The Physiopathology of T- Cell Acute Lymphoblastic Leukemia: Focus on Molecular Aspects

Somatic mutations associate with clonal expansion of CD8+ T cells

Somatic mutations in T cells can cause cancer but also have implications for immunological diseases and cell therapies. The mutation spectrum in nonmalignant T cells is unclear. Here, we examined somatic mutations in CD4+ and CD8+ T cells from 90 patients with hematological and immunological disorders and used T cell receptor (TCR) and single-cell sequencing to link mutations with T cell expansions and phenotypes. CD8+ cells had a higher mutation burden than CD4+ cells. Notably, the biggest variant allele frequency (VAF) of non-synonymous variants was higher than synonymous variants in CD8+ T cells, indicating non-random occurrence. The non-synonymous VAF in CD8+ T cells strongly correlated with the TCR frequency, but not age. We identified mutations in pathways essential for T cell function and often affected lymphoid neoplasia. Single-cell sequencing revealed cytotoxic TEMRA phenotypes of mutated T cells. Our findings suggest that somatic mutations contribute to CD8+ T cell expansions without malignant transformation.

Wiskott Aldrich syndrome protein (WASp)-deficient Th1 cells promote R-loop-driven transcriptional insufficiency and transcription-coupled nucleotide excision repair factor (TC-NER)-driven genome-instability in the pathogenesis of T cell acute lymphoblastic leukemia

BACKGROUND

T-ALL is an aggressive hematological tumor that develops as the result of a multi-step oncogenic process which causes expansion of hematopoietic progenitors that are primed for T cell development to undergo malignant transformation and growth. Even though first-line therapy has a significant response rate, 40% of adult patients and 20% of pediatric patients will relapse. Therefore, there is an unmet need for treatment for relapsed/refractory T-ALL to develop potential targeted therapies.

METHODS

Pediatric T-ALL patient derived T cells were grown under either nonskewingTh0 or Th1-skewing conditions to further process for ChIP-qPCR, RDIP-qPCR and other RT-PCR assays. Endogenous WASp was knocked out using CRISPR-Cas9 and was confirmed using flow cytometry and western blotting. LC-MS/MS was performed to find out proteomic dataset of WASp-interactors generated from Th1-skewed, human primary Th-cells. DNA-damage was assessed by immunofluorescence confocal-imaging and single-cell gel electrophoresis (comet assay). Overexpression of RNaseH1 was also done to restore normal Th1-transcription in WASp-deficient Th1-skewed cells.

RESULTS

We discovered that nuclear-WASp is required for suppressing R-loop production (RNA/DNA-hybrids) at Th1-network genes by ribonucleaseH2 (RNH2) and topoisomerase1. Nuclear-WASp is associated with the factors involved in preventing and dissolving R-loops in Th1 cells. In nuclear- WASp-reduced malignant Th1-cells, R-loops accumulate in vivo and are processed into DNA-breaks by transcription-coupled-nucleotide-excision repair (TC-NER). Several epigenetic modifications were also found to be involved at Th1 gene locus which are responsible for active/repressive marks of particular genes. By demonstrating WASp as a physiologic regulator of programmed versus unprogrammed R-loops, we suggest that the transcriptional role of WASp in vivo extends also to prevent transcription-linked DNA damage during malignancy and through modification of epigenetic dysregulations.

CONCLUSION

Our findings present a provocative possibility of resetting R-loops as a therapeutic intervention to correct both immune deficiency and malignancy in T-cell acute lymphoblastic leukemia patients and a novel role of WASp in the epigenetic regulation of T helper cell differentiation in T-ALL patients, anticipating WASp's requirement for the suppression of T-ALL progression.

Fifth Edition of the World Health Organization Classification of Tumors of the Hematopoietic and Lymphoid Tissues: Acute Lymphoblastic Leukemias, Mixed-Phenotype Acute Leukemias, Myeloid/Lymphoid Neoplasms With Eosinophilia, Dendritic/Histiocytic Neoplasms, and Genetic Tumor Syndromes

This manuscript represents a review of lymphoblastic leukemia/lymphoma (acute lymphoblastic leukemia/lymphoblastic lymphoma), acute leukemias of ambiguous lineage, mixed-phenotype acute leukemias, myeloid/lymphoid neoplasms with eosinophilia and defining gene rearrangements, histiocytic and dendritic neoplasms, and genetic tumor syndromes of the 5th edition of the World Health Organization Classification of Tumors of the Hematopoietic and Lymphoid Tissues. The diagnostic, clinicopathologic, cytogenetic, and molecular genetic features are discussed. The differences in comparison to the 4th revised edition of the World Health Organization classification of hematolymphoid neoplasms are highlighted.

Aggressive Mediastinal Lymphomas

The mediastinum contains essentially all major intrathoracic organs except for the lungs. A variety of both benign and malignant tumors can involve the mediastinum, of which lymphoma is the most common malignancy. Compared to secondary mediastinal involvement by systemic lymphomas, primary mediastinal lymphomas are less common with several specific entities that are mainly confined to mediastinal lymph nodes, and/or thymus. This review will summarize the clinical, histologic, immunophenotypic and molecular genetic features of the most common and most aggressive primary mediastinal lymphomas as well as provide suggested immunohistochemistry panels and differential diagnoses.

The CNS microenvironment promotes leukemia cell survival by disrupting tumor suppression and cell cycle regulation in pediatric T-cell acute lymphoblastic leukemia

A major obstacle in improving survival in pediatric T-cell acute lymphoblastic leukemia is understanding how to predict and treat leukemia relapse in the CNS. Leukemia cells are capable of infiltrating and residing within the CNS, primarily the leptomeninges, where they interact with the microenvironment and remain sheltered from systemic treatment. These cells can survive in the CNS, by hijacking the microenvironment and disrupting normal functions, thus promoting malignant transformation. While the protective effects of the bone marrow niche have been widely studied, the mechanisms behind leukemia infiltration into the CNS and the role of the CNS niche in leukemia cell survival remain unknown. We identified a dysregulated gene expression profile in CNS infiltrated T-ALL and CNS relapse, promoting cell survival, chemoresistance, and disease progression. Furthermore, we discovered that interactions between leukemia cells and human meningeal cells induced epigenetic alterations, such as changes in histone modifications, including H3K36me3 levels. These findings are a step towards understanding the molecular mechanisms promoting leukemia cell survival in the CNS microenvironment. Our results highlight genetic and epigenetic alterations induced by interactions between leukemia cells and the CNS niche, which could potentially be utilized as biomarkers to predict CNS infiltration and CNS relapse.

