Acute Myeloid Leukemia: How Do We Measure Success?

SFXN3 is a Prognostic Marker and Promotes the Growth of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with rapid progression and frequent mutations. Sideroflexin3 (SFXN3) has been shown to be involved in various neurodegenerative diseases. However, the role of SFXN3 in AML remains unclear. The level and prognostic value of SFXN3 were assessed in pan-cancer, especially AML, based on the data obtained from the TCGA database. The effect and mechanism of SFXN3 in AML were measured by fluorescence-activated cell sorting (FACS), qRT-PCR, western blotting in vitro and in vivo. The correlation between SFXN3 and the infiltration of immune cells in AML was assessed via cibersort and ssGSEA analyses. SFXN3 is expressed at higher levels in AML, and high SFXN3 level is associated with decreased overall survival rate (OSR) in AML. Next, knockdown of SFXN3 results in enhanced cell apoptosis and dropped cell proliferation. Then, knockdown of SFXN3 caused a reduction in the expression of CyclinD1 (CCND1) and nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NFKB1). Finally, SFXN3 may related to the immunosuppressive state of AML. Increased SFXN3 expression is detected in AML, which indicates a poor prognosis and may link to immunosuppressive state of AML. In addition, SFXN3 can inhibit AML cells apoptosis and promote cell proliferation via enhancing CCND1 and NFKB1 levels.

DesA Prognostic Risk Model of LncRNAs in Patients With Acute Myeloid Leukaemia Based on TCGA Data

Purpose: This study aimed to combine the clinical data of acute myeloid leukaemia (AML) from The Cancer Genome Atlas (TCGA) database to obtain prognosis-related biomarkers, construct a prognostic risk model using long non-coding RNAs (lncRNAs) in AML and help patients with AML make clinical treatment decisions.

Methods: We analysed the transcriptional group information of 151 patients with AML obtained from TCGA and extracted the expressions of lncRNAs. According to the mutation frequency, the patients were divided into the high mutation group (genomic unstable group, top 25% of mutation frequency) and low mutation group (genomic stable group, 25% after mutation frequency). The ‘limma’ R package was used to analyse the difference in lncRNA expressions between the two groups, and the “survival,” “caret,” and “glmnet” R packages were used to screen lncRNAs that are related to clinical prognosis. Subsequently, a prognosis-related risk model was constructed and verified through different methods.

Results: According to the lncRNA expression data in TCGA, we found that seven lncRNAs (i.e. AL645608.6, LINC01436, AL645608.2, AC073534.2, LINC02593, AL512413.1, and AL645608.4) were highly correlated with the clinical prognosis of patients with AML, so we constructed a prognostic risk model of lncRNAs based on LINC01436, AC073534.2, and LINC02593. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses of differentially expressed lncRNA-related target genes were performed, receiver operating characteristic (ROC) curves were created, the applicability of the model in children was assessed using the TARGET database and the model was externally verified using the GEO database. Furthermore, different expression patterns of lncRNAs were validated in various AML cell lines derived from Homo sapiens.

Conclusions: We have established a lncRNA prognostic model that can predict the survival of patients with AML. The Kaplan-Meier analysis showed that this model distinguished survival differences between patients with high- and low-risk status. The ROC analysis confirmed this finding and showed that the model had high prediction accuracy. The Kaplan-Meier analysis of the clinical subgroups showed that this model can predict prognosis independent of clinicopathological factors. Therefore, the proposed prognostic lncRNA risk model can be used as an independent biomarker of AML.

Role of CD25 expression on prognosis of acute myeloid leukemia: A literature review and meta-analysis

The gene expression for interleukin-2 receptor subunit alpha (CD25/IL2RA) is frequently altered in adults with acute myeloid leukemia (AML). Increasing evidence indicates that the elevated expression of CD25 may be correlated with poor survival for AML patients. Thus, we performed this meta-analysis to further evaluate the prognostic value of elevated CD25 in AML. Eligible studies were gathered by searching on PubMed, Web of Science, and Embase. Using the R language 3.6.0 software, Pooled hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs) of overall survival (OS) and disease-free survival (DFS)/relapse-free survival (RFS)/event-free survival (EFS) for total and subgroup analyses were calculated to investigate the association of elevated CD25 and outcomes of AML patients. Ten studies with a total of 1640 participants were enrolled in this meta-analysis. Pooled HRs suggested that overexpression of CD25 predicted poor outcomes on both OS (HR = 2.27, 95%CI 1.95–2.64) and DFS/RFS/EFS (HR = 1.77, 95%CI 1.44–2.17) in overall population. Subgroup analyses stratified by ethnicity, AML subtype, cut-off value, statistical methodologies and detection method draw similar results. Our meta-analysis indicates that elevated CD25 expression is a poor prognostic factor for AML patients. Considering limited number of samples, further relevant studies are warranted.

