Acute myeloid leukemia

NIPBL: a new player in myeloid cell differentiation

The nucleophosmin 1 gene (NPM1) is the most frequently mutated gene in acute myeloid leukemia. Notably, NPM1 mutations are always accompanied by additional mutations such as those in cohesin genes RAD21, SMC1A, SMC3, and STAG2 but not in the cohesin regulator, nipped B-like (NIPBL). In this work, we analyzed a cohort of adult patients with acute myeloid leukemia and NPM1 mutation and observed a specific reduction in the expression of NIPBL but not in other cohesin genes. In our zebrafish model, overexpression of the mutated form of NPM1 also induced downregulation of nipblb, the zebrafish ortholog of human NIPBL To investigate the hematopoietic phenotype and the interaction between mutated NPM1 and nipblb, we generated a zebrafish model with nipblb downregulation which showed an increased number of myeloid progenitors. This phenotype was due to hyper-activation of the canonical Wnt pathway: myeloid cells blocked in an undifferentiated state could be rescued when the Wnt pathway was inhibited by dkk1b mRNA injection or indomethacin administration. Our results reveal, for the first time, a role for NIPBL during zebrafish hematopoiesis and suggest that an interplay between NIPBL/NPM1 may regulate myeloid differentiation in zebrafish and humans through the canonical Wnt pathway and that dysregulation of these interactions may drive leukemic transformation.

Recent Treatment Advances and the Role of Nanotechnology, Combination Products, and Immunotherapy in Changing the Therapeutic Landscape of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia that is becoming more prevalent particularly in the older (65 years of age or older) population. For decades, "7 + 3" remission induction therapy with cytarabine and an anthracycline, followed by consolidation therapy, has been the standard of care treatment for AML. This stagnancy in AML treatment has resulted in less than ideal treatment outcomes for AML patients, especially for elderly patients and those with unfavourable profiles. Over the past two years, six new therapeutic agents have received regulatory approval, suggesting that a number of obstacles to treating AML have been addressed and the treatment landscape for AML is finally changing. This review outlines the challenges and obstacles in treating AML and highlights the advances in AML treatment made in recent years, including Vyxeos®, midostaurin, gemtuzumab ozogamicin, and venetoclax, with particular emphasis on combination treatment strategies. We also discuss the potential utility of new combination products such as one that we call "EnFlaM", which comprises an encapsulated nanoformulation of flavopiridol and mitoxantrone. Finally, we provide a review on the immunotherapeutic landscape of AML, discussing yet another angle through which novel treatments can be designed to further improve treatment outcomes for AML patients.

Outcome and Prognostic Factors of High-Risk Acute Myeloid Leukemia After Allogeneic Hematopoietic Stem Cell Transplantation

Background

Allogeneic transplantation remains one of the best therapies for high-risk acute myeloid leukemia (HR-AML).

Material/Methods

This study retrospectively analyzed 126 patients with HR-AML after allogeneic hematopoietic stem cell transplantation (allo-HCST).

Results

The disease-free survival (DFS) rates of 1 year and 3 years were 58.83% (95%CI: 50.75–68.20%) and 53.09% (95%CI: 44.59–63.22%) respectively. The cumulative relapse rates of 1 year and 3 years were 21.1% (95%CI: 14.4–28.8%) and 25.9% (95%CI: 18.1–34.5%) respectively. The cumulative incidences of III to IV acute graft-versus-host disease (aGVHD) for 100 days was 8.70% (95%CI: 4.6–14.5%). The cumulative rate of extensive chronic graft-versus-host disease (cGVHD) for 1-year was 4.1% (95%CI: 1.5–8.7%). The cumulative transplantation related mortality rate of 1 year and 3 years were 20.1% (95%CI: 13.6–27.6%) and 21.0% (95%CI: 14.3–28.6%) respectively. Univariate analysis revealed that lower overall survival was correlated with age, bacterial or fungal infection, disease status at transplantation, III–IV aGVHD, post-transplantation lymphoproliferative disorders (PTLD), white blood cell engraftment, and extramedullary involvement (P<0.05). The results of multivariate analysis were that the aforementioned factors were also related to lower overall survival except for PTLD (P<0.05). The results of univariate and multivariate analysis were that extramedullary involvement, III–IV aGVHD, and status pre-transplantation influenced DFS (P<0.05). The risk factors for relapse were status pre-transplantation and extramedullary involvement by univariate and multivariate analysis (P<0.05).

Conclusions

HR-AML has inferior prognosis. Our study indicated the necessity of achieving remission status prior to hematopoietic stem cell transplantation, and administration of preventive treatments on high-risk patients after hematopoietic stem cell transplantation. In addition, adequate prevention and treatment of complications are needed.

Identification of FLT3 and NPM1 Mutations in Patients with Acute Myeloid Leukaemia

Objective:

The most frequent acquired molecular abnormalities and important prognostic indicators in patients with Acute Myeloid Leukaemia (AML) are fms-like tyrosine kinase-3 gene (FLT3) and nucleophosmin-1 (NPM1) mutations. Our study aims to develop a cost effective and comprehensive in-house conventional PCR method for detection of FLT3-ITD, FLT3-D835 and NPM1 mutations and to evaluate the frequency of these mutations in patients with cytogenetically normal (CN) AML in our population.

Methods:

A total of 199 samples from AML patients (95 women, 104 men) were included in the study. Mutation analyses were performed using polymerase chain reaction (PCR) and gene sequencing.

Result:

Sixty-eight patients were positive for the mutations. FLT3-ITD mutations were detected in 32 patients (16.1%), followed by FLT3-D835 in 5 (2.5%) and NPM1 in 54 (27.1%). Double mutations of NPM1 and FLT3-ITD were detected in 23 cases (11.6%). Assays validation were performed using Sanger sequencing and showed 100% concordance with in house method.

Conclusion:

The optimized in-house PCR assays for the detection of FLT3-ITD, FLT3-D835 and NPM1 mutations in AML patients were robust, less labour intensive and cost effective. These assays can be used as diagnostic tools for mutation detection in AML patients since identification of these mutations are important for prognostication and optimization of patient care.

Role of alternative donor allogeneic hematopoietic stem cell transplantation in patients with intermediate- or poor-risk acute myeloid leukemia in first complete remission

Allogeneic hematopoietic stem cell transplantation (HCT) offers the most effective prevention of relapse and has significant overall survival (OS) benefits for patients with acute myeloid leukemia (AML) in first complete remission (CR1). We conducted a retrospective analysis of a cohort of patients with intermediate- or poor-risk AML. The purpose of the present study was to investigate the role of alternative donors for AML in CR1. We analyzed 1561 patients who underwent HCT from an HLA-matched related donor (MRD), HLA 8/8-matched unrelated donor (MUD), or umbilical cord blood (UCB). The results of a multivariate analysis showed that HCT from UCB (HR = 1.28, 95% CI: 1.07-1.52), age ≥50 years (HR = 1.36, 95% CI: 1.14-1.62), male (HR = 1.42, 95% CI: 1.21-1.66), PS > 1 (HR = 1.68, 95% CI: 1.17-2.42), and poor-risk cytogenetics (HR = 1.53, 95% CI: 1.29-1.81) had an inferior prognostic impact on OS. We conclude that an MUD is the best alternative to an HLA identical MRD for patients with AML in CR1. UCB is an alternative option if neither MRD nor MUD are available, or when patients need to receive urgent HCT for poor-risk AML in CR1.

