Continuing challenges and current issues in acute lymphoblastic leukemia

Indigofera suffruticosa aerial parts extract induce G2/M arrest and ATR/CHK1 pathway in Jurkat cells

BACKGROUND

Indigofera suffruticosa Mill. is used as a folk medicine for treating patients with leukemia, however very little is known regarding the molecular mechanism of its anti-leukemic activity and the chemical profile of the active extract. The present study aimed to reveal the molecular effect of I. suffruticosa aerial parts extract (ISAE) on leukemia cells and its chemical constituents.

METHODS

Cytotoxicity of ISAE were determined by resazurin viability assay, multitox - Glo multiplex cytotoxicity assay, and Annexin V staining assay. Cell cycle profiles were revealed by propidium iodide staining assay. The effects of ISAE on G2/M arrest signaling and DNA damage were evaluated by Western blot assay and phospho-H2A.X staining assay. The chemical profile of ISAE were determined by tandem mass spectroscopy and molecular networking approach.

RESULTS

We showed that the acute lymphoblastic leukemia cell line Jurkat cell was more responsive to ISAE treatment than other leukemia cell lines. In contrast, ISAE did not induce cytotoxic effects in normal fibroblast cells. Cell cycle analysis revealed that ISAE triggered G2/M arrest in Jurkat cells in dose- and time-dependent manners. Elevation of annexin V-stained cells and caspase 3/7 activity suggested ISAE-induced apoptosis. Furthermore, ISAE alone could increase the phosphorylation of CDK1 at Y15 and activate the ATR/CHK1/Wee1/CDC25C signaling pathway. However, the addition of caffeine, a widely used ATR inhibitor to ISAE, reduced the phosphorylation of ATR, CHK1, and CDK1, as well as G2/M arrest in Jurkat cells. Moreover, increased phospho-H2A.X stained cells indicated the involvement of DNA damage in the anti-leukemic effect of ISAE. Finally, qualitative analysis using UPLC-tandem mass spectroscopy and molecular networking revealed that tryptanthrin was the most abundant organoheterocyclic metabolite in ISAE. At equivalent concentrations to ISAE, tryptanthrin induced G2/M arrest of Jurkat cells, which can be prevented by caffeine.

CONCLUSIONS

ISAE causes G2/M arrest via activating ATR/CHK1/CDK1 pathway and tryptanthrin is one of the active components of ISAE. Our findings provide subtle support to the traditional use of I. suffruitcosa in leukemia management in folk medicine.

The Role of WRAP53 in Cell Homeostasis and Carcinogenesis Onset

The WD repeat containing antisense to TP53 (WRAP53) gene codifies an antisense transcript for tumor protein p53 (TP53), stabilization (WRAP53α), and a functional protein (WRAP53β, WDR79, or TCAB1). The WRAP53β protein functions as a scaffolding protein that is important for telomerase localization, telomere assembly, Cajal body integrity, and DNA double-strand break repair. WRAP53β is one of many proteins known for containing WD40 domains, which are responsible for mediating a variety of cell interactions. Currently, WRAP53 overexpression is considered a biomarker for a diverse subset of cancer types, and in this study, we describe what is known about WRAP53β's multiple interactions in cell protein trafficking, Cajal body formation, and DNA double-strand break repair and its current perspectives as a biomarker for cancer.

Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach

The diagnosis of a mediastinal mass may be challenging for clinicians, since lesions arising within the mediastinum include a variety of disease entities, frequently requiring a multidisciplinary approach. Age and sex represent important information, which need to be integrated with imaging and laboratory findings. In addition, the location of the mediastinal lesion is fundamental; indeed, we propose to illustrate mediastinal diseases based on the compartment of origin. We consider that this structured approach may serve as hint to the diagnostic modalities and management of mediastinal diseases. In this review, we present primary mediastinal tumours in the evolving context of new diagnostic and therapeutic tools, with recently described entities, based on our own experience with >900 cases encountered in the past 10 years.