Extracellular vesicles impose quiescence on residual hematopoietic stem cells in the leukemic niche

Progressive remodeling of the bone marrow microenvironment is recognized as an integral aspect of leukemogenesis. Expanding acute myeloid leukemia (AML) clones not only alter stroma composition, but also actively constrain hematopoiesis, representing a significant source of patient morbidity and mortality. Recent studies revealed the surprising resistance of long-term hematopoietic stem cells (LT-HSC) to elimination from the leukemic niche. Here, we examine the fate and function of residual LT-HSC in the BM of murine xenografts with emphasis on the role of AML-derived extracellular vesicles (EV). AML-EV rapidly enter HSC, and their trafficking elicits protein synthesis suppression and LT-HSC quiescence. Mechanistically, AML-EV transfer a panel of miRNA, including miR-1246, that target the mTOR subunit Raptor, causing ribosomal protein S6 hypo-phosphorylation, which in turn impairs protein synthesis in LT-HSC. While HSC functionally recover from quiescence upon transplantation to an AML-naive environment, they maintain relative gains in repopulation capacity. These phenotypic changes are accompanied by DNA double-strand breaks and evidence of a sustained DNA-damage response. In sum, AML-EV contribute to niche-dependent, reversible quiescence and elicit persisting DNA damage in LT-HSC.

Diagnostic and Prognostic Utility of Fluorescence In situ Hybridization (FISH) Analysis in Acute Myeloid Leukemia

PURPOSE OF REVIEW

Acute myeloid leukemia (AML) is a hematologic neoplasia consisting of incompletely differentiated hematopoietic cells of the myeloid lineage that proliferate in the bone marrow, blood, and/or other tissues. Clinical implementation of fluorescence in situ hybridization (FISH) in cytogenetic laboratories allows for high-resolution analysis of recurrent structural chromosomal rearrangements specific to AML, especially in AML with normal karyotypes, which comprises approximately 33-50% of AML-positive specimens. Here, we review the use of several FISH probe strategies in the diagnosis of AML. We also review the standards and guidelines currently in place for use by clinical cytogenetic laboratories in the evaluation of AML.

RECENT FINDINGS

Updated standards and guidelines from the WHO, ACMG, and NCCN have further defined clinically significant, recurring cytogenetic anomalies in AML that are detectable by FISH. FISH continues to be a powerful technique in the diagnosis of AML, with higher resolution than conventional cytogenetic analysis, rapid turnaround time, and a considerable diagnostic and prognostic utility.

Expression of multiple leukemic stem cell markers is associated with poor prognosis in de novo acute myeloid leukemia

Leukemic stem cells (LSCs) play a crucial role in chemotherapy resistance in acute myeloid leukemia (AML). Although the association between the expression of individual LSC markers and poor prognosis has been reported, few studies have evaluated the prognostic effect of multiple LSC markers in patients with AML. Herein, we examined three LSC markers (CD25, CD96, and CD123) and the combined effect of their expression on clinical outcome. We retrospectively analyzed 80 adult patients with de novo AML who received intensive chemotherapy. Multiple LSC marker expression was significantly associated with shorter three-year overall survival (OS), compared with single or no LSC marker expression (18.2 vs. 65.0%, p < .001). Multivariate analysis showed that the expression of multiple LSC markers remained significant in terms of three-year OS (hazard ratio: 3.80, p = .001). Therefore, the combined evaluation of several LSC markers can predict the clinical outcome in patients with AML.

Acute myeloid leukaemia disrupts endogenous myelo-erythropoiesis by compromising the adipocyte bone marrow niche

Acute myeloid leukaemia (AML) is distinguished by the generation of dysfunctional leukaemic blasts, and patients characteristically suffer from fatal infections and anaemia due to insufficient normal myelo-erythropoiesis. Direct physical crowding of bone marrow (BM) by accumulating leukaemic cells does not fully account for this haematopoietic failure. Here, analyses from AML patients were applied to both in vitro co-culture platforms and in vivo xenograft modelling, revealing that human AML disease specifically disrupts the adipocytic niche in BM. Leukaemic suppression of BM adipocytes led to imbalanced regulation of endogenous haematopoietic stem and progenitor cells, resulting in impaired myelo-erythroid maturation. In vivo administration of PPARγ agonists induced BM adipogenesis, which rescued healthy haematopoietic maturation while repressing leukaemic growth. Our study identifies a previously unappreciated axis between BM adipogenesis and normal myelo-erythroid maturation that is therapeutically accessible to improve symptoms of BM failure in AML via non-cell autonomous targeting of the niche.

The biomarkers of leukemia stem cells in acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by morphology and chromosome aberrations with high mortality. Leukemia stem cells (LSCs) in AML played important roles in leukemia initiation, progression, and were considered to be the root of chemotherapeutic drug resistance and disease relapse. The identification and targeting LSCs depended on membrane markers like CD34, CD38, CD123, TIM3, CD25, CD32 and CD96. In addition, the transcription factors were also therapeutic targets in eradicating LSCs, such as histone deacetylases (HDACs), NF-κB, HIF-1α and β-catenin. Besides membrane markers and transcription factors, intracellular reactive oxygen species (ROS), telomerase and microRNAs were identified to be new targets for ablating LSCs in AML.