T-lymphoblastic leukemia/lymphoma

Chidamide triggers pyroptosis in T-cell lymphoblastic lymphoma/leukemia via the FOXO1/GSDME axis

BACKGROUND

T-cell lymphoblastic lymphoma/acute lymphoblastic leukemia (T-LBL/ALL) is an aggressive form of hematological malignancy associated with poor prognosis in adult patients. Histone deacetylases (HDACs) are aberrantly expressed in T-LBL/ALL and are considered potential therapeutic targets. Here, we investigated the antitumor effect of a novel HDAC inhibitor, chidamide, on T-LBL/ALL.

METHODS

HDAC1, HDAC2 and HDAC3 levels in T-LBL/ALL cell lines and patient samples were compared with those in normal controls. Flow cytometry, transmission electron microscopy, and lactate dehydrogenase release assays were conducted in Jurkat and MOLT-4 cells to assess apoptosis and pyroptosis. A specific forkhead box O1 (FOXO1) inhibitor was used to rescue pyroptosis and upregulated gasdermin E (GSDME) expression caused by chidamide treatment. The role of the FOXO1 transcription factor was evaluated by dual-luciferase reporter and chromatin immunoprecipitation assays. The efficacy of chidamide in vivo was evaluated in a xenograft mouse.

RESULTS

The expression of HDAC1, HDAC2 and HDAC3 was significantly upregulated in T-LBL/ALL. Cell viability was obviously inhibited after chidamide treatment. Pyroptosis, characterized by cell swelling, pore formation on the plasma membrane and lactate dehydrogenase leakage, was identified as a new mechanism of chidamide treatment. Chidamide triggered pyroptosis through caspase 3 activation and GSDME transcriptional upregulation. Chromatin immunoprecipitation assays confirmed that chidamide led to the increased transcription of GSDME through a more relaxed chromatin structure at the promoter and the upregulation of FOXO1 expression. Moreover, we identified the therapeutic effect of chidamide in vivo .

CONCLUSIONS

This study suggested that chidamide exerts an antitumor effect on T-LBL/ALL and promotes a more inflammatory form of cell death via the FOXO1/GSDME axis, which provides a novel choice of targeted therapy for patients with T-LBL/ALL.

The ESCRT protein CHMP5 promotes T cell leukemia by enabling BRD4-p300-dependent transcription

Addiction to oncogene-rewired transcriptional networks is a therapeutic vulnerability in cancer cells, underscoring a need to better understand mechanisms that relay oncogene signals to the transcriptional machinery. Here, using human and mouse T cell acute lymphoblastic leukemia (T-ALL) models, we identify an essential requirement for the endosomal sorting complex required for transport protein CHMP5 in T-ALL epigenetic and transcriptional programming. CHMP5 is highly expressed in T-ALL cells where it mediates recruitment of the coactivator BRD4 and the histone acetyl transferase p300 to enhancers and super-enhancers that enable transcription of T-ALL genes. Consequently, CHMP5 depletion causes severe downregulation of critical T-ALL genes, mitigates chemoresistance and impairs T-ALL initiation by oncogenic NOTCH1 in vivo. Altogether, our findings uncover a non-oncogene dependency on CHMP5 that enables T-ALL initiation and maintenance.

Evaluating the immune effector functions induced by humanized anti-CD99 antibody in eliminating T lymphoblastic leukemia/lymphoma cells

Monoclonal antibodies (mAbs) have emerged as targeted immunotherapies with clinical effectiveness and low adverse effects for various cancers. However, antibody drugs for treating aggressive T cell malignancies, T lymphoblastic leukemia/lymphoma (T-ALL/T-LBL), are still limited. Therefore, a potential mAb for treating T-ALL/T-LBL with minimal toxicity to normal cells needs to be developed. We have previously demonstrated that our in-house produced mouse anti-human CD99 mAb MT99/3 and its humanized version, HuMT99/3, which recognize a newly identified epitope of CD99 can induce apoptosis of T-ALL/T-LBL cells without affecting non-malignant peripheral blood cells. Nevertheless, the immune effector functions activated by HuMT99/3 against T-ALL/T-LBL cells remain unexplored. In this study, we evaluated the anticancer activities of HuMT99/3 against T-ALL/T-LBL cells via immune effector functions. T-ALL/T-LBL cell lines were used as target cells, including Jurkat E6.1, MOLT-4, and SUP-T1. The results demonstrated that HuMT99/3 could mediate potent antibody-dependent cellular cytotoxicity (ADCC) activity to kill all cell lines by activating the Fc receptor CD16 on effector cells. HuMT99/3 significantly enhanced the phagocytosis of monocytes on all three malignant T cell lines through antibody-dependent cellular phagocytosis (ADCP) activity. In addition, HuMT99/3 could activate complement to destroy T-ALL cell lines through complement-dependent cytotoxicity (CDC) activity, without affecting the T-LBL cell line and normal PBMCs. Furthermore, the mAb MT99/3 significantly inhibited tumor growth in a T-ALL xenograft model. These findings provide valuable insights into the development of monoclonal antibodies targeting CD99 as promising therapeutics for T-ALL/T-LBL treatment with minimal toxicity to normal peripheral blood cells.

