Advances in the Diagnosis and Treatment of Pediatric Acute Lymphoblastic Leukemia

Flow cytometric detection of leukemic blasts in Libyan pediatric patients with acute lymphoblastic leukemia

The diagnosis of acute lymphoblastic leukemia (ALL), which is the most common type of cancer in children, has become more accurate with the use of flow cytometry. Here, this technology was used to immunophenotype leukemic cells in peripheral blood samples from Libyan pediatric ALL patients. We recruited 152 newly diagnosed patients at Tripoli Medical Center (Tripoli, Libya) by morphological examination of blood and bone marrow. Twenty-three surface and cytoplasmic antigen markers were used to characterize B and T cells in circulating blood cells by four-color flow cytometry. Six children (3.9%) turned out to have biphenotypic acute leukemia, 88 (57.9%) had B ALL, and 58 (38.1%) had T ALL. There were 68 cases of pro-B ALL CD10-positive (44.7%), 8 cases of pro-B ALL CD10-negative (5.2%), 6 cases of pre-B ALL (3.9%), and 6 of mature-B ALL (3.9%). CD13 was the most commonly expressed myeloid antigen in ALL. We present immunophenotypic data for the first time describing ALL cases in Libya. The reported results indicate that the most common subtype was pro-B ALL, and the frequency of T-ALL subtype was higher compared to previous studies. Six cases were positive for both myeloid and B lymphoid markers. Our findings may provide the basis for future studies to correlate immunophenotypic profile and genetic characteristics with treatment response among ALL patients.

Diagnostic and treatment strategies for pediatric acute lymphoblastic leukemia in low- and middle-income countries

The survival rate of children and adolescents with acute lymphoblastic leukemia (ALL), the most common pediatric cancer, has improved significantly in high-income countries (HICs), serving as an excellent example of how humans can overcome catastrophic diseases. However, the outcomes in children with ALL in low- and middle-income countries (LMICs), where approximately 80% of the global population live, are suboptimal because of limited access to diagnostic procedures, chemotherapeutic agents, supportive care, and financial assistance. Although the implementation of therapeutic strategies in resource-limited countries could theoretically follow the same path of improvement as modeled in HICs, intensification of chemotherapy may simply result in increased toxicities. With the advent of genetic diagnosis, molecular targeted therapy, and immunotherapy, the management of ALL is changing dramatically in HICs. Multidisciplinary collaborations between institutions in LMICs and HICs will provide access to strategies that are suitable for institutions in LMICs, enabling them to minimize toxicities while improving outcomes. This article summarizes important aspects of the diagnosis and treatment of pediatric ALL that were mostly developed in HICs but that can be realistically implemented by institutions in countries with limited resources through resource-adapted multidisciplinary collaborations.

Valrubicin-loaded immunoliposomes for specific vesicle-mediated cell death in the treatment of hematological cancers

We created valrubicin-loaded immunoliposomes (Val-ILs) using the antitumor prodrug valrubicin, a hydrophobic analog of daunorubicin. Being lipophilic, valrubicin readily incorporated Val-lLs that were loaded with specific antibodies. Val-ILs injected intravenously rapidly reached the bone marrow and spleen, indicating their potential to effectively target cancer cells in these areas. Following the transplantation of human pediatric B-cell acute lymphoblastic leukemia (B-ALL), T-cell acute lymphoblastic leukemia (T-ALL), or acute myeloid leukemia (AML) in immunodeficient NSG mice, we generated patient-derived xenograft (PDX) models, which were treated with Val-ILs loaded with antibodies to target CD19, CD7 or CD33. Only a small amount of valrubicin incorporated into Val-ILs was needed to induce leukemia cell death in vivo, suggesting that this approach could be used to efficiently treat acute leukemia cells. We also demonstrated that Val-ILs could reduce the risk of contamination of CD34+ hematopoietic stem cells by acute leukemia cells during autologous peripheral blood stem cell transplantation, which is a significant advantage for clinical applications. Using EL4 lymphoma cells on immunocompetent C57BL/6 mice, we also highlighted the potential of Val-ILs to target immunosuppressive cell populations in the spleen, which could be valuable in impairing cancer cell expansion, particularly in lymphoma cases. The most efficient Val-ILs were found to be those loaded with CD11b or CD223 antibodies, which, respectively, target the myeloid-derived suppressor cells (MDSC) or the lymphocyte-activation gene 3 (LAG-3 or CD223) on T4 lymphocytes. This study provides a promising preclinical demonstration of the effectiveness and ease of preparation of Val-ILs as a novel nanoparticle technology. In the context of hematological cancers, Val-ILs have the potential to be used as a precise and effective therapy based on targeted vesicle-mediated cell death.

Analysis of factors affecting the clinical efficacy and quality of life in the treatment of pediatric acute lymphoblastic leukemia

Objective

To analyze the factors affecting the long-term clinical efficacy and quality of life in the treatment of pediatric acute lymphoblastic leukemia (ALL).

Methods

This is a retrospective study. One hundred children with ALL were collected before June, 2018 at The First Affiliated Hospital of Yangtze University and followed up for five years. Not only were their five-years survival rates analyzed, but univariate and multivariate analyses were also performed for factors that might affect their five-year survival rates. The MOS 36-Item Short Form of Health Survey (SF-36) was utilized to investigate the surviving children after five years in order to analyze the factors that may affect the quality of life of the children.

Results

The five-years survival rate of one hundred children with ALL after treatment was 91.00% (91/100). Univariate and multivariate Logistic regression analyses were performed on the factors that may affect the long-term efficacy of pediatric ALL. The results showed that white blood cell count at first diagnosis, prednisone response test, treatment compliance and recurrence were independent risk factors for the long-term efficacy of pediatric ALL(p<0.05). The SF-36 survey of 91 surviving children after five years showed that prednisone response test and treatment compliance were independent risk factors affecting the quality of life of pediatric ALL(p<0.05).

Conclusion

In the initial diagnosis of pediatric ALL, sufficient attention and control should be given to the factors that may affect the long-term clinical efficacy and quality of life, and appropriate treatment plans should be adopted. Meanwhile, the treatment compliance of children should be improved during treatment to improve the survival rate and quality of life of pediatric ALL.

Presence of leukemic clone-specific immunoglobulin heavy chain rearrangements in neonatal blood spots of children with B-cell precursor acute lymphoblastic leukemia

INTRODUCTION

Childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) can be traced back to birth using leukemic clone-specific immunoglobulin heavy chain (IGH) rearrangements, implying prenatal origin of this disease.

METHODS

We retrospectively analyzed neonatal blood spots (Guthrie cards) of 24 patients with childhood BCP-ALL aged 1-9.6 years (median 3.1 years) for the presence of clonotypic IGH rearrangements identified in diagnostic bone marrow samples. Based on the sequences of IGH rearrangements, 2 patient-specific primers were designed for each patient and used in semi-nested polymerase chain reaction for the detection of preleukemic clones at birth.

RESULTS

Clonotypic IGH rearrangements were detected in neonatal blood spots of 54.2% of patients (13/24). In two cases with double IGH rearrangements detected at diagnosis, only one rearrangement was present at birth, while in the third case both leukemic rearrangements were detected in neonatal blood. Guthrie card-positive findings were significantly more frequent in children ≤5 years of age than in older children (p = 0.011). Regarding patients' characteristics at birth and at diagnosis, Guthrie card-positivity was not associated with sex, birth weight and mother's age, as well as with white blood cell count, percentage of bone marrow blasts, immunophenotype and the presence of ETV6/RUNX1 and TCF3/PBX1 fusion genes at diagnosis.

CONCLUSION

Our study confirms that a large proportion of childhood BCP-ALL originates in utero, regardless of the molecular subtype defined by chromosomal aberrations. The observed trend toward younger age at diagnosis in Guthrie card-positive versus Guthrie card-negative patients implies that the age at diagnosis depends on the presence of preleukemic clone at birth, as well as on the timing of postnatal transforming genetic events.

B-Lymphoblastic Lymphoma in Children: A Case Series From a Single Institution

BACKGROUND

Pediatric B-lymphoblastic lymphoma is an uncommon subtype of non-Hodgkin lymphoma. Studies regarding the biology, clinical course, and approach to relapse are limited.

OBSERVATIONS

We present a series of children with B-lymphoblastic lymphoma to describe the clinical course at diagnosis and relapse as well as the role of tumor cytogenetics, immunotherapy, and hematopoietic stem cell transplant.

