Treatment of acute myeloid leukemia

Chloroquine enhances the efficacy of chemotherapy drugs against acute myeloid leukemia by inactivating the autophagy pathway

Current therapy for acute myeloid leukemia (AML) is largely hindered by the development of drug resistance of commonly used chemotherapy drugs, including cytarabine, daunorubicin, and idarubicin. In this study, we investigated the molecular mechanisms underlying the chemotherapy drug resistance and potential strategy to improve the efficacy of these drugs against AML. By analyzing data from ex vivo drug-response and multi-omics profiling public data for AML, we identified autophagy activation as a potential target in chemotherapy-resistant patients. In THP-1 and MV-4-11 cell lines, knockdown of autophagy-regulated genes ATG5 or MAP1LC3B significantly enhanced AML cell sensitivity to the chemotherapy drugs cytarabine, daunorubicin, and idarubicin. In silico screening, we found that chloroquine phosphate mimicked autophagy inactivation. We showed that chloroquine phosphate dose-dependently down-regulated the autophagy pathway in MV-4-11 cells. Furthermore, chloroquine phosphate exerted a synergistic antitumor effect with the chemotherapy drugs in vitro and in vivo. These results highlight autophagy activation as a drug resistance mechanism and the combination therapy of chloroquine phosphate and chemotherapy drugs can enhance anti-AML efficacy.

Serum circRNA_100199 is a Prognostic Biomarker in Acute Myeloid Leukemia

Background

An aberrant level of serum microRNA expression has been demonstrated to be a prognostic marker for acute myeloid leukemia (AML). The therapeutic relevance of serum circRNA 100199 remained unknown, however. This research aimed to investigate the probable prognostic significance of serum circRNA_100199 for AML.

Methods

This study included a total of 200 participants consisting of 114 AML-diagnosed patients and 86 healthy people. Blood samples were taken, and the level of circRNA_100199 in the serum was measured using quantitative reverse transcription polymerase chain reaction (qRT-PCR) to explore its potential clinical significance.

Results

Our study demonstrated that circRNA_100199 expression in the serum was substantially higher in AML subjects than in healthy persons. This increase in serum circRNA_100199 levels was particularly noticeable in M4/M5 subtype AML patients, and those with poor cytogenetic risk or higher white blood cell counts. Using receiver operating characteristic (ROC) analysis, AML cases were effectively differentiated from healthy persons based on the level of serum circRNA_100199. Furthermore, it was found that high serum circRNA_100199 expression was strongly linked with shorter survival times and more severe clinical features. Our study also confirmed that high serum circRNA_100199 expression was an independent predictor of relapse-free survival (RFS) and overall survival (OS) in AML patients. Interestingly, the serum expression level of circRNA_100199 was significantly reduced following treatment, and its levels were substantially lower in AML patients who achieved complete remission (CR) than those who did not.

Conclusion

Overall, these findings suggest that serum circRNA_100199 has the potential to be a favorable prognostic biomarker for AML.

Cuproptosis-related lncRNAs as potential biomarkers of AML prognosis and the role of lncRNA HAGLR/miR-326/CDKN2A regulatory axis in AML

Acute myeloblastic leukemia (AML) is the most prevalent form of AML in adults. Despite the availability of various treatment options, including radiotherapy and chemotherapy, many patients fail to respond to treatment or relapse. Copper is a necessary cofactor for all organisms; however, it turns toxic when concentrations reach a certain threshold maintained by homeostatic systems that have been conserved through evolution. However, the mechanism through which excess copper triggers cell death remains unknown. In this study, data on long non-coding RNAs (lncRNAs) related to cuproptosis were retrieved from publicly available databases. LASSO and univariate and multivariate Cox regression analyses were performed to establish an lncRNA model associated with cuproptosis specific to AML. To investigate the risk model, the Kaplan-Meier curve, principal component analysis, functional enrichment analysis, and nomographs were employed. The underlying clinicopathological characteristics were determined, and drug sensitivity predictions against the model were identified. Six cuproptosis-related lncRNA-based risk models were identified as the independent prognostic factors. By regrouping patients using a model-based method, we were able to more accurately differentiate patients according to their responses to immunotherapy. In addition, prospective compounds targeting AML subtypes have been identified. Using qRT-PCR, we examined the expression levels of six cuproptosis-associated lncRNAs in 30 clinical specimens. The cuproptosis-associated lncRNA risk-scoring model developed herein has implications in monitoring AML prognosis and in the clinical prediction of the response to immunotherapy. Furthermore, we identified and verified the ceRNA of the cuproptosis-related lncRNA HAGLR/miR-326/CDKN2A regulatory axis using bioinformatic tools. HAGLR is highly expressed in AML and AML cell lines. HAGLR inhibition significantly reduced the proliferation of AML cells and promoted apoptosis. Elesclomol promotes the degradation of CDKN2A and inhibits the proliferation of AML cells. Elesclomol combined with si-HAGLR inhibited the AML progression of AML both in vitro and in vivo.

Mining of transcriptome identifies CD109 and LRP12 as possible biomarkers and deregulation mechanism of T cell receptor pathway in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a heterogeneous disease with highest mortality compared to other types of leukemia. There is a need to find the gene abnormalities and mechanisms behind them due to their heterogenic nature. The present study is aimed to understand genes, pathways and biomarker proteins influenced by transcriptomic deregulation due to AML. Differentially expressed gene (DEG), protein-protein interaction network, gene ontology, KEGG pathway, variant analysis and secretome analyses were performed using different AML RNAseq datasets. A total of 655 DEGs including 291 up-regulated and 364 down-regulated genes, which were satisfied with a fold change of 1.5 were identified. Top hub genes for AML were identified as TP53, PTPRC and AKT1. This integrative bioinformatics approach revealed the deregulation of T Cell Receptor (TCR) pathway and altered immune response related genes. The survival analysis revealed the associated deregulation of multiple TCR pathway related genes. Variant analysis identified the benign and likely benign nature of many important target genes and markers screened, which were found to have an important role in the progression of AML. DEGs and secretome analysis found out a set of seven molecules represents potential biomarkers for AML. In vitro analytical validation showed overexpression pattern of CD109 and LRP12 in AML cell line and HL-60 cells than the normal human bone marrow-derived stromal cell line HS-5. Here we report first time for CD109 and LRP12 as a possible biomarkers for the diagnostic significance. Amino acid substitutions detected by variant analysis and deregulation of immune checkpoint molecules revealed their role in reducing immune response and inability to fight cancer cells. In conclusion, this study highlights the possibility of new biomarkers for AML and the mechanism of decrease in immune response due to the downregulation of co-stimulatory immune molecules, which needs further clinical validation investigations.