Given the mediastinal anatomical heterogeneity, the correct positioning of mediastinal lesions becomes primal, in order to first establish a clinical suspicion and then to assist in planning biopsy and surgical procedurehttps://bit.ly/3p0gsk3

Improved survival after allogeneic transplantation for acute lymphoblastic leukemia in adults: a Danish population-based study

We investigated trends of survival in a population-based cohort study of all 181 adults who received HCT for ALL in Denmark between 2000-2019. Patients had a median (min-max) age of 36 (18-74) years at HCT and were followed for a median of eight years. Overall survival (OS) improved over time with an estimated 2-year OS of 49% (CI 27-66%) in year 2000 versus 77% (CI 59-88%) in year 2019. More patients achieved cure over time (OR for cure per year 1.07, CI 1.00-1.15), while the rate of death in non-cured patients remained stable (HR of excess mortality per year 0.99, CI 0.93-1.06). Relapse decreased over time (HR 0.92 per year, CI 0.87-0.98), whereas non-relapse mortality did not change notably (HR 0.98 per year, CI 0.93-1.04). In conclusion, survival after HCT in adults with ALL has improved over the past two decades, primarily due to more patients achieving cure.

The Complexity of the Tumor Microenvironment and Its Role in Acute Lymphoblastic Leukemia: Implications for Therapies

The microenvironment that surrounds a tumor, in addition to the tumor itself, plays an important role in the onset of resistance to molecularly targeted therapies. Cancer cells and their microenvironment interact closely between them by means of a molecular communication that mutually influences their biological characteristics and behavior. Leukemia cells regulate the recruitment, activation and program of the cells of the surrounding microenvironment, including those of the immune system. Studies on the interactions between the bone marrow (BM) microenvironment and Acute Lymphoblastic Leukemia (ALL) cells have opened a scenario of potential therapeutic targets which include cytokines and their receptors, signal transduction networks, and hypoxia-related proteins. Hypoxia also enhances the formation of new blood vessels, and several studies show how angiogenesis could have a key role in the pathogenesis of ALL. Knowledge of the molecular mechanisms underlying tumor-microenvironment communication and angiogenesis could contribute to the early diagnosis of leukemia and to personalized molecular therapies. This article is part of a Special Issue entitled: Innovative Multi-Disciplinary Approaches for Precision Studies in Leukemia edited by Sandra Marmiroli (University of Modena and Reggio Emilia, Modena, Italy) and Xu Huang (University of Glasgow, Glasgow, United Kingdom).

Inhibitory effect of hydnocarpin D on T-cell acute lymphoblastic leukemia via induction of autophagy-dependent ferroptosis

Hydnocarpin D (HD) is a bioactive flavonolignan compound that possesses promising anti-tumor activity, although the mechanism is not fully understood. Using T cell acute lymphoblastic leukemia (T-ALL) cell lines Jurkat and Molt-4 as model system, we found that HD suppressed T-ALL proliferation in vitro, via induction of cell cycle arrest and subsequent apoptosis. Furthermore, HD increased the LC3-II levels and the formation of autophagolysosome vacuoles, both of which are markers for autophagy. The inhibition of autophagy by either knockdown of ATG5/7 or pre-treatment of 3-MA partially rescued HD-induced apoptosis, thus suggesting that autophagy enhanced the efficacy of HD. Interestingly, this cytotoxic autophagy triggered ferroptosis, as evidenced by the accumulation of lipid ROS and decrease of GSH and GPX4, while inhibition of autophagy impeded ferroptotic cell death. Our study suggests that HD triggers multiple cell death processes and is an interesting compound that should be evaluated in future preclinical studies.