The Flow Cytometric Evaluation of B- and T-Lymphoblastic Leukemia/Lymphoma

Lymphoblastic leukemia/lymphoma, a neoplasm of precursor B or T lineage lymphoid cells, usually involves the bone marrow and peripheral blood, and may involve nodal and/or extranodal sites. The diagnosis is based on morphologic assessment, immunophenotypic analysis, usually by flow cytometry, and genetic analysis, including cytogenetics and FISH analysis, as well as molecular diagnostic analysis. This review will focus on the flow cytometric immunophenotypic findings in B- and T-lymphoblastic leukemia/lymphoma, which include expressions of early B or T cell markers, low-level expressions of CD45, as well as expressions of terminal deoxynucleotidyl transferase (TdT), and, in many cases, stem/progenitor cell marker CD34.

Polycythemia secondary to bilaterally enlarged kidneys in T-Cell acute lymphoblastic leukemia: a case report and literature review

BACKGROUND

Polycythemia is a rare disease that can cause hypertension. Secondary polycythemia with increased production of erythropoietin (EPO) is associated with several kidney diseases, including hydronephrosis and cystic disease. However, there have been no reports of a case presenting with polycythemia secondary to bilateral nephromegaly caused by renal infiltration of T-cell acute lymphoblastic leukemia (T-ALL).

CASE PRESENTATION

A 32-year-old Japanese man presented with marked hypertension (215/150 mmHg) with renal insufficiency (creatinine 3.7 mg/dL), proteinuria, hematuria, bilateral nephromegaly, polycythemia (hemoglobin 20.2 g/dL), and increased serum EPO (38.7 mIU/mL, range 4.2-23.7 mIU/mL). Based on renal and bone marrow biopsy findings, he was diagnosed with T-ALL and bilaterally enlarged kidneys caused by renal infiltration of leukemic cells. There was no evidence of endocrine hypertension or fluid retention. Remission induction chemotherapy led to a decrease in kidney size, hemoglobin levels, and serum EPO levels, and allowed dose reductions of most hypertensive drugs, suggesting that hypertension was secondary to polycythemia. The patient's renal function gradually improved and hemodialysis was discontinued after 1 month of chemotherapy.

CONCLUSIONS

We report a case of marked hypertension and secondary polycythemia induced by severe renal infiltration of T-ALL at diagnosis, which were synchronically improved with induction chemotherapy. This case history suggests the importance of considering lymphoproliferative diseases in the differential diagnosis of secondary polycythemia, leading to severe hypertension.

The Proteomics of T-Cell and Early T-Cell Precursor (ETP) Acute Lymphocytic Leukemia: Prognostic Patterns in Adult and Pediatric-ETP ALL

BACKGROUND

The 5-year overall survival (OS) rates of T-cell lymphocytic leukemia (T-ALL) are better for children (>90%) compared to adults (~57%). The early T-cell precursor (ETP) T-ALL subtype is prognostically unfavorable in adults, but less significant in pediatric T-ALL, and the diagnosis and prognosis of "near"-ETP is controversial. We compared protein and RNA expression patterns in pediatric and adult T-ALL to identify prognostic subgroups, and to further characterize ETP and near-ETP T-ALL in both age groups.

METHODS

Protein expression was assessed using RPPA methodology for 321 target proteins in 361 T-ALL patient samples from 292 pediatrics and 69 adults, including 103 ETP-ALL. RNA-sequencing was performed on 81 pediatric T-ALL samples.

RESULTS

We identified recurrent protein expression patterns that classified patients into ten protein expression signatures using the "MetaGalaxy" analysis. In adults, Cox regression analysis identified two risk-groups associated with OS (p = 0.0002) and complete remission duration (p < 0.001). Cluster analysis of adults and pediatric-ETP patients identified three ETP-clusters strongly associated with age. Pediatric ETP-patients with a pediatric-dominant expression profile were associated with a shorter OS (p = 0.04) and event-free survival (p = 0.05) compared to pediatric ETP-patients with an ETP expression profile that was also identified in adults.