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Using RNA-seq data of AML patients, two biomarkers including CD109 and LRP12 for the diagnostic significance were identified based on DEGs, GO/KEGG, and PPI network analysis.

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The transcriptome mining unmasked the complexity of gene alterations in AML by identifying immune response related genes deregulation and significance of TCR signalling.

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Several genes were identified as AML hub genes by network analysis, variant analysis identified non-synonymous variants in co-stimulatory checkpoint targets and the co-inhibitory targets.

Induction Therapy and Survival for Acute Myeloid Leukemia in Hispanic Adults from Puerto Rico

BACKGROUND

Acute myeloid leukemia (AML) is the most common type of leukemia in adults. There are no previous studies evaluating AML treatment patterns in Puerto Rico. We describe the first-line therapy patterns and survival of patients diagnosed with AML in Puerto Rico using the Puerto Rico Central Cancer Registry Health Insurance Linkage Database (2011-2015).

METHODS

We describe patient characteristics according to intensive, non-intensive, and non-treatment status. We used Cox proportional hazard models to evaluate the factors associated with the risk of death stratified by intensive and non-intensive therapy. For this study, 385 patients with AML were included.

RESULTS

The mean age was 67 years old and 50.1% were female. Nearly half of AML patients (46.8%) received intensive treatment, 23.6% received non-intensive treatment, and 26.2% did not receive treatment. The overall 3-year survival rate was 17.9%. Among those who received intensive therapy, the risk of death among females was lower than males (hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.44-0.93). Patients 60 years or older who received intensive treatment had a higher risk of death than younger patients (HR: 1.67, 95% CI: 1.09-2.55). Patients with poor/adverse risk receiving intensive (HR: 3.43, 95% CI: 1.76-6.69) or non-intensive (HR: 4.32, 95% CI: 1.66-11.28) treatment had a higher risk of death than patients with a favorable risk category.

CONCLUSION

Our findings are the first step to monitor the quality of care of patients with AML in Puerto Rico, particularly related to the administration of appropriate induction therapies, which is one of the most important predictors of AML survival.

The Question of Survival or Death: What Is the Role of Autophagy in Acute Myeloid Leukemia (AML)?

Autophagy plays a critical role in balancing sources of energy in response to harsh conditions and nutrient deprivation. Autophagy allows cells to survive in harsh condition and also serve as a death mechanism. Any dysregulation in autophagy signaling may lead to several disorders. Autophagy has been proposed to explain chemotherapy resistance in acute myeloid leukemia (AML). This signaling pathway can either act as a tumor suppressive function or chemo-resistance mechanism. Conventional chemotherapy drugs enhance apoptosis and indicate clinical benefit, but in some cases, relapse and chemotherapy resistance are observed. In leukemia, autophagy may promote cell survival in response to chemotherapy drugs. Therefore, new strategies by inhibiting or activating autophagy may find a broad application for treating leukemia and may significantly enhance clinical outcomes. In this review, we discussed the dimensional role of autophagy in leukemia.

Serum hsa_circ_0079480 is a novel prognostic marker for acute myeloid leukemia

Background

The dysregulated expression of serum circular RNAs (circRNAs) has previously been linked to the prognosis of acute myeloid leukemia (AML) patients, but the clinical and prognostic relevance of serum hsa_circ_0079480 levels in this oncogenic setting have yet to be established. Herein, we assessed the putative prognostic relevance of circulating hsa_circ_0079480 levels in AML patient serum.

Methods

Serum was prepared from blood samples collected from 236 AML patients and 160 healthy controls, with hsa_circ_0079480 levels therein being quantified by quantitative real‐time reverse transcription‐polymerase chain reaction (qRT‐PCR) after which the clinical value of these levels was assessed.

Results

Acute myeloid leukemia patients were found to exhibit significant hsa_circ_0079480 upregulation in their serum as compared to serum from healthy controls, with such upregulation being most profound in individuals with M4/M5 type disease and to be more common in patients with poor cytogenic risk or high white blood cell counts. Receiver operating characteristic (ROC) curves demonstrated that serum hsa_circ_0079480 levels were able to effectively differentiate between patients with AML and healthy controls. Moreover, the upregulation of serum hsa_circ_0079480 was found to be closely related to clinicopathological findings and to be an independent predictor of reduced overall and relapse‐free survival among individuals diagnosed with AML. Furthermore, serum hsa_circ_0079480 levels were markedly decreased after treatment in this patient population, with these levels being lower in patients that achieved complete remission as compared to those patients that did not.

Conclusion

Levels of hsa_circ_0079480 in patient serum may offer value as a prognostic biomarker in AML.

Low dose of homoharringtonine and cytarabine-based priming induction regimens for patients with de novo acute myeloid leukemia and high-risk myelodysplastic syndrome aged over 70 years

OBJECTIVES

Our objective is to retrospectively analyze the response to low dose of homoharringtonine (HHT) and cytarabine-based priming induction regimens in patients above 70 years with de novo acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS).

PATIENTS AND METHODS

We retrospectively analyzed these very elderly newly diagnosed patients with AML and high-risk MDS, who received low dose of HHT and cytarabine-based priming induction regimens between March 2006 and September 2019.

RESULTS

Of the 24 patients, 11 patients (47.8%) achieved complete remission (CR) and 3 (13%) partial remission, and the overall response rate was 60.9%. The estimated median overall survival (OS) time was 12 months and the 1-year OS rate was 47.8%. Patients without CR and Charlson's Comorbidity Index > 2 may be the two independent prognostic factors. The median OS was significantly higher for patients with CR after induction chemotherapy than those without CR (22.93 vs. 8.5 months, p < .01).