Pre-clinical evaluation of Minnelide as a therapy for acute myeloid leukemia

Background

There is an urgent need for novel and effective treatment options for acute myeloid leukemia (AML). Triptolide, a diterpenoid tri-epoxide compound isolated from the herb Tripterygium wilfordii and its water-soluble pro-drug-Minnelide have shown promising anti-cancer activity. A recent clinical trial for patients with solid tumors confirmed the safety and efficacy at biologically equivalent doses of 0.2 mg/kg/day and lower.

Methods

Cell viability of multiple AML cell lines as well as patient apheresis samples were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) based assay. Apoptosis was evaluated by estimating the amount of cleaved caspase. AML cell line (THP1-Luc) was implanted in immunocompromised mice and treated with indicated doses of Minnelide. Leukemic burden before and after treatment was evaluated by imaging in an In Vivo Imaging System (IVIS).

Results

In the current study, we show that Minnelide, at doses below maximum tolerated dose (MTD) demonstrates leukemic clearance of both primary AML blasts and luciferase expressing THP-1 cells in mice. In vitro, multiple primary AML apheresis samples and AML cell lines (THP-1, KG1, Kasumi-1, HL-60) were sensitive to triptolide mediated cell death and apoptosis in low doses. Treatment with triptolide led to a significant decrease in the colony forming ability of AML cell lines as well as in the expression of stem cell markers. Additionally, it resulted in the cell cycle arrest in the G1/S phase with significant downregulation of c-Myc, a major transcriptional regulator mediating cancer cell growth and stemness.

Conclusion

Our results suggest that Minnelide, with confirmed safety and activity in the clinic, exerts a potent anti-leukemic effect in multiple models of AML at doses easily achievable in patients.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1901-8) contains supplementary material, which is available to authorized users.

Radiocarbon Tracers in Toxicology and Medicine: Recent Advances in Technology and Science

This review summarizes recent developments in radiocarbon tracer technology and applications. Technologies covered include accelerator mass spectrometry (AMS), including conversion of samples to graphite, and rapid combustion to carbon dioxide to enable direct liquid sample analysis, coupling to HPLC for real-time AMS analysis, and combined molecular mass spectrometry and AMS for analyte identification and quantitation. Laser-based alternatives, such as cavity ring down spectrometry, are emerging to enable lower cost, higher throughput measurements of biological samples. Applications covered include radiocarbon dating, use of environmental atomic bomb pulse radiocarbon content for cell and protein age determination and turnover studies, and carbon source identification. Low dose toxicology applications reviewed include studies of naphthalene-DNA adduct formation, benzo[a]pyrene pharmacokinetics in humans, and triclocarban exposure and risk assessment. Cancer-related studies covered include the use of radiocarbon-labeled cells for better defining mechanisms of metastasis and the use of drug-DNA adducts as predictive biomarkers of response to chemotherapy.

Importance of prognostic stratification via gene mutation analysis in elderly patients with acute myelogenous leukemia

INTRODUCTION

Acute myelogenous leukemia (AML) in elderly patients is associated with an increased incidence of complications and treatment-related toxicity because of the frequency of comorbid disease and age-related deterioration in organ function. Despite advances in AML treatment in recent years, elderly patients have experienced limited benefit, and their outcomes remain poor. This study aimed to perform a comprehensive gene mutation analysis in elderly AML patients and identify gene mutations that could serve as prognostic factors.

METHODS

An analysis of gene mutations was performed for 281 AML patients, including 98 elderly patients aged 65 years or above.

RESULTS

Compared to younger AML patients, elderly patients showed a higher frequency of the following gene mutations: TP53 (P = 0.026), PTPN11 (P = 0.006), RUNX1 (P = 0.024), TET2 (P = 0.002), and ASXL1 (P = 0.023). The complete remission rate was significantly lower in DNMT3A mutation-positive cases (4.26%, P = 0.011) and TP53 mutation-positive cases (2.13%, P = 0.031) than in negative cases. The overall survival rate was significantly poorer in cases with FLT3-ITD (P = 0.003), DNMT3A (P = 0.033), or TP53 mutation (P < 0.001). Conversely, cases with PTPN11 mutation (P = 0.014) had a significantly more favorable prognosis. In multivariate analysis, FLT3-ITD (P = 0.011) and TP53 mutation positivity (P = 0.002) were independent poor prognostic factors, as were a performance status of 3 or above (P < 0.001) and poor cytogenetic prognosis (P = 0.001). In contrast, PTPN11 mutation positivity (P = 0.023) was an independent favorable prognosis factor.

CONCLUSION

Analysis of gene mutations in elderly AML patients is very important, not only for establishing prognosis, but also for introducing appropriate molecular-targeted treatments.

Enigmatic Ladies of the Rings: How Cohesin Dysfunction Affects Myeloid Neoplasms Insurgence

The genes of the cohesin complex exert different functions, ranging from the adhesion of sister chromatids during the cell cycle, DNA repair, gene expression and chromatin architecture remodeling. In recent years, the improvement of DNA sequencing technologies allows the identification of cohesin mutations in different tumors such as acute myeloid leukemia (AML), acute megakaryoblastic leukemia (AMKL), and myelodysplastic syndromes (MDS). However, the role of cohesin dysfunction in cancer insurgence remains elusive. In this regard, cells harboring cohesin mutations do not show any increase in aneuploidy that might explain their oncogenic activity, nor cohesin mutations are sufficient to induce myeloid neoplasms as they have to co-occur with other causative mutations such as NPM1, FLT3-ITD, and DNMT3A. Several works, also using animal models for cohesin haploinsufficiency, correlate cohesin activity with dysregulated expression of genes involved in myeloid development and differentiation. These evidences support the involvement of cohesin mutations in myeloid neoplasms.

The prognostic value of matrix metalloproteinase-7 and matrix metalloproteinase-15 in acute myeloid leukemia

Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, are involved in a variety of physiological and pathological processes. We analyzed 11 data sets from Gene Expression Omnibus Database and found that MMP7 and MMP15 were highly expressed in multiple carcinomas. GSE13204 showed that MMP7 and MMP15 were overexpressed in acute myeloid leukemia (AML) patients. The Cancer Genome Atlas data set exhibited that high expression of MMP7 or MMP15 in bone marrow (BM) of AML patients predicted poor overall survival. The χ ² test results indicated that high expression level of MMP7 and MMP15 were correlated with high-risk stratification and high BM blast cell percentage in AML patients. To confirm these findings, we performed reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and found that MMP7 and MMP15 were highly expressed in three AML cell lines. Further study showed that MMP7 and MMP15 were highly expressed both in BM and peripheral blood in collected AML samples compared with healthy individuals. Additionally, long noncoding RNA (lncRNA) microarray of BM samples of AML patients revealed that multiple lncRNAs were correlated with MMP7 and MMP15, suggesting that lncRNAs might be involved in the pathogenesis of AML via modulating MMPs. In conclusion, our study uncovers the potential roles of MMP7 and MMP15 in the prognosis of AML.