CONCLUSION

Our study demonstrates that proteomics are predictive of outcome in adult T-ALL and that we can identify a small subset of pediatric ETP with an inferior outcome. The observation that there are age-specific patterns supports the idea that the origin of T-ALL in most pediatric and adult patients is different, while overlapping patterns suggests that there are some with a common pathophysiology. Proteomics could enhance risk stratification in both pediatric and adults with T-ALL.

Chidamide maintenance therapy after allo-HSCT in SET-NUP214 fusion positive T-ALL patients: A report of two cases

T-cell acute lymphoblastic leukemia (T-ALL) is a highly invasive hematological malignancy originated from T-lineage progenitor cells. The clonal proliferation and aggregation of primordial cells in bone marrow inhibit normal hematopoietic function, resulting in a series of hematocytopenia and infiltration symptoms. SET-NUP214 fusion is a recurrent event that is common in adult male T-ALL patients. It originates from chromosome del(9)(q34.11; q34.13) or t(9; 9)(q34; q34). Hematopoietic stem cell transplantation (HSCT) can significantly improve the survival rate of these patients. Due to the poor prognosis of patients and high relapse rate after remission, more effective strategies need to be proposed to improve prognosis and prevent relapse. Chidamide is a novel oral benzamide histone deacetylase inhibitor (HDACi) that can exert anti-tumor effects through multiple mechanisms. Here we report chidamide maintenance therapy after allo-HSCT in patients with SET-NUP214 fusion positive T-ALL. Both patients improved effectively during follow-up, confirming the efficacy of chidamide in improving the condition of these patients and may provide valuable clinical information for the treatment of this rare and understudied disease.

Exploring the Biological Activity of a Humanized Anti-CD99 ScFv and Antibody for Targeting T Cell Malignancies

CD99, a type I transmembrane protein, emerges as a promising therapeutic target due to its heightened expression in T cell acute lymphoblastic leukemia (T-ALL). This characteristic renders it a potential marker for minimal residual disease detection and an appealing target for antibody-based treatments. Previous studies have revealed that a mouse monoclonal antibody, mAb MT99/3, selectively binds to CD99, triggering apoptosis in T-ALL/T-LBL cells while preserving the integrity of healthy cells. By targeting CD99, mAb MT99/3 suppresses antigen presentation and disrupts T cell functions, offering promise for addressing hyperresponsive T cell conditions. To facilitate clinical translation, we developed a humanized ScFv variant of mAb MT99/3, termed HuScFvMT99/3 in "ScFvkh" design. Structural analysis confirms its resemblance to the original antibody, and the immunoreactivity of HuScFvMT99/3 against CD99 is preserved. The fully humanized version of antibody HuMT99/3 was further engineered, exhibiting similar binding affinity at the 10-10 M level and specificity to the CD99 epitope without antigenic shift. HuMT99/3 demonstrates remarkable selectivity, recognizing both malignant and normal T cells but inducing apoptosis only in T-ALL/T-LBL cells, highlighting its potential for safe and targeted therapy.

Early autologous and/or allogeneic stem cell transplantation for adult patients with advanced stage T- lymphoblastic leukemia/lymphoma or Burkitt lymphoma. A retrospective single-centre analysis

T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) and Burkitt lymphoma (BL) are uncommon, highly aggressive diseases originating either from immature precursor T cells or from mature B cells in BL. We retrospectively analyzed the outcome of an early autologous and/or allogeneic stem cell transplantation (SCT) concept in 28 patients with advanced stage T-ALL/LBL and BL after three to four remission induction/consolidation chemotherapy cycles. Considering only patients in first complete remission (CR), the 5-year overall survival (OS) and event-free survival (EFS) was 91% in patients with BL and 73% in patients with T-ALL/LBL with a 5-year relapse incidence (RI) of 9% in patients with BL and 27% in patients with T-ALL/LBL. All relapsing patients finally succumbed to the disease (n = 10) or complications/toxicity after having received a salvage allogeneic transplant (n = 5). Despite the low patient number our retrospective single-centre analysis by incorporating an early intensive high-dose chemo-/radiotherapy strategy with either autologous or allogeneic stem cell transplantation, although preliminary, show promising long-term outcome. Further studies are highly warranted to better define those patients who might benefit most from such a treatment approach.

Molecular significance of circRNAs in malignant lymphoproliferative disorders: pathogenesis and novel biomarkers or therapeutic targets

Recent studies have shown that circular RNAs (CircRNAs) have the novel functions and molecular mechanisms in the pathogenesis of malignant diseases. CircRNAs have been found to be associated with the occurrence and development of lymphoproliferative diseases, impacting on lymphocyte proliferation. This article provides a review of the pathogenesis of circRNAs in malignant lymphoproliferative disorders, focusing on conditions such as acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), and lymphoma. Additionally, it discusses the potential value of circRNAs as novel biomarkers or therapeutic targets in these disorders.