Bartonella henselae Infection and Lymphadenopathy in a Patient With T Cell Acute Lymphoblastic Leukemia

Patients undergoing therapy for T cell acute lymphoblastic leukemia are at risk of infections during their treatment course. Cat scratch disease caused by Bartonella hensalae can masquerade as leukemic relapse and cause systemic infection. Obtaining a thorough exposure history may aid clinicians in making the diagnosis.

Thymic-Epithelial-Cell-Dependent Microenvironment Influences Proliferation and Apoptosis of Leukemic Cells

T-cell acute lymphoblastic leukemia (T-ALL) is a hematological cancer characterized by the infiltration of immature T-cells in the bone marrow. Aberrant NOTCH signaling in T-ALL is mainly triggered by activating mutations of NOTCH1 and overexpression of NOTCH3, and rarely is it linked to NOTCH3-activating mutations. Besides the known critical role of NOTCH, the nature of intrathymic microenvironment-dependent mechanisms able to render immature thymocytes, presumably pre-leukemic cells, capable of escaping thymus retention and infiltrating the bone marrow is still unclear. An important challenge is understanding how leukemic cells shape their tumor microenvironment to increase their ability to infiltrate and survive within. Our previous data indicated that hyperactive NOTCH3 affects the CXCL12/CXCR4 system and may interfere with T-cell/stroma interactions within the thymus. This study aims to identify the biological effects of the reciprocal interactions between human leukemic cell lines and thymic epithelial cell (TEC)-derived soluble factors in modulating NOTCH signaling and survival programs of T-ALL cells and TECs. The overarching hypothesis is that this crosstalk can influence the progressive stages of T-cell development driving T-cell leukemia. Thus, we investigated the effect of extracellular space conditioned by T-ALL cell lines (Jurkat, TALL1, and Loucy) and TECs and studied their reciprocal regulation of cell cycle and survival. In support, we also detected metabolic changes as potential drivers of leukemic cell survival. Our studies could shed light on T-cell/stroma crosstalk to human leukemic cells and propose our culture system to test pharmacological treatment for T-ALL.

The role and mechanism of AZD5363 anti-leukemia activity in T-cell acute lymphoblastic leukemia

BACKGROUND

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive and heterogeneous hematologic malignancy. Chemotherapy resistance and refractory relapses are the most important challenges in T-ALL. PI3K/Akt/mTOR pathway has been implicated in regulating cell survival, T-ALL development and resistance to chemotherapy. We explored the effects of AZD5363 (a potent pan-Akt inhibitor) alone and in combination with autophagy inhibitor hydroxycholoroquine sulfate (HCQ) in cultured CCRF-CEM, Jurkat and PF382 cells and a T-ALL xenograft mouse model.

METHODS

A xenograft mouse model was used to investigate the effect of AZD5363 on T-ALL progression. MTT assay, flow cytometry, siRNA, transmission electron microscopy and western blotting were performed in cultured CCRF-CEM, Jurkat and PF382 cells. The interaction between AZD5363 and HCQ was explored by molecular docking.

RESULTS

AZD5363 delayed T-ALL progression and increased the expression of cleaved caspase-3 and LC3B-II in mice. AZD5363 decreased cells viability by arresting cell cycle in the G1 phase and inducing apoptosis, and, significantly increased the number of autophagosomes (p < 0.01). The increased expression of cleaved caspase-3 and LC3B-II, and phosphorylation of Akt and mTOR were significantly, inhibited by AZD5363. HCQ blocked AZD5363-induced autophagy and enhanced AZD5363-induced cell death (p < 0.01).

CONCLUSIONS

AZD5363 suppressed T-ALL progression and its anti-leukemia activity was enhanced by HCQ in T-ALL cells, which might provide a potential therapeutic strategy for human T-ALL.

Therapeutic challenges in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

Exploring the pharmacological mechanisms of Shuanghuanglian against T-cell acute lymphoblastic leukaemia through network pharmacology combined with molecular docking and experimental validation

CONTEXT

Due to the poor prognosis of T-cell acute lymphoblastic leukaemia (T-ALL), there is an urgent need to identify safer and more cost-effective drugs.

OBJECTIVE

This study evaluated the antitumour activity of Shuanghuanglian (SHL) on T-ALL cells and elucidated the mechanism.

MATERIALS AND METHODS

Jurkat and Molt4 cells were treated with SHL (0.1, 0.2 and 0.4 mg/mL) for 24 and 48 h. The controls were treated with RPMI 1640 containing 10% foetal bovine serum. Cell viability was evaluated through Cell Counting Kit-8 assay. Patterns of death and signalling pathway alterations caused by SHL were identified by network pharmacology combined with GO enrichment analysis and then were verified by Hoechst 33342 staining, Annexin V-FITC/PI staining and Western blotting. Interactions of the active ingredients with targets were analysed by molecular docking.

RESULTS

The IC₅₀ values of SHL in Jurkat and Molt4 cells were 0.30 ± 0.10 and 0.48 ± 0.07 mg/mL, respectively, at 24 h and 0.27 ± 0.05 and 0.30 ± 0.03 mg/mL at 48 h. In T-ALL, 117 target genes of SHL were mainly enriched in the apoptosis and NOTCH signalling pathways. SHL induced apoptosis was confirmed by Hoechst 33342 staining and flow cytometry. The protein levels of cleaved caspase-7 and cleaved PARP were significantly increased but those of cleaved NOTCH1 and MYC were reduced. The active ingredients of SHL can interact with γ-secretase.Discussion and conclusions: SHL induces apoptosis in T-ALL cells via the NOTCH1-MYC pathway and may be a potential drug for the treatment of T-ALL.

Rigosertib is more potent than wortmannin and rapamycin against adult T-cell leukemia-lymphoma

Human T lymphotropic virus type 1 (HTLV-1) infection can cause adult T-cell lymphoblastic leukemia (ATLL), an incurable, chemotherapy-resistant malignancy. In a quest for new therapeutic targets, our study sought to determine the levels of AKT, mTOR, and PI3K in ATLL MT-2 cells, HTLV-1 infected NIH/3T3 cells (Inf-3T3), and HTLV-1 infected patients (Carrier, HAM/TSP, and ATLL). Furthermore, the effects of rigosertib, wortmannin, and rapamycin on the PI3K/Akt/mTOR pathway to inhibit the proliferation of ATLL cells were examined. The results showed that mRNA expression of Akt/PI3K/mTOR was down-regulated in carrier, HAM/TSP, and ATLL patients, as well as MT-2, and Inf-3T3 cells, compared to the healthy individuals and untreated MT-2 and Inf-3T3 as controls. However, western blotting revealed an increase in the phosphorylated and activated forms of AKT and mTOR. Treating the cells with rapamycin, wortmannin, and rigosertib decreased the phosphorylated forms of Akt and mTOR and restored their mRNA expression levels. Using these inhibitors also significantly boosted the expression of the pro-apoptotic genes, Bax/Bcl-2 ratio as well as the expression of the tumor suppressor gene p53 in the MT-2 and Inf-3T3cells. Rigosertib was more potent than wortmannin and rapamycin in inducing sub-G1 and G2-M cell cycle arrest, as well as late apoptosis in the Inf-3T3 and MT-2 cells. It also synergized the cytotoxic effects of vincristine. These findings demonstrate that HTLV-1 downregulation of the mRNA level may occur as a negative feedback response to increased PI3K-Akt-mTOR phosphorylation by HTLV-1. Therefore, using rigosertib alone or in combination with common chemotherapy drugs may be beneficial in ATLL patients.

Identification of compounds that preferentially suppress the growth of T-cell acute lymphoblastic leukemia-derived cells

T-cell acute lymphoblastic leukemia (T-ALL) is one of the most frequently occurring cancers in children and is associated with a poor prognosis. Here, we performed large-scale screening of natural compound libraries to identify potential drugs against T-ALL. We identified three low-molecular-weight compounds (auxarconjugatin-B, rumbrin, and lavendamycin) that inhibited the proliferation of the T-ALL cell line CCRF-CEM, but not that of the B lymphoma cell line Raji in a low concentration range. Among them, auxarconjugatin-B and rumbrin commonly contained a polyenyl 3-chloropyrrol in their chemical structure, therefore we chose auxarconjugatin-B for further analyses. Auxarconjugatin-B suppressed the in vitro growth of five human T-ALL cell lines and two T-ALL patient-derived cells, but not that of adult T-cell leukemia patient-derived cells. Cultured normal T cells were several-fold resistant to auxarconjugatin-B. Auxarconjugatin-B and its synthetic analogue Ra#37 depolarized the mitochondrial membrane potential of CCRF-CEM cells within 3 h of treatment. These compounds are promising seeds for developing novel anti-T-ALL drugs.

Effect of siRNA-mediated silencing of p53R2 gene on sensitivity of T-ALL cellsto Daunorubicin

INTRODUCTION

p53R2 is a p53-inducible protein that, as one of the subunits of ribonucleotide reductase, plays an important role in providing dNTPs for DNA repair. Although p53R2 is associated with cancer progression, its role in T-cell acute lymphoblastic leukemia (T-ALL) cells is unknown. Therefore, in this study, we evaluated the effect of p53R2 silencing on double-stranded DNA breaks, apoptosis and cell cycle of T-ALL cells treated with Daunorubicin.

METHODS

Transfection was performed using Polyethyleneimine (PEI). Gene expression was measured using real-time PCR and protein expression was evaluated using Western blotting. Cell metabolic activity and IC50 were calculated using MTT assay, formation of double-stranded DNA breaks was checked using immunohistochemistry for γH2AX, and cell cycle and apoptosis were evaluated using flow cytometry.

RESULTS

We found that p53 silencing synergistically inhibited the growth of T-ALL cells by Daunorubicin. p53R2 siRNA in combination with Daunorubicin but not alone increases the rate of DNA double-strand breaks in T-ALL cells. In addition, p53R2 siRNA significantly increased Daunorubicin-induced apoptosis. p53R2 siRNA also caused a non-significant increase in cells in G2 phase.

CONCLUSION

The results of the present study showed that silencing of p53R2 using siRNA can significantly increase the antitumor effects of Daunorubicin on T-ALL cells. Therefore, p53R2 siRNA has the potential to be used as an adjuvant therapy in combination with Daunorubicin in T-ALL.

Identification of NRF2 Activation as a Prognostic Biomarker in T-Cell Acute Lymphoblastic Leukaemia

The standard-of-care treatment of T-cell acute lymphoblastic leukaemia (T-ALL) with chemotherapy usually achieves reasonable rates of initial complete response. However, patients who relapse or do not respond to conventional therapy show dismal outcomes, with cure rates below 10% and limited therapeutic options. To ameliorate the clinical management of these patients, it is urgent to identify biomarkers able to predict their outcomes. In this work, we investigate whether NRF2 activation constitutes a biomarker with prognostic value in T-ALL. Using transcriptomic, genomic, and clinical data, we found that T-ALL patients with high NFE2L2 levels had shorter overall survival. Our results demonstrate that the PI3K-AKT-mTOR pathway is involved in the oncogenic signalling induced by NRF2 in T-ALL. Furthermore, T-ALL patients with high NFE2L2 levels displayed genetic programs of drug resistance that may be provided by NRF2-induced biosynthesis of glutathione. Altogether, our results indicate that high levels of NFE2L2 may be a predictive biomarker of poor treatment response in T-ALL patients, which would explain the poor prognosis associated with these patients. This enhanced understanding of NRF2 biology in T-ALL may allow a more refined stratification of patients and the proposal of targeted therapies, with the ultimate goal of improving the outcome of relapsed/refractory T-ALL patients.

Pdx1 expression in hematopoietic cells activates Kras-mutation to drive leukemia in KC (Pdx1-Cre; LSL-KrasG12D/+) mice

The highly utilized KC model has a reported lethality rate of about 30%, which has been attributed to pancreas cancer. However, a competing cause of lethality in KC mice is due to the activation of mutant-Kras gene (KrasG12D/+) in the multipotent progenitor cells (MPP), and subsequent development of Kras-mutant T-cell acute lymphoblastic leukemia (T-ALL). Overall, 20% (5/25) of KC mice developed T-ALL by 9 months of age. Transplantation of pooled bone marrow from KC mice into CD45 congenic mice caused T-ALL in 100% of recipient mice, confirming that mutant-Kras expression in the hematologic compartment is driving the development of T-ALL in the KC mouse model. These results are an essential consideration for investigators using this model. Further, the lower penetrance of T-ALL in KC mice (versus existing leukemia models) suggests this model could be considered as an alternative research model to evaluate onset and factors that exacerbate the development of T-ALL.

An update on genetic aberrations in T-cell neoplasms

T-cell neoplasms are a highly heterogeneous group of leukaemias and lymphomas that represent 10-15% of all lymphoid neoplasms. Traditionally, our understanding of T-cell leukaemias and lymphomas has lagged behind that of B-cell neoplasms, in part due to their rarity. However, recent advances in our understanding of T-cell differentiation, based on gene expression and mutation profiling and other high throughput methods, have better elucidated the pathogenetic mechanisms of T-cell leukaemias and lymphomas. In this review, we provide an overview of many of the molecular abnormalities that occur in various types of T-cell leukaemia and lymphoma. Much of this knowledge has been used to refine diagnostic criteria that has been included in the fifth edition of the World Health Organization. This knowledge is also being used to improve prognostication and identify novel therapeutic targets, and we expect this progress will continue, eventually resulting in improved outcomes for patients with T-cell leukaemias and lymphomas.

The survival of childhood leukemia: An 8-year single-center experience

BACKGROUND

The survival of childhood leukemia has improved. We aimed to report the survival rate and the associated factors in children with acute leukemia during an 8-year follow-up.

AIMS

This study investigates the 8-year survival rates of children with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) in Shiraz, the largest oncology center in Southern Iran. We also aimed to assess the independent factors associated with higher mortality in childhood leukemia.

METHODS

Children 0-18 years with acute leukemia were followed from 2013 to 2021 in Shiraz, Iran. The 8-year overall survival (OS) and event-free survival (EFS) rates were estimated by the Kaplan-Meier method. Independent factors associated with survival were assessed by the Cox regression hazard modeling.

RESULTS

We included 786 children, with 43.5% female, and a mean age of 6.32 ± 4.62 years. Patients with AML compared to ALL experienced more relapse (34.6% vs. 22.5%, p = .01) and death (31.7% vs. 11.3%, p < .001). The cumulative 8-year OS and EFS were 81% (95% confidence interval (CI), 74.3% to 86.1%) and 68.3% (95% CI, 63.5% to 72.7%) in ALL patients and 63.5% (95% CI, 52.1% to 72.9%) and 43% (95% CI, 33.1% to 52.6%) in AML patients. Multivariable analysis revealed that hepatomegaly (hazard ratio = 4, 95% CI, 1.0 to 22.3, p = .05) was the main independent risk factor of death in ALL patients. No definite risk factor was defined for AML patients.

CONCLUSION

The survival of childhood leukemia has recently increased dramatically in low-middle income countries. Hepatomegaly was introduced as a potential risk factor for lower survival in ALL patients. Further multicenter studies are needed to confirm the validity of this association.

Notch Partners in the Long Journey of T-ALL Pathogenesis

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological disease that arises from the oncogenic transformation of developing T cells during T-lymphopoiesis. Although T-ALL prognosis has improved markedly in recent years, relapsing and refractory patients with dismal outcomes still represent a major clinical issue. Consequently, understanding the pathological mechanisms that lead to the appearance of this malignancy and developing novel and more effective targeted therapies is an urgent need. Since the discovery in 2004 that a major proportion of T-ALL patients carry activating mutations that turn NOTCH1 into an oncogene, great efforts have been made to decipher the mechanisms underlying constitutive NOTCH1 activation, with the aim of understanding how NOTCH1 dysregulation converts the physiological NOTCH1-dependent T-cell developmental program into a pathological T-cell transformation process. Several molecular players have so far been shown to cooperate with NOTCH1 in this oncogenic process, and different therapeutic strategies have been developed to specifically target NOTCH1-dependent T-ALLs. Here, we comprehensively analyze the molecular bases of the cross-talk between NOTCH1 and cooperating partners critically involved in the generation and/or maintenance and progression of T-ALL and discuss novel opportunities and therapeutic approaches that current knowledge may open for future treatment of T-ALL patients.

Enfermedad mínima residual por citometría de flujo en pacientes con leucemia linfoblástica aguda

Antecedentes. La citometría de flujo (CMF) es una técnica que permite el análisis multiparamétrico de poblaciones celulares, siendo esencial en la investigación biomédica y como herramienta diagnóstica. Esta técnica rápida tiene una alta sensibilidad, evaluandocaracterísticas en la población de interés como es el caso del tamaño, granularidad, complejidad del citoplasma celular y proteínas de que permiten la clasificación fenotípica y funcional de un gran número de células. Por estas razones, esta técnica ha adquiridoimportancia en el diagnóstico y seguimiento de enfermedades y anomalías hematológicas, como leucemias, síndromes mielodisplásicos y síndromes mieloproliferativos, entre otras. Objetivo. La presente revisión se enfoca en los avances en la implementación de la CMF en la Enfermedad Mínima Residual (EMR) presente en la Leucemia Linfoblástica Aguda (LLA), la cual es una población mínima leucémica que se detecta en un paciente después de suministrar un tratamiento oncológico, donde se evalúa su eficacia, el riesgo de una recaída y el proceso de remisión completa. Metodología. Se realiza una revisión no sistemática deliteratura en bases de datos, de los últimos 15 años, donde evalúen las implicaciones del uso de citometría de flujo en la EMR, de esta revisión se extraen aspectos relevantes al momento de emplear la CMF para el diagnóstico y seguimiento de pacientes con leucemias. Resultados. La CMF es una técnica muy versátil e importante para el diagnóstico y seguimiento de la EMR por su alta sensibilidad para la detección de bajos números de células resistentes a la terapia. Adicionalmente se muestra la importancia de la estandarización de protocolos como EUROFLOW para un adecuado procesamiento y análisis clínico de las muestras de pacientes.

Pediatric T-cell Lymphoblastic Leukemia/Lymphoma Diagnosed at Routine Adenoidectomy Specimen

Postoperative routine pathologic evaluation of tonsillectomy and adenoidectomy specimens rarely reveals a diagnosis of malignancy. The object of this case report is to highlight this rare clinical occurrence. A 4-year-old boy presented with symptoms of sleep-disordered breathing and had a history of recurrent tonsillitis. Physical examination revealed adenoid hypertrophy and Brodsky Grade 1 bilateral tonsillar hypertrophy. The patient underwent adenoidectomy and tonsillectomy. The adenoids were found to be MAGS Grade 4 (Modified Adenoid Grading System) hypertrophic causing 100% obstruction. After the histologic examination, T-cell lymphoblastic leukemia/lymphoma was diagnosed. Proper treatment allowed full recovery. Currently, no consensus has been made about routine pathological evaluation. To achieve a cost-effective and precautionary approach, we recommend pathological follow-up of cases with unusual intraoperative findings with/without clinical malignancy suspicion.

A Dual Role for FADD in Human Precursor T-Cell Neoplasms

A reduction in FADD levels has been reported in precursor T-cell neoplasms and other tumor types. Such reduction would impact on the ability of tumor cells to undergo apoptosis and has been associated with poor clinical outcomes. However, FADD is also known to participate in non-apoptotic functions, but these mechanisms are not well-understood. Linking FADD expression to the severity of precursor T-cell neoplasms could indicate its use as a prognostic marker and may open new avenues for targeted therapeutic strategies. Using transcriptomic and clinical data from patients with precursor T-cell neoplasms, complemented by in vitro analysis of cellular functions and by high-throughput interactomics, our results allow us to propose a dual role for FADD in precursor T-cell neoplasms, whereby resisting cell death and chemotherapy would be a canonical consequence of FADD deficiency in these tumors, whereas deregulation of the cellular metabolism would be a relevant non-canonical function in patients expressing FADD. These results reveal that evaluation of FADD expression in precursor T-cell neoplasms may aid in the understanding of the biological processes that are affected in the tumor cells. The altered biological processes can be of different natures depending on the availability of FADD influencing its ability to exert its canonical or non-canonical functions. Accordingly, specific therapeutic interventions would be needed in each case.

Targeting Leukemia-Initiating Cells and Leukemic Niches: The Next Therapy Station for T-Cell Acute Lymphoblastic Leukemia?

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive subtype of hematological malignancy characterized by its high heterogeneity and potentially life-threatening clinical features. Despite the advances in risk stratification and therapeutic management of T-ALL, patients often suffer from treatment failure and chemotherapy-induced toxicity, calling for greater efforts to improve therapeutic efficacy and safety in the treatment of T-ALL. During the past decades, increasing evidence has shown the indispensable effects of leukemia-initiating cells (LICs) and leukemic niches on T-ALL initiation and progression. These milestones greatly facilitate precision medicine by interfering with the pathways that are associated with LICs and leukemic niches or by targeting themselves directly. Most of these novel agents, either alone or in combination with conventional chemotherapy, have shown promising preclinical results, facilitating them to be further evaluated under clinical trials. In this review, we summarize the latest discoveries in LICs and leukemic niches in terms of T-ALL, with a particular highlight on the current precision medicine. The challenges and future prospects are also discussed.

Molecular Diagnostic Testing for Hematopoietic Neoplasms: Linking Pathogenic Drivers to Personalized Diagnosis

Molecular diagnostics inhabit an increasingly central role in characterizing hematopoietic malignancies. This brief review summarizes the genomic targets important for many major categories of hematopoietic neoplasia by focusing on disease pathogenesis. In myeloid disease, recurrent mutations in key functional classes drive clonal hematopoiesis, on which additional variants can specify clinical presentation and accelerate progression. Lymphoblastic leukemias are frequently initiated by oncogenic fusions that block lymphoid maturation while, in concert with additional mutations, driving proliferation. The links between genetic aberrations and lymphoma patient outcomes have been clarified substantially through the clustering of genomic profiles. Finally, the addition of next-generation sequencing strategies to cytogenetics is refining risk stratification for plasma cell myeloma. In all categories, molecular diagnostics shed light on the unique mechanistic underpinnings of each individual malignancy, thereby empowering more rational, personalized care for these patients.

Therapeutic potential of inhibiting histone 3 lysine 27 demethylases: a review of the literature

Histone 3 lysine 27 (H3K27) demethylation constitutes an important epigenetic mechanism of gene activation. It is mediated by the Jumonji C domain-containing lysine demethylases KDM6A and KDM6B, both of which have been implicated in a wide myriad of diseases, including blood and solid tumours, autoimmune and inflammatory disorders, and infectious diseases. Here, we review and summarise the pre-clinical evidence, both in vitro and in vivo, in support of the therapeutic potential of inhibiting H3K27-targeting demethylases, with a focus on the small-molecule inhibitor GSK-J4. In malignancies, KDM6A/B inhibition possesses the ability to inhibit proliferation, induce apoptosis, promote differentiation, and heighten sensitivity to currently employed chemotherapeutics. KDM6A/B inhibition also comprises a potent anti-inflammatory approach in inflammatory and autoimmune disorders associated with inappropriately exuberant inflammatory and autoimmune responses, restoring immunological homeostasis to inflamed tissues. With respect to infectious diseases, KDM6A/B inhibition can suppress the growth of infectious pathogens and attenuate the immunopathology precipitated by these pathogens. The pre-clinical in vitro and in vivo data, summarised in this review, suggest that inhibiting H3K27 demethylases holds immense therapeutic potential in many diseases.

Inhibition of the m6A reader IGF2BP2 as a strategy against T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignant leukemia with extremely limited treatment for relapsed patients. N6‐methyladenosine (m⁶A) reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) participates in the initiation and growth of cancers by communicating with various targets. Here, we found IGF2BP2 was highly expressed in T-ALL. Gain and loss of IGF2BP2 demonstrated IGF2BP2 was essential for T-ALL cell proliferation in vitro and loss of IGF2BP2 prolonged animal survival in a human T-ALL xenograft model. Mechanistically, IGF2BP2 directly bound to T-ALL oncogene NOTCH1 via an m⁶A dependent manner. Furthermore, we identified a small-molecule IGF2BP2 inhibitor JX5 and treatment of T-ALL with JX5 showed similar functions as knockdown of IGF2BP2. These findings not only shed light on the role of IGF2BP2 in T-ALL, but also provide an alternative γ‑Secretase inhibitors (GSI) therapy to treat T-ALL.

Ultrastructural and Morphological Effects in T-Lymphoblastic Leukemia CEM-SS Cells Following Treatment with Nordamnacanthal and Damnacanthal from Roots of Morinda elliptica

Background: Morinda elliptica (family Rubiaceae), locally known as ‘mengkudu kecil’, has been used by the Malays for medicinal purposes. Anthraquinones isolated from the roots of Morinda elliptica, namely nordamnacanthal and damnacanthal, have been widely reported to exhibit anticancer and antioxidant properties in various cancer models in vitro and in vivo. Aim: This study analyzed the morphological and ultrastructural effects of damnacanthal and nordamnacanthal on T-lymphoblastic leukemia CEM-SS cells. Method: Light microscopy, Giemsa staining, Wright’s staining, scanning electron microscopy, and transmission electron microscopy were carried out to determine apoptosis, necrosis, and ultrastructural changes that occurred within the cells. Results: The outcomes showed that these compounds induced cell death by apoptosis and necrosis, specifically at higher doses of 10 and 30 μg/mL. Condensation and fragmentation of the nuclear chromatin, which further separated into small, membrane-bound vesicles known as apoptotic bodies, were observed in the nuclei and cytoplasm. The plasma membranes and cytoskeletons also showed marked morphological changes upon treatment with damnacanthal and nordamnacanthal, indicating apoptosis. Conclusion: Therefore, we report that damnacanthal and nordamnacanthal exhibit anticancer properties by inducing apoptosis and necrosis in CEM-SS cells, and they have potential as a drug for the treatment of T-lymphoblastic leukemia.

Design of a targeted next-generation DNA sequencing panel for pediatric T-cell lymphoblastic lymphoma to unravel biology and optimize treatment

Low incidence and molecular heterogeneity of pediatric T-cell lymphoblastic lymphoma (T-LBL) require an international, large-scale effort to identify novel clinical biomarkers. The ongoing international clinical trial LBL2018 (NCT04043494) represents an ideal opportunity to implement a common analytic approach. Targeted next-generation sequencing is well-suited for this purpose; however, selection of relevant target genes for T-LBL remains subject of ongoing debates. Our group has recently designed and evaluated a first target panel of 80 candidate genes for T-LBL. The present study aimed at developing a novel optimized gene panel for large-scale application and to promote an international agreement on a common core panel. Small sequence variants obtained from our former study were systematically analyzed and classified with regards to pathogenic relevance, to prioritize candidate genes. Additional genes were curated from literature and online databases for a more comprehensive analysis of relevant functions and signaling pathways. The new target panel TGP-T-LBL entails 84 candidate genes which are key actors in NOTCH, PI3K-AKT, JAK-STAT, RAS signaling, epigenetic regulation, transcription, DNA repair, cell cycle regulation and ribosomal function. From our former gene panel, 35 out of 80 candidate genes were selected for the novel panel. Forty-six out of 84 genes are currently being analyzed in the ongoing international trial LBL2018. Exploratory analysis of prognostic relevance on mutation-level suggested a potential association of PIK3CA variants c.1624G > A(p.Glu542Lys) and c.1633G > A(p.Glu545Lys) to occurrence of relapse, emphasizing particular relevance of mutation analysis in PI3K-AKT signaling. Our approach promotes comprehensive and clinically relevant mutational profiling of pediatric T-LBL. This article is protected by copyright. All rights reserved.

MicroRNA-139, an Emerging Gate-Keeper in Various Types of Cancer

Mounting data show that MIR139 is commonly silenced in solid cancer and hematological malignancies. MIR139 acts as a critical tumor suppressor by tuning the cellular response to different types of stress, including DNA damage, and by repressing oncogenic signaling pathways. Recently, novel insights into the mechanism of MIR139 silencing in tumor cells have been described. These include epigenetic silencing, inhibition of POL-II transcriptional activity on gene regulatory elements, enhanced expression of competing RNAs and post-transcriptional regulation by the microprocessor complex. Some of these MIR139-silencing mechanisms have been demonstrated in different types of cancer, suggesting that these are more general oncogenic events. Reactivation of MIR139 expression in tumor cells causes inhibition of tumor cell expansion and induction of cell death by the repression of oncogenic mRNA targets. In this review, we discuss the different aspects of MIR139 as a tumor suppressor gene and give an overview on different transcriptional mechanisms regulating MIR139 in oncogenic stress and across different types of cancer. The novel insights into the expression regulation and the tumor-suppressing activities of MIR139 may pave the way to new treatment options for cancer.

Clinico-biological features of T-cell acute lymphoblastic leukemia with fusion proteins

T-cell acute lymphoblastic leukemias (T-ALL) represent 15% of pediatric and 25% of adult ALL. Since they have a particularly poor outcome in relapsed/refractory cases, identifying prognosis factors at diagnosis is crucial to adapting treatment for high-risk patients. Unlike acute myeloid leukemia and BCP ALL, chromosomal rearrangements leading to chimeric fusion-proteins with strong prognosis impact are sparsely reported in T-ALL. To address this issue an RT-MPLA assay was applied to a consecutive series of 522 adult and pediatric T-ALLs and identified a fusion transcript in 20% of cases. PICALM-MLLT10 (4%, n = 23), NUP214-ABL1 (3%, n = 19) and SET-NUP214 (3%, n = 18) were the most frequent. The clinico-biological characteristics linked to fusion transcripts in a subset of 235 patients (138 adults in the GRAALL2003/05 trials and 97 children from the FRALLE2000 trial) were analyzed to identify their prognosis impact. Patients with HOXA trans-deregulated T-ALLs with MLLT10, KMT2A and SET fusion transcripts (17%, 39/235) had a worse prognosis with a 5-year EFS of 35.7% vs 63.7% (HR = 1.63; p = 0.04) and a trend for a higher cumulative incidence of relapse (5-year CIR = 45.7% vs 25.2%, HR = 1.6; p = 0.11). Fusion transcripts status in T-ALL can be robustly identified by RT-MLPA, facilitating risk adapted treatment strategies for high-risk patients.

Effect of GATA3 rs3824662 gene polymorphism in Han Chinese children with pre-B-cell acute lymphoblastic leukemia with 10 years follow-up

PURPOSE

To evaluate the influence of GATA3 rs3824662 on pre-B-cell acute lymphoblastic leukemia (pre-B-cell ALL) susceptibility and long-term prognosis in Han Chinese children with pre-B-cell ALL treated with the CCLG-2008 protocol at the Children's Hospital of Soochow University.

METHODS

A total of 256 patients with childhood pre-B-cell ALL under the CCLG-2008 protocol were enrolled in this study, and 174 healthy children were used as case controls. GATA3 rs3824662 genotyping was performed using a polymerase chain reaction, followed by Sanger sequencing. The association of genotype with clinical characteristics, treatment response, adverse events, and outcomes were analyzed.

RESULTS

The A allele frequency of GATA3 rs3824662 in patients with pre-B cell ALL was significantly higher than that in healthy children (OR = 1.41, 95% CI = 1.042-1.908; P = 0.026). Among patients with pre-B-cell ALL, the GATA3 rs3824662 AA genotype was associated with poor prednisolone response and high blast cell burden on day 15 of the induction therapy (P = 0.011 and 0.007, respectively). Patients with the rs3824662 AA variant suffered more episodes of sepsis than those with the CC or CA variants (P = 0.021). The GATA3 rs3824662 AA genotype was significantly associated with sepsis [hazard ratio (HR) = 3.375; P = 0.01]. No significant differences were found in the cumulative incidence of relapse, overall survival, and event-free survival among all genotypes.

CONCLUSION

GATA3 rs3824662 was associated with susceptibility in Han Chinese children with pre-B-cell ALL and could be a possible risk factor for poor early treatment response and treatment-related sepsis.

Therapeutic strategies, including allogeneic stem cell transplantation, to overcome relapsed/refractory adult T-cell acute lymphoblastic leukemia

INTRODUCTION

The long-term survival of relapsed/refractory (R/R) adult T-cell acute lymphoblastic leukemia (T-ALL) is quite poor, and early T-cell precursor (ETP) ALL has recently been described as a high-risk T-ALL subgroup. However, the optimal therapeutic approach to R/R adult T-ALL remains poorly established.

AREAS COVERED

At present, cytoreductive therapy followed by allogeneic stem cell transplantation (allo-SCT) is considered to be the most clinically relevant and curative modality for R/R T-ALL. Above all, achieving minimal residual disease (MRD) is a key factor for successful allo-SCT and maintaining long-term remission for R/R patients. As a salvage regimen, nelarabine is the only therapy that was specifically approved for use in patients with R/R T-ALL. A combination of conventional chemotherapeutic agents and novel agents, such as venetoclax, can be used as alternatives for cytoreduction and bridging to transplantation. Relevant literatures published in the last 30 years were searched from PubMed to review the topic of T-ALL, and allo-SCT.

EXPERT OPINION

An effective salvage regimen, to achieve negative MRD, followed by allo-SCT is currently the best way to improve the clinical outcomes of adult R/R T-ALL. Moreover, posttransplant therapies, such as prophylactic or preemptive donor leukocyte infusion and hypomethylating agents, need to be considered as sequential therapy.

Aggressive T-cell lymphomas: 2021 Updates on diagnosis, risk stratification and management

INTRODUCTION

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 27 different subtypes of peripheral T-cell lymphoma (PTCL), and we are now beginning to understand the differences between the various subtypes beyond histologic variations.

MOLECULAR PATHOGENESIS OF VARIOUS SUBTYPES OF PTCL

Gene expression profiling (GEP) can help in diagnosis and prognostication of various subtypes including PTCL-nos and anaplastic large cell lymphoma (ALCL). In addition, mutational analysis is now being incorporated in clinical trials of novel agents to evaluate various biomarkers of response to allow better therapeutic choices for patients.

TARGETED THERAPIES

There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. This includes the CD30 directed antibody drug conjugate brentuximab vedotin. Other notable targets are CD25, CCR4, inhibition of PI3kinase - m TOR and JAK/STAT pathways. The ALK inhibitors are promising for ALK expressing tumors.

IMMUNOTHERAPIES

Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL. The use of checkpoint inhibitors in the treatment of PTCL is still controversial. The most promising results have been seen in cases of extranodal natural killer cell/T-cell (ENK/T) lymphomas and cutaneous T-cell lymphomas (CTCL). Bispecific antibody based treatments as well as CAR-T cell based therapies are in clinical trials.

State-of-Art of Cellular Therapy for Acute Leukemia

With recent clinical breakthroughs, immunotherapy has become the fourth pillar of cancer treatment. Particularly, immune cell-based therapies have been envisioned as a promising treatment option with curative potential for leukemia patients. Hence, an increasing number of preclinical and clinical studies focus on various approaches of immune cell-based therapy for treatment of acute leukemia (AL). However, the use of different immune cell lineages and subsets against different types of leukemia and patient disease statuses challenge the interpretation of the clinical applicability and outcome of immune cell-based therapies. This review aims to provide an overview on recent approaches using various immune cell-based therapies against acute B-, T-, and myeloid leukemias. Further, the apparent limitations observed and potential approaches to overcome these limitations are discussed.

The New Therapeutic Strategies in Pediatric T-Cell Acute Lymphoblastic Leukemia

Childhood acute lymphoblastic leukemia is a genetically heterogeneous cancer that accounts for 10–15% of T-cell acute lymphoblastic leukemia (T-ALL) cases. The T-ALL event-free survival rate (EFS) is 85%. The evaluation of structural and numerical chromosomal changes is important for a comprehensive biological characterization of T-ALL, but there are currently no genetic prognostic markers. Despite chemotherapy regimens, steroids, and allogeneic transplantation, relapse is the main problem in children with T-ALL. Due to the development of high-throughput molecular methods, the ability to define subgroups of T-ALL has significantly improved in the last few years. The profiling of the gene expression of T-ALL has led to the identification of T-ALL subgroups, and it is important in determining prognostic factors and choosing an appropriate treatment. Novel therapies targeting molecular aberrations offer promise in achieving better first remission with the hope of preventing relapse. The employment of precisely targeted therapeutic approaches is expected to improve the cure of the disease and quality of life of patients. These include therapies that inhibit Notch1 activation (bortezomib), JAK inhibitors in ETP-ALL (ruxolitinib), BCL inhibitors (venetoclax), and anti-CD38 therapy (daratumumab). Chimeric antigen receptor T-cell therapy (CAR-T) is under investigation, but it requires further development and trials. Nelarabine-based regimens remain the standard for treating the relapse of T-ALL.

Circular RNA circRNA_0000094 sponges microRNA-223-3p and up-regulate F-box and WD repeat domain containing 7 to restrain T cell acute lymphoblastic leukemia progression

Circular RNAs (circRNAs) exert crucial regulatory effects in the pathogenesis of multiple tumors. This work aimed to probe into the role of circ_0000094 in T cell acute lymphoblastic leukemia (T-ALL). In this work, quantitative real-time polymerase chain reaction (qRT-PCR) was applied to quantify circ_0000094, miR-223-3p, and F-box and WD repeat domain containing 7 (FBW7) mRNA expressions in lymph node samples from T-ALL patients; Western blot was adopted to examine FBW7 protein expression in T-ALL cells; cell proliferation was detected by cell counting kit-8 (CCK-8) experiment; apoptosis was examined by flow cytometry; Transwell experiments were applied to assess T-ALL cell migration and invasion; the interactions among circ_0000094 and miR-223-3p, and miR-223-3p and FBW7 were validated by bioinformatics prediction, dual-luciferase reporter gene assay, and RNA immunoprecipitation experiment. We reported that, circ_0000094 expression was markedly reduced in T-ALL and circ_0000094 was predominantly located in the cytoplasm; gain-of-function and loss-of-function assays verified that circ_0000094 overexpression remarkably suppressed T-ALL cell proliferation, migration, and invasion, and enhanced apoptosis while knocking down circ_0000094 enhanced the malignant phenotypes of T-ALL cells; "rescue experiments" implied that miR-223-3p mimics partly reversed the inhibitory effects on the malignant phenotype of T-ALL cells due to the circ_0000094 up-regulation; circ_0000094 was proved to be a molecular sponge for miR-223-3p, and it could up-regulate the expression of FBW7 via repressing miR-223-3p expression. Taken together, it was concluded that circ_0000094 impedes T-ALL progression by modulating the miR-223-3p/FBW7 axis.

The depletion of Circ-PRKDC enhances autophagy and apoptosis in T-cell acute lymphoblastic leukemia via microRNA-653-5p/Reelin mediation of the PI3K/AKT/mTOR signaling pathway

A range of circular (Circ) RNAs have been demonstrated to be of therapeutic significance for the treatment of acute lymphoblastic leukemia (ALL). Here, we investigated the mechanisms underlying the action of Circ-PRKDC and the microRNA-653-5p/Reelin (miR-653-5p/RELN) axis in T-cell ALL (T-ALL).Clinical specimens were obtained from patients with T-ALL (n = 39) and healthy controls (n = 30). In each specimen, we determined the expression levels of Circ-PRKDC, miR-653-5p, and RELN. Human T-ALL cells (Jurkat) were transfected with Circ-PRKDC- or miR-653-5p-related sequences to investigate cell proliferation, apoptosis, and autophagy. We also determined the levels of Circ-PRKDC, miR-653-5p, RELN, and signaling proteins related to phosphoinositide 3-kinase (PI3K), AKT, and mammalian target of rapamycin (mTOR). Finally, we decoded the interactions between Circ-PRKDC, miR-653-5p, and RELN. The expression levels of Circ-PRKDC and RELN were upregulated in T-ALL tissues and cells while the levels of miR-653-5p were downregulated. Thereafter, then silencing of Circ-PRKDC, or the enforced expression of miR-653-5p, repressed the expression of RELN and the activation of the PI3K/AKT/mTOR signaling pathway, thus enhancing cell autophagy and apoptosis, and disrupting cell proliferation. Circ-PRKDC acted a sponge for miR-653-5p while miR-653-5p targeted RELN. The knockdown of miR-653-5p abrogated the silencing of Circ-PRKDC-induced effects in T-ALL cells. The depletion of Circ-PRKDC elevated miR-653-5p to silence RELN-mediated PI3K/AKT/mTOR signaling activation, thereby enhancing autophagy and apoptosis in T-ALL cells.

Acute Lymphoblastic Leukemia Cell Lines in Immunology Research

A considerable portion of our knowledge on T and B cell biology is acquired from research using acute lymphoblastic leukemia (ALL) cell lines, which are invaluable tools used in many immunology and leukemia studies. Here, we discuss the advantages and limitations of ALL cell lines and provide guidelines on their proper usage.

Comprehensive Overview of Gene Rearrangements in Childhood T-Cell Acute Lymphoblastic Leukaemia

Acute lymphoblastic leukaemia (ALL) is a relevant form of childhood neoplasm, as it accounts for over 80% of all leukaemia cases. T-cell ALL constitutes a genetically heterogeneous cancer derived from T-lymphoid progenitors. The diagnosis of T-ALL is based on morphologic, immunophenotypic, cytogenetic, and molecular features, thus the results are used for patient stratification. Due to the expression of surface and intracellular antigens, several subtypes of T-ALL can be distinguished. Although the aetiology of T-ALL remains unclear, a wide spectrum of rearrangements and mutations affecting crucial signalling pathways has been described so far. Due to intensive chemotherapy regimens and supportive care, overall cure rates of more than 80% in paediatric T-ALL patients have been accomplished. However, improved knowledge of the mechanisms of relapse, drug resistance, and determination of risk factors are crucial for patients in the high-risk group. Even though some residual disease studies have allowed the optimization of therapy, the identification of novel diagnostic and prognostic markers is required to individualize therapy. The following review summarizes our current knowledge about genetic abnormalities in paediatric patients with T-ALL. As molecular biology techniques provide insights into the biology of cancer, our study focuses on new potential therapeutic targets and predictive factors which may improve the outcome of young patients with T-ALL.

NOTCH1 Signaling in Head and Neck Squamous Cell Carcinoma

Biomarker-driven targeted therapies are lacking for head and neck squamous cell carcinoma (HNSCC), which is common and lethal. Efforts to develop such therapies are hindered by a genomic landscape dominated by the loss of tumor suppressor function, including NOTCH1 that is frequently mutated in HNSCC. Clearer understanding of NOTCH1 signaling in HNSCCs is crucial to clinically targeting this pathway. Structural characterization of NOTCH1 mutations in HNSCC demonstrates that most are predicted to cause loss of function, in agreement with NOTCH1's role as a tumor suppressor in this cancer. Experimental manipulation of NOTCH1 signaling in HNSCC cell lines harboring either mutant or wild-type NOTCH1 further supports a tumor suppressor function. Additionally, the loss of NOTCH1 signaling can drive HNSCC tumorigenesis and clinical aggressiveness. Our recent data suggest that NOTCH1 controls genes involved in early differentiation that could have different phenotypic consequences depending on the cancer's genetic background, including acquisition of pseudo-stem cell-like properties. The presence of NOTCH1 mutations may predict response to treatment with an immune checkpoint or phosphatidylinositol 3-kinase inhibitors. The latter is being tested in a clinical trial, and if validated, it may lead to the development of the first biomarker-driven targeted therapy for HNSCC.

Inside Perspective of the Synthetic and Computational Toolbox of JAK Inhibitors: Recent Updates

The mechanisms of inflammation and cancer are intertwined by complex networks of signaling pathways. Dysregulations in the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway underlie several pathogenic conditions related to chronic inflammatory states, autoimmune diseases and cancer. Historically, the potential application of JAK inhibition has been thoroughly explored, thus triggering an escalation of favorable results in this field. So far, five JAK inhibitors have been approved by the Food and Drug Administration (FDA) for the treatment of different diseases. Considering the complexity of JAK-depending processes and their involvement in multiple disorders, JAK inhibitors are the perfect candidates for drug repurposing and for the assessment of multitarget strategies. Herein we reviewed the recent progress concerning JAK inhibition, including the innovations provided by the release of JAKs crystal structures and the improvement of synthetic strategies aimed to simplify of the industrial scale-up.

Thymoquinone synergizes with arsenic and interferon alpha to target human T-cell leukemia/lymphoma

AIMS

To reduce the dose of arsenic used against human T-cell leukemia/lymphoma and to sensitize cells to drug treatment, we combined arsenic/interferon-alpha (As/IFN-α) with thymoquinone (TQ) in HTLV-I positive (HuT-102 and C91) and HTLV-1 negative (CEM and Jurkat) cell lines.

MAIN METHODS

Cells were treated with TQ, As/IFN-α and combinations. Trypan blue and flow cytometry were used to investigate viability and cell cycle effects. Annexin-V staining, rhodamine assay and western blotting were used to determine apoptosis induction and changes in protein expression. Efficacy of single drugs and combinations were tested in adult T-cell leukemia (HuT-102) mouse xenograft model.

KEY FINDINGS

TQ/As/IFN-α led to a more pronounced and synergistic time-dependent inhibitory effect on HTLV-I positive cells in comparison to As/IFN-α. While As/IFN-α combination was not effective against CEM or Jurkat cells, the triple combination TQ/As/IFN-α sensitized these two cell lines and led to a pronounced time-dependent inhibition of cell viability. TQ/As/IFN-α significantly induced apoptosis in all four cell lines and disrupted the mitochondrial membrane potential. Apoptosis was confirmed by the cleavage of caspase 3 and poly (ADP-ribose) polymerase (PARP), downregulation of Bcl-2 and XIAP and upregulation of Bax. TQ alone or in combination activated p53 in HTLV-1 positive cell lines. Strikingly, TQ/As/IFN-α resulted in a pronounced significant decrease in tumor volume in HuT-102 xenograft mouse model, as compared to separate treatments or double combination therapy.

SIGNIFICANCE

Our results suggest a strong potential for TQ to enhance the drug targeting effects of the standard clinical drugs As and IFN-α against CD4+ malignant T-cells.