Histone deacetylase inhibitor chidamide regulates the Wnt/β-catenin pathway by MYCN/DKK3 in B-ALL

Our previous studies revealed that MYCN downregulates the expression of DKK3, activates the Wnt/β-catenin signalling pathway at the transcriptional level, and thereby promotes the development of B cell acute lymphocytic leukaemia (B-ALL) but does not affect the methylation of the DKK3 promoter. Some studies have shown that MYCN is associated with histone acetylation. We speculate that histone deacetylase inhibitors (HDACis) can inhibit the Wnt/β-catenin signalling pathway by inhibiting MYCN and increasing the expression of DKK3. Based on previous experiments, we tested this hypothesis by analysing the changes in MYCN, DKK3 and the Wnt/β-catenin signalling pathways in B-ALL cells after treatment with the selective HDACi chidamide. The in vitro and in vivo experiments confirmed that chidamide inhibited the expression of MYCN and increased the expression of DKK3 by inhibiting the activity of histone deacetylase, and these effects resulted in inhibition of the Wnt/β-catenin signalling pathway and the proliferation of B-ALL cells. These findings indicate that chidamide might be used alone or in combination with other chemotherapy regimens for patients with B-ALL and thus provide a new approach to the treatment of B-ALL.

Association between high-density lipoprotein cholesterol level and risk of hematologic malignancy

This study investigated the relationships between HDL-C and major types of blood cancers. Competing risks regression was used to examine the hazard ratios of hematologic malignancies in 9,596,145 individuals (≥20 years) using data from the Korean National Health Insurance Service (2009-2017). The incidence of the following hematologic cancers was determined based on the International Classification of Diseases 10th revision: Multiple Myeloma (MM), Hodgkin Lymphoma (HL), Non-Hodgkin Lymphoma (NHL), Lymphoid Leukemia (LL), and Myeloid Leukemia (ML). During an average of 8.3 years of follow-up (79,179,225 person-years), 15,864 incident hematologic malignancies were identified. Compared to those in the highest HDL-C quartile, subjects in the lowest HDL-C quartile had the highest risk of all hematologic cancers combined (adjusted hazard ratio [HR], 95% confidence interval [95% CI] = 1.31, 1.25-1.37) and of each respective type of blood cancer, as follows: MM (HR 1.61, 95% CI, 1.46-1.76), HL (HR 1.35, 95% CI 1.07-1.70), NHL (HR 1.12, 95%CI 1.04-1.21), LL (HR 1.36, 95% CI 1.16-1.61), and ML (HR 1.33, 95% CI 1.22-1.45). Low HDL-C level was significantly associated with increased risk of hematologic malignancy, suggesting that a low HDL-C level is an independent risk factor and preclinical marker for hematologic malignancy.

Transcriptome Profiling and Cytological Assessments for Identifying Regulatory Pathways Associated With Diorcinol N-Induced Autophagy in A3 Cells

Fungal secondary metabolites serve as a rich resource for exploring lead compounds with medicinal importance. Diorcinol N (DN), a fungal secondary metabolite isolated from an endophytic fungus, Arthrinium arundinis, exhibits robust anticancer activity. However, the anticancer mechanism of DN remains unclear. In this study, we examined the growth-inhibitory effect of DN on different human cancer cell lines. We found that DN decreased the viability of A3 T-cell leukemia cells in a time- and concentration-dependent manner. Transcriptome analysis indicated that DN modulated the transcriptome of A3 cells. In total, 9,340 differentially expressed genes were found, among which 4,378 downregulated genes and 4,962 upregulated genes were mainly involved in autophagy, cell cycle, and DNA replication. Furthermore, we demonstrated that DN induced autophagy, cell cycle arrest in the G1/S phase, and downregulated the expression of autophagy- and cell cycle-related genes in A3 cells. By labeling A3 cells with acridine orange/ethidium bromide, Hoechst 33,258, and monodansylcadaverine and via transmission electron microscopy, we found that DN increased plasma membrane permeability, structural disorganization, vacuolation, and autophagosome formation. Our study provides evidence for the mechanism of anticancer activity of DN in T-cell leukemia (A3) cells and demonstrates the promise of DN as a lead or even candidate molecule for the treatment of acute lymphoblastic leukemia.

Prognostic factors for survival after allogeneic transplantation in acute lymphoblastic leukemia

Allogeneic stem cell transplantation (allo-SCT) offers a curative option in adult patients with acute lymphoblastic leukemia (ALL). Prognostic factors for survival after allo-SCT have not been sufficiently defined: pheno-/genotype, patients´ age, conditioning regimens and remission at allo-SCT are under discussion. We analyzed the outcome of 180 consecutive adult ALL-patients undergoing allo-SCT at our center between 1995 and 2018 to identify specific prognostic factors. In our cohort 19% were older than 55 years, 28% had Philadelphia-positive B-ALL, 24% T-ALL. 54% were transplanted in first complete remission (CR1), 13% in CR2 after salvage therapy, 31% reached no remission (8% within first-line, 23% within salvage therapy). In 66% conditioning contained total body irradiation (TBI). With a median follow-up of 10 years, we observed an overall survival of 33% at 10 years, and a progression free survival of 31%. The cumulative incidence of relapse was 41% at 10 years, the cumulative incidence of non-relapse mortality 28%. Acute graft-versus-host disease (GvHD) II°-IV° occurred in 31%, moderate/severe chronic GvHD in 27%. Survival was better in patients reaching CR before allo-SCT and in those receiving TBI. No difference between patients younger/older than 55 years and between different phenotypes was observed. Survival after allo-SCT improved considerably over the last decades.

Molecular mechanisms and therapeutic implications of tetrandrine and cepharanthine in T cell acute lymphoblastic leukemia and autoimmune diseases

Inappropriately activated T cells mediate autoimmune diseases and T cell acute lymphoblastic leukemia (T-ALL). Glucocorticoid and chemotherapeutic agents have largely extended lives of these patients. However, serious side effects and drug resistance often limit the prognosis of considerable number of the patients. The efficient treatment of autoimmune diseases or T-ALL with drug resistance remains an important unmet demand clinically. Bisbenzylisoquinoline alkaloids tetrandrine and cepharanthine have been applied for the treatment of certain types of autoimmune diseases and cancers, while studies on their action mechanisms and their further applications combined with glucocorticoids or chemotherapeutic agents remains to be expanded. This review introduced molecular mechanisms of tetrandrine and cepharanthine in T cells, including their therapeutic implications. Both tetrandrine and cepharnthine influence the growth of activated T cells via several kinds of signaling pathways, such as NF-κB, caspase cascades, cell cycle, MAPK, and PI3K/Akt/mTOR. According to recent preclinical and clinical studies, P-glycoprotein inhibitory effect of tetrandrine and cepharnthine could play a significant role on T cell-involved refractory diseases. Therefore, tetrandrine or cepharanthine combined with glucocorticoid or other anti-leukemia drugs would bring a new hope for patients with glucocorticoid-resistant autoimmune disease or refractory T-ALL accompanied with functional P-glycoprotein. In conclusion, bisbenzylisoquinoline alkaloids tetrandrine and cepharanthine can regulate several signaling pathways in abnormally activated T cells with low toxicity. Bisbenzylisoquinoline alkaloids deserve to be paid more attention as a lead compound to develop new drugs for the treatment of T cell-involved diseases in the future.

Functional and structural evaluation of the antileukaemic enzyme L-asparaginase II expressed at low temperature by different Escherichia coli strains

Acute lymphoblastic leukaemia (ALL) affects lymphoblastic cells and is the most common neoplasm during childhood. Among the pharmaceuticals used in the treatment protocols for ALL, Asparaginase (ASNase) from Escherichia coli (EcAII) is an essential biodrug. Meanwhile, the use of EcAII in neoplastic treatments causes several side effects, such as immunological reactions, hepatotoxicity, neurotoxicity, depression, and coagulation abnormalities. Commercial EcAII is expressed as a recombinant protein, similar to novel enzymes from different organisms; in fact, EcAII is a tetrameric enzyme with high molecular weight (140 kDa), and its overexpression in recombinant systems often results in bacterial cell death or the production of aggregated or inactive EcAII protein, which is related to the formation of inclusion bodies. On the other hand, several commercial expression strains have been developed to overcome these expression issues, but no studies on a systematic evaluation of the E. coli strains aiming to express recombinant asparaginases have been performed to date. In this study, we evaluated eleven expression strains at a low temperature (16 °C) with different characteristics to determine which is the most appropriate for asparaginase expression; recombinant wild-type EcAII (rEcAII) was used as a prototype enzyme and the secondary structure content, oligomeric state, aggregation and specific activity of the enzymes were assessed. Structural analysis suggested that a correctly folded tetrameric rEcAII was obtained using ArcticExpress (DE3), a strain that co-express chaperonins, while all other strains produced poorly folded proteins. Additionally, the enzymatic assays showed high specific activity of proteins expressed by ArcticExpress (DE3) when compared to the other strains used in this work.