Acute T-cell lymphoblastic leukemia: chimeric antigen receptor technology may offer a new hope

Acute lymphoblastic leukemia (ALL) is a prevalent malignancy affecting the hematopoietic system, encompassing both B-cell ALL (B-ALL) and T-cell ALL (T-ALL). T-ALL, characterized by the proliferation of T-cell progenitors in the bone marrow, presents significant treatment challenges, with patients often experiencing high relapse rates and poor long-term survival despite advances in chemotherapy and hematopoietic stem cell transplantation (HSCT). This review explores the pathogenesis and traditional treatment strategies of T-ALL, emphasizing the promising potential of chimeric antigen receptor (CAR) technology in overcoming current therapeutic limitations. CAR therapy, leveraging genetically modified immune cells to target leukemia-specific antigens, offers a novel and precise approach to T-ALL treatment. The review critically analyzes recent developments in CAR-T and CAR-NK cell therapies, their common targets, optimization strategies, clinical outcomes, and the associated challenges, providing a comprehensive overview of their clinical prospects in T-ALL treatment.

Capsaicin: A chili pepper bioactive phytocompound with a potential role in suppressing cancer development and progression

Cancer profoundly influences morbidity and fatality rates worldwide. Patients often have dismal prognoses despite recent improvements in cancer therapy regimens. However, potent biomolecules derived from natural sources, including medicinal and dietary plants, contain biological and pharmacological properties to prevent and treat various human malignancies. Capsaicin is a bioactive phytocompound present in red hot chili peppers. Capsaicin has demonstrated many biological effects, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic capabilities. This review highlights the cellular and molecular pathways through which capsaicin exhibits antineoplastic activities. Our work also depicts the synergistic anticancer properties of capsaicin in conjunction with other natural bioactive components and approved anticancer drugs. Capsaicin inhibits proliferation in various cancerous cells, and its antineoplastic actions in numerous in vitro and in vivo carcinoma models impact oncogenesis, tumor-promoting and suppressor genes, and associated signaling pathways. Capsaicin alone or combined with other phytocompounds or approved antineoplastic drugs triggers cell cycle progression arrest, generating reactive oxygen species and disrupting mitochondrial membrane integrity, ultimately stimulating caspases and promoting death. Furthermore, capsaicin alone or in combination can promote apoptosis in carcinoma cells by enhancing the p53 and c-Myc gene expressions. In conclusion, capsaicin alone or in combination can have enormous potential for cancer prevention and intervention, but further high-quality studies are needed to firmly establish the clinical efficacy of this phytocompound.

Key candidate genes and pathways in T lymphoblastic leukemia/lymphoma identified by bioinformatics and serological analyses

T-cell acute lymphoblastic leukemia (T-ALL)/T-cell lymphoblastic lymphoma (T-LBL) is an uncommon but highly aggressive hematological malignancy. It has high recurrence and mortality rates and is challenging to treat. This study conducted bioinformatics analyses, compared genetic expression profiles of healthy controls with patients having T-ALL/T-LBL, and verified the results through serological indicators. Data were acquired from the GSE48558 dataset from Gene Expression Omnibus (GEO). T-ALL patients and normal T cells-related differentially expressed genes (DEGs) were investigated using the online analysis tool GEO2R in GEO, identifying 78 upregulated and 130 downregulated genes. Gene Ontology (GO) and protein-protein interaction (PPI) network analyses of the top 10 DEGs showed enrichment in pathways linked to abnormal mitotic cell cycles, chromosomal instability, dysfunction of inflammatory mediators, and functional defects in T-cells, natural killer (NK) cells, and immune checkpoints. The DEGs were then validated by examining blood indices in samples obtained from patients, comparing the T-ALL/T-LBL group with the control group. Significant differences were observed in the levels of various blood components between T-ALL and T-LBL patients. These components include neutrophils, lymphocyte percentage, hemoglobin (HGB), total protein, globulin, erythropoietin (EPO) levels, thrombin time (TT), D-dimer (DD), and C-reactive protein (CRP). Additionally, there were significant differences in peripheral blood leukocyte count, absolute lymphocyte count, creatinine, cholesterol, low-density lipoprotein, folate, and thrombin times. The genes and pathways associated with T-LBL/T-ALL were identified, and peripheral blood HGB, EPO, TT, DD, and CRP were key molecular markers. This will assist the diagnosis of T-ALL/T-LBL, with applications for differential diagnosis, treatment, and prognosis.