CONCLUSION

Our study provides a hint of the efficacy of low dose of HHT and cytarabine-based priming induction regimens for patients aged over 70 years with de novo AML and high-risk MDS should be further studied.

Comprehensive analysis of cytoskeleton regulatory genes identifies ezrin as a prognostic marker and molecular target in acute myeloid leukemia

PURPOSE

Despite great advances that have been made in the understanding of the molecular complexity of acute myeloid leukemia (AML), very little has been translated into new therapies. Here, we set out to investigate the impact of cytoskeleton regulatory genes on clinical outcomes and their potential as therapeutic targets in AML.

METHODS

Gene expression and clinical data were retrieved from The Cancer Genome Atlas (TCGA) AML study and used for survival and functional genomics analyses. For pharmacological tests, AML cells were exposed to ezrin (EZR) inhibitors and submitted to several cellular and molecular assays.

RESULTS

High EZR expression was identified as an independent marker of worse outcomes in AML patients from the TCGA cohort (p < 0.05). Functional genomics analyses suggested that EZR contributes to responses to stimuli and signal transduction pathways in leukemia cells. EZR pharmacological inhibition with NSC305787 and NSC668394 reduced viability, proliferation, autonomous clonal growth, and cell cycle progression in AML cells (p < 0.05). NSC305787 had a greater potency and efficiency than NSC668394 in leukemia models. At the molecular level, EZR inhibitors reduced EZR, S6 ribosomal protein and 4EBP1 phosphorylation, and induced PARP1 cleavage in AML cells. NSC305787, but not NSC668394, favored a gene network involving cell cycle arrest and apoptosis in Kasumi 1 AML cells.

CONCLUSIONS

From our data we conclude that EZR expression may serve as a prognostic factor in AML. Our preclinical findings indicate that ezrin inhibitors may be employed as a putative novel class of AML targeting drugs.

MiR-335-3p inhibits cell proliferation, induces cell cycle arrest and apoptosis in acute myeloid leukemia by targeting EIF3E

Here, we aimed to investigate the biological roles and the regulatory mechanisms of miR-335-3p in acute myeloid leukemia (AML). We first found miR-335-3p was significantly down-regulated in blood samples from leukemia patients and cell lines using reverse transcription quantitative PCR. Through CCK-8 assay and flow cytometry, we observed that miR-335-3p overexpression significantly inhibited cell proliferation, induced cell cycle G0/G1 arrest and apoptosis in AML cell lines (THP-1 and U937). Moreover, miR-335-3p directly targets EIF3E and negatively regulated its expression. More importantly, EIF3E overexpression reversed the effects of miR-335-3p on cell proliferation, G1/S transition and apoptosis. Furthermore, miR-335-3p overexpression obviously downregulated the expression of CDK4, Cyclin D1 and Bcl-2, while upregulated the expression of p21 and Bad, which were significantly rescued by the co-transfection of pcDNA3.1-EIF3E. Collectively, our study proposes that miR-335-3p/EIF3E axis could be a promising therapeutic target to mitigate the progression of AML.

The Neurokinin-1 Receptor Antagonist Aprepitant: An Intelligent Bullet against Cancer?

Neurokinin-1 receptor (NK-1R) antagonists exert antitumor action, are safe and do not cause serious side-effects. These antagonists (via the NK-1R) exert multiple actions against cancer: antiproliferative and anti-Warburg effects and apoptotic, anti-angiogenic and antimetastatic effects. These multiple effects have been shown for a broad spectrum of cancers. The drug aprepitant (an NK-1R antagonist) is currently used in clinical practice as an antiemetic. In in vivo and in vitro studies, aprepitant also showed the aforementioned multiple antitumor actions against many types of cancer. A successful combination therapy (aprepitant and radiotherapy) has recently been reported in a patient suffering from lung carcinoma: the tumor mass disappeared and side-effects were not observed. Aprepitant could be considered as an intelligent bullet against cancer. The administration of aprepitant in cancer patients to prevent recurrence and metastasis after surgical procedures, thrombosis and thromboembolism is discussed, as is the possible link, through the substance P (SP)/NK-1R system, between cancer and depression. Our main aim is to review the multiple antitumor actions exerted by aprepitant, and the use of this drug is suggested in cancer patients. Altogether, the data support the reprofiling of aprepitant for a new therapeutic use as an antitumor agent.

Antiproliferative effects of L-asparaginase in acute myeloid leukemia

The antitumor enzyme L-asparaginase (L-Asp) has commonly been used for the treatment of acute lymphoblastic leukemia. However, the effects of L-Asp on acute myeloid leukemia (AML) and their underlying mechanisms have not been fully elucidated. In the present study, the effects of L-Asp on cell proliferation and apoptosis were investigated using the AML cell lines U937, HL-60 and KG-1a. The effects of combining L-Asp with mitoxantrone (MIT) and cytarabine (Ara-c) were also analyzed. The combination of MIT and Ara-C is known as MA therapy, and is a widely used therapeutic regimen for the treatment of elderly patients with refractory AML. When applied alone, L-Asp inhibited cell proliferation and induced apoptosis in each of the cell lines tested. Furthermore, the combined use of L-Asp with MA therapy further potentiated the inhibition of cell proliferation while increasing the induction of apoptosis. These findings provide evidence for the potential antitumor effect of L-Asp in AML, and indicate that improved efficacy maybe achieved by combining L-Asp with MIT and Ara-c. This combination may provide a promising new therapeutic strategy for the treatment of AML.

Serum miR-22 is a novel prognostic marker for acute myeloid leukemia

Background

It has been demonstrated that aberrant expression of serum microRNAs is potential markers for the prognostic prediction of acute myeloid leukemia (AML). However, the clinical significance of serum miR‐22 remained uncovered. In this study, we aimed to explore the potential prognostic value of serum miR‐22 for AML.

Methods

Blood samples were collected from 124 patients with AML and 60 healthy individuals. Serum miR‐22 level was detected by quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR), and its potential clinical value was investigated.