[The study of expression and prognostic value of CD123 in acute myeloid leukemia bone marrow blasts]

Objective: To study the expression of CD123 in bone marrow (BM) blasts of acute myeloid leukemia (AML) patients to explore the relationship between CD123 expression and therapeutic response and prognosis. Methods: This study retrospectively analyzed expression and distribution of CD123 in BM blasts in 137 cases of newly diagnosed AML (excluded M(3)) , CD123 detected by flow cytometry≥20% was defined as positive, including 84 CD123(+) AML and 53 CD123(-) AML, efficacy and prognosis were compared between the two groups. Results: ① Among 137 patients, 84 were in group CD123(+) (61.3%) , and 53 in group CD123(-) (38.7%) . All 137 patients were classified into risk groups based on cytogenetic and molecular biology abnormalities. No significant differences were seen between the three risk groups with regard to their CD123 levels (χ(2)=0.861, P=0.650) . Compared with CD123(-) group, the CD123(+) group had higher WBC[47.7 (1.0-264.0) vs 22.4 (0.7-211.0) , z=-2.592, P=0.010]. ② The rates of first complete remission (CR1) and recurrence of CD123(+) group were 54.8% (46/84) and 50.8% (32/63) , respectively; and CD123(-) group were 73.6% (39/53) and 41.7% (20/48) , respectively. There was significant difference of CR1 between the two groups (χ(2)=5.121, P=0.027) , whereas no significant difference of the recurrence rate (χ(2)=0.911, P=0.340) . ③ The median dutations of OS between CD123(+) group and CD123(-) group were 20.0 (95%CI 13.1-26.9) months vs 44.0 (95%CI 23.6-47.3) months, respectively (χ(2)=5.874, P=0.015) ; The median durations of DFS were 7.8 (95%CI 1.4-14.1) months vs 18.6 (95%CI 0-39.7) months, respectively, no differences were observed between the two groups (χ(2)=2.939, P=0.086) . ④ CD123 retained an adverse prognosis value on DFS and OS within the intermediate group and patients ≤ 50 years older. Conclusions: CD123 widely expressed in AML patients, which was an independent risk factor for CR1 and OS, which implicating its important role in evaluating the induction chemotherapy response and prognosis of AML.

Comparison of Myeloablative Versus Reduced-Intensity Conditioning Regimens for Allogeneic Hematopoietic Stem Cell Transplantation in Acute Myeloid Leukemia: A Cohort Study

Objective

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment modality for a variety of malignant and non-malignant hematologic disorders. Myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC) regimens could have different clinical outcomes. This purpose of this study was to assess the long-term outcome of MAC versus RIC regimens in patients with acute myeloid leukemia (AML) undergoing allogeneic HSCT.

Materials and Methods

We retrospectively compared long-term outcomes with MAC and RIC regimens in patients with AML who underwent allo-HSCT at our tertiary transplantation center.

Results

We analyzed survival outcomes after MAC-HSCT versus RICHSCT among 107 adult patients with AML diagnosed from 2001 through 2017. Of those, 44 patients underwent a MAC regimen, whereas 63 patients received a RIC regimen. The median follow-up time was 37 months (range: 6-210) for the entire group. The 3-year overall survival (OS) for RIC and MAC patients was 67% and 60%, respectively (p>0.05). The 3-year progression-free survival (PFS) for RIC and MAC patients was 88% and 77%. In multivariate analysis, the type of conditioning regimen (RIC vs. MAC) did not influence PFS (p=0.24). Acute graft-versus-host disease (GVHD) was seen in five of the RIC patients and 9 of the MAC patients. Chronic GVHD was seen in 16 of the RIC patients and 6 of the MAC patients. There was no significant difference between the two groups in terms of acute GVHD (p=0.089), but there was a significant difference between the two groups in terms of chronic GVHD (p=0.03).

Conclusion

This retrospective analysis confirmed that MAC and RIC regimens had a consistently equivalent rate of OS and PFS in AML patients who underwent allo-HSCT. The choice of MAC versus RIC conditioning regimen might be decided on the basis of patient and disease characteristics.

miR-345-5p regulates proliferation, cell cycle, and apoptosis of acute myeloid leukemia cells by targeting AKT2

Acute myeloid leukemia (AML) is a malignant clonal hematopoietic disease, which is caused by hematopoietic stem cell abnormalities. Epigenetic regulation, especially of microRNAs (miRNAs), mostly results from external or environmental effects and is critical to AML. In this study, for the first time, we report that decreased expression of miR-345-5p facilitates the proliferation of leukemia cells in AML. Further study demonstrated that AKT1/2 was the target of miR-345-5p and was responsible for the dysregulation of leukemia cell proliferation and apoptosis. Inhibition of AKT1/2 ameliorated this malignant effect, which provides new insight into AML diagnosis, treatment, prognosis, and next-step translational investigations.

Induction and Therapeutic Targeting of Human NPM1c+ Myeloid Leukemia in the Presence of Autologous Immune System in Mice

Development of targeted cancer therapy requires a thorough understanding of mechanisms of tumorigenesis as well as mechanisms of action of therapeutics. This is challenging because by the time patients are diagnosed with cancer, early events of tumorigenesis have already taken place. Similarly, development of cancer immunotherapies is hampered by a lack of appropriate small animal models with autologous human tumor and immune system. In this article, we report the development of a mouse model of human acute myeloid leukemia (AML) with autologous immune system for studying early events of human leukemogenesis and testing the efficacy of immunotherapeutics. To develop such a model, human hematopoietic stem/progenitor cells (HSPC) are transduced with lentiviruses expressing a mutated form of nucleophosmin (NPM1), referred to as NPM1c. Following engraftment into immunodeficient mice, transduced HSPCs give rise to human myeloid leukemia, whereas untransduced HSPCs give rise to human immune cells in the same mice. The de novo AML, with CD123⁺ leukemic stem or initiating cells (LSC), resembles NPM1c⁺ AML from patients. Transcriptional analysis of LSC and leukemic cells confirms similarity of the de novo leukemia generated in mice with patient leukemia and suggests Myc as a co-operating factor in NPM1c-driven leukemogenesis. We show that a bispecific conjugate that binds both CD3 and CD123 eliminates CD123⁺ LSCs in a T cell-dependent manner both in vivo and in vitro. These results demonstrate the utility of the NPM1c⁺ AML model with an autologous immune system for studying early events of human leukemogenesis and for evaluating efficacy and mechanism of immunotherapeutics.

Colonization with multidrug resistant organisms determines the clinical course of patients with acute myeloid leukemia undergoing intensive induction chemotherapy

Introduction

The global spread of multidrug-resistant organisms (MDRO) complicates treatment and isolation measures in hospitals and has shown to increase mortality. Patients with disease- or therapy-related immunodeficiency are especially at risk for fatal infections caused by MDRO. The impact of MDRO colonization on the clinical course of AML patients undergoing intensive induction chemotherapy—a potentially curative but highly toxic treatment option—has not been systematically studied.

Materials & methods

312 AML patients undergoing intensive induction chemotherapy between 2007 and 2015 were examined for MDRO colonization. Patients with evidence for MDRO before or during the hospital stay of induction chemotherapy were defined as colonized, patients who never had a positive swab for MDRO were defined as noncolonized.