The ESCRT protein CHMP5 promotes T cell leukemia by controlling BRD4-p300-dependent transcription

Oncogene activity rewires cellular transcription, creating new transcription networks to which cancer cells become addicted, by mechanisms that are still poorly understood. Using human and mouse models of T cell acute lymphoblastic leukemia (T-ALL), we identify an essential nuclear role for CHMP5, a cytoplasmic endosomal sorting complex required for transport (ESCRT) protein, in establishing and maintaining the T-ALL transcriptional program. Nuclear CHMP5 promoted the T-ALL gene program by augmenting recruitment of the co-activator BRD4 by the histone acetyl transferase p300 selectively at enhancers and super-enhancers, an interaction that potentiated H3K27 acetylation at these regulatory enhancers. Consequently, loss of CHMP5 diminished BRD4 occupancy at enhancers and super-enhancers and impaired RNA polymerase II pause release, which resulted in downregulation of key T-ALL genes, notably MYC. Reinforcing its importance in T-ALL pathogenesis, CHMP5 deficiency mitigated chemoresistance in human T-ALL cells and abrogated T-ALL induction by oncogenic NOTCH1 in vivo. Thus, the ESCRT protein CHMP5 is an essential positive regulator of the transcriptional machinery promoting T-ALL disease.

Severe haemorrhagic diathesis due to acquired hypofibrinogenemia in a patient with early T-cell precursor acute lymphoblastic leukaemia/lymphoma: a case report

The most frequent haematological malignancy associated with acquired hypo/dysfibrinogenemia is multiple myeloma. We present an unusual case of severe haemorrhagic diathesis due to acquired hypofibrinogenemia in a patient with early T-cell precursor acute lymphoblastic leukaemia/lymphoma (ETP-ALL/LBL). A 57-year-old male was admitted to the General Internal Medicine Department of Padova University Hospital for acute massive haematomas of the left lower extremity associated with macrohaematuria. Coagulation tests showed prolonged prothrombin time, activated partial thromboplastin time and thrombin time due to isolated severe hypofibrinogenemia (antigen 0.70 g/L and activity 26%). The radiological workup showed a bulky lesion located in the anterior mediastinum, and a biopsy led to the diagnosis of ETP-ALL/LBL. Fibrinogen replacement therapy failed to correct the bleeding diathesis and we were able to exclude other frequent causes of acquired hypofibrinogenemia (i.e., liver dysfunction, fibrinogen-specific antibody or drug toxicity); therefore, we hypothesised that hypofibrinogenemia might stem either from enhanced removal of fibrinogen from the circulation or consumptive coagulopathy. Notably, only after initiating a specific chemotherapy treatment did the patient start showing improvement in bleeding symptoms and achieve normal fibrinogen levels.

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.

Diagnostic utility of LMO2 immunohistochemistry in distinguishing T-lymphoblastic leukemia/lymphoma from thymoma

Distinguishing T-lymphoblastic leukemia/lymphoma (T-ALL/T-LBL) from thymomas (especially B1 or B2 type) can be challenging particularly in limited trucut biopsy material where appreciating architecture is difficult or the background epithelial component does not provide tangible evidence for definite diagnosis. As a pathologist, it is important to accurately diagnose these neoplasms because they have entirely distinct management protocols. Recent studies have reported that LIM Domain Only 2 (LMO2) is expressed in neoplastic lymphoblasts of T-ALL/T-LBL and is absent in thymocytes of normal thymuses or thymomas. An observational study was done to test the sensitivity and specificity of LMO2 in differentiating neoplastic lymphoblasts from thymocytes of thymomas/normal thymuses. Our study showed that LMO2 had sensitivity of 70% and specificity of 100% in diagnosing LBL. None of the thymomas (B1 or B2 type) showed expression of LMO2 in the neoplastic cells. LMO2 is a reliable marker of transformed T-cell precursors and should be routinely included in immunohistochemical panel when evaluating thymic/mediastinal neoplasms.