Results

Our results showed that serum miR‐22 expression was significantly downregulated in AML subjects compared to healthy controls. Serum miR‐22 levels were lowest in AML patients with M4/M5 subtypes, and low serum miR‐22 expression occurred more frequently in AML patients with higher white blood cell counts or poor cytogenetic risk. Receiver operating characteristic (ROC) analysis revealed that serum miR‐22 well differentiated AML cases from healthy controls. In addition, serum miR‐22 downregulation was closely associated with worse clinical features and shorter survival. Low serum miR‐22 expression was confirmed to be an independent predictor for overall survival and relapse‐free survival in AML patients. Moreover, the expression level of serum miR‐22 was dramatically increased following treatment. In addition, serum miR‐22 levels were significantly higher in AML patients achieving complete remission (CR) than those without CR.

Conclusion

Collectively, serum miR‐22 might serve as a novel and promising prognostic biomarker for AML.

The Neurokinin-1 Receptor Antagonist Aprepitant, a New Drug for the Treatment of Hematological Malignancies: Focus on Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy. To treat the disease successfully, new therapeutic strategies are urgently needed. One of these strategies can be the use of neurokinin-1 receptor (NK-1R) antagonists (e.g., aprepitant), because the substance P (SP)/NK-1R system is involved in cancer progression, including AML. AML patients show an up-regulation of the NK-1R mRNA expression; human AML cell lines show immunoreactivity for both SP and the NK-1R (it is overexpressed: the truncated isoform is more expressed than the full-length form) and, via this receptor, SP and NK-1R antagonists (aprepitant, in a concentration-dependent manner) respectively exert a proliferative action or an antileukemic effect (apoptotic mechanisms are triggered by promoting oxidative stress via mitochondrial Ca⁺⁺ overload). Aprepitant inhibits the formation of AML cell colonies and, in combination with chemotherapeutic drugs, is more effective in inducing cytotoxic effects and AML cell growth blockade. NK-1R antagonists also exert an antinociceptive effect in myeloid leukemia-induced bone pain. The antitumor effect of aprepitant is diminished when the NF-κB pathway is overactivated and the damage induced by aprepitant in cancer cells is higher than that exerted in non-cancer cells. Thus, the SP/NK-1R system is involved in AML, and aprepitant is a promising antitumor strategy against this hematological malignancy. In this review, the involvement of this system in solid and non-solid tumors (in particular in AML) is updated and the use of aprepitant as an anti-leukemic strategy for the treatment of AML is also mentioned (a dose of aprepitant (>20 mg/kg/day) for a period of time according to the response to treatment is suggested). Aprepitant is currently used in clinical practice as an anti-nausea medication.

Current and Future Molecular Targets for Acute Myeloid Leukemia Therapy

OPINION STATEMENT

Acute myeloid leukemia (AML) disease prognosis is poor and there is a high risk of chemo-resistant relapse for both young and old patients. Thus, there is a demand for alternative and target-specific drugs to improve the 5-year survival rate. Current treatment mainstays include chemotherapy, or mutation-specific targeting molecules including FLT3 inhibitors, IDH inhibitors, and monoclonal antibodies. Efforts to devise new, targeted therapy have included recent advances in methods for high-throughput genomic screening and the availability of computer-assisted techniques for the design of novel agents predicted to specifically inhibit mutant molecules involved in leukemogenesis. Crosstalk between the leukemia cells and the bone marrow microenvironment through cell surface molecules, such as the integrins αvβ3 and αvβ5, might influence drug response and AML progression. This review article focuses on current AML treatment options, new AML targeted therapies, the role of integrins in AML progression, and a potential therapeutic agent-integrin αvβ3 antagonist.

MicroRNA-33b regulates sensitivity to daunorubicin in acute myelocytic leukemia by regulating eukaryotic translation initiation factor 5A-2

In this study, we aimed to study the effect of miR-33b in regulating sensitivity to daunorubicin (DNR) in acute myelocytic leukemia (AML). We used quantitative real-time polymerase chain reaction and Cell Counting Kit-8 assay to detect the level of miR-33b and cell viability. Cell apoptosis and the expression of eIF5A-2 and MCL-1 protein were detected by flow cytometry analysis and Western Blot analysis, respectively. MiR-33b mimic increased sensitivity of AML cells against DNR, while miR-33b inhibitor had the opposite effect. Furthermore, the results showed that the eIF5A-2 gene was a direct target of miR-33b, and miR-33b regulated eIF5A-2 mRNA and protein expression. Silencing of eIF5A-2 by RNA interference increased the sensitivity of AML cells against DNR. We also found that MCL-1 contributed to the regulation of DNR sensitivity, which was dependent on downregulation of eIF5A-2. Finally, knockdown of eIF5A-2 eliminated the effects of miRNA-33b mimic or inhibitor on DNR sensitivity. These findings indicate that miR-33b maybe as a new therapeutic target in AML cells.

Long Non-Coding RNA TUG1 Modulates Proliferation, Migration, And Invasion Of Acute Myeloid Leukemia Cells Via Regulating miR-370-3p/MAPK1/ERK

Background

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults. Long non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) has been discovered to participate in multiple cancers including AML. However, the detailed mechanism of TUG1 in AML remains obscure.

Materials and methods

AML cell lines HL-60 and Kasumi-1 were taken as cell models. TUG1 knockdown or overexpression cell lines were generated. Then, the biological influence of TUG1 on cancer cells was studied using CCK-8 assay, transwell assay and Western blot in vitro. Interaction between TUG1 and miR-370-3p was determined by bioinformatics analysis, RT-PCR, and luciferase assay. Western blot, RT-PCR, and luciferase assay were carried out to validate the interaction between miR-370-3p and its target gene Mitogen-Activated Protein Kinase 1 (MAPK1).

Results

Knockdown of TUG1 markedly reduced viability and metastasis of AML cells, while its overexpression had the opposite effect. MAPK1 was verified as a target gene of miR-370-3p. TUG1 could reduce the level of functional miR-370-3p, facilitate MAPK1 expression, and in turn activate ERK1/2 signaling.

Conclusion

TUG1 could modulate malignant phenotypes of AML cells via miR-370-3p/MAPK1/ERK signaling. Our study would help to clarify the mechanism of AML tumorigenesis and progression.