The role of noncoding mutations in blood cancers

The search for oncogenic mutations in haematological malignancies has largely focused on coding sequence variants. These variants have been critical in understanding these complex cancers in greater detail, ultimately leading to better disease monitoring, subtyping and prognostication. In contrast, the search for oncogenic variants in the noncoding genome has proven to be challenging given the vastness of the search space, the intrinsic difficulty in assessing the impact of variants that do not code for functional proteins, and our still primitive understanding of the function harboured by large parts of the noncoding genome. Recent studies have broken ground on this quest, identifying somatically acquired and recurrent mutations in the noncoding genome that activate the expression of proto-oncogenes. In this Review, we explore some of the best-characterised examples of noncoding mutations in haematological malignancies, and highlight how a significant majority of these variants impinge on gene regulation through the formation of aberrant enhancers and promoters. We delve into the challenges faced by those that embark on a search for noncoding driver mutations, and provide a framework distilled from studies that have successfully identified such variants to overcome some of the most salient hurdles. Finally, we discuss the current therapeutic strategies being explored to target the oncogenic mechanism supported by recurrent noncoding variants. We postulate that the continued discovery and functional characterisation of somatic variants in the noncoding genome will not only advance our understanding of haematological malignancies, but offer novel therapeutic avenues and provide important insights into transcriptional regulation on a broader scale.

Summary: This Review highlights the challenging but rewarding search for somatic mutations in the noncoding genome, and how such variants nucleate aberrant enhancers and promoters that drive the expression of proto-oncogenes.

Subdural Hygroma: A Morbid Complication of Intrathecal Chemotherapy in a Patient with B-Cell Acute Lymphocytic Leukemia

A subdural hygroma is an accumulation of cerebrospinal fluid in the subdural space that may occur secondary to trauma and surgery, or for iatrogenic reasons, such as a lumbar puncture. Lumbar puncture is a procedure used commonly for intrathecal chemotherapy for patients with B-cell acute lymphocytic leukemia (B-ALL) though subdural hygroma is a very rare complication. We present a case of a fatal, refractory subdural hygroma in a patient with B-ALL.

New biomarkers and therapeutic strategies in acute lymphoblastic leukemias: Recent advances

Acute lymphoblastic leukemia (ALL) represents a heterogeneous group of hematologic malignancies, and it is normally characterized by an aberrant proliferation of immature lymphoid cells. Moreover, dysregulation of multiple signaling pathways that normally regulate cellular transcription, growth, translation, and proliferation is frequently encountered in this malignancy. ALL is the most frequent tumor in childhood, and adult ALL patients still correlate with poor survival. This review focuses on modern therapies in ALL that move beyond standard chemotherapy, with a particular emphasis on immunotherapeutic approaches as new treatment strategies. Bi-specific T-cell Engagers (BiTE) antibodies, the chimeric antigen receptor (CAR)-T cells, or CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats [CRISPR]-associated nuclease 9) represent other new innovative approaches for this disease. Target and tailored therapy could make the difference in previously untreatable cases, i.e., precision and personalized medicine. Clinical trials will help to select the most efficient novel therapies in ALL management and to integrate them with existing treatments to achieve durable cures.

Transplantation in adults with relapsed/refractory acute lymphoblastic leukemia who are treated with blinatumomab from a phase 3 study

BACKGROUND

Blinatumomab, a bispecific T-cell-engaging (BiTE®) immuno-oncology therapy, demonstrated superior overall survival versus standard-of-care chemotherapy (SOC) in adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R ALL) in the phase 3 TOWER study. Herein, the authors reported clinical features and outcomes for those patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) after treatment with blinatumomab.

METHODS

In the TOWER study, adults with R/R ALL were randomized 2:1 to receive blinatumomab or SOC. Study treatment consisted of 2 cycles of induction with blinatumomab or SOC followed by consolidation and maintenance therapy. At any time after the first cycle, patients who were eligible for HSCT could proceed to HSCT.

RESULTS

Of the 97 patients who underwent HSCT during the study, baseline characteristics generally were comparable and donor types were similar between the patients treated with blinatumomab (65 patients) and those receiving SOC (32 patients). There was no evidence to suggest that the survival benefit of HSCT differed between the patients treated with blinatumomab and those receiving SOC (P = .68). On the basis of descriptive statistics, a survival benefit of HSCT versus no HSCT was not observed in patients who achieved complete remission with full, partial, or incomplete hematologic recovery with blinatumomab (odds ratio, 1.17; 95% CI, 0.54-2.53). The best outcomes were achieved in patients with no prior salvage therapy and with minimal residual disease response to blinatumomab regardless of on-study HSCT status.

CONCLUSIONS

Survival was found to be driven by response to study treatment and by salvage status regardless of on-study HSCT status. These data should be interpreted with caution because the current study was not designed to prospectively assess survival outcomes associated with HSCT after blinatumomab.

LAY SUMMARY

Evidence before this study: Blinatumomab is associated with superior morphologic and molecular response rates and superior overall outcome when compared with standard of care chemotherapy in adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia. Added value of this study: The best outcomes with blinatumomab were observed in patients who achieved minimal residual disease remission in first salvage treatment regardless of subsequent allogeneic stem cell transplantation (HSCT). Implications of all the available evidence: Patients achieving CR/CRh/CRi following blinatumomab can have a durable response with or without HSCT.

CD20-negative primary middle ear diffuse large B-cell lymphoma coexpressing MYC and BCL-2 secondary to acute lymphoblastic leukemia: A case report

RATIONALE

Second diffuse large B-cell lymphoma (DLBCL) after treatment of acute lymphoblastic leukemia (ALL) is uncommon. To our knowledge, primary middle ear DLBCL which presents CD20-negative and coexpression of MYC and BCL-2 has not been reported yet.

PATIENT CONCERNS

A 20-year-old Chinese man complained fever and weakness for 2 months. Subsequently bone marrow morphology and flow cytometry immunophenotype suggested ALL. Administrated with 9 cycles of multiagent combined chemotherapy, he felt right ear progressive hearing loss, otalgia, aural fullness. Otoendoscopic examination revealed a pitchy mass obstructing the right external auditory canal. Then the mass resection was performed for biopsy and immunohistochemistry examination.

DIAGNOSIS

The mass was diagnosed as DLBCL which was negative for CD20 and double expression of MYC and BCL-2.

INTERVENTIONS

Chemotherapy.

OUTCOMES

The patient eventually gave up and died of severe infection.

LESSONS

Although intensive chemotherapy has markedly improved the survival of ALL, more and more secondary cancers have been reported. In addition, primary middle ear lymphoma is much rare; hence, it is easy to be misdiagnosed. Furthermore, DLBCL with negative CD20 and double expression of MYC and BCL-2 is aggressive, which is characterized by chemotherapy resistance and inferior survival rates. We discuss this case aiming at raising awareness of tumors secondary to ALL and exploring the appropriate treatment options for the rare DLBCL.

Prolonged Survival of Acute Lymphoblastic Leukemia with Intrathecal Treatments for Isolated Central Nervous System Relapse

Acute lymphoblastic leukemia is commonly cured when diagnosed in the pediatric population. It portends a poorer prognosis if present in adult patients. Although adults frequently achieve complete remission, relapse rates are substantial, particularly among the elderly and high-risk populations. In the absence of prophylactic intrathecal chemotherapy, more than half of patients may develop CNS involvement or relapse, which is associated with significant risk for systemic illness. This report describes a patient with acute lymphoblastic leukemia with repeated isolated CNS relapses. This case should remind clinicians that isolated CNS disease in the absence of systemic recurrence could successfully respond to intrathecal therapy and offer patients a favorable quality of life.