Idasanutlin and navitoclax induce synergistic apoptotic cell death in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy in which activating mutations in the Notch pathway are thought to contribute to transformation, in part, by activating c-Myc. Increased c-Myc expression induces oncogenic stress that can trigger apoptosis through the MDM2-p53 tumor suppressor pathway. Since the great majority of T-ALL cases carry inactivating mutations upstream in this pathway but maintain wildtype MDM2 and TP53, we hypothesized that T-ALL would be selectively sensitive to MDM2 inhibition. Treatment with idasanutlin, an MDM2 inhibitor, induced only modest apoptosis in T-ALL cells but upregulated the pro-apoptotic BH3 domain genes BAX and BBC3, prompting us to evaluate the combination of idasanutlin with BH3 mimetics. Combination treatment with idasanutlin and navitoclax, a potent Bcl-2/Bcl-xL inhibitor, induces more consistent and potent synergistic killing of T-ALL PDX lines in vitro than venetoclax, a Bcl-2 specific inhibitor. Moreover, a marked synergic response to combination treatment with idasanutlin and navitoclax was seen in vivo in all four T-ALL xenografts tested, with a significant increase in overall survival in the combination treatment group. Collectively, these preclinical data show that the combination of idasanutlin and navitoclax is highly active in T-ALL and may merit consideration in the clinical setting.

Retracted: Britannin mediates apoptosis and glycolysis of T-cell lymphoblastic lymphoma cells by AMPK-dependent autophagy

The above article, published online on 19 September 2022 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/abs/10.1002/jbt.23211), has been retracted by agreement between the authors, the journal Editor in Chief, Hari Bhat, and Wiley Periodicals, LLC. The article is being retracted at the authors' request because some of the data underlying this article refer to a different cell line from the one reported in it. As a result, the article's conclusions do not accurately reflect the full data and cannot be considered reliable.

Study of Extramedullary Lymphoblastic Lymphoma (LBL) Diagnosed by Flowcytometric Immunophenotyping (FCI) on Fine Needle Aspirate (FNA) Sample-A Case Series of 18 Cases

Background

Lymphoblastic lymphoma (LBL) accounts for about 2% of all lymphomas. Recognition of T/B-LBL albeit of their rareness is very important as they present as localized diseases with low tumor burden. They can present both at nodal and extranodal sites. Limitation of diagnosis and classification of lymphoma on fine needle aspirate (FNA) can be minimized by clubbing it with flowcytometric immunophenotyping (FCI) to ensure diagnostic accuracy rapidly.

Aim

Study of a series of 18 cases of LBL to assess the utility of FCI on FNA and effusion samples in extramedullary LBL.

Methods and Material

FCI was done on FNA and effusion samples from 130 morphologically diagnosed/suspicious cases of lymphoreticular malignancy, followed by peripheral blood and bone marrow (BM) examination. The patients diagnosed to have B/T LBL, based on WHO 2017 classification, were selected for further analyses.

Results

FCI of 130 cases showed 91 mature and 18 precursor lymphoid neoplasms. These 18 cases were from lymph nodes (11), pleural fluid (03), and soft tissue masses (04). Peripheral blood and BM of 15/18 cases were normal of which FCI revealed T-LBL (11) and B-LBL (04). Two cases (both T LBL) showed BM involvement (<25%), while one case of B-LBL which was misdiagnosed as mature lymphoma by immunohistochemistry (IHC) evolved as B ALL.

Conclusions

Diagnosis of extramedullary B/T-LBL needs comprehensive evaluation of clinical presentation, cytomorphology, and immunophenotyping. Rapid and accurate diagnosis by FCI on FNA and effusion samples allows early therapeutic decisions, thereby avoiding leukemic dissemination.

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.

The β-catenin-LINC00183-miR-371b-5p-Smad2/LEF1 axis promotes adult T-cell lymphoblastic lymphoma progression and chemoresistance

BACKGROUND

High-intensity chemotherapy regimens are often used in adult T-cell lymphoblastic lymphoma (T-LBL) patients. Nevertheless, the response rate remains unsatisfactory due to emergence of chemoresistance. Growing evidence has shown that long non-coding RNAs (lncRNAs) are involved in tumor progression and chemoresistance. Herein, we investigated the potential role of lncRNAs in T-LBLs.

METHODS

RNAseq was used to screen and identify candidate lncRNAs associated with T-LBL progression and chemoresistance. Luciferase reporter assay was used to examine the binding of miR-371b-5p to the 3'UTR of Smad2 and LEF1, and the binding of TCF-4/LEF1 to the promoter of LINC00183. Chromatin immunoprecipitation assay was undertaken to analyze the connection between LEF1 and the LINC00183 promoter region. RNA immunoprecipitation assays were used to explore the mechanism whereby LINC00183 regulated miR-371b-5p. MTT and flow cytometry assays were used to measure apoptosis of T-LBL cells.