Long-term cardiac-specific mortality among 44,292 acute myeloid leukemia patients treated with chemotherapy: a population-based analysis

Background: Acute myeloid leukemia (AML) is a common hematological malignancy treated with regimens containing anthracycline, an agent with cardiotoxicity. However, the cardiac-specific mortality in AML patients receiving chemotherapy remains unknown.

Methods: In this population-based study, patients diagnosed with AML between 1973 and 2015 were identified in the Surveillance, Epidemiology, and End Results database. Cumulative mortality by cause of death was calculated. To quantify the excessive cardiac-specific death compared with the general population, standardized mortality ratios (SMRs) were calculated. Multivariate Cox regression analyses were performed to identify risk factors associated with cardiac-specific death and AML-specific death.

Results: A total of 64,679 AML patients were identified between 1973 and 2015; 68.48% of patients (44,292) received chemotherapy. Among all possible competing causes of death, AML was associated with the highest cumulative mortality. The AML patients who received chemotherapy showed excessive cardiac-specific mortality compared with the general population, with an SMR of 6.35 (95% CI: 5.89-6.82). Age, year of diagnosis, sex, and marital status were independently associated with patient prognosis.

Conclusion: Cardiac-specific mortality in AML patients receiving chemotherapy is higher than that in the general population.

MiR-9 functions as a tumor suppressor in acute myeloid leukemia by targeting CX chemokine receptor 4

MicroRNAs (miRNAs) play key roles in the pathogenesis of many cancers, including acute myeloid leukemia (AML). Although miRNA-9 (miR-9) is involved in the leukemogenesis of AML, the underlying mechanisms remain to be elucidated. In this study, we found that miR-9 and C-X-C chemokine receptor 4 (CXCR4) were differentially expressed in myeloid leukemia, particularly in AML. The inverse correlation between miR-9 and CXCR4 was identified in AML samples and cell lines. The AML patients simultaneously with high levels of CXCR4 and low expression of miR-9 possessed poor prognosis. In vitro, miR-9 inhibited the proliferation, apoptosis resistance, migration, and invasion of AML cells. Dual luciferase assays verified CXCR4 as a direct target of miR-9. The suppressive effects of miR-9 on AML cells were counteracted or mimicked by CXCR4 overexpression or depletion, respectively. Overall, this study reveals that miR-9 retards the aggressive behaviors of AML cells by repressing CXCR4. Thus, miR-9/CXCR4 axis may represent a potential therapeutic target for AML.

miR-134 increases the antitumor effects of cytarabine by targeting Mnks in acute myeloid leukemia cells

The relapse and resistance to cytarabine (Ara-C) therapy is still a dominating obstacle to the successful clinical treatment of acute myeloid leukemia (AML). Recent studies have shown that dysregulation of miRNAs might modulate the resistance of cancer cells to anticancer drugs; yet, the mechanism is not fully understood. In this study, we showed a significant downregulation of miR-134 in human multidrug-resistant leukemia cells and relapsed/refractory AML patient samples. Overexpression of miR-134 sensitized K562/A02 and HL-60/ADM cells to Ara-C, inhibited cell colony formation, and enhanced the ability of Ara-C to induce apoptosis. Mechanistic analyses revealed that Mnks was a putative target of miR-134, which was inversely correlated with miR-134 expression in human multidrug-resistant leukemia cells and relapsed/refractory AML patient samples. Further investigation showed that miR-134 increased the anti-tumor effects of Ara-C through inhibiting phosphorylation of eukaryotic initiation factor 4E and downregulating Mcl-1 and bcl2, which was independent of p38 and Erk1/2 activation. Taken together, our results demonstrate that miR-134 plays a pivotal role in AML Ara-C resistance through increasing cell sensitivity to Ara-C and promoting apoptosis by targeting Mnks.

Myeloid leukemia with transdifferentiation plasticity developing from T-cell progenitors

Unfavorable patient survival coincides with lineage plasticity observed in human acute leukemias. These cases are assumed to arise from hematopoietic stem cells, which have stable multipotent differentiation potential. However, here we report that plasticity in leukemia can result from instable lineage identity states inherited from differentiating progenitor cells. Using mice with enhanced c-Myc expression, we show, at the single-cell level, that T-lymphoid progenitors retain broad malignant lineage potential with a high capacity to differentiate into myeloid leukemia. These T-cell-derived myeloid blasts retain expression of a defined set of T-cell transcription factors, creating a lymphoid epigenetic memory that confers growth and propagates myeloid/T-lymphoid plasticity. Based on these characteristics, we identified a correlating human leukemia cohort and revealed targeting of Jak2/Stat3 signaling as a therapeutic possibility. Collectively, our study suggests the thymus as a source for myeloid leukemia and proposes leukemic plasticity as a driving mechanism. Moreover, our results reveal a pathway-directed therapy option against thymus-derived myeloid leukemogenesis and propose a model in which dynamic progenitor differentiation states shape unique neoplastic identities and therapy responses.

Effect of Age on Treatment Decision-Making in Elderly Patients With Acute Myeloid Leukemia

BACKGROUND

Patients aged ≥ 70 years with acute myeloid leukemia (AML) have a poorer prognosis than those aged 60 to 69 years.

PATIENTS AND METHODS

We retrospectively analyzed the cases of 183 patients aged ≥ 70 years with a performance status of ≤ 2 treated at our institution from 2000 to 2014. Treatment consisted of anthracycline- and cytarabine-based chemotherapy for 93 patients and lower intensity therapy with low-dose cytarabine or hypomethylating agent cycles for 90 patients.

RESULTS

A total of 57 patients (61%) achieved complete remission in the intensive chemotherapy group versus only 11 (12%) in the lower intensity treatment group (P < .0001). The median overall survival (OS) was 14.5 months and 11.7 months with a 3-year OS rate of 34% and 18% (P = .005) for the intensive and lower intensity groups, respectively. The difference remained significant when considering patients aged ≤ 75 years, but not for patients aged > 75 years. Similarly, a significant difference was only observed when considering favorable and intermediate cytogenetic factors (P = .007) but not unfavorable karyotypes. On multivariate analysis, age did not appear as an independent prognostic factor.

CONCLUSION

With intensive chemotherapy, the median OS significantly increased after the introduction of an improved supportive care policy compared with historical controls (14 vs. 5.4 months, with a 3-year OS rate of 33% vs. 8%). After 2006, a more "personalized" therapeutic approach tended to erase the difference in terms of OS, especially in patients aged > 75 years.

Antrodia camphorata induces G1 cell-cycle arrest in human premyelocytic leukemia (HL-60) cells and suppresses tumor growth in athymic nude mice

Antrodia camphorata is a well-known medicinal mushroom in Taiwan.

A combination of temsirolimus, an allosteric mTOR inhibitor, with clofarabine as a new therapeutic option for patients with acute myeloid leukemia

Signaling through the phosphatidylinositol 3-kinase (PI3K) pathway and its downstream effectors, Akt and mechanistic target of rapamycin (mTOR), is aberrantly activated in acute myeloid leukemia (AML) patients, where it contributes to leukemic cell proliferation, survival, and drug-resistance. Thus, inhibiting mTOR signaling in AML blasts could enhance their sensitivity to cytotoxic agents. Preclinical data also suggest that allosteric mTOR inhibition with rapamycin impaired leukemia initiating cells (LICs) function. In this study, we assessed the therapeutic potential of a combination consisting of temsirolimus [an allosteric mTOR complex 1 (mTORC1) inhibitor] with clofarabine, a nucleoside analogue with potent inhibitory effects on both ribonucleotide reductase and DNA polymerase. The drug combination (CLO-TOR) displayed synergistic cytotoxic effects against a panel of AML cell lines and primary cells from AML patients. Treatment with CLO-TOR induced a G₀/G₁-phase cell cycle arrest, apoptosis, and autophagy. CLO-TOR was pro-apoptotic in an AML patient blast subset (CD34⁺/CD38⁻/CD123⁺), which is enriched in putative leukemia initiating cells (LICs). In summary, the CLO-TOR combination could represent a novel valuable treatment for AML patients, also in light of its efficacy against LICs.

Molecular prognostic factors in cytogenetically normal acute myeloid leukemia

Chromosomal abnormalities are detected in 50-60% of patients with acute myeloid leukemia (AML) and are important predictors of prognosis and risk of relapse. The remaining patients, those with cytogenetically normal AML, are a seemingly homogeneous group that in fact consists of subsets of patients with distinct clinical outcomes. This heterogeneity is likely related to acquired gene mutations, as well as altered miRNA and gene-expression profiles, which occur within the group. The identification of recurrent molecular abnormalities has improved prognostication and provided insight into mechanisms of leukemogenesis for patients with cytogenetically normal AML, as well as led to the discovery of novel therapeutic targets. As the number of mutations continues to expand, bioinformatic algorithms that allow for integration of multiple markers will be necessary to provide optimal care for patients with this disease.

Increased anti-leukemic activity of decitabine via AR-42-induced upregulation of miR-29b: a novel epigenetic-targeting approach in acute myeloid leukemia

Histone deacetylase (HDAC) inhibitors either alone or in combination with hypomethylating agents have limited clinical effect in acute myeloid leukemia (AML). Previously, we demonstrated that AML patients with higher miR (microRNA)-29b expression had better response to the hypomethylating agent decitabine. Therefore, an increase in miR-29b expression preceding decitabine treatment may provide a therapeutic advantage. We previously showed that miR-29b expression is suppressed by a repressor complex that includes HDACs. Thus, HDAC inhibition may increase miR-29b expression. We hypothesized that priming AML cells with the novel HDAC inhibitor (HDACI) AR-42 would result in increased response to decitabine treatment via upregulation of miR-29b. Here, we show that AR-42 is a potent HDACI in AML, increasing miR-29b levels and leading to downregulation of known miR-29b targets (that is, SP1, DNMT1, DNMT3A and DNMT3B). We then demonstrated that the sequential administration of AR-42 followed by decitabine resulted in a stronger anti-leukemic activity in vitro and in vivo than decitabine followed by AR-42 or either drug alone. These preclinical results with AR-42 priming before decitabine administration represent a promising, novel treatment approach and a paradigm shift with regard to the combination of epigenetic-targeting compounds in AML, where decitabine has been traditionally given before HDACIs.

The tumor suppressive role of miRNA-370 by targeting FoxM1 in acute myeloid leukemia

BACKGROUND

Recent evidence has accumulated that MicroRNA (miRNA) dysregulation occurs in the majority of human malignancies including acute myeloid leukemia (AML) and may contribute to onco-/leukemo-genesis.

METHODS

The expression levels of miR-370 and FoxM1 were assessed in 48 newly diagnosed AML patients, 40 AML patients in 1st complete remission (CR) and 21 healthy controls. Quantitative real-time PCR, western blots, colony formation assay, and β-Galactosidase ( SA-β-Gal) staining were used to characterize the changes induced by overexpression or inhibition of miR-370 or FoxM1.

RESULTS

We found that the down-regulation of miR-370 expression was a frequent event in both leukemia cell lines and primary leukemic cells from patients with de novo AML. Lower levels of miR-370 expression were found in 37 of 48 leukemic samples from AML patients compared to those in bone marrow cells derived from healthy adult individuals. Ectopic expression of miR-370 in HL60 and K562 cells led to cell growth arrest and senescence. In contrast, depletion of miR-370 expression using RNA interference enhanced the proliferation of those leukemic cells. Mechanistically, miR-370 targets the transcription factor FoxM1, a well established oncogenic factor promoting cell cycle progression. Moreover, when HL60 and K562 cells were treated with 5-aza-2'-deoxycytidine, a DNA methylation inhibitor, miR-370 expression was up-regulated, which indicates epigenetic silencing of miR-370 in leukemic cells.

CONCLUSIONS

Taken together, miR-370 may function as a tumor suppressor by targeting FoxM1, and the epigenetic silence of miR-370 thus leads to derepression of FoxM1 expression and consequently contributes to AML development and progression.