CONCLUSIONS

The prognostic significance of cytogenetic changes in B-lymphoblastic lymphoma is not well described but may offer improved risk stratification. Immunotherapy may offer salvage options for relapsed disease and can serve as a bridge to transplant.

Effect of peppermint inhalation versus Swedish massage on chemotherapy induced-nausea and vomiting in children with leukemia: Multi-arm randomised trial design

BACKGROUND

Chemotherapy is the foremost treatment for children with leukemia, while causing different serious side-effects. Chemotherapy-induced nausea and vomiting are the most common deliberating side effects and critical concerns of pediatric oncology nurses among those children.

AIM

To investigate the effect of peppermint inhalation versus Swedish massage on chemotherapy-induced nausea and vomiting in children with leukemia.

DESIGN

A multi-arm randomised trial design with three parallel groups.

SETTING

This study was conducted at outpatient and inpatient Hematology/leukemia Units at Alexandria University Children's Hospital at Smouha.

METHODS

Seventy-five children with leukemia received the first chemotherapy session. They were randomly allocated into three equal groups, 25 children in each group (control, peppermint inhalation, and Swedish massage groups). Every child is assessed for nausea and vomiting before chemotherapy administration and after for three days for consecutive three sessions of treatment.

RESULTS

Study findings revealed that children in peppermint inhalation and Swedish massage groups showed significant reduction in mean total score of chemotherapy-induced nausea and vomiting among peppermint inhalation and Swedish groups (15.120 ± 4.585 and 14.680 ± 3.158, respectively) was observed on third chemotherapy session than in control group (45.680 ± 5.793) (p < 0.001).

CONCLUSION

It can be concluded that Swedish massage and peppermint inhalation therapies may have significant antiemetic effects as alleviating the chemotherapy induced nausea and vomiting for children with leukemia.

PRACTICE IMPLICATIONS

This study directs the pediatric oncology nurses to incorporate peppermint inhalation and Swedish massage therapies besides antiemetic drugs in pediatric oncology unit protocols for management of chemotherapy induced nausea and vomiting.

The influence of WeChat education and care program on anxiety, depression, insomnia, and general state of health in parents of pediatric acute lymphoblastic leukemia patients

PURPOSE

WeChat-based education and care program serves as a promising nursing method for relieving mental stress in parents of pediatric patients. This study purposed to explore the influence of the WeChat education and care program (WECP) on mental health, insomnia, and general state of health in parents of pediatric acute lymphoblastic leukemia (ALL) patients.

METHODS

Totally, 146 parents of 73 primary pediatric ALL patients were randomized into the WECP group (74 parents of 37 patients) and standard care (SC) group (72 parents of 36 patients) to receive a 6-month corresponding intervention. Self-rating anxiety scale (SAS), self-rating depression scale (SDS), Athens insomnia scale (AIS), and 12-item general health questionnaire (GHQ-12) were assessed in parents of patients.

RESULTS

SAS scores at the third month (M3) (P = 0.041) and M6 (P = 0.032) were reduced in WECP group versus SC group. SAS-defined anxiety rate at M6 (P = 0.035) was declined in WECP group versus SC group. SDS score at M6 was descended in WECP group versus SC group (P = 0.024). However, there was no discrepancy in SDS-defined depression rate at any time point between groups (all P > 0.05). AIS scores at M1 (P = 0.015) and M6 (P = 0.021), as well as GHQ-12 scores at M3 (P = 0.007) and M6 (P = 0.001) were decreased in WECP group versus SC group. By subgroup analyses, WECP exhibited good effects at M6 in mothers, but not in fathers.

CONCLUSION

WECP is a feasible and efficacy intervention to improve mental stress and health status among parents of pediatric ALL patients, especially in mothers.

Biological Markers of High-Risk Childhood Acute Lymphoblastic Leukemia

Childhood acute lymphoblastic leukemia (ALL) has witnessed substantial improvements in prognosis; however, a subset of patients classified as high-risk continues to face higher rates of relapse and increased mortality. While the National Cancer Institute (NCI) criteria have traditionally guided risk stratification based on initial clinical information, recent advances highlight the pivotal role of biological markers in shaping the prognosis of childhood ALL. This review delves into the emerging understanding of high-risk childhood ALL, focusing on molecular, cytogenetic, and immunophenotypic markers. These markers not only contribute to unraveling the underlying mechanisms of the disease, but also shed light on specific clinical patterns that dictate prognosis. The paradigm shift in treatment strategies, exemplified by the success of tyrosine kinase inhibitors in Philadelphia chromosome-positive leukemia, underscores the importance of recognizing and targeting precise risk factors. Through a comprehensive exploration of high-risk childhood ALL characteristics, this review aims to enhance our comprehension of the disease, offering insights into its molecular landscape and clinical intricacies in the hope of contributing to future targeted and tailored therapies.

Bioinformatics-Guided Discovery of miRNAs Involved in Apoptosis Modulated by Parthenolide Combined with Vincristine in The NALM6 Cell Line

OBJECTIVE

Acute lymphoblastic leukemia (ALL) is a highly heterogeneous leukemia. Despite the current improvement in conventional chemotherapy and high survival rates, the outcomes remain challenging. Sesquiterpen extracted from the Tanacetum parthenium, parthenolide, is a potential anticancer agent that can modulate the expression of miRNAs and induce apoptosis. The objective of this study was to investigate the effect of parthenolide in combination with vincristine and alone on the apoptosis rate and expression of miR-125b-5p, miR-181b-5p, and miR-17-5p in the NALM6 cell line.

MATERIALS AND METHODS

In this experimental study, cell viability and metabolic activity were determined through MTT assay and PI staining. Flow cytometry was applied to evaluate the rate of apoptosis. The expression of miRNAs was assessed using real-time polymerase chain reaction. Bioinformatic analyses, including Cytoscape, RNAhybrid, and signaling pathway analysis were employed to investigate the association of miR-17-5p, miR-181b-5p and miR-125b- 5p with apoptosis. Further, molecular docking served to validate the modulation of these miRNAs by parthenolide and vincristine treatment.

RESULTS

The MTT assay indicated that 7.7 μM of parthenolide decreased the metabolic activity to 50% after 48 hours. PI staining analysis indicated that at concentrations below the half maximal inhibitory concentration, parthenolide caused 50% cell death. Flow cytometric analysis indicated that parthenolide (1.925 μM) in combination with vincristine (1.2 nM) induced apoptosis in 83.2% of the cells. Real-time quantitative reverse transcription polymerase chain reaction (qRTPCR) analysis showed significant changes in the expression levels of miR-17-5p, miR-125b-5p, and miR-181b-5p. Moreover, the combination therapy downregulated the expression of miRNAs significantly. This was consistent with our bioinformatic analysis demonstrating that the studied miRNAs are regulators of apoptosis. Finally, molecular docking validated the modulation of the miRNAs by parthenolide and vincristine.

CONCLUSION

Parthenolide in combination with vincristine triggers apoptosis at a high rate in the NALM6 cell line. Moreover, this combination therapy can decrease the expression of miR-17-5p, miR-181b-5p, and miR-125b-5p.

Effect of oral silymarin on liver function in pediatric acute lymphoblastic leukemia in the maintenance phase: a double-blind randomized clinical trial

Introduction: Liver dysfunction is one of the most common disorders in patients with acute lymphoblastic leukemia (ALL). In recent studies, silymarin has been observed to have hepatic protective effects. Therefore, in this study, the effect of oral silymarin on the hepatic functions of patients with ALL was investigated. Methods: In the present double-blind clinical trial study, 121 patients with ALL over 5 years of age were divided into two groups after obtaining informed consent. The subjects were randomly divided into a silymarin-treatment group and a placebo group. In the silymarin-treatment group, patients received 70 mg oral capsules of silymarin twice daily or syrup of silymarin three times a day (each 5 ml of syrup contains 50 mg of silymarin). Patients were examined once a month for 9 months to receive capsules and measure the levels of alanine aminotransferase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), bilirubin, albumin, and cholesterol. Results: Comparison of changes before and after treatment in the two groups showed that receiving oral silymarin resulted in a slight significant decrease in the levels of ALT, AST, GGT, and bilirubin (p < 0.05), but had no effect on ALP, albumin, and cholesterol (p > 0.05). Discussion: The results of the present study showed that in pediatric patients with ALL, silymarin intake improves liver function. The very strong antioxidant effect of silymarin may explain its protective effect on the liver. Clinical Trial Registration: IRCT20150119020715N10.