Results

Of 312 AML patients 90 were colonized and 130 were noncolonized. Colonized patients suffered from significantly more days with fever, spent more days on the intensive care unit and had a higher median C-reactive protein value during the hospital stay. These findings did not result in a prolonged length of hospital stay or an increased mortality rate for colonized patients. However, in a subgroup analysis, patients colonized with carbapenem-resistant enterobacteriaceae (CRE) had a significantly reduced 60- and 90-day, as well as 1- and 2-year survival rates when compared to noncolonized patients.

Conclusion

Our analysis highlights the importance of intensive MDRO screening especially in patients with febrile neutropenia since persisting fever can be a sign of MDRO-colonization. CRE-colonized patients require special surveillance, since they seem to be at risk for death.

Contribution and prognostic value of TSGA10 gene expression in patients with acute myeloid leukemia (AML)

BACKGROUND

Different studies have investigated TSGA10 expression in various cancerous tissues but, so far no study has been conducted on newly diagnosed (ND) AML patients. The association of TSGA10 gene expression with hypoxia inducible factor (HIF) and angiogenic factors has remained to be fully elucidated and is still a controversial issue. The present study was designed to investigate this association in patients newly diagnosed with AML.

METHODS

We evaluated TSGA10, HIF-1α and VEGF mRNA levels in ND AML patients and healthy subjects using real-time PCR technique. Data were analyzed via comparative Livak method.

RESULTS

Based on the results of this study, TSGA10 gene expression was decreased in 28 out of 30 (93.3%) samples while VEGF and HIF-1α expression levels were increased in all ND AML patients compared to healthy controls. Diagnostic evaluation was performed by receiver operating characteristic (ROC) curve and area under the curve (AUC) calculation. Respectively, using cut-off relative quantification of 1.604, 0.0329, and 0.0042, the sensitivity values of TSGA10, VEGF, and HIF-1α gene expression were 86.7%, 90%, and 100%. Also, specificity values were 100%, 100% and 100%, respectively. TSGA10 expression was shown to be reduced in ND AML patients compared with healthy subjects and we found a negative correlation between TSGA10 and VEGF expression.

CONCLUSIONS

Since TSGA10 interacts with HIF-1 and affects its transcriptional activity, in ND AML patients with decreased TSGA10 expression, VEGF expression was high suggesting a TSGA10 mediated regulation of HIF-1 target genes. Altogether, the current study showed that TSGA10 could be considered as a tumor suppressor in AML patients.

Recent advances in functional nanostructured materials for bone-related diseases

Bone-related diseases seriously threaten people's health and research studies have been dedicated towards searching for new and effective treatment methods. Nanotechnologies have opened up a new field in recent decades and nanostructured materials, which exist in a variety of forms, are considered to be promising materials in this field. This article reviews the most recent progress in the development of nanostructured materials for bone-related diseases, including osteoporosis, osteoarthritis, bone metastasis, osteomyelitis, myeloma, and bone defects. We highlight the advantages and functions of nanostructured materials, including sustained release, bone targeting, scaffolding in bone tissue engineering, etc., in bone-related diseases. We also include the remaining challenges of these emerging materials.

Inhibited CD47 gene affects the clearance of acute myelogenous leukemia stem cells

OBJECTIVE

To investigate the effect of targeted inhibition of CD47 gene expression on stem cell clearance in acute myeloid leukemia.

METHODS

After the lentiviral CD47-siRNA was transfected into acute myelogenous leukemia stem cells (LSCs), the proliferative status of acute myelogenous LSCs was detected by cell counting kit-8, and the apoptosis of stem cells of acute myeloid leukemia was detected by annexin/propidium iodide flow assays. The expression of Bcl-2, Bcl-xl, MCL-1, PIK3p110β, and interleukin (IL)-3 in acute myeloid LSCs was detected by Western blot analysis and the activity of protein phosphatase 2A (PP2A) and the protein content of CD96 and CD90 were measured by enzyme-linked immunosorbent assay kits.

RESULTS

After transfection of the lentivirus CD47-siRNA into acute myeloid LSCs, compared with the empty vector transfection group (control group), the cell viability of the CD47-siRNA transfection group was decreased, and the apoptosis rate was increased. Furthermore, the antiapoptotic protein Bcl-2, Bcl-xl, and MCL-1 and the content of IL-3 protein, CD96, and CD90 was decreased, whereas the activity of PIK3p110β and PP2A protein was increased.

CONCLUSION

Targeted inhibition of CD47 could inhibit the proliferation of myeloid LSCs, promote apoptosis, mobilize the cells into the cell cycle, and reduce the high expression of immune proteins on the cell surface, therefore providing a theoretical basis for the elimination and eradication of LSCs.

Analysis of Efficacy and Prognostic Factors of CLAG Treatment in Chinese Patients with Refractory or Relapsed Acute Myeloid Leukemia

BACKGROUND/AIMS

The aim of this work was to investigate the efficacy and predictive factors of CLAG treatment in refractory or relapsed (R/R) acute myeloid leukemia (AML) patients.

METHODS

Sixty-seven R/R AML patients were enrolled in this prospective cohort study and treated by a CLAG regimen: 5 mg/m2/day cladribine (days 1-5), 2 g/m2/day cytarabine (days 1-5), and 300 μg/day filgrastim (days 0-5). The median follow-up duration was 10 months.

RESULTS

A total of 57 out of 67 patients were evaluable for remission after CLAG therapy, of whom 57.9% achieved a complete remission (CR) and the overall remission rate was 77.2%. The median overall survival (OS) was 10.0 months, with a 1-year OS of 40.3 ± 6.0% and 3-year OS of 16.7 ± 5.7%. CR at first induction after the initial diagnosis was associated with a favorable CR. Age above 60 years, high risk stratification, second or higher salvage therapy, and bone marrow (BM) blasts ≥42.1% were correlated with an unfavorable CR. Secondary disease, age ≥60 years, high risk stratification, and second or higher salvage therapy were associated with worse OS. Patients developed thrombocytopenia (41, 61%), febrile neutropenia (37, 55%), leukopenia (33, 49%), neutropenia (18, 27%), and anemia (9, 13%).

CONCLUSION

CLAG was effective and well tolerated for R/R AML. BM blasts ≥42.1%, age ≥60 years, high risk stratification, and second or higher salvage therapy were independent factors for a poor prognosis.

Midostaurin reduces Regulatory T cells markers in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy in which the only curative approach is allogeneic stem cell transplant (Allo-HSCT). The recognition and elimination of leukemic clones by donor T-cells contribute significantly to Allo-HSCT success. FLT3-ITD, a common mutation in AML, is associated with poor prognosis. Recently, midostaurin became the first FDA approved FLT3-inhibitor for pre-transplant patients with FLT3-ITD in combination with standard therapy. In addition to their multikinase activity which may affect T-cell signaling, FLT3-inhibitors induce apoptosis of malignant cells which may also enhance antigen presentation to activate T-cells. Considering the increased clinical use of these inhibitors in patients with AML, and the limited clinical benefit derived from their use as single agents, understanding how FLT3-inhibitors affect T cell population and function is needed to improve their clinical benefit. We examined the effect of four different FLT3 inhibitors (midostaurin, sorafenib, tandutinib, and quizartenib) on T cell populations in peripheral blood mononuclear cells (PBMC) obtained from healthy donors and from patients with AML. Midostaurin exhibited a significant decrease in CD4 + CD25 + FOXP3+ T cell population and FOXP3 mRNA expression in healthy and AML PBMCs. Similarly, samples collected from patients with AML treated with midostaurin showed a reduction in Tregs markers. Interferon-γ(IFN-γ), tumor necrosis factor-α(TNF-α), and IL-10 levels were also reduced following midostaurin treatment. Considering the FDA approval of midostaurin for use in patients with AML in the pre-transplant setting, our finding will have important clinical implication as it provides the rationale for functional investigation of the use of midostaurin in post-transplant patients.

Loss of K607 and E877 interaction is a key reason for JAK2 K607N mutation caused acute myeloid leukemia

Oncogenic activation of tyrosine kinase signaling pathway is recurrent in human leukemia. The acquired Janus kinase 2 (JAK2) K607N somatic mutation was detected in about 6.8% of acute myeloid leukemia (AML) patients. However, roles of JAK2 K607N mutation in the leukemogenesis of AML remain unclear. In this study, loss of interaction between K607 and E877 was identified as key reasons for JAK2 K607N mutation constitutive activation. JAK2 K607N and mutations (K607A, K607G and E877A) abolished the K607 and E877 interaction caused JAK2 constitutive activation. While, mutations (K607R, E877D) repairing this interaction reduced K607N mutation's activity. Furthermore, our studies showed that disruption of K607 and E877 interaction abolished JH1/JH2 domains' interactions and led to JAK2 constitutive activation. More importantly, JAK2 K607N and mutations disrupted this interaction enhanced JAK2-STAT5 pathway activation and the proliferation of Ba/F3 cells. Thus our studies provide clues in understanding the leukemogenesis of JAK2 K607N mutation in AML.

Conjugation of haematopoietic stem cells and platelets decorated with anti-PD-1 antibodies augments anti-leukaemia efficacy

Patients with acute myeloid leukaemia who relapse following therapy have few treatment options and face poor outcomes. Immune checkpoint inhibition, for example, by antibody-mediated programmed death-1 (PD-1) blockade, is a potent therapeutic modality that improves treatment outcomes in acute myeloid leukaemia. Here, we show that systemically delivered blood platelets decorated with anti-PD-1 antibodies (aPD-1) and conjugated to haematopoietic stem cells (HSCs) suppress the growth and recurrence of leukaemia in mice. Following intravenous injection into mice bearing leukaemia cells, the HSC-platelet-aPD-1 conjugate migrated to the bone marrow and locally released aPD-1, significantly enhancing anti-leukaemia immune responses, and increasing the number of active T cells, production of cytokines and chemokines, and survival time of the mice. This cellular conjugate also promoted resistance to re-challenge with leukaemia cells. Taking advantage of the homing capability of HSCs and in situ activation of platelets for the enhanced delivery of a checkpoint inhibitor, this cellular combination-mediated drug delivery strategy can significantly augment the therapeutic efficacy of checkpoint blockade.

Survival outcomes of CD34+CD38-LSCs and their expression of CD123 in adult AML patients

Background and aim

Acute myeloid leukemia (AML) is one of the most common leukemias in adults. AML is generally regarded as a stem cell disease characterized by an accumulation of undifferentiated and functionally heterogeneous populations of cells, The aim of the present study was to identify leukemia stem cells in patients with AML and their correlations with treatment outcomes namely remission status, disease free survival, and overall survival.

Results

The mean percentages of CD34⁺CD38^- and CD34⁺CD38^low/−CD123⁺ LSCs were 2.2± 0.4and 22.3± 2.6, respectively. The percentages of CD34⁺cells, CD34⁺CD38^- and CD34⁺CD38^low/−CD123⁺ LSCs were significantly lower in AML patients with complete remission than those without complete response (P<0.001, P<0.004, P<0.001 respectively). The mean OS of all study patients was 20.03±1.2 months while the median OS was 21 months (95% CI=18.32-21.48). The mean DFS was 16.96±1.02 months and the median was 18 months (95% CI=8.9-11.4). DFS and OS were significantly higher among those who achieved CR than those without CR. In addition, there were significant negative effects of WBCs, CD34⁺cells, CD34⁺CD38^- and CD34⁺CD38^-CD123⁺LSCs on DFS and OS.

Patients and methods

We investigated 30 patients with newly diagnosed AML; all patients underwent complete history taking, and thorough physical and clinical examination, complete blood count. Peripheral smears and bone marrow aspirates were also examined. Cytochemistry and immunophenotyping of leukemic cells were performed routinely in bone marrow using monoclonal antibodies. Flow cytometry was used to analyze leukemia stem cells and their expression of CD123.

Conclusion

Our study elucidated that CD34+CD38-LSCs, with or without CD123+LSCs phenotype was present in a significant proportion of AML patients and it could be responsible for resistance to traditional treatments, and high percentage of MRD that was translated into significantly high number of non CR, poor DFS, and OS.

Efficacy and safety of lenalidomide for the treatment of acute myeloid leukemia: a systematic review and meta-analysis

Background

Lenalidomide is effective for the treatment of low-risk myelodysplastic syndromes with deletion 5q abnormalities. However, whether lenalidomide leads to a significant improvement in treatment response and overall survival (OS) in cases of acute myeloid leukemia (AML) remains controversial. A systematic review and a meta-analysis were performed to evaluate the efficacy and safety of lenalidomide in the treatment of AML.

Methods

Clinical studies were identified from the Cochrane Central Register of Controlled Trials, PubMed, Embase, and ClinicalTrials.gov. Efficacy outcomes included overall response rate (ORR), complete remission (CR), and OS. Safety was evaluated based on the incidence of grade 3 and 4 treatment-related adverse events (AEs).

Results

Eleven studies were included in our meta-analysis; collectively these studies featured 407 AML patients. Pooled estimates for overall ORR and CR were 31% (95% CI: 26%–36%) and 21% (95% CI: 16%–27%), respectively. Thrombocytopenia, anemia, neutropenia, and infection were the most common grade 3 and 4 AEs.

Conclusion

Lenalidomide may have some clinical activity in AML, but the population that would benefit from lenalidomide and incorporating lenalidomide into combination drug strategies need to be better defined.

Enhanced Anti-Leukemic Effects through Induction of Immunomodulating Microenvironment by Blocking CXCR4 and PD-L1 in an AML Mouse Model

Previously, we found that dual therapy by the CXCR4 inhibitor Plerixafor and cytosine arabinoside (Ara-C) effectively eradicated leukemia cells and concurrently activated immune cells in acute myeloid leukemia (AML). To reveal the significance of programmed death-ligand1 (PD-L1) in AML and as a strategic approach, we investigated the anti-leukemic effect of a triple combinational therapy by utilizing Plerixafor and anti-PD-L1 in combination with chemotherapy in an AML mouse model. We examined leukemic myeloid blast cells in multiple organs after the successive treatment with Ara-C, Plerixafor, and anti-PD-L1. The results showed that noticeable benefits of triple combinational therapy for eradication of myeloid blast cells in vivo with prolonged survival rates. The frequencies of regulatory T cells (Tregs), monocytic-myeloid-derived suppressor cells (M-MDSCs), and granulocytic-myeloid-derived suppressor cells (G-MDSCs), in the peripheral blood of leukemic mice were consistently decreased, even when mice were sacrificed alive at D + 26 after completion of the triple combinational therapy, compared to the other subgroups. These findings imply that the modulation by the triple combinational therapy may lead to more efficient leukemic myeloid blast cell ablation through the suppression of Tregs or M-MDSCs and G-MDSCs in AML. Although Plerixafor and PD-L1 antagonist do not have a direct anti-leukemic role, our results provide some clues and guidelines to develop clinically therapeutic strategies for chemotherapy-resistant patients by the modulation of leukemic microenvironments.