RESULTS

LINC00183 was upregulated in T-LBL progression and chemoresistant tissues in both the Sun Yat-sen University Cancer Center dataset and the First Affiliated Hospital of Anhui Medical University dataset. High expression of LINC00183 was correlated with poorer overall survival and progression-free survival of T-LBL patients compared to those with low expression of LINC00183. Furthermore, miR-371b-5p was negatively regulated by LINC00183. In vivo and in vitro assays showed that LINC00183-mediated T-LBL chemoresistance depended on miR-371b-5p expression. The direct binding of miR-371b-5p to Smad2 and LEF1 was verified by luciferase assays. It was shown that TCF4/LEF1 could bind to the LINC00183 promoter site and increase its transcript level. Downregulation of miR-371b-5p led to increased expression of Smad2/LEF1, and in turn increased LINC00183 expression. Additionally, phospho-Smad2 promotes nuclear translocation of β-catenin, LINC00183 downregulation decreased chemoresistance induced by β-catenin and TGF-β1 in T-LBL cells.

CONCLUSION

We unraveled a β-catenin-LINC00183-miR-371b-5p-Smad2/LEF1 feedback loop that promotes T-LBL progression and chemoresistance, indicating that LINC00183 may serve as a potential therapeutic target in T-LBLs.

The β-catenin-LINC00183-miR-371b-5p-Smad2/LEF1 axis promotes adult T-cell lymphoblastic lymphoma progression and chemoresistance

Background

High-intensity chemotherapy regimens are often used in adult T-cell lymphoblastic lymphoma (T-LBL) patients. Nevertheless, the response rate remains unsatisfactory due to emergence of chemoresistance. Growing evidence has shown that long non-coding RNAs (lncRNAs) are involved in tumor progression and chemoresistance. Herein, we investigated the potential role of lncRNAs in T-LBLs.

Methods

RNAseq was used to screen and identify candidate lncRNAs associated with T-LBL progression and chemoresistance. Luciferase reporter assay was used to examine the binding of miR-371b-5p to the 3’UTR ofSmad2andLEF1, and the binding of TCF-4/LEF1 to the promoter of LINC00183. Chromatin immunoprecipitation assay was undertaken to analyze the connection between LEF1 and the LINC00183 promoter region. RNA immunoprecipitation assays were used to explore the mechanism whereby LINC00183 regulated miR-371b-5p. MTT and flow cytometry assays were used to measure apoptosis of T-LBL cells.

Results

LINC00183 was upregulated in T-LBL progression and chemoresistant tissues in both the Sun Yat-sen University Cancer Center dataset and the First Affiliated Hospital of Anhui Medical University dataset. High expression of LINC00183 was correlated with poorer overall survival and progression-free survival of T-LBL patients compared to those with low expression of LINC00183. Furthermore, miR-371b-5p was negatively regulated by LINC00183. In vivo and in vitro assays showed that LINC00183-mediated T-LBL chemoresistance depended on miR-371b-5p expression. The direct binding of miR-371b-5p to Smad2 and LEF1 was verified by luciferase assays. It was shown that TCF4/LEF1 could bind to the LINC00183 promoter site and increase its transcript level. Downregulation of miR-371b-5p led to increased expression of Smad2/LEF1, and in turn increased LINC00183 expression. Additionally, phospho-Smad2 promotes nuclear translocation of β-catenin, LINC00183 downregulation decreased chemoresistance induced by β-catenin and TGF-β1 in T-LBL cells.

Conclusion

We unraveled a β-catenin-LINC00183-miR-371b-5p-Smad2/LEF1 feedback loop that promotes T-LBL progression and chemoresistance, indicating that LINC00183 may serve as a potential therapeutic target in T-LBLs.

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.

Mature Type T-Lymphoblastic Leukemia/Lymphoma Presenting With Isolated Central Nervous System Symptomatology in a Patient With Giant Cell Arteritis on Long-Term Steroid Treatment

T-lymphoblastic leukemia/lymphoma (T-ALL/T-LBL) is a malignancy comprised of T-lymphoblasts that can present as one of four clinical subtypes (pro-T, pre-T, cortical T, and mature T). Clinical presentation is typically characterized by leukocytosis with diffuse lymphadenopathy and/or hepatosplenomegaly. Beyond clinical presentation, specific immunophenotypic and cytogenetic classifications are utilized to diagnose mature T-ALL. In later disease stages it can spread to the central nervous system (CNS); however, presentation of mature T-ALL by way of CNS pathology and clinical symptomatology alone is rare. Even more rare is the presence of poor prognostic factors without correlating significant clinical presentation. We present a case of mature T-ALL in an elderly female with isolated CNS symptoms in combination with poor prognostic factors including terminal deoxynucleotidyl transferase (TdT) negativity and a complex karyotype. Our patient lacked the classical symptomatology and laboratory findings of mature T-ALL but deteriorated quickly upon diagnosis due to the aggressive genetic profile of her cancer.

FIP1L1-PDGFRA fusion gene in T-lymphoblastic lymphoma: A case report

BACKGROUND

T-lymphoblastic lymphoma (T-LBL) is an aggressive malignancy of T-lymphoid precursors, rarely co-occurring with myeloid/lymphoid neoplasms with eosinophilia (M/LNs-Eo), with consequent rearrangement of tyrosine kinase (TK)-related genes. The FIP1L1-PDGFRA fusion gene is the most frequent molecular abnormality seen in eosinophilia-associated myeloproliferative disorders, but is also present in acute myeloid leukemia (AML), T-lymphoblastic leukemia/lymphoma (TLL), or both simultaneously. T-LBL mainly affects children and young adults, involving lymph node, bone marrow, and thymus. It represents about 85% of all immature lymphoblastic lymphomas, whereas immature B-cell lymphomas comprise approximately 15% of all cases of LBL.

CASE

In this case report, we present an example of T cell lymphoblastic lymphoma with coexistent eosinophelia, treated successfully with a tyrosine-kinase inhibitor (TKI).

CONCLUSION

FIP1L1-PDGFRA-positive T-LBL and myeloproliferative disorders have excellent response to low-dose treatment with (TKI) imatinib. Most patients achieve rapid and complete hematologic and molecular remission within weeks.

Identification of a Novel Curcumin Derivative Influencing Notch Pathway and DNA Damage as a Potential Therapeutic Agent in T-ALL

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy considered curable by modern clinical management. Nevertheless, the prognosis for T-ALL high-risk cases or patients with relapsed and refractory disease is still dismal. Therefore, there is a keen interest in developing more efficient and less toxic therapeutic approaches. T-ALL pathogenesis is associated with Notch signaling alterations, making this pathway a highly promising target in the fight against T-ALL. Here, by exploring the anti-leukemic capacity of the natural polyphenol curcumin and its derivatives, we found that curcumin exposure impacts T-ALL cell line viability and decreases Notch signaling in a dose- and time-dependent fashion. However, our findings indicated that curcumin-mediated cell outcomes did not depend exclusively on Notch signaling inhibition, but might be mainly related to compound-induced DNA-damage-associated cell death. Furthermore, we identified a novel curcumin-based compound named CD2066, endowed with potentiated anti-proliferative activity in T-ALL compared to the parent molecule curcumin. At nanomolar concentrations, CD2066 antagonized Notch signaling, favored DNA damage, and acted synergistically with the CDK1 inhibitor Ro3306 in T-ALL cells, thus representing a promising novel candidate for developing therapeutic agents against Notch-dependent T-ALL.

Deep learning-based transcriptome model predicts survival of T-cell acute lymphoblastic leukemia

Identifying subgroups of T-cell acute lymphoblastic leukemia (T-ALL) with poor survival will significantly influence patient treatment options and improve patient survival expectations. Current efforts to predict T-ALL survival expectations in multiple patient cohorts are lacking. A deep learning (DL)-based model was developed to determine the prognostic staging of T-ALL patients. We used transcriptome sequencing data from TARGET to build a DL-based survival model using 265 T-ALL patients. We found that patients could be divided into two subgroups (K0 and K1) with significant difference (P&lt; 0.0001) in survival rate. The more malignant subgroup was significantly associated with some tumor-related signaling pathways, such as PI3K-Akt, cGMP-PKG and TGF-beta signaling pathway. DL-based model showed good performance in a cohort of patients from our clinical center (P = 0.0248). T-ALL patients survival was successfully predicted using a DL-based model, and we hope to apply it to clinical practice in the future.

T-Cell Lymphoblastic Lymphoma with Cutaneous Involvement in a Child: A Rare Case Report

T-cell lymphoblastic lymphoma (T-LBL) is a heterogeneous malignancy derived from T-cells that more commonly affects teens and males. Most commonly, T-LBL exhibits signs of lymph nodes, bone marrow, and mediastinal mass invasion, but in rare cases, the disease manifests cutaneously. We present a case of both cutaneous and systemic presentation of T-LBL in 9-year-old man in which the skin immunophenotype analysis showed TdT expression with positivity of CD3, CD4 and CD99. Review of all currently described cases of cutaneous T-LBL revealed that the most frequently positive tumor markers were TdT (100%), CD3 (100%), CD4 (59.1%) and CD99 (40.9%). Cutaneous involvement may be a prognostic factor in treating T-LBL with chemotherapy.

Phosphoproteomic Analysis Reveals a Different Proteomic Profile in Pediatric Patients With T-Cell Lymphoblