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Cancer Science Jun 2024Our study highlights the discovery of recurrent copy number alterations in noncoding regions, specifically blood enhancer cluster (BENC-CNA), in B-precursor acute...
Our study highlights the discovery of recurrent copy number alterations in noncoding regions, specifically blood enhancer cluster (BENC-CNA), in B-precursor acute lymphoblastic leukemia (BCP-ALL) cell lines. We demonstrate that BENC-CNA acts as a super-enhancer, driving MYC expression and possibly contributing to the immortalization and proliferative advantage of BCP-ALL cells in vitro.
PubMed: 38923173
DOI: 10.1111/cas.16260 -
Molecular Oncology Jun 2024Persistence of quiescent leukemia stem cells (LSCs) after treatment most likely contributes to chemotherapy resistance and poor prognosis of leukemia patients....
Persistence of quiescent leukemia stem cells (LSCs) after treatment most likely contributes to chemotherapy resistance and poor prognosis of leukemia patients. Identification of this quiescent cell population would facilitate eradicating LSCs. Here, using a cell-tracing PKH26 (PKH) dye that can be equally distributed to daughter cells following cell division in vivo, we identify a label-retaining slow-cycling leukemia cell population from AML1-ETO9a (AE9a) leukemic mice. We find that, compared with cells not maintaining PKH-staining, a higher proportion of PKH-retaining cells are in G0 phase, and PKH-retaining cells exhibit increased colony formation ability and leukemia initiation potential. In addition, PKH-retaining cells possess high chemo-resistance and are more likely to be localized to the endosteal bone marrow region. Based on the transcriptional signature, HLA class II histocompatibility antigen gamma chain (Cd74) is highly expressed in PKH-retaining leukemia cells. Furthermore, cell surface CD74 was identified to be highly expressed in LSCs of AE9a mice and CD34 human leukemia cells. Compared to LinCD74 leukemia cells, LinCD74 leukemia cells of AE9a mice exhibit higher stemness properties. Collectively, our findings reveal that the identified slow-cycling leukemia cell population represents an LSC population, and CD74 leukemia cells possess stemness properties, suggesting that CD74 is a candidate LSC surface marker.
PubMed: 38922758
DOI: 10.1002/1878-0261.13690 -
Pediatric Reports May 2024Leukocytosis in neonates can occur because of infectious, inflammatory, malignant, or physiological processes. Hyperleukocytosis is defined as a total leukocyte count...
Leukocytosis in neonates can occur because of infectious, inflammatory, malignant, or physiological processes. Hyperleukocytosis is defined as a total leukocyte count (TLC) exceeding 100,000 per mm, warranting immediate evaluation. Neonates with hyperleukocytosis are at risk of leukostasis and the associated severe complications, including respiratory distress, myocardial ischemia, hyperuricemia, acute renal failure, infarction, and hemorrhage. Differentiating leukemia and leukemoid reactions in neonates presenting with elevated TLC is challenging but critical. We present a unique case of a preterm male neonate with hyperleukocytosis, initially suspected to have an underlying malignancy. The neonate's clinical course was complicated by respiratory distress syndrome and anemia of prematurity, necessitating neonatal intensive care unit management. Further investigation revealed high human herpesvirus 6 (HHV-6) DNA levels in the whole blood, leading to a chromosomally integrated HHV-6 (ciHHV-6) diagnosis. CiHHV-6 is characterized by HHV-6 DNA integration into the host genome. Accurate diagnosis relies on whole-blood quantitative PCR, distinguishing ciHHV-6 from an active infection. The neonate remained asymptomatic, and antiviral treatment was deemed unnecessary. This case underscores the importance of recognizing ciHHV-6 as a potential cause of hyperleukocytosis in neonates and highlights the value of whole-blood PCR for differentiation. Understanding the spectrum of HHV-6 infection in neonates is vital for appropriate management and prognostication.
PubMed: 38921702
DOI: 10.3390/pediatric16020037 -
Marine Drugs May 2024Acute myeloid leukemia (AML) is a hematologic malignancy characterized by infiltration of the blood and bone marrow, exhibiting a low remission rate and high recurrence...
Acute myeloid leukemia (AML) is a hematologic malignancy characterized by infiltration of the blood and bone marrow, exhibiting a low remission rate and high recurrence rate. Current research has demonstrated that class I HDAC inhibitors can downregulate anti-apoptotic proteins, leading to apoptosis of AML cells. In the present investigation, we conducted structural modifications of marine cytotoxin Santacruzamate A (SCA), a compound known for its inhibitory activity towards HDACs, resulting in the development of a novel series of potent class I HDACs hydrazide inhibitors. Representative hydrazide-based compound exhibited concentration-dependent induction of apoptosis in AML cells as a single agent. Moreover, exhibited a synergistic anti-AML effect when combined with Venetoclax, a clinical Bcl-2 inhibitor employed in AML therapy. This combination resulted in a more pronounced downregulation of anti-apoptotic proteins Mcl-1 and Bcl-xL, along with a significant upregulation of the pro-apoptotic protein cleaved-caspase3 and the DNA double-strand break biomarker γ-H2AX compared to monotherapy. These results highlighted the potential of as a promising lead compound for AML treatment, particularly when used in combination with Venetoclax.
Topics: Humans; Sulfonamides; Leukemia, Myeloid, Acute; Histone Deacetylase Inhibitors; Drug Synergism; Bridged Bicyclo Compounds, Heterocyclic; Apoptosis; Cell Line, Tumor; Antineoplastic Agents; Histone Deacetylase 1; Histone Deacetylases; Animals; Caspase 3; Myeloid Cell Leukemia Sequence 1 Protein
PubMed: 38921561
DOI: 10.3390/md22060250 -
Hematology Reports Jun 2024Acute promyelocytic leukemia is a rare form of acute myeloid leukemia in which immature promyelocytes abnormally proliferate in the bone marrow. In most cases, the...
Acute promyelocytic leukemia is a rare form of acute myeloid leukemia in which immature promyelocytes abnormally proliferate in the bone marrow. In most cases, the disease is characterised by the translocation t(15;17) (q24;q21), which causes the formation of PML::RARA, an oncogenic fusion protein responsible for blocking myeloid differentiation and survival advantage. Here, we present a case of acute promyelocytic leukemia with two unusual features: basophilic differentiation and a three-way translocation involving chromosomes 12, 15 and 17. In the few cases reported, basophilic differentiation was associated with a poor prognosis. In contrast, our patient responded promptly to the standard treatment with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) and obtained complete remission. To our knowledge, this is the first report of basophilic acute promyelocytic leukemia with the three-way translocation t(12;17;15) (p13; q24;q21).
PubMed: 38921185
DOI: 10.3390/hematolrep16020037 -
Hematology Reports Jun 2024Relapsed B-cell acute lymphoblastic leukemia (B-ALL) remains an unresolved matter of concern regarding adverse outcomes. This case study aimed to evaluate the...
Relapsed B-cell acute lymphoblastic leukemia (B-ALL) remains an unresolved matter of concern regarding adverse outcomes. This case study aimed to evaluate the effectiveness of blinatumomab, with or without door lymphocyte infusion (DLI), in treating measurable residual disease (MRD)-positive B-ALL. All patients who received blinatumomab salvage therapy were included in this study. Eleven patients were included in the study. All patients were evaluated for MRD-negativity. Before starting blinatumomab therapy, seven patients tested positive for MRD, three tested negative, and one had refractory disease. Hematopoietic cell transplantation (HCT) was reserved for five patients with persistent MRD. Six patients became MRD-negative and subsequent HCT was not performed. Only two patients relapsed; one patient died of relapse, and the other one received carfilzomib-based therapy and was MRD-negative thereafter. Nine patients were MRD-negative at a median follow-up of 28 months (15-52 months). Two of three MRD-positive post-transplant patients remained in complete molecular remission after preemptive DLI at the last follow-up date. In the first salvage, blinatumomab may achieve complete remission and bridging to HCT in pediatric patients with end-of-induction MRD-positive B-cell precursor ALL. The decision on how to treat post-transplant relapse continues to affect survival outcomes. Blinatumomab combined with DLI may extend the armamentarium of release options for high-risk pediatric patients. This approach is encouraging for high-risk ALL patients who are MRD-positive post-transplantation.
PubMed: 38921183
DOI: 10.3390/hematolrep16020035 -
Hematology Reports May 2024Viral infections, including those caused by COVID-19, can produce striking morphologic changes in peripheral blood. Distinguishing between reactive changes and abnormal...
Viral infections, including those caused by COVID-19, can produce striking morphologic changes in peripheral blood. Distinguishing between reactive changes and abnormal morphology of monocytes remains particularly difficult, with low consensus rates reported amongst hematopathologists. Here, we report a patient who developed transient monocytosis of 11.06 × 10/L with 32% promonocytes and 1% blasts during hospitalization that was secondary to severe COVID-19 infection. Three days later, the clinical status of the patient improved and the WBC had decreased to 8.47 × 10/L with 2.2 × 10/L monocytes. Flow cytometry studies did not reveal immunophenotypic findings specific for an overt malignant population. At no time during admission did the patient develop cytopenia(s), and she was discharged upon clinical improvement. However, the peripheral blood sample containing promonocytes was sent for molecular testing with an extended next-generation sequencing myeloid panel and was positive for pathogenic Type A and R882H mutations. Subsequently, despite an essentially normal complete blood count, the patient underwent a bone marrow assessment that showed acute myeloid leukemia with 77% promonocytes. This case emphasizes the critical importance of a full work up to exclude acute leukemia when classical promonocyte morphology is encountered in the peripheral blood. Promonocytes are not a part of the reactive changes associated with COVID-19 and remain specific to myeloid neoplasia.
PubMed: 38921181
DOI: 10.3390/hematolrep16020033 -
Cancer Cell International Jun 2024Assessment of measurable residual disease (MRD) is an essential prognostic tool for B-lymphoblastic leukaemia (B-ALL). In this study, we evaluated the utility of...
BACKGROUND
Assessment of measurable residual disease (MRD) is an essential prognostic tool for B-lymphoblastic leukaemia (B-ALL). In this study, we evaluated the utility of next-generation sequencing (NGS)-based MRD assessment in real-world clinical practice.
METHOD
The study included 93 paediatric patients with B-ALL treated at our institution between January 2017 and June 2022. Clonality for IGH or IGK rearrangements was identified in most bone marrow samples (91/93, 97.8%) obtained at diagnosis.
RESULTS
In 421 monitoring samples, concordance was 74.8% between NGS and multiparameter flow cytometry and 70.7% between NGS and reverse transcription-PCR. Elevated quantities of clones of IGH alone (P < 0.001; hazard ratio [HR], 22.2; 95% confidence interval [CI], 7.1-69.1), IGK alone (P = 0.011; HR, 5.8; 95% CI, 1.5-22.5), and IGH or IGK (P < 0.001; HR, 7.2; 95% CI, 2.6-20.0) were associated with an increased risk of relapse. Detection of new clone(s) in NGS was also associated with inferior relapse-free survival (P < 0.001; HR, 18.1; 95% CI, 3.0-108.6). Multivariable analysis confirmed age at diagnosis, BCR::ABL1-like mutation, TCF3::PBX1 mutation, and increased quantity of IGH or IGK clones during monitoring as unfavourable factors.
CONCLUSION
In conclusion, this study highlights the usefulness of NGS-based MRD as a routine assessment tool for prognostication of paediatric patients with B-ALL.
PubMed: 38918782
DOI: 10.1186/s12935-024-03404-3 -
Cancer Cell International Jun 2024Acute myeloid leukemia (AML), a malignancy Often resistant to common chemotherapy regimens (Cytarabine (Ara-c) + Daunorubicin (DNR)), is accompanied by frequent...
BACKGROUND
Acute myeloid leukemia (AML), a malignancy Often resistant to common chemotherapy regimens (Cytarabine (Ara-c) + Daunorubicin (DNR)), is accompanied by frequent relapses. Many factors are involved in causing chemoresistance. Heme Oxygenase-1 (HO-1) and Hypoxia-Inducible Factor 1-alpha (HIF-1α) are two of the most well-known genes, reported to be overexpressed in AML and promote resistance against chemotherapy according to several studies. The main chemotherapy agent used for AML treatment is Ara-c. We hypothesized that simultaneous targeting of HO-1 and HIF-1α could sensitize AML cells to Ara-c.
METHOD
In this study, we used our recently developed, Trans-Activator of Transcription (TAT) - Chitosan-Carboxymethyl Dextran (CCMD) - Poly Ethylene Glycol (PEG) - Nanoparticles (NPs), to deliver Ara-c along with siRNA molecules against the HO-1 and HIF-1α genes to AML primary cells (ex vivo) and cell lines including THP-1, KG-1, and HL-60 (in vitro). Subsequently, the effect of the single or combinational treatment on the growth, proliferation, apoptosis, and Reactive Oxygen Species (ROS) formation was evaluated.
RESULTS
The designed NPs had a high potential in transfecting cells with siRNAs and drug. The results demonstrated that treatment of cells with Ara-c elevated the generation of ROS in the cells while decreasing the proliferation potential. Following the silencing of HO-1, the rate of apoptosis and ROS generation in response to Ara-c increased significantly. While proliferation and growth inhibition were considerably evident in HIF-1α-siRNA-transfected-AML cells compared to cells treated with free Ara-c. We found that the co-inhibition of genes could further sensitize AML cells to Ara-c treatment.
CONCLUSIONS
As far as we are aware, this study is the first to simultaneously inhibit the HO-1 and HIF-1α genes in AML using NPs. It can be concluded that HO-1 causes chemoresistance by protecting cells from ROS damage. Whereas, HIF-1α mostly exerts prolific and direct anti-apoptotic effects. These findings imply that simultaneous inhibition of HO-1 and HIF-1α can overcome Ara-c resistance and help improve the prognosis of AML patients.
PubMed: 38918761
DOI: 10.1186/s12935-024-03393-3 -
Critical Reviews in Oncology/hematology Jun 2024The presence of FLT3 mutations, including the most common FLT3-ITD (internal tandem duplications) and FLT3-TKD (tyrosine kinase domain), is associated with an... (Review)
Review
The presence of FLT3 mutations, including the most common FLT3-ITD (internal tandem duplications) and FLT3-TKD (tyrosine kinase domain), is associated with an unfavorable prognosis in patients affected by Acute Myeloid Leukemia (AML). In this setting, in recent years, new FLT3-inhibitors have demonstrated efficacy in improving survival and treatment response. Nevertheless, the development of primary and secondary mechanisms of resistance poses a significant obstacle to their efficacy. Understanding these mechanisms is crucial for developing novel therapeutic approaches to overcome resistance and improve the outcomes of patients. In this context, the use of novel FLT3 inhibitors and the combination of different targeted therapies have been studied. This review provides an update on the molecular alterations involved in FLT3 AML mechanisms of resistance, exploring how the molecular monitoring may be used to guide treatment strategy in FLT3-mutated AML.
PubMed: 38917943
DOI: 10.1016/j.critrevonc.2024.104424