Toward Predicting Acute Myeloid Leukemia Patient Response to 7 + 3 Induction Chemotherapy via Diagnostic Microdosing

Acute myeloid leukemia (AML) is a rare yet deadly cancer of the blood and bone marrow. Presently, induction chemotherapy with the DNA damaging drugs cytarabine (ARA-C) and idarubicin (IDA), known as 7 + 3, is the standard of care for most AML patients. However, 7 + 3 is a relatively ineffective therapy, particularly in older patients, and has serious therapy-related toxicities. Therefore, a diagnostic test to predict which patients will respond to 7 + 3 is a critical unmet medical need. We hypothesize that a threshold level of therapy-induced 7 + 3 drug-DNA adducts determines cytotoxicity and clinical response. We further hypothesize that in vitro exposure of AML cells to nontoxic diagnostic microdoses enables prediction of the ability of AML cells to achieve that threshold during treatment. Our test involves dosing cells with very low levels of ¹⁴C-labeled drug followed by DNA isolation and quantification of drug-DNA adducts via accelerator mass spectrometry. Here, we have shown proof of principle by correlating ARA-C- and DOX-DNA adduct levels with cellular IC₅₀ values of paired sensitive and resistant cancer cell lines and AML cell lines. Moreover, we have completed a pilot retrospective trial of diagnostic microdosing for 10 viably cryopreserved primary AML samples and observed higher ARA-C- and DOX-DNA adducts in the 7 + 3 responders than nonresponders. These initial results suggest that diagnostic microdosing may be a feasible and useful test for predicting patient response to 7 + 3 induction chemotherapy, leading to improved outcomes for AML patients and reduced treatment-related morbidity and mortality.

Characterization of Mutations in the Mitochondrial Encoded Electron Transport Chain Complexes in Acute Myeloid Leukemia

Acute Myeloid Leukemia is a devastating and heterogeneous, hematological malignancy characterized by the uncontrolled proliferation of undifferentiated myeloid progenitor cells—blasts. Mutations in certain mitochondrial proteins, such as IDH2 have been shown to contribute to leukemogenesis. However, the role of mutations in mitochondrial-encoded Electron Transport Chain (ETC) genes have thus far not been well elucidated in AML. Here, we use TCGA data to characterize mutations in the ETC genes and their association with clinical outcomes in AML. We found that mitochondrial ETC mutations—in Complex I, III, IV and/or V (ATP Synthase)—were present in 8% of patients with AML and were significantly more frequent in older patients. Patients with ETC mutations had worse overall survival than ETC wild type patients (OS: 9.3 vs 20.1 months; p-value: 0.007). Additionally, mutations in either or both Complex I and IV were associated with TP53 mutations (p-value: 0.009), and among TP53 mutated patients, mutations in either or both Complex I and IV were significantly associated with worse overall survival (OS: 0.85 vs 9.4 months; p-value: 0.008). Elucidation of the mechanisms by which ETC mutations contribute to AML pathogenesis and progression would facilitate the development of novel therapeutic targets.

Chimeric Antigen Receptor-Engineered T Cell Therapy in Acute Myeloid Leukaemia

Acute myeloid leukaemia (AML) is a disease with a very poor outcome and remains an area of significant unmet need, necessitating novel therapeutic strategies. The progress made in the field of immunotherapy, in particular chimeric antigen receptor (CAR)-engineered T cells, has given rise to many hopes for pathologies such as B cell acute lymphoblastic leukaemia and B cell lymphoma, and many studies have attempted to translate these successes to AML. This review summarises the recent advances in, and defines an ideal target for, CAR T cell therapy in AML.

Small Molecules Co-targeting CKIα and the Transcriptional Kinases CDK7/9 Control AML in Preclinical Models

CKIα ablation induces p53 activation, and CKIα degradation underlies the therapeutic effect of lenalidomide in a pre-leukemia syndrome. Here we describe the development of CKIα inhibitors, which co-target the transcriptional kinases CDK7 and CDK9, thereby augmenting CKIα-induced p53 activation and its anti-leukemic activity. Oncogene-driving super-enhancers (SEs) are highly sensitive to CDK7/9 inhibition. We identified multiple newly gained SEs in primary mouse acute myeloid leukemia (AML) cells and demonstrate that the inhibitors abolish many SEs and preferentially suppress the transcription elongation of SE-driven oncogenes. We show that blocking CKIα together with CDK7 and/or CDK9 synergistically stabilize p53, deprive leukemia cells of survival and proliferation-maintaining SE-driven oncogenes, and induce apoptosis. Leukemia progenitors are selectively eliminated by the inhibitors, explaining their therapeutic efficacy with preserved hematopoiesis and leukemia cure potential; they eradicate leukemia in MLL-AF9 and Tet2^-/-;Flt3^ITD AML mouse models and in several patient-derived AML xenograft models, supporting their potential efficacy in curing human leukemia.

Signalling mechanisms that regulate metabolic profile and autophagy of acute myeloid leukaemia cells

Acute myeloid leukaemia (AML) comprises a heterogeneous group of hematologic neoplasms characterized by diverse combinations of genetic, phenotypic and clinical features representing a major challenge for the development of targeted therapies. Metabolic reprogramming, mainly driven by deregulation of the nutrient‐sensing pathways as AMPK, mTOR and PI3K/AKT, has been associated with cancer cells, including AML cells, survival and proliferation. Nevertheless, the role of these metabolic adaptations on the AML pathogenesis is still controversial. In this work, the metabolic status and the respective metabolic networks operating in different AML cells (NB‐4, HL‐60 and KG‐1) and their impact on autophagy and survival was characterized. Data show that whereas KG‐1 cells exhibited preferential mitochondrial oxidative phosphorylation metabolism with constitutive co‐activation of AMPK and mTORC1 associated with increased autophagy, NB‐4 and HL‐60 cells displayed a dependent glycolytic profile mainly associated with AKT/mTORC1 activation and low autophagy flux. Inhibition of AKT is disclosed as a promising therapeutical target in some scenarios while inhibition of AMPK and mTORC1 has no major impact on KG‐1 cells’ survival. The results highlight an exclusive metabolic profile for each tested AML cells and its impact on determination of the anti‐leukaemia efficacy and on personalized combinatory therapy with conventional and targeted agents.

Predictors of short-term and long-term mortality in critically ill patients admitted to the intensive care unit following allogeneic stem cell transplantation

Historically, the mortality of patients admitted to the ICU after allogeneic stem cell transplantation (alloSCT) is high. Advancements in transplantation procedures, infectious monitoring and supportive care may have improved the outcome. This study aimed to determine short-term and long-term mortality after ICU admission of patients after alloSCT and to identify prognostic clinical and transplantation-related determinants present at ICU admission for long-term outcome. A multicenter cohort study was performed to determine 30-day and 1-year mortality within 2 years following alloSCT. A total of 251 patients were included. The 30-day and 1-year mortality was 55% and 80%, respectively. Platelet count <25 × 10⁹/L (OR: 2.26, CI: 1.02-5.01) and serum bilirubin >19 μmol/L (OR: 2.47 CI: 1.08-5.65) at admission, other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 4.59, CI: 1.49-14.1) and vasoactive medication within 24 h (OR: 2.35, CI: 1.28-4.31) were associated with increased 30-day mortality. Other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 1.9, CI: 1.13-3.19), serum bilirubin >77 (OR: 2.05, CI: 1.28-3.30) and vasoactive medication within 24 h (OR: 1.65, CI: 1.12-2.43) were associated with increased 1-year mortality. Neutropenia was associated with decreased 30-day and 1-year mortality (OR: 0.29, CI: 0.14-0.59 and OR: 0.70, CI: 0.48-0.98). Myeloablative conditioning and T cell-depleted transplantation were not associated with increased mortality.

Effects of all-trans retinoic acid (ATRA) in addition to chemotherapy for adults with acute myeloid leukaemia (AML) (non-acute promyelocytic leukaemia (non-APL))

BACKGROUND

Acute myeloid leukaemia (AML) is the most common acute leukaemia affecting adults. Most patients diagnosed with AML are at advanced age and present with co-morbidities, so that intensive therapy such as stem cell transplantation (SCT) is impossible to provide or is accompanied by high risks for serious adverse events and treatment-related mortality. Especially for these patients, it is necessary to find out whether all-trans retinoic acid (ATRA), an intermediate of vitamin A inducing terminal differentiation of leukaemic cell lines, added to chemotherapy confers increased benefit or harm when compared with the same chemotherapy alone.

OBJECTIVES

This review aims to determine benefits and harms of ATRA in addition to chemotherapy compared to chemotherapy alone for adults with AML (not those with acute promyelocytic leukaemia (non-APL)).

SEARCH METHODS

We searched the Central Register of Controlled Trials (CENTRAL), MEDLINE, study registries and relevant conference proceedings up to July 2018 for randomised controlled trials (RCTs). We also contacted experts for unpublished data.

SELECTION CRITERIA

We included RCTs comparing chemotherapy alone with chemotherapy plus ATRA in patients with all stages of AML. We excluded trials if less than 80% of participants were adults or participants with AML, and if no subgroup data were available. Patients with myelodysplastic syndrome (MDS) were included, if they had a refractory anaemia and more than 20% of blasts.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of trials. We contacted study authors to obtain missing information. We used hazard ratios (HR) for overall survival (OS) and disease-free survival (DFS; instead of the pre-planned event-free survival, as this outcome was not reported), and we calculated risk ratios (RR) for the other outcomes quality of life, on-study mortality and adverse events. We presented all measures with 95% confidence intervals (CIs). We assessed the certainty of evidence using GRADE methods.

MAIN RESULTS

Our search resulted in 2192 potentially relevant references, of which we included eight trials with 28 publications assessing 3998 patients. Overall, we judged the potential risk of bias of the eight included trials as moderate. Two of eight trials were published as abstracts only. All the included trials used different chemotherapy schedules and one trial only evaluated the effect of the hypomethylating agent decitabine, a drug know to affect epigenetics, in combination with ATRA.The addition of ATRA to chemotherapy resulted in probably little or no difference in OS compared to chemotherapy only (2985 participants; HR 0.94 (95% confidence interval (CI) 0.87 to 1.02); moderate-certainty evidence). Based on a mortality rate at 24 months of 70% with chemotherapy alone, the mortality rate with chemotherapy plus ATRA was 68% (95% CI 65% to 71%).For DFS, complete response rate (CRR) and on-study mortality there was probably little or no difference between treatment groups (DFS: 1258 participants, HR 0.99, 95% CI 0.87 to 1.12; CRR: 3081 participants, RR 1.02, 95% CI 0.96 to 1.09; on-study mortality: 2839 participants, RR 1.02, 95% CI 0.81 to 1.30, all moderate-certainty evidence).Three trials with 1428 participants reported the adverse events 'infection' and 'cardiac toxicity': There was probably no, or little difference in terms of infection rate between participants receiving ATRA or not (RR 1.05, 95% CI 0.96 to 1.15; moderate-certainty evidence). We are uncertain whether ATRA decreases cardiac toxicity (RR 0.46, 95% CI 0.24 to 0.90; P = 0.02, very low certainty-evidence, however, cardiac toxicity was low).Rates and severity of diarrhoea and nausea/vomiting were assessed in two trials with 337 patients and we are uncertain whether there is a difference between treatment arms (diarrhoea: RR 2.19, 95% CI 1.07 to 4.47; nausea/vomiting: RR 1.46, 95% CI 0.75 to 2.85; both very low-certainty evidence).Quality of life was not reported by any of the included trials.

AUTHORS' CONCLUSIONS

We found no evidence for a difference between participants receiving ATRA in addition to chemotherapy or chemotherapy only for the outcome OS. Regarding DFS, CRR and on-study mortality, there is probably no evidence for a difference between treatment groups. Currently, it seems the risk of adverse events are comparable to chemotherapy only.As quality of life has not been evaluated in any of the included trials, further research is needed to clarify the effect of ATRA on quality of life.

Hexosamine Biosynthetic Pathway Inhibition Leads to AML Cell Differentiation and Cell Death

Treatment for acute myeloid leukemia (AML) has remained unchanged for past 40 years. Targeting cell metabolism is a promising avenue for future cancer therapy. We found that enzymes involved in metabolic hexosamine biosynthetic pathway (HBP) are increased in patients with AML. Inhibiting GFAT (the rate-limiting enzyme of HBP) induced differentiation and apoptosis in AML cells, sparing normal cells. UDP-GlcNAc, the end product of HBP, is the substrate for O-GlcNAcylation, a posttranslational modification. O-GlcNAc transferase (OGT) is the enzyme which transfers GlcNAc from UDP-GlcNAc to target proteins. Inhibition of O-GlcNAcylation, using OGT inhibitors as well as genetic knockdown of OGT, also led to cell differentiation and apoptosis of AML cells. Finally, HBP inhibition in vivo reduced the tumor growth in a subcutaneous AML xenograft model and tumor cells showed signs of differentiation in vivo A circulating AML xenograft model also showed clearance of tumor load in bone marrow, spleen, and blood, after HBP inhibition, with no signs of general toxicity. This study reveals an important role of HBP/O-GlcNAcylation in keeping AML cells in an undifferentiated state and sheds light into a new area of potential AML therapy by HBP/O-GlcNAc inhibition. Mol Cancer Ther; 17(10); 2226-37. ©2018 AACR.