Temsirolimus, an mTOR inhibitor, in combination with lower-dose clofarabine as salvage therapy for older patients with acute myeloid leukaemia: results of a phase II GIMEMA study (AML-1107)

The mammalian target of rapamycin (mTOR) signalling pathway has emerged as an important therapeutic target for acute myeloid leukaemia (AML). This study assessed the combination of temsirolimus, an mTOR inhibitor, and lower-dose clofarabine as salvage therapy in older patients with AML. Induction consisted of clofarabine 20mg/m(2) on days 1-5 and temsirolimus 25mg (flat dose) on days 1, 8 and 15. Patients achieving complete remission with (CR) or without (CRi) full haematological recovery could receive monthly temsirolimus maintenance. In 53 evaluable patients, the overall remission rate (ORR) was 21% (8% CR, 13% CRi). Median disease-free survival was 3·5months, and median overall survival was 4months (9·1months for responders). The most common non-haematological severe adverse events included infection (48%), febrile neutropenia (34%) and transaminitis (11%). The 30-d all-cause induction mortality was 13%. Laboratory data from 25 patients demonstrated that a >50%in vivo inhibition of S6 ribosomal protein phosphorylation was highly correlated with response rate (75% with inhibition versus 0% without inhibition; P=0·0001), suggesting that targeting the mTOR pathway is clinically relevant. The acceptable safety profile and the predictive value of target inhibition encourage further investigation of this novel regimen.

Immunophenotype distinction between acute promyelocytic leukaemia and CD15- CD34- HLA-DR- acute myeloid leukaemia with nucleophosmin mutations

Acute promyelocytic leukaemia (APL) is a unique clinicobiologic entity that can be successfully treated with All-trans Retinoic Acid ATRA-based regimens. Some cases of acute myeloid leukaemia (AML) with nucleophosmin (NPM) mutations have an immunophenotype that is similar to APL. The objective of the study is to compare antigenic expression in a group of APL patients with that in AML patients with NPM mutations and an APL-like immunophenotype (CD15- CD34- HLA-DR-). A consecutive series of 40 APL and 12 NPM patients with an APL-like phenotype were included in the study. Immunophenotypic patterns were investigated by multiparametric flow cytometry. Promyelocytic leukaemia-retinoic acid receptor-α transcript type, NPM and FLT3 mutations were investigated using conventional methods. Statistically significant differences were found between APL and NPM-mutated AML in CD33, CD13, CD2 and CD110 reactivity. CD2 expression was absent in every patient with NPM-mutated AML. In addition, mean fluorescence intensity and the coefficient of variation (cv) of CD33 and CD13 showed statistical differences between the two groups for CD33 (p = 0.007) and a trend to significance for CD13 (p = 0.05). Furthermore, among 45 evaluable patients, CD110 expression statistically differentiates between the two groups: [2/33 (6%) in the APL group and 8/12 (66.6%) in the NPM-mutated AML (p = 0.014)]. However, these traits were subtle, raising the possibility of practical diagnostic challenges. In conclusion, CD110 and CD33 reactivity may be useful to distinguish APL from NPM-mutated AML with CD15, CD34 and HLA-DR negativity. Nevertheless, cytogenetic and molecular characterization is necessary to establish the accurate diagnosis of AML.

Assessment of the consistency and robustness of results from a multicenter trial of remission maintenance therapy for acute myeloid leukemia

Background

Data from a randomized multinational phase 3 trial of 320 adults with acute myeloid leukemia (AML) demonstrated that maintenance therapy with 3-week cycles of histamine dihydrochloride plus low-dose interleukin-2 (HDC/IL-2) for up to 18 months significantly improved leukemia-free survival (LFS) but lacked power to detect an overall survival (OS) difference.

Purpose

To assess the consistency of treatment benefit across patient subsets and the robustness of data with respect to trial centers and endpoints.

Methods

Forest plots were constructed with hazard ratios (HRs) of HDC/IL-2 treatment effects versus no treatment (control) for prospectively defined patient subsets. Inconsistency coefficients (I²) and interaction tests (X²) were used to detect any differences in benefit among subsets. Robustness of results to the elimination of individual study centers was performed using "leave-one-center-out" analyses. Associations between treatment effects on the endpoints were evaluated using weighted linear regression between HRs for LFS and OS estimated within countries.

Results

The benefit of HDC/IL-2 over controls was statistically consistent across all subsets defined by baseline prognostic variables. I² and P-values of X² ranged from 0.00 to 0.51 and 0.14 to 0.91, respectively. Treatment effects were statistically significant in 14 of 28 subsets analyzed. The "leave-one-center-out" analysis confirmed that no single center dominated (P-values ranged from 0.004 to 0.020 [mean 0.009]). The HRs representing the HDC/IL-2 effects on LFS and OS were strongly correlated at the country level (R² = 0.84).

Limitations

Small sample sizes in some of the subsets analyzed.

Conclusions

These analyses confirm the consistency and robustness of the HDC/IL-2 effect as compared with no treatment. LFS may be an acceptable surrogate for OS in future AML trials. Analyses of consistency and robustness may aid interpretation of data from multicenter trials, especially in populations with rare diseases, when the size of randomized clinical trials is limited.

Trial Registration

ClinicalTrials.gov: NCT00003991

MicroRNA expression in acute myeloid leukemia

Acute myeloid leukemia (AML) is a group of diseases that are very heterogeneous with regard to cytogenetic aberrations, gene mutations, and changes in expression of numerous genes. A new class of genes known as microRNAs recently was found to be involved in myeloid leukemogenesis. These genes are transcribed into regulatory, noncoding RNAs that control mRNA and protein expression of target genes. Genome-wide analyses of microRNA expression have revealed signatures associated with selected cytogenetic and molecular subsets of AML and have led to the recognition of previously unreported molecular pathways involved in myeloid leukemogenesis. In cytogenetically normal AML, microRNA-expression profiling has also provided prognostic information in addition to that obtained from cytogenetics and analyses of gene mutations and aberrant gene expression. This article reviews recent studies that were focused on the alterations of microRNA expression in AML and their diagnostic and prognostic significance.

Cytogenetic and molecular diagnostic characterization combined to postconsolidation minimal residual disease assessment by flow cytometry improves risk stratification in adult acute myeloid leukemia

A total of 143 adult acute myeloid leukemia (AML) patients with available karyotype (K) and FLT3 gene mutational status were assessed for minimal residual disease (MRD) by flow cytometry. Twenty-two (16%) patients had favorable, 115 (80%) intermediate, and 6 (4%) poor risk K; 19 of 129 (15%) carried FLT3-ITD mutation. Considering postconsolidation MRD status, patients with good/intermediate-risk K who were MRD(-) had 4-year relapse-free survival (RFS) of 70% and 63%, and overall survival (OS) of 84% and 67%, respectively. Patients with good- and intermediate-risk K who were MRD(+) had 4-year RFS of 15% and 17%, and OS of 38% and 23%, respectively (P < .001 for all comparisons). FLT3 wild-type patients achieving an MRD(-) status, had a better outcome than those who remained MRD(+) (4-year RFS, 54% vs 17% P < .001; OS, 60% vs 23%, P = .002). Such an approach redefined cytogenetic/genetic categories in 2 groups: (1) low-risk, including good/intermediate K-MRD(-) with 4-year RFS and OS of 58% and 73%, respectively; and (2) high risk, including poor-risk K, FLT3-ITD mutated cases, good/intermediate K-MRD(+) categories, with RFS and OS of 22% and 17%, respectively (P < .001 for all comparisons). In AML, the integrated evaluation of baseline prognosticators and MRD improves risk-assessment and optimizes postremission therapy.

Challenges in treating older patients with acute myeloid leukemia

Whereas in younger patients diagnosed with acute myeloid leukemia (AML) treatment is straightforward and the goal is cure, the optimal treatment decision for older adults remains highly controversial. Physicians need to determine whether palliation, “something” beyond palliation, intensive therapy, or an investigational therapy is the most appropriate treatment option. This requires understanding of the biology and risk profile of the AML, clinical judgment in evaluating the functional status of the patient, communication skills in understanding the patient's wishes and social background, and medical expertise in available therapies. The physician has to accurately inform the patient about (a) the unique biological considerations of his leukemia and his prognosis; (b) the risks and benefits of all available treatment options; (c) novel therapeutic approaches and how the patient can get access to these treatments. Last but not least, he has to recommend a treatment. This paper tries to discuss each of these issues.

Randomized trial of two schedules of low-dose gemtuzumab ozogamicin as induction monotherapy for newly diagnosed acute myeloid leukaemia in older patients not considered candidates for intensive chemotherapy. A phase II study of the EORTC and GIMEMA leukaemia groups (AML-19)

This study compared two schedules of low-dose gemtuzumab ozogamicin (GO) as induction monotherapy for untreated acute myeloid leukaemia in older patients unfit for intensive chemotherapy, to identify the more promising regimen for further study. Patients were randomized to receive either best supportive care or a course of GO according to one of two schedules: 3 mg/m(2) on days 1, 3 and 5 (arm A), or GO 6 mg/m(2) on day 1 and 3 mg/m(2) on day 8 (arm B). Primary endpoint was the rate of disease non-progression (DnP), defined as the proportion of patients either achieving a response or maintaining a stable disease following GO induction in each arm. Fifty-six patients were randomized in the two GO arms (A, n = 29; B, n = 27). The rate of DnP was 38% [90% confidence interval (CI), 23-55] in arm A, and 63% (90% CI, 45-78) in arm B. Peripheral cytopenias were the most common adverse events for both regimens. The all-cause early mortality rate was 14% in arm A and 11% in arm B. The day 1 + 8 schedule, which was associated with the highest rate of DnP, met the statistical criteria to be selected as the preferred regimen for phase III comparison with best supportive care.

Azacitidine prolongs overall survival compared with conventional care regimens in elderly patients with low bone marrow blast count acute myeloid leukemia

PURPOSE

In a phase III randomized trial, azacitidine significantly prolonged overall survival (OS) compared with conventional care regimens (CCRs) in patients with intermediate-2- and high-risk myelodysplastic syndromes. Approximately one third of these patients were classified as having acute myeloid leukemia (AML) under current WHO criteria. This analysis compared the effects of azacitidine versus CCR on OS in this subgroup.

PATIENTS AND METHODS

Patients were randomly assigned to receive subcutaneous azacitidine 75 mg/m(2)/d or CCR (best supportive care [BSC] only, low-dose cytarabine (LDAC), or intensive chemotherapy [IC]).

RESULTS

Of the 113 elderly patients (median age, 70 years) randomly assigned to receive azacitidine (n = 55) or CCR (n = 58; 47% BSC, 34% LDAC, 19% IC), 86% were considered unfit for IC. At a median follow-up of 20.1 months, median OS for azacitidine-treated patients was 24.5 months compared with 16.0 months for CCR-treated patients (hazard ratio = 0.47; 95% CI, 0.28 to 0.79; P = .005), and 2-year OS rates were 50% and 16%, respectively (P = .001). Two-year OS rates were higher with azacitidine versus CCR in patients considered unfit for IC (P = .0003). Azacitidine was associated with fewer total days in hospital (P < .0001) than CCR.

CONCLUSION

In older adult patients with low marrow blast count (20% to 30%) WHO-defined AML, azacitidine significantly prolongs OS and significantly improves several patient morbidity measures compared with CCR.

MicroRNA expression profiling in acute myeloid and chronic lymphocytic leukaemias

Altered expression of microRNAs, a new class of noncoding RNAs that regulate messenger RNA and protein expression of target genes, has been recently demonstrated to have an essential role in the process of leukaemogenesis. Distinctive patterns of activation and/or silencing of multiple microRNAs (microRNA signatures) associated with certain cytogenetic and molecular subsets of leukaemia have been identified using genome-wide high-throughput profiling assays. This has led not only to the discovery of new molecular pathways implicated in leukaemogenesis, but also supplied prognostic information complementing that gained from cytogenetics, gene mutations and altered gene expression in acute and chronic leukaemias. We review herein results of current studies analysing changes of microRNA expression in acute myeloid leukaemia and chronic lymphocytic leukaemia, and discuss their potential biologic, diagnostic and prognostic relevance.