The evolution of nutritional care in children and young people with acute lymphoblastic leukaemia: a narrative review

BACKGROUND

Acute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy in the world. Advances in treatment protocols have resulted in survival rates of >80% in most high-income countries (HIC); however, children and young people (CYP) with ALL continue to face significant nutrition-related challenges during treatment.

METHODS

This narrative review outlines the changing landscape of treatment and survivorship for CYP with ALL and the advances in nutrition knowledge that call for changes to clinical nutrition practice.

RESULTS

The incidence of ALL has remained stable in HIC; however, there have been significant advances in survival over the past 30 years. Overweight and obesity are increasingly prevalent in CYP with ALL at diagnosis, during treatment and in survivorship. Coupled with poor diet quality, high-energy and saturated fat intakes, altered eating behaviours and inactivity, this necessitates the need for a shift in nutrition intervention. Undernutrition remains a concern for CYP with high-risk treatment protocols where oral or enteral nutrition support remains a cornerstone of maintaining nutrition status.

CONCLUSIONS

With improved treatment protocols and high survival rates, a shift to focusing on diet quality, prevention of excessive weight gain and obesity during treatment and survivorship is necessary.

Stem cell-like reprogramming is required for leukemia-initiating activity in B-ALL

B cell acute lymphoblastic leukemia (B-ALL) is a multistep disease characterized by the hierarchical acquisition of genetic alterations. However, the question of how a primary oncogene reprograms stem cell-like properties in committed B cells and leads to a preneoplastic population remains unclear. Here, we used the PAX5::ELN oncogenic model to demonstrate a causal link between the differentiation blockade, the self-renewal, and the emergence of preleukemic stem cells (pre-LSCs). We show that PAX5::ELN disrupts the differentiation of preleukemic cells by enforcing the IL7r/JAK-STAT pathway. This disruption is associated with the induction of rare and quiescent pre-LSCs that sustain the leukemia-initiating activity, as assessed using the H2B-GFP model. Integration of transcriptomic and chromatin accessibility data reveals that those quiescent pre-LSCs lose B cell identity and reactivate an immature molecular program, reminiscent of human B-ALL chemo-resistant cells. Finally, our transcriptional regulatory network reveals the transcription factor EGR1 as a strong candidate to control quiescence/resistance of PAX5::ELN pre-LSCs as well as of blasts from human B-ALL.

Acute Lymphoblastic Leukemia with Central Nervous System Involvement-Challenges in Management

The survival of patients with acute lymphoblastic leukemia (ALL) has dramatically improved during the last six decades. This improvement is secondary to improved diagnostics, risk stratification of treatment by biological features and response to treatment, improved supportive care, and the introduction of new treatment modalities such as immunotherapy and molecular targeted therapy. However, many questions remain concerning the involvement of the central nervous system (CNS) in leukemia, including ones pertaining to the risk factors for CNS involvement and relapse, the optimal treatment strategy to prevent relapse, and the role of newer therapies. This review discusses these questions by addressing the diagnosis of CNS leukemia, the current clinical trial data for treatment regimens with CNS activity, and issues specific to treatment in low- and middle-income countries (LMICs).

[Blinatumomab as bridging therapy in two children with B-cell acute lymphoblastic leukemia complicated by invasive fungal disease]

This article reports two cases of children with B-cell acute lymphoblastic leukemia (B-ALL) complicated by invasive fungal disease (IFD) who received bridging treatment using blinatumomab. Case 1 was a 4-month-old female infant who experienced recurrent high fever and limb weakness during chemotherapy. Blood culture was negative, and next-generation sequencing (NGS) of peripheral blood, bronchoalveolar lavage fluid, and cerebrospinal fluid were all negative. Chest CT and cranial MRI revealed obvious infection foci. Case 2 was a 2-year-old male patient who experienced recurrent high fever with multiple inflammatory masses during chemotherapy. Candida tropicalis was detected in peripheral blood and abscess fluid using NGS, while blood culture and imaging examinations showed no obvious abnormalities. After antifungal and blinatumomab therapy, both cases showed significant improvement in symptoms, signs, and imaging, and B-ALL remained in continuous remission. The report indicates that bridging treatment with blinatumomab in children with B-ALL complicated by IFD can rebuild the immune system and control the underlying disease in the presence of immunosuppression and severe fungal infection.

Changed cortical thickness and sulcal depth in pediatric acute lymphoblastic leukemia survivors treated with chemotherapy only

The purpose of this study is to observe the changes of cortical morphological characteristics and their potential contribution to cognitive function in ALL survivors by using surface-based morphometry (SBM). Using SBM analysis, we calculated and compared group differences in cortical thickness, sulcal depth, gyrification, and fractal dimension of the cerebral cortex between 18 pediatric ALL survivors treated on chemotherapy-only protocols and off treatment within 2 years, and 18 healthy controls (HCs) with two-sample t-tests [P < 0.05, family-wise error (FWE) corrected]. Relationships between abnormal cortical characteristic values and cognitive function parameters were investigated with partial correlation analysis, taking age as a covariate. We found decreased cortical thickness mainly located in the prefrontal and temporal region, and increased sulcal depth in left rostral middle frontal cortex and left pars orbitalis in the ALL survivors compared to HCs. There were no statistically significant differences in the gyrification and fractal dimension between the two groups. In ALL survivors, cortical thickness and sulcal depth of above areas values revealed no significant correlation with the cognitive function parameters. In conclusion, pediatric ALL survivors show decreased cortical thickness in prefrontal and temporal regions, and increased sulcal depth in prefrontal region. These results suggest that SBM-based approach can be used to assess changes of cortical morphological characteristics in pediatric ALL survivors.

Influence of Minimal Residual Disease at Day 15 of Induction Therapy on Survival of Children with Acute Lymphoblastic Leukemia

OBJECTIVE

The aim of the study was to evaluate the impact of minimal residual disease (MRD) on day 15 of induction therapy (d15) on the treatment outcome in children with acute lymphoblastic leukemia (ALL).

MATERIALS AND METHODS

The study included 74 patients (1-18 years) with ALL, who were treated at the Pediatric Clinic of the University Clinical Center Banja Luka from January 2011 to May 2021. All patients were treated according to ALL IC-BFM 2009 protocol. MRD on bone marrow was assessed d15, using the multiparameter flow cytometry method (FCM).

RESULTS

Of all, 59.46% of patients had MRD d15 0.1-10%, MRD<0.1% had 18.92% of patients, and 21.62% had MRD >10%. Patients with the lowest MRD had the highest 5-year overall survival (OS) and event-free survival (89.5% and 91% respectively) and the lowest cumulative risk for relapse or death (9.7% and 8.1%), in contrast to patients with MRD>10% in whom OS was 80.0%, and the risk of recurrence is 20%. Predicted MRD d15 was significantly associated with prednisone response assessed in the peripheral blood on day 8 (P<0.001) and statistically significantly positive correlation (r=0.498; P<0.001) was found.

CONCLUSION

MRD measurement d15 has a great prognostic significance for patients in the standard and high risk groups, but not for patients in the intermediate risk group. The introduction of additional testing is necessary for better identification of patients with an increased risk of disease recurrence.

High-throughput screening as a drug repurposing strategy for poor outcome subgroups of pediatric B-cell precursor Acute Lymphoblastic Leukemia

Although a great cure rate has been achieved for pediatric BCP-ALL, approximately 15% of patients do not respond to conventional chemotherapy and experience disease relapse. A major effort to improve the cure rates by treatment intensification would result in an undesirable increase in treatment-related toxicity and mortality, raising the need to identify novel therapeutic approaches. High-throughput (HTP) drug screening enables the profiling of patients' responses in vitro and allows the repurposing of compounds currently used for other diseases, which can be immediately available for clinical application. The aim of this study was to apply HTP drug screening to identify potentially effective compounds for the treatment of pediatric BCP-ALL patients with poor prognosis, such as patients with Down Syndrome (DS) or carrying rearrangements involving PAX5 or KMT2A/MLL genes. Patient-derived Xenografts (PDX) samples from 34 BCP-ALL patients (9 DS CRLF2r, 15 PAX5r, 10 MLLr), 7 human BCP-ALL cell lines and 14 hematopoietic healthy donor samples were screened on a semi-automated HTP drug screening platform using a 174 compound library (FDA/EMA-approved or in preclinical studies). We identified 9 compounds active against BCP-ALL (ABT-199/venetoclax, AUY922/luminespib, dexamethasone, EC144, JQ1, NVP-HSP990, paclitaxel, PF-04929113 and vincristine), but sparing normal cells. Ex vivo validations confirmed that the BCL2 inhibitor venetoclax exerts an anti-leukemic effect against all three ALL subgroups at nanomolar concentrations. Overall, this study points out the benefit of HTP screening application for drug repurposing to allow the identification of effective and clinically translatable therapeutic agents for difficult-to-treat childhood BCP-ALL subgroups.

Improving quality and quantity of life for childhood cancer survivors globally in the twenty-first century

The contributions of cooperative groups to performing large-cohort clinical trials and long-term survivorship studies have facilitated advances in treatment, supportive care and, ultimately, survival for patients with paediatric cancers. As a result, the number of childhood cancer survivors in the USA alone is expected to reach almost 580,000 by 2040. Despite these substantial improvements, childhood cancer survivors continue to have an elevated burden of chronic disease and an excess risk of early death compared with the general population and therefore constitute a large, medically vulnerable population for which delivery of high-quality, personalized care is much needed. Data from large survivorship cohorts have enabled the identification of compelling associations between paediatric cancers, cancer therapy and long-term health conditions. Effectively translating these findings into clinical care that improves the quality and quantity of life for survivors remains an important focus of ongoing research. Continued development of well-designed clinical studies incorporating dissemination and implementation strategies with input from patient advocates and other key stakeholders is crucial to overcoming these gaps. This Review highlights the global progress made and future efforts that will be needed to further increase the quality and quantity of life-years gained for childhood cancer survivors.

Back to the future: the amazing journey of the therapeutic anti-leukemia enzyme asparaginase Erwinia chrysanthemi

For several decades, asparaginase has been considered world-wide as an essential component of combination chemotherapy for the treatment of childhood acute lymphoblastic leukemia (ALL). Discovered over 60 years ago, two main unmanipulated asparaginase products originated from primary bacteria sources, namely Escherichia coli and Erwinia chrysanthemi, have been available for clinical use. A pegylated product of the Escherichia coli asparaginase was subsequently developed and is now the main product used by several international co-operative groups. The various asparaginase products all display the same mechanism of action (hydrolysis of circulating asparagine) and are associated with similar efficacy and toxicity patterns. However, their different pharmacokinetics, pharmacodynamics and immunological properties require distinctive modalities of application and monitoring. Erwinia chrysanthemi asparaginase was initially used as a first-line product, but subsequently became a preferred second-line product for children who experienced immunological reactions to the Escherichia coli asparaginase products. An asparaginase product displaying the same characteristics of the Erwinia chrysanthemi asparaginase has recently been produced by use of recombinant technology, thus securing a preparation available for use as an alternative, or as a back-up in case of shortages, for the non-recombinant product. The long journey of the Erwinia chrysanthemi asparaginase product as it has developed throughout the last several decades has made it possible for almost every child and adult with ALL to complete the asparaginase-based protocol treatment when an immunological reaction has occurred to any Escherichia coli asparaginase product.

Super Enhancer Regulatory Gene FYB1 Promotes the Progression of T Cell Acute Lymphoblastic Leukemia by Activating IGLL1

Background

Arising from T progenitor cells, T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignant tumor, accounting for 15% of childhood ALL and 25% of adult ALL. Composing of putative enhancers in close genomic proximity, super enhancer (SE) is critical for cell identity and the pathogenesis of multiple cancers. Belonging to the cytosolute linker protein group, FYB1 is essential for TCR signaling and extensively studied in terms of tumor pathogenesis and metastasis. Dissecting the role of FYN binding protein 1 (FYB1) in T-ALL holds the potential to improve the treatment outcome and prognosis of T-ALL.

Methods

In this study, SEs were explored using public H3K27ac ChIP-seq data derived from T-ALL cell lines, AML cell lines and hematopoietic stem and progenitor cells (HSPCs). Downstream target of FYB1 gene was identified by RNA-seq. Effects of shRNA-mediated downregulation of FYB1 and immunoglobulin lambda-like polypeptide 1 (IGLL1) on self-renewal of T-ALL cells were evaluated in vitro and/or in vivo.

Results

As an SE-driven gene, overexpression of FYB1 was observed in T-ALL, according to the Cancer Cell Line Encyclopedia database. In vitro, knocking down FYB1 led to comprised growth and enhanced apoptosis of T-ALL cells. In vivo, downregulation of FYB1 significantly decreased the disease burden by suppressing tumor growth and improved survival rate. Knocking down FYB1 resulted in significantly decreased expression of IGLL1 that was also an SE-driven gene in T-ALL. As a downstream target of FYB1, IGLL1 exerted similar role as FYB1 in inhibiting growth of T-ALL cells.

Conclusion

Our results suggested that FYB1 gene played important role in regulating self-renewal of T-ALL cells by activating IGLL1, representing a promising therapeutic target for T-ALL patients.

Rituximab administration in pediatric patients with newly diagnosed acute lymphoblastic leukemia

Polyethylene glycol (PEG)-asparaginase (pegaspargase) is a key agent in chemotherapy for acute lymphoblastic leukemia (ALL), but recipients frequently experience allergic reactions. We hypothesized that by decreasing antibody-producing CD20-positive B cells, rituximab may reduce these reactions. Children and adolescents (aged 1-18 years) with newly diagnosed B-ALL treated on the St. Jude Total XVII study were randomized to induction therapy with or without rituximab on day 3 (cohort 1) or on days 6 and 24 (cohort 2). Patient clinical demographics, CD20 expression, minimal residual disease (MRD), rituximab reactions, pegaspargase allergy, anti-pegaspargase antibodies, and pancreatitis were evaluated. Thirty-five patients received rituximab and 37 did not. Among the 35 recipients, 16 (45.7%) experienced a grade 2 or higher reaction to rituximab. There were no differences between recipients and non-recipients in the incidence of pegaspargase reactions (P  >  0.999), anti-pegaspargase antibodies (P  =  0.327), or pancreatitis (P  =  0.480). CD20 expression on day 8 was significantly lower in rituximab recipients (P  <  0.001), but there were no differences in MRD levels on day 8, 15, or at the end of induction. Rituximab administration during induction in pediatric patients with B-ALL was associated with a high incidence of infusion reactions with no significant decrease in pegaspargase allergies, anti-pegaspargase antibodies, or MRD.

Ex vivo Drug Sensitivity Imaging-based Platform for Primary Acute Lymphoblastic Leukemia Cells

Resistance of acute lymphoblastic leukemia (ALL) cells to chemotherapy, whether present at diagnosis or acquired during treatment, is a major cause of treatment failure. Primary ALL cells are accessible for drug sensitivity testing at the time of new diagnosis or at relapse, but there are major limitations with current methods for determining drug sensitivity ex vivo. Here, we describe a functional precision medicine method using a fluorescence imaging platform to test drug sensitivity profiles of primary ALL cells. Leukemia cells are co-cultured with mesenchymal stromal cells and tested with a panel of 40 anti-leukemia drugs to determine individual patterns of drug resistance and sensitivity ("pharmacotype"). This imaging-based pharmacotyping assay addresses the limitations of prior ex vivo drug sensitivity methods by automating data analysis to produce high-throughput data while requiring fewer cells and significantly decreasing the labor-intensive time required to conduct the assay. The integration of drug sensitivity data with genomic profiling provides a basis for rational genomics-guided precision medicine. Key features Analysis of primary acute lymphoblastic leukemia (ALL) blasts obtained at diagnosis from bone marrow aspirate or peripheral blood. Experiments are performed ex vivo with mesenchymal stromal cell co-culture and require four days to complete. This fluorescence imaging-based protocol enhances previous ex vivo drug sensitivity assays and improves efficiency by requiring fewer primary cells while increasing the number of drugs tested to 40. It takes approximately 2-3 h for sample preparation and processing and a 1.5-hour imaging time. Graphical overview.

Pediatric T-cell acute lymphoblastic leukemia blast signature and MRD associated immune environment changes defined by single cell transcriptomics analysis

Different driver mutations and/or chromosomal aberrations and dysregulated signaling interactions between leukemia cells and the immune microenvironment have been implicated in the development of T-cell acute lymphoblastic leukemia (T-ALL). To better understand changes in the bone marrow microenvironment and signaling pathways in pediatric T-ALL, bone marrows collected at diagnosis (Dx) and end of induction therapy (EOI) from 11 patients at a single center were profiled by single cell transcriptomics (10 Dx, 5 paired EOI, 1 relapse). T-ALL blasts were identified by comparison with healthy bone marrow cells. T-ALL blast-associated gene signature included SOX4, STMN1, JUN, HES4, CDK6, ARMH1 among the most significantly overexpressed genes, some of which are associated with poor prognosis in children with T-ALL. Transcriptome profiles of the blast cells exhibited significant inter-patient heterogeneity. Post induction therapy expression profiles of the immune cells revealed significant changes. Residual blast cells in MRD+ EOI samples exhibited significant upregulation (P < 0.01) of PD-1 and RhoGDI signaling pathways. Differences in cellular communication were noted in the presence of residual disease in T cell and hematopoietic stem cell compartments in the bone marrow. Together, these studies generate new insights and expand our understanding of the bone marrow landscape in pediatric T-ALL.

Polo-like kinase 1 Decrease During Induction Therapy Could Indicate Good Treatment Response, Favorable Risk Stratification, and Prolonged Survival in Pediatric Acute Lymphoblastic Leukemia

OBJECTIVE

Polo-like kinase 1 (PLK1) modulates leukemia cell apoptosis, proliferation, and cell cycle arrest in the progression of acute lymphoblastic leukemia (ALL). This study intended to investigate the dysregulation of PLK1 and its association with induction therapy response and prognosis in pediatric ALL patients.

MATERIALS AND METHODS

Bone marrow mononuclear cell samples were collected from 90 pediatric ALL patients at baseline and on the 15th day of induction therapy (D15), as well as from 20 controls after enrollment, for the detection of PLK1 by reverse transcription-quantitative polymerase chain reaction.

RESULTS

PLK1 was increased in pediatric ALL patients compared with controls ( P <0.001). In pediatric ALL patients, PLK1 decreased from baseline to D15 ( P <0.001). Lower PLK1 at baseline was associated with a good prednisone response ( P =0.002), while decreased PLK1 at D15 was related to good prednisone response ( P =0.001), better bone marrow response ( P =0.025), and favorable risk stratification ( P =0.014). In addition, reduced PLK1 at baseline was linked with better event-free survival (EFS) ( P =0.046), and decreased PLK1 at D15 was related to prolonged EFS ( P =0.027) and overall survival (OS) ( P =0.047). Moreover, PLK1 decline ≥25% was linked to favorable EFS ( P =0.015) and OS ( P =0.008). Further multivariate Cox proportional regression analysis revealed that PLK1 decline ≥25% was independently linked with prolonged EFS (hazard ratio (HR)=0.324, P =0.024) and OS (HR=0.211, P =0.019).

CONCLUSION

The reduction of PLK1 after induction therapy reflects a good treatment response and correlates with a favorable survival profile in pediatric ALL patients.

The results of the modified St Jude Total Therapy XV Protocol in the treatment of low- and middle-income children with acute lymphoblastic leukemia

The St Jude Total Therapy Study XV was the first clinical trial to prospectively use minimal residual disease levels during and after remission induction therapy to guide risk-directed treatment. We used the Total Therapy XV protocol with minimal modification in treating 115 newly diagnosed pediatric acute lymphoblastic leukemia patients from low- and middle-income groups from January 2011 to December 2017. The mean age at diagnosis was 5.97 ± 3.96 years. The median follow-up period was 88 months. Three (2.6%) patients had bone marrow relapse, and one (0.87%) had an isolated central nervous system relapse. Nineteen of the patients (16.52%) died due to infection-related complications, three (2.61%) died due to progressive disease, and one (0.87%) died due to hematopoietic stem cell transplant complications. Five-year overall survival was 80%, and event-free survival was 78.3%. Our results showed that the Total XV treatment protocol could be used successfully in patients with ALL from low- and middle-income populations. However, infection-related deaths remain a significant problem.

A longitudinal study of the peripheral and central auditory pathways in individuals with acute lymphoid leukemia

OBJECTIVE

To characterize the peripheral and central auditory pathways in individuals with Acute Lymphoid Leukemia (ALL) and compare assessment results before and during chemotherapy.

METHOD

The study included 17 subjects with ALL, divided into two age groups: 3 to 6 (11 individuals) and 7 to 16 years old (6 individuals). Each subject was evaluated twice (before and 3 to 6 months after chemotherapy treatment) with the following procedures: medical history survey, otoscopy, Pure-Tone Threshold (PTA) and speech audiometry, acoustic immittance measures, Brainstem Auditory Evoked Potentials (BAEP) and Long-Latency Auditory Evoked Potentials (LLAEP).

RESULTS

PTA was normal. Tympanometry was abnormal in the second assessment in 2 individuals aged 3 to 6 years. One subject in each age group had absent ipsilateral acoustic reflexes. In high-frequency audiometry, 1 individual had abnormal results. BAEP was abnormal in 5 (first assessment) and 7 individuals (second assessment) aged 3 to 6 years and 2 (first assessment) and 1 individual (second assessment) aged 7 to 16 years. As for LLAEP, P1 latency was increased in 5 (first assessment) and 7 individuals (second assessment) aged 3 to 6 years.

CONCLUSION

No hearing loss was identified in the behavioral audiological assessment. BAEP was more affected in the 3-to-6-year-old group, with greater impairment in the lower brainstem in the first and second assessments. In LLAEP, P1 was the most impaired component in children aged 3 to 6 years, and P2 and N2 were so for those 7 to 16 years old, especially in the second assessment.

Determining Optimal Combination Regimens for Patients with Multiple Myeloma

While many novel therapies have been approved in recent years for treating patients with multiple myeloma, there is still no established curative regimen, especially for patients with high-risk disease. In this work, we use a mathematical modeling approach to determine combination therapy regimens that maximize healthy lifespan for patients with multiple myeloma. We start with a mathematical model for the underlying disease and immune dynamics, which was presented and analyzed previously. We add the effects of three therapies to the model: pomalidomide, dexamethasone, and elotuzumab. We consider multiple approaches to optimizing combinations of these therapies. We find that optimal control combined with approximation outperforms other methods, in that it can quickly produce a combination regimen that is clinically-feasible and near-optimal. Implications of this work can be used to optimize doses and advance the scheduling of drugs.

Pharmacogenetics of 6-mercaptopurine in a black Zimbabwean cohort treated for acute lymphoblastic leukaemia

Background: 6-mercaptopurine usage is associated with myelotoxicity and increased risk in patients carrying metabolism-related genetic variations. This study aimed to determine the frequency of candidate gene polymorphisms and their association with 6-mercaptopurine intolerance. Methods: A total of 41 patients on acute lymphoblastic leukaemia treatment were genotyped for TPMT and NUDT15 (rs116855232) alleles, and their association with dose intensity was analyzed. Results: The defective TPMT*3C allele frequency was 9.8%. The median maintenance dose intensity for TPMT*1/*3C participants was considerably lower (47%) when compared with the TPMT*1/*1 wild-type (77%), although not statistically significant. Conclusion: This is the first pharmacogenetics study carried out in a black Zimbabwean leukemia patient cohort. The high defective TPMT*3C (9.8%) allele frequency points to the potential utility of pharmacogenetics testing for safe usage of 6-mercaptopurine in this population.

Prognostic Significance of CD20 Expression in Children with Philadelphia Chromosome-Negative B-Cell Precursor Acute Lymphoblastic Leukemia

INTRODUCTION

The prognostic significance of CD20 in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) remains unclear. Therefore, in this study, we evaluated the prognostic value of CD20 expression in leukemia blasts in pediatric BCP-ALL at our institute.

METHODS

Between 2005 and 2017, 796 children with newly diagnosed Philadelphia-negative BCP-ALL were enrolled consecutively; clinical characteristics and treatment outcomes were analyzed and compared between CD20-positive and CD20-negative groups.

RESULTS

CD20 positivity was observed in 22.7% of enrolled patients. The analysis of overall and event-free survival showed that white blood cell count ≥50 × 109/L, no ETV6-RUNX1, day 33 minimal residual disease (MRD) ≥0.1%, and week 12 MRD ≥0.01% were independent risk factors. Meanwhile, in the CD20-positive group, week 12 MRD ≥0.01% was the only factor associated with long-term survival. Moreover, subgroup analysis revealed that in patients with extramedullary involvement (p = 0.047), MRD ≥0.1% on day 33 (p = 0.032), or MRD ≥0.01% at week 12 (p = 0.004), CD20 expression led to a poorer outcome compared to those without CD20 expression.

CONCLUSIONS

Pediatric BCP-ALL with CD20 expression had unique clinicopathological characteristics, and MRD remained the major prognostic factor. CD20 expression had no prognostic value in pediatric BCP-ALL.

[Optimized treatment of childhood B-lineage acute lymphoblastic leukemia]

Childhood acute lymphoblastic leukemia (ALL) accounts for about 75% of childhood leukemia cases, and B-lineage acute lymphoblastic leukemia (B-ALL) accounts for more than 80% of childhood ALL cases. Over the past half century, new molecular biological targets discovered by new techniques have been used in precise stratification of disease prognosis, and there has been a gradual increase in the 5-year overall survival rate of childhood ALL. With the increasing attention to long-term quality of life, the treatment of childhood B-ALL has been constantly optimized from induction therapy to the intensity of maintenance therapy, including the treatment of extramedullary leukemia without radiotherapy, which has been tried with successful results. The realization of optimized treatment also benefits from the development of new techniques associated with immunology and molecular biology and the establishment of standardized clinical cohorts and corresponding biobanks. This article summarizes the relevant research on the implementation of precise stratification and the intensity reduction and optimization treatment of B-ALL in recent years, providing reference for clinicians.

Translational advances in the treatment of childhood acute lymphoblastic leukemia: narrative review of current and emerging molecular and immunotherapies

Background and Objective

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy of lymphoid origin in children. The prognosis for newly diagnosed ALL in the pediatric population is generally favorable, with a 5-year overall survival rate of more than 90%. Though conventional therapy has led to meaningful improvements in cure rates for new-onset pediatric ALL, one-third of patients still experience a relapse or refractory disease, contributing to a significant cause of pediatric cancer-related mortality.

Methods

An extensive literature review was undertaken via various databases of medical literature, focusing on both results of larger clinical trials, but also with evaluation of recent abstract publications at large hematologic conferences.

Key Content and Findings

Remission is achievable in most of these patients by re-induction with currently available therapies, but the long-term overall survival rate is deemed suboptimal and remains a therapeutic challenge. As part of never-ceasing efforts to improve pediatric ALL outcomes, newer modalities, including targeted molecular therapies as well as immunotherapy, and chimeric antigen receptor (CAR) T-cell therapy, are currently being employed to increase treatment effectiveness as well as lessen the side effects from conventional chemotherapy. These approaches explore the use of early genome-based disease characterization and medications developed against actionable molecular targets.

Conclusions

Additional clinical research is nonetheless required to learn more about the potentially harmful effects of targeted therapies and investigate the possibility of these agents replacing or decreasing the use of conventional chemotherapy in treating pediatric ALL.

The Relevance of Telomerase and Telomere-Associated Proteins in B-Acute Lymphoblastic Leukemia

Telomeres and telomerase are closely linked to uncontrolled cellular proliferation, immortalization and carcinogenesis. Telomerase has been largely studied in the context of cancer, including leukemias. Deregulation of human telomerase gene hTERT is a well-established step in leukemia development. B-acute lymphoblastic leukemia (B-ALL) recovery rates exceed 90% in children; however, the relapse rate is around 20% among treated patients, and 10% of these are still incurable. This review highlights the biological and clinical relevance of telomerase for B-ALL and the implications of its canonical and non-canonical action on signaling pathways in the context of disease and treatment. The physiological role of telomerase in lymphocytes makes the study of its biomarker potential a great challenge. Nevertheless, many works have demonstrated that high telomerase activity or hTERT expression, as well as short telomeres, correlate with poor prognosis in B-ALL. Telomerase and related proteins have been proven to be promising pharmacological targets. Likewise, combined therapy with telomerase inhibitors may turn out to be an alternative strategy for B-ALL.

Knockdown of MEF2D inhibits the development and progression of B-cell acute lymphoblastic leukemia

Background

Myocyte enhancer factor 2D (MEF2D) is involved in the progression of various malignant tumors. However, its impact on B-cell acute lymphoblastic leukemia (B-ALL) has not been elucidated.

Methods

In this study, the expression level of MEF2D in B-ALL patients was validated through the Gene Expression Omnibus (GEO) database and clinical specimens. MEF2D-knockdown B-ALL cell lines were constructed by lentivirus transfection, and the effects of MEF2D on the viability, apoptosis, cycle progression, and drug sensitivity of B-ALL cells were verified by Cell Counting Kit-8 (CCK-8) and flow cytometry (FCM). The effect of MEF2D on the proliferation of B-ALL cells in vivo was verified via the construction of a xenograft mouse model. The mechanism of MEF2D regulating B-ALL cells was explored by RNA sequencing analysis, quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemical (IHC).

Results

In this study, overexpression of MEF2D was observed in B-ALL patients and was remarkably correlated to disease progression in ALL patients. The knockdown of MEF2D expression suppressed cell viability, induced cell apoptosis, blockaded cell cycle progression, enhanced drug sensitivity of B-ALL cells in vitro, and reduced the tumor load in vivo. Furthermore, mechanistic studies revealed that MEF2D knockdown downregulated the expression of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway.

Conclusions

Our research demonstrated that MEF2D was markedly expressed in B-ALL. MEF2D knockdown inhibited cancer progression of B-ALL both in vitro and in vivo, which may be related to the downregulation of the PI3K-AKT signaling pathway. The data suggest that MEF2D plays a vital role in the process of tumorigenesis and may be a potential novel target for B-ALL therapy.

Single-cell heterogeneity and dynamic evolution of Ph-like acute lymphoblastic leukemia patient with novel TPR-PDGFRB fusion gene

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a refractory and recurrent subtype of B-cell ALL enriched with kinase-activating rearrangements. Incomplete understanding of the heterogeneity within the tumor cells presents a major challenge for the diagnosis and therapy of Ph-like ALL. Here, we exhibited a comprehensive cell atlas of one Ph-like ALL patient with a novel TPR-PDGFRB fusion gene at diagnosis and relapse by using single-cell RNA sequencing (scRNA-seq). Twelve heterogeneous B-cell clusters, four with strong MKI67 expression indicating highly proliferating B cells, were identified. A relapse-enriched B-cell subset associated with poor prognosis was discovered, implicating the transcriptomic evolution during disease progression. Integrative single-cell analysis was performed on Ph-like ALL and Ph⁺ ALL patients, and revealed Ph-like specific B-cell subpopulations and shared malignant B cells characterized by the ectopic expression of the inhibitory receptor CLEC2D. Collectively, scRNA-seq of Ph-like ALL with a novel TPR-PDGFRB fusion gene provides valuable insights into the underlying heterogeneity associated with disease progression and offers useful information for the development of immunotherapeutic techniques in the future.

Soluble Hemojuvelin and Ferritin: Potential Prognostic Markers in Pediatric Hematopoietic Cell Transplantation

OBJECTIVE

Iron overload (IO) is a common and life-threatening complication resulting from the therapy of AL and HCT patients. This study aimed to evaluate the prognostic value of 12 serum biomarkers of iron metabolism in pediatric patients treated for AL or undergoing HCT.

PATIENTS

Overall, 50 patients with AL after intensive treatment and 32 patients after HCT were prospectively included in the study. AL patients at diagnosis and healthy controls served as reference groups.

METHODS

The impact of the following 12 serum iron metabolism parameters on the outcome of AL/HCT patients was analyzed: iron, transferrin (Tf), total iron-binding capacity (TIBC), ferritin, ferritin heavy chains (FTH1), ferritin light chains (FTL), hepcidin, soluble hemojuvelin (sHJV), soluble ferroportin-1 (sFPN1), erythroferrone (ERFE), erythropoietin (EPO), and soluble transferrin receptor (sTfR).

RESULTS

With a median follow-up of 2.2 years, high levels of ferritin and low levels of sHJV had an adverse prognostic impact on OS and EFS in children after HCT. If these patients were combined with those with AL after intensive chemotherapy, the results were confirmed for OS and EFS both for ferritin and sHJV.

CONCLUSIONS

Among the 12 analyzed serum parameters of iron metabolism, increased levels of ferritin and decreased levels of sHJV had an adverse prognostic impact on survival in children after HCT. More data are needed to clarify the relationship between ferritin, sHJV, and mortality of AL children after intensive chemotherapy, and more extensive prospective studies are required to prove sHJV predictivity.

Correlation of the surface expression of thymic stromal lymphopoietin receptor with the presence of CRLF2 gene rearrangements in children with B-lineage acute lymphoblastic leukemia

INTRODUCTION

In this study, we aimed to compare the immunophenotype of tumor cells in children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) harboring rearrangements of the CRLF2 gene with that in children without such aberrations with a specific focus on the surface expression of the related protein thymic stromal lymphopoietin receptor (TSLPR).

METHODS

We examined bone marrow samples from 46 patients with primary BCP-ALL who had CRLF2 rearrangements detected by FISH (CRLF2(+) cohort). A total of 140 consecutive patients with intact CRLF2 were included in a control CRLF2(-) cohort. TSLPR expression was studied by flow cytometry.

RESULTS

The majority of CRLF2(+) patients were conventionally positive (≥20% positive cells) for TSLPR (33 of 46, 71.7%). Among the remaining children in this group, two were completely TSLPR-negative, seven had less than 10% TSLPR-positive cells, and four had between 10% and 20% TSLPR-positive cells. By contrast, the majority of CRLF2(-) patients had no TSLPR-positive cells (119 of 140, 85.0%), while in 15 cases (10.7%), the percentage of TSLPR-positive cells was below 10%, and in six cases (4.3%), it was between 10% and 20%. Receiver operator characteristic analysis revealed a threshold of only 1.6% TSLPR-positive cells for the effective prediction of the presence of CRLF2 rearrangement. Moreover, this threshold retained its predictive value when only children with low TSLPR positivity were studied.

CONCLUSION

When surface TSLPR is detected at the diagnosis of BCP-ALL, close attention should be given to the search for chromosomal aberrations involving CRLF2 at any level of expression.

The Landscape of Secondary Genetic Rearrangements in Pediatric Patients with B-Cell Acute Lymphoblastic Leukemia with t(12;21)

The most frequent chromosomal rearrangement in childhood B-cell acute lymphoblastic leukemia (B-ALL) is translocation t(12;21)(p13;q22). It results in the fusion of the ETV6::RUNX1 gene, which is active in the regulation of multiple crucial cellular pathways. Recent studies hypothesize that many translocations are influenced by RAG-initiated deletions, as well as defects in the RAS and NRAS pathways. According to a "two-hit" model for the molecular pathogenesis of pediatric ETV6::RUNX1-positive B-ALL, the t(12;21) translocation requires leukemia-causing secondary mutations. Patients with ETV6::RUNX1 express up to 60 different aberrations, which highlights the heterogeneity of this B-ALL subtype and is reflected in differences in patient response to treatment and chances of relapse. Most studies of secondary genetic changes have concentrated on deletions of the normal, non-rearranged ETV6 allele. Other predominant structural changes included deletions of chromosomes 6q and 9p, loss of entire chromosomes X, 8, and 13, duplications of chromosome 4q, or trisomy of chromosomes 21 and 16, but the impact of these changes on overall survival remains unclarified. An equally genetically diverse group is the recently identified new B-ALL subtype ETV6::RUNX1-like ALL. In our review, we provide a comprehensive description of recurrent secondary mutations in pediatric B-ALL with t(12;21) to emphasize the value of investigating detailed molecular mechanisms in ETV6::RUNX1-positive B-ALL, both for our understanding of the etiology of the disease and for future clinical advances in patient treatment and management.

Venetoclax Drug Increases the Apoptosis of T and B Acute Lymphoblastic Leukemia Cells by Reducing the Expression of BCL-2

Venetoclax, a specific inhibitor of the BCL2 protein, is administered for the treatment of acute lymphoblastic leukemia. However, despite being utilized in conjunction with chemotherapy, the drug exhibits instances of resistance. The exact mechanisms responsible for this resistance remain relatively obscure. Within the context of this investigation, the study aimed to explore the involvement of anti- and pro-apoptotic proteins as one of the potential mechanisms underlying this resistance phenomenon. Blast cells were extracted from patients diagnosed with B&T acute lymphoid leukemia. Subsequently, these cells were subjected to a cultivation process. Following the cultivation, treatment with the Venetoclax drug was administered to both groups of B&T cells. Additionally, one group from each cell type was designated as a control. The relative expression levels of genes BCL-2, MCL-1, and BIM were assessed in comparison to the control group. Annexin V-fluorescein isothiocyanate and propidium iodide staining was done to check cell apoptosis. The results showed a significant increase in the expression of BIM gene and a significant decrease in BCL-2 gene compared to the control group, but the change in the expression of MCL-1 gene was not significant. Also, an increase in apoptosis was observed in the treatment groups compared to the control. Although it was shown that changes in the expression of pro- and anti-apoptotic genes can lead to an increase in cell apoptosis and a decrease in the number of blast cells, more studies are needed to investigate the simultaneous effect of Venetoclax drug with other drugs and also in the form of a clinical trial.

Targeted Treatment and Immunotherapy in High-risk and Relapsed/ Refractory Pediatric Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia is the most frequent pediatric malignancy in children, comprising 30% of all pediatric malignancies; adult ALL comprises 5% of all ALL cases, which have a 186.6 per 1 million incidence. In pediatric ALL (pALL), on which this review focuses, approximately 1 in 285 children are diagnosed with cancer before the age of 20, and approximately 1 in 530 young adults between the ages of 20 and 39 years old is a childhood cancer survivor. The survival probability in pALL is now very high, approximately 80-90%. Thus, the most important is to improve supportive care and treatment based on relapse risk, optimally being based on the genetic feature of malignant cells. Improvements made by now are mainly the classifying of subgroups based on genetic characteristics such as aneuploidy or translocation and aligning them with treatment response. Relevant genetic changes in ALL pathogenesis are transcription regulators of lymphoid development (PAX5, IKZF1, EBF1, and LEF1) and/or coactivators (TBL1XR1 and ERG), lymphoid signaling (BTLA, and CD200 TOX), and tumor suppressor genes (CDKN2A, CDKN2B, RB1, and TP53). This review aims to summarize treatment strategies inhibiting tyrosine kinases, influencing different signaling pathways, BCL inhibitors, and anti-CD therapy (anti-cluster differentiation therapy) in pALL. CAR T-cell therapy (chimeric antigen receptors T-cell therapy) is under research and requires further development.

High frequency of heat shock protein 27 overexpression is a highly effective, high-coverage marker for minimal residual disease detection in children with B-cell acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. Minimal residual disease (MRD) detection is the most powerful prognostic tool for monitoring treatment efficacy and predicting clinical outcomes. We aimed to identify key leukemia-associated markers, the proportions of differential expression in patients, and the most effective marker combination for MRD detection by flow cytometry.

METHODS

Bone marrow samples were collected from 132 pediatric patients with newly diagnosed (n = 115) or relapsed (n = 17) B-cell precursor (BCP)-ALL. We used CD19, CD10, CD34, CD45 as backbone markers to identify immature B cells and analyzed the differential expression of 18 leukemia-associated markers using seven-color multiparameter flow cytometry.

RESULTS

Leukemic cells in all 132 patients expressed leukemia-associated markers. The most commonly overexpressed marker was heat shock protein 27 (Hsp27) (108 patients, 81%), followed by CD73 (102 patients, 77%) and CD123 (80 patients, 60%). CD38 was underexpressed in 64 patients (48%). Hsp27 overexpression persisted in 50 out of 57 follow-up MRD bone marrow samples (87%) and was associated with older age at diagnosis. Hsp27 overexpression was not associated with MRD levels or genetic abnormalities including hyperdiploidy, t(12;21)/ETV6-RUNX1, t(1;19)/TCF3-PBX1, t(9;22)/BCR-ABL1, or 11q23/KMT2A rearrangements. Four remaining leukemia-associated markers (Hsp27, CD73, CD58, CD24) after in silico deletion from the original panel could collectively detect leukemia-associated cell profiles in 100% of cases in this cohort and 98% of cases in a validation cohort.

CONCLUSION

Hsp27 combined with CD73, CD58, CD24, and backbone markers allows monitoring MRD in virtually all patients with BCP-ALL.

TPEN/TPGS (T2) combo dramatically reduces Philadelphia chromosome-positive pro-lymphoblastic B leukemia in BALB/c mice

Acute lymphoblastic leukemia (ALL) is hematological neoplasia that affects human beings from early life to adulthood. Although ALL treatment has been effective, an important percentage of ALL patients are resilient to treatment. Therefore, there is an urgent need for testing a new combination of compounds for the treatment of this disease. Recently, combined TPEN and TPGS (T2 combo) have shown selective cytotoxic effects in vitro leukemia cells such as Jurkat, K562, and Ba/F3 cells. In this study, we aimed to test the effect of combined TPEN and TPGS agents (T2 combo) at a fixed dose (TPEN 5 mg/kg: TPGS 100 mg/kg) on leukemic Ba/F3-BCR-ABL P210 BALB-c mice model. We found that 4 successive 2-day apart intravenous injections of T2 combo showed a statistically significant reduction of Ba/F3 BCR-ABL leukemia cells (- 69%) in leukemia BALB/c mice (n = 6) compared to untreated leukemia group (n = 6). Moreover, the T2 combo was innocuous to non-leukemia BALB/c mice (n = 3) compared to untreated non-leukemia mice (control, n = 3). After treatments (day 42), all mice were left to rest until day 50. Outstandingly, the leukemia BALB/c mice treated with the T2 combo showed a lower percentage of Ba/F3-BCR-ABL P210 cells (- 84%) than untreated leukemia BALB/c mice. Furthermore, treatment of leukemia and non-leukemia mice with T2 combo showed no significant tissue alteration/damage according to the histopathological analysis of brain, heart, liver, kidney, and spleen samples; however, T2 combo significantly reduced the number of leukocytes in the bone marrow of treated leukemia mice. We conclude that the T2 combo specifically affects leukemia cells but no other tissue/organs. Therefore, we anticipate that the T2 combo might be a potential pro-oxidant combination for the treatment of leukemia patients.

Prognostic significance of steroid response in pediatric acute lymphoblastic leukemia: The CCCG-ALL-2015 study

Introduction

Whether steroid response is an independent risk factor for acute lymphoblastic leukemia (ALL) is controversial. This study aimed to investigate the relationship between response to dexamethasone and prognosis in children with ALL.

Methods

We analyzed the data of 5,161 children with ALL who received treatment in accordance with the Chinese Children's Cancer Group ALL-2015 protocol between January 1, 2015, and December 31, 2018, in China. All patients received dexamethasone for 4 days as upfront window therapy. Based on the peripheral lymphoblast count on day 5, these patients were classified into the dexamethasone good response (DGR) and dexamethasone poor response (DPR) groups. A peripheral lymphoblast count ≥1× 10⁹/L indicated poor response to dexamethasone.

Results

The age, white blood cell counts, prevalence of the BCR/ABL1 and TCF3/PBX1 fusion genes, and rates of recurrence in the central nervous system were higher in the DPR than in the DGR group (P<0.001). Compared to the DPR group, the DGR group had a lower recurrence rate (18.6% vs. 11%) and higher 6-year event-free survival (73% vs. 83%) and overall survival (86% vs. 92%) rates; nevertheless, subgroup analysis only showed significant difference in the intermediate-risk group (P<0.001).

Discussion

Response to dexamethasone was associated with an early treatment response in our study. In the intermediate-risk group, dexamethasone response added a prognostic value in addition to minimal residual disease, which may direct early intervention to reduce the relapse rate.

Cancer-associated fibroblasts in acute leukemia

Although the prognosis for acute leukemia has greatly improved, treatment of relapsed/refractory acute leukemia (R/R AL) remains challenging. Recently, increasing evidence indicates that the bone marrow microenvironment (BMM) plays a crucial role in leukemogenesis and therapeutic resistance; therefore, BMM-targeted strategies should be a potent protocol for treating R/R AL. The targeting of cancer-associated fibroblasts (CAFs) in solid tumors has received much attention and has achieved some progress, as CAFs might act as an organizer in the tumor microenvironment. Additionally, over the last 10 years, attention has been drawn to the role of CAFs in the BMM. In spite of certain successes in preclinical and clinical studies, the heterogeneity and plasticity of CAFs mean targeting them is a big challenge. Herein, we review the heterogeneity and roles of CAFs in the BMM and highlight the challenges and opportunities associated with acute leukemia therapies that involve the targeting of CAFs.

Specific lncRNA signatures discriminate childhood acute leukaemias: a pilot study

BACKGROUND

Long non-coding RNAs are RNAs longer than 200 bps that do not encode any proteins and are able to alter gene expression by acting on different steps of regulation, including DNA methylation and chromatin structure. They represent a class of biomarkers of crescent interest in the hematologic and oncologic fields. Recent studies showed that the expression levels of specific lncRNAs correlate with the prognosis of paediatric patients with Acute Lymphoblastic Leukaemia.

METHODS

We used NGS approaches to analyse the transcriptome of 9 childhood B-ALL patients and 6 childhood T-ALL patients, in comparison with B and T healthy lymphocytes from cord blood. We validate our findings both ex vivo, in a different cohort of 10 B-ALL and 10 T-ALL patients, and in silico using public datasets.

RESULTS

We characterised the lncRNA landscape for B-ALL, T-ALL, healthy B, and T cell progenitors. From the characterised signature, we selected candidate lncRNAs able to discriminate not only B-ALL and T-ALL from healthy subjects but also between the two types of leukaemia, and subsequently validated their potential as a diagnostic tool in an additional cohort of paediatric patients. We confirmed our finding with open access transcriptomic data, comparing ALL lncRNAs with AML lncRNA landscape as well. Finally, expression correlation analyses of T-ALL selected lncRNA biomarkers suggested a possible role in lymphocyte activation and the β-catenin signalling pathway for AC247036.1 and involvement in hedgehog signalling for HHIP-AS1.

CONCLUSIONS

Our work identified a lncRNA signature discriminating paediatric B-ALL and T-ALL from healthy subjects, between them and from AML. This study provides the keystone to future clinical studies determining the theragnostic value of the characterised long non coding transcriptome panorama in a clinical setting for childhood patient management.

One-point flow cytometric MRD measurement to identify children with excellent outcome after intermediate-risk BCP-ALL: results of the ALL-MB 2008 study

BACKGROUND

 Measurement of minimal residual disease (MRD) with multicolor flow cytometry (MFC) has become an important tool in childhood acute lymphoblastic leukemia (ALL), mainly to identify rapid responders and reduce their therapy intensity. Protocols of the Moscow-Berlin (MB) group use a comparatively low (for standard risk; SR) or moderate (for intermediate risk; ImR) treatment intensity from the onset, based on initial patient characteristics. Recently, we reported that 90% of SR patients-50% B cell precursor (BCP-ALL)-MFC-MRD negative at end of induction (EOI)-had 95% event-free survival (EFS).  METHODS: In the present study, we applied this method to children with initial ImR features.

RESULTS

 In study MB 2008, 1105 children-32% of BCP-ALL patients-were assigned to the ImR group. Of these, 227 were treated in clinics affiliated with MFC laboratories of the MB group network, and included in this MFC-MRD pilot study. A single-point MFC-MRD measurement at the EOI with the threshold of 0.01% identified 65% of patients-20% of all BCP-ALL patients-with EFS of 93.5%.

CONCLUSION

 Taking both studies together, the combination of clinical parameters and a one-point MRD measurement identifies 70% of BCP-ALL patients with an excellent outcome after low- or moderate-intensity therapy and avoids overtreatment of a significant proportion of patients.

Viral Infection Profile in Children Treated for Acute Lymphoblastic Leukemia—Results of Nationwide Study

Viral infections can be a serious complication of therapy in children with acute lymphoblastic leukemia (ALL). In this study, we focused on the incidence and the profile of viral infection in children with ALL treated in 17 pediatric oncology centers in Poland in the two-year periods of 2018–2019 and 2020–2021. We also compared the frequency of viral infections in 2018–2019 to that in 2020–2021. In 2020–2021, a total of 192 children with ALL had a viral infection during intensive chemotherapy. A total number of 312 episodes of viral infections were diagnosed. The most common infections detected in the samples were: COVID-19 (23%), rhinovirus (18%), and respiratory syncytial virus (14%). COVID-19 and BK virus infections were the reason for the death 1% of all patients. In 2018–2019, a total of 53 ALL patients who had a viral infection were reported and 72 viral events were observed, mainly adenovirus (48.6%), rotavirus (31.9%), and herpes zoster (8.3%). No deaths were reported during this period. The cumulative incidence of viral infections in 2018–2019 was 10.4%, while for 2020–2021, it was 36.7%. In conclusion, a high incidence of COVID-19 infection was observed among pediatric patients with ALL in Poland. The mortality rate in our material was low. The viral profile in ALL children undergoing chemotherapy can be useful for clinicians to improve prophylactic and therapeutic strategies.