Philadelphia-like acute lymphoblastic leukemia: diagnostic dilemma and management perspectives

Acute lymphoblastic leukemia (ALL) is an aggressive hematologic malignancy characterized by suboptimal outcomes in the adult age group. Recently, a new subtype called Philadelphia (Ph)-like ALL has been described. This subgroup is characterized by high cytokine receptor and tyrosine kinase signaling expression, resulting in kinase activation through stimulation of two main pathways, the ABL and JAK/STAT pathways. The diagnostic method or approach for Ph-like ALL is still not standardized and efforts are ongoing to identify an easy and applicable diagnostic method. Accurate and standard testing approaches are much needed and this will facilitate better understanding of this subgroup, including better estimation of the prevalence and incidence in different age groups and the clinical outcomes of such new entity. Here, we review the currently available diagnostic tools, activated pathways, and different therapeutic approaches used to target this subgroup.

Simple Physical Model Unravels Influences of Chemokine on Shape Deformation and Migration of Human Hematopoietic Stem Cells

We studied the dynamic behavior of human hematopoietic stem cells (HSC) on the in vitro model of bone marrow surfaces in the absence and presence of chemokine (SDF1α). The deformation and migration of cells were investigated by varying the chemokine concentration and surface density of ligand molecules. Since HSC used in this study were primary cells extracted from the human umbilical cord blood, it is not possible to introduce molecular reporter systems before or during the live cell imaging. To account for the experimental observations, we propose a simple and general theoretical model for cell crawling. In contrast to other theoretical models reported previously, our model focuses on the nonlinear coupling between shape deformation and translational motion and is free from any molecular-level process. Therefore, it is ideally suited for the comparison with our experimental results. We have demonstrated that the results in the absence of SDF1α were well recapitulated by the linear model, while the nonlinear model is necessary to reproduce the elongated migration observed in the presence of SDF1α. The combination of the simple theoretical model and the label-free, live cell observations of human primary cells opens a large potential to numerically identify the differential effects of extrinsic factors such as chemokines, growth factors, and clinical drugs on dynamic phenotypes of primary cells.

CD16+NK-92 and anti-CD123 monoclonal antibody prolongs survival in primary human acute myeloid leukemia xenografted mice

Patients with acute myeloid leukemia (AML) often relapse after initial therapy because of persistence of leukemic stem cells that frequently express the IL-3 receptor alpha chain CD123. Natural killer (NK) cell-based therapeutic strategies for AML show promise and we explore the NK cell lines, NK-92 and CD16⁺ NK-92, as a treatment for AML. NK-92 has been tested in phase I clinical trials with minimal toxicity; irradiation prior to infusion prevents risk of engraftment. The CD16 negative NK-92 parental line was genetically modified to express the high affinity Fc gamma receptor, enabling antibody-dependent cell-mediated cytotoxicity, which we utilized in combination with an anti-CD123 antibody to target leukemic stem cells. NK-92 was preferentially cytotoxic against leukemic stem and progenitor cells compared with bulk leukemia in in vitro assays, while CD16⁺ NK-92 in combination with an anti-CD123 mAb mediated antibody-dependent cell-mediated cytotoxicity against CD123⁺ leukemic targets. Furthermore, NK-92 infusions (with or without prior irradiation) improved survival in a primary AML xenograft model. Mice xenografted with primary human AML cells had a superior survival when treated with irradiated CD16⁺NK-92 cells and an anti-CD123 monoclonal antibody (7G3) versus treatment with irradiated CD16⁺NK-92 cells combined with an isotype control antibody. In this proof-of-principle study, we show for the first time that a CD16⁺NK-92 cell line combined with an antibody that targets a leukemic stem cell antigen can lead to improved survival in a relevant pre-clinical model of AML.

A novel scoring system for acute myeloid leukemia risk assessment based on the expression levels of six genes

Acute myeloid leukemia (AML) is the most common type of acute leukemia and is a heterogeneous clonal disorder. At present, the pathogenesis of AML and potential methods to effectively prevent AML have become areas of interest in research. In the present study, two messenger ribonucleic acid sequencing datasets of patients with AML were downloaded from the Cancer Genome Atlas and Gene Expression Omnibus databases. The differentially expressed genes (DEGs) of the poor and good prognosis groups were screened using the Linear Models for Microarray Data package, and the prognosis-related genes were screened using univariate Cox regression analysis. A total of 206 significant DEGs were identified. Following univariate and multivariate Cox regression analysis, 14 genes significantly associated with prognosis were screened and six of these genes, including triggering receptor expressed on myeloid cells 2 (TREML2), cysteine-glutamate transporter (SLC7A11), NACHT, LRR, and PYD domains-containing protein 2 (NLRP2), DNA damage-inducible transcript 4 protein (DDIT4), lymphocyte‑specific protein 1 (LSP1) and C-type lectin domain family 11 member A (CLEC11A), were used to construct model equations for risk assessment. The prognostic scoring system was used to evaluate risk for each patient, and the results showed that patients in the low-risk group had a longer survival time, compared with those in the high-risk group (P=9.59e-06 for the training dataset and P=0.00543 for the validation dataset). A total of eight main Kyoto Encyclopedia of Genes and Genomes pathways were identified, the top three of which were hematopoietic cell lineage, focal adhesion, and regulation of actin cytoskeleton. Taken together, the results showed that the scoring system established in the present study was credible and that the six genes were identified, which were significantly associated with the risk assessment of AML, offer potential as prognostic biomarkers. These findings may provide clues for further clarifying the pathogenesis of AML.

Treatment patterns, healthcare resource utilization, and costs in patients with acute myeloid leukemia in commercially insured and Medicare populations

OBJECTIVE

To describe the setting, duration, and costs of induction and consolidation chemotherapy for adults with newly-diagnosed acute myeloid leukemia (AML), who are candidates for standard induction chemotherapy, in the US.

METHODS

Adults newly-diagnosed with AML who received standard induction chemotherapy in an inpatient setting were identified from the Truven Health Analytics MarketScan (2006-2015) and SEER-Medicare (2007-2011) databases. Patients were observed from induction therapy start to the first of hematopoietic stem cell transplant, 180 days after induction discharge, health plan enrollment/data availability end, or death. Induction and consolidation chemotherapy were identified using Diagnosis-Related Group codes (chemotherapy with acute leukemia) or procedure codes for AML chemotherapy administration. AML treatment episode setting (inpatient or outpatient), duration, and costs (2015 USD, payers' perspective) were described for commercially insured patients and Medicare beneficiaries.

RESULTS

In total, 459 commercially insured patients and 563 Medicare beneficiaries (mean age = 54 and 66 years; 53% and 54% male; respectively) were identified. For induction therapy, mean costs were $145,189 for commercially insured patients and $85,734 for Medicare beneficiaries, and median inpatient duration was 31 days (both). Following induction, 64% of commercially insured patients and 53% of Medicare beneficiaries had ≥1 consolidation cycle; 75% and 65% of consolidation cycles were in an inpatient setting, respectively. For consolidation cycles, in the inpatient setting, mean costs were $28,137 for commercially insured patients and $28,843 for Medicare beneficiaries, median cycle duration was 6 days (both); in the outpatient setting, mean costs were $11,271 for commercially insured patients and $5,803 Medicare beneficiaries, median duration was 5 days (both).

LIMITATIONS

Granular information on chemotherapy type administered was unavailable.

CONCLUSIONS

This is the first exploratory study providing a complete picture of recent AML treatment patterns and management costs among commercially insured patients and Medicare beneficiaries. There is substantial heterogeneity in the management and costs of AML.