cur) on leukemic stem cell and leukemic cell lines, including KG-1a and KG-1 (FLT3+ LSCs), EoL-1 (FLT3+ LCs), and U937 (FLT3- LCs). The cytotoxicity of co-treatments of doxorubicin (Dox) or idarubicin (Ida) at concentrations of the IC10-IC80 values and each concentration of Cur at the IC20, IC30, IC40, and IC50 values (conditions 1, 2, 3, and 4) was determined by MTT assays. Dox-Cur increased cytotoxicity in leukemic cells. Dox-Cur co-treatment showed additive and synergistic effects in several conditions. The effect of this co-treatment on FLT3 expression in KG-1a, KG-1, and EoL-1 cells was examined by Western blotting. Dox-Cur decreased FLT3 protein levels and total cell numbers in all the cell lines in a dose-dependent manner. In summary, this study exhibits a novel report of Dox-Cur co-treatment in both enhancing cytotoxicity of Dox and inhibiting cell proliferation via FLT3 protein expression in leukemia stem cells and leukemic cells. This is the option of leukemia treatment with reducing side effects of chemotherapeutic drugs to leukemia patients.

Analysis of FLT3-Activating Mutations in Patients With Acute Myelogenous Leukemia in Jordan: Association With FAB Subtypes and Identification of Subgroups With Poor Prognosis

BACKGROUND

FLT3 mutations are common in acute myeloid leukemia (AML), particularly in French-American-British M2 subtype AML and in cytogenetically normal (CN) AML; however, its incidence in Jordan is poorly studied. An FLT3 mutation implies poor prognosis in AML patients. We aimed to assess the incidence and prognostic value of FLT3 mutations in AML in Jordan.

PATIENTS AND METHODS

One hundred thirty-two newly diagnosed unselected AML patients were included. Patient data were collected, including demographics as well as morphologic, cytogenetic, and molecular testing results. FLT3 mutations were detected by real-time reverse transcriptase PCR, next-generation sequencing, or both. Survival analysis and comparisons of incidence, remission rate, relapse, and survival outcomes between FLT3-mutated and wild-type groups were done and prognostic factors identified.

RESULTS

FLT3 mutation was detected in 40% of AML patients. The highest incidence was associated with M2 subtype AML (47%) and CN-AML (50%). There was a significant negative association between FLT3 mutations and overall survival (OS), as well as a trend toward improved relapse-free survival, with 3-year OS being 19.17% vs 34.16% (P < .0001) and 33.6% vs 71.0% (P = .085), respectively. Patients with FLT3 mutation had a significantly better complete remission rate after induction (67.9% vs 63.3%, P = .001). Also, OS improved in patients with complete remission (P = .0015) and who then continued to allogeneic hematopoietic cell transplantation compared to FLT3 wild-type patients (P < .001).

CONCLUSION

FLT3 mutation is common in Jordanian AML patients, with the highest incidence occurring in patients with M2 or CN disease. It implies a poor prognosis, with poor OS and relapse-free survival, which may be abrogated by early allogeneic transplantation and/or peritransplantation provision of FLT3 inhibitors.

Reduced Mitochondrial Apoptotic Priming Drives Resistance to BH3 Mimetics in Acute Myeloid Leukemia

Acquired resistance to BH3 mimetic antagonists of BCL-2 and MCL-1 is an important clinical problem. Using acute myelogenous leukemia (AML) patient-derived xenograft (PDX) models of acquired resistance to BCL-2 (venetoclax) and MCL-1 (S63845) antagonists, we identify common principles of resistance and persistent vulnerabilities to overcome resistance. BH3 mimetic resistance is characterized by decreased mitochondrial apoptotic priming as measured by BH3 profiling, both in PDX models and human clinical samples, due to alterations in BCL-2 family proteins that vary among cases, but not to acquired mutations in leukemia genes. BCL-2 inhibition drives sequestered pro-apoptotic proteins to MCL-1 and vice versa, explaining why in vivo combinations of BCL-2 and MCL-1 antagonists are more effective when concurrent rather than sequential. Finally, drug-induced mitochondrial priming measured by dynamic BH3 profiling (DBP) identifies drugs that are persistently active in BH3 mimetic-resistant myeloblasts, including FLT-3 inhibitors and SMAC mimetics.

Midostaurin and cyclosporine drug interaction: A case report

WHAT IS KNOWN AND OBJECTIVE

Allogeneic stem cell transplantation patients are often on immunosuppression including calcineurin inhibitors post-transplant for prevention of graft-versus-host disease. Recent data suggested that addition of midostaurin, a FLT-3 mutant kinase inhibitor, maintenance can reduce risk of relapse by 46% at 18 months post-transplant.

CASE DESCRIPTION

Patient is a post-allogenetic stem cell transplant patient started on midostaurin for maintenance therapy. Patient had stable serum levels of cyclosporine with a sudden 70% increase in serum level shortly after starting midostaurin. Patient had no other medication changes or laboratory abnormalities that would suggest the change was caused by alternate factors.

WHAT IS NEW AND CONCLUSION

This data suggest that midostaurin and cyclosporine have a possible previously unidentified drug interaction leading to elevation immunosuppression serum levels that need to be accounted for in practice.

Allogeneic transplantation outcomes amongst a contemporary cohort of high-risk myelodysplastic syndrome and acute myeloid leukemia patients aged ≥70 years

Allogeneic hematopoietic stem cell transplantation (HSCT) is an integral therapy for patients with hematological malignancies, myelodysplasia, and bone marrow failure. Its use has been increasing over the past decade, as understanding of the treatment and its related toxicities has led to changes in patient selection, conditioning regimens, and post-transplant care. Older (age ≥65 years) patients are often considered unfit for transplantation; however, more recent data suggest that older patients, when selected appropriately, tolerate transplantation well. We report our institutional experience with HSCT in patients aged ≥70 years. A cohort of 22 patients underwent HSCT. Median overall survival was 5.16 years [95% confidence interval (CI): 1.5-8.7 years], and median post-transplant survival was 2.2 years (myelodysplastic syndrome: median 1.3 years, 95% CI: 4.7 months-2.2 years; acute myeloid leukemia: median not reached). Thirty-day mortality following HSCT was 9.5% (n = 2). These data provide further support for the use of HSCT in selected older patients, and highlight the impact of HSCT on overall survival among a patient cohort primarily of acute myeloid leukemia and myelodysplasia.

Relative receptor tyrosine kinases and anti-apoptotic transcripts hold potential for predicting inferior outcome in adult acute myeloid leukemia: a prospective pilot study

INTRODUCTION

Acute myeloid leukemia is characterized by accumulation of immature cells because of imbalance between proliferation and apoptosis. In AML, simultaneous expression of proliferative (FLT-3, c-KIT) and antiapoptotic genes (BCL-2), are unknown.

PATIENTS AND METHODS

We prospectively assessed proliferative and antiapoptotic gene transcripts using Taqman probe chemistry in 48 adult AML patients. A stepwise Cox regression model was applied for independent prognostic factors.

RESULTS

Thirty-two of 48 (75%) patients achieved complete remission. At follow-up ranging from 0.5 to 57.3 months, event-free survival (EFS) was 26.9 ± 6.3% (range, 15.5%-39.6%) and OS 34.5 ± 7.46% (range, 20.5%-48.9%). High white blood cell count correlated with an inferior complete remission rate (P = .021). Cytogenetics and FLT-3 internal tandem duplication did not predict EFS or OS. The transcripts of FLT-3, c-KIT, and BCL-2 showed a significant linear association with each other in Pearson correlation (FLT-3 vs. c-KIT: R = 0.8234; P < .001; c-KIT vs. BCL-2: R = 0.3377; P = .01; FLT-3 vs. BCL-2: R = 0.3815; P = .007). In a validation cohort (Microarray Data Set GSE1159) of adult AML patients, the global gene expression profile depicted a similar interrelationship. Patients with a greater platelet count were associated with increased transcript levels of BCL-2 (P = .034). In univariate analysis, a high transcript level of FLT-3 and high transcript ratio of FLT-3/BCL-2 and FLT-3 and c-KIT/BCL-2 significantly predicted OS (P = .043, .028, and .028, respectively). In a stepwise Cox regression model, high FLT-3 and c-KIT/BCL-2 ratio predicted OS (HR, 2.29).

CONCLUSION

To our knowledge, this is the first study that evaluated proliferative and antiapoptotic transcripts simultaneously, and results have shown that it is the relative levels of these transcripts that determine outcome in AML patients rather than their expression in isolation.

Novel acylureidoindolin-2-one derivatives as dual Aurora B/FLT3 inhibitors for the treatment of acute myeloid leukemia

A series of 6-acylureido derivatives containing a 3-(pyrrol-2-ylmethylidene)indolin-2-one scaffold were synthesized as potential dual Aurora B/FLT3 inhibitors by replacing the 6-arylureido moiety in 6-arylureidoindolin-2-one-based multi-kinase inhibitors. (Z)-N-(2-(pyrrolidin-1-yl)ethyl)-5-((6-(3-(2-fluoro-4-methoxybenzoyl)ureido)-2-oxoindolin-3-ylidene)methyl)-2,4-dimethyl-1H-pyrrole-3-carboxamide (54) was identified as a dual Aurora B/FLT3 inhibitor (IC50 = 0.4 nM and 0.5 nM, respectively). Compound 54 also exhibited potent cytotoxicity with single-digit nanomolar IC50 values against the FLT3 mutant-associated human acute myeloid leukemia (AML) cell lines MV4-11 (FLT3-ITD) and MOLM-13 (FLT3-ITD). Compound 54 also specifically induced extrinsic apoptosis by inhibiting the phosphorylation of the Aurora B and FLT3 pathways in MOLM-13 cells. Compound 54 had a moderate pharmacokinetic profile. The mesylate salt of 54 efficiently inhibited tumor growth and reduced the mortality of BALB/c nude mice (subcutaneous xenograft model) that had been implanted with AML MOLM-13 cells. Compound 54 is more potent than sunitinib not only against FLT3-WT AML cells but also active against sunitinib-resistant FLT3-ITD AML cells. This study demonstrates the significance of dual Aurora B/FLT3 inhibitors for the development of potential agents to treat AML.

Protective role of functionalized single walled carbon nanotubes enhance ex vivo expansion of hematopoietic stem and progenitor cells in human umbilical cord blood

In this study, carboxylic acid functionalized single walled carbon nanotubes (f-SWCNT-COOH) was shown to support the viability and ex vivo expansion of freeze-thawed, non-enriched hematopoietic stem and progenitor cells (HSPC) in human umbilical cord blood-mononucleated cells (UCB-MNC). Our in vitro experiments showed that f-SWCNT-COOH increased the viability of the CD45(+) cells even without cytokine stimulation. It also reduced mitochondrial superoxides and caspase activity in CD45(+) cells. f-SWCNT-COOH drastically reduced the proportions of CD45(-) cells in the non-enriched UCB-MNC. Phenotypic expression analysis and functional colony forming units (CFU) showed significant ex vivo expansion of HSPC, particularly of CD45(+)CD34(+)CD38(-) population and granulocyte-macrophage (GM) colonies, in f-SWCNT-COOH augmented cultures supplemented with basal cytokines. In vivo data suggested that f-SWCNT-COOH expanded UCB-MNC could repopulate immunodeficient mice models with minimal acute or sub-acute symptoms of graft-versus-host disease (GVHD) and f-SWCNT-COOH dependent toxicity.

FROM THE CLINICAL EDITOR

In this paper a novel method is presented by using single wall functionalized carbon nanotubes to enhance viability and ex vivo expansion of freeze-thawed, non-enriched hematopoietic stem and progenitor cells in human umbilical cord blood -mononucleated cells. Detailed data is presented about enhanced viability, including improved repopulation of immunodeficient mice models with minimal acute or sub-acute symptoms of graft-versus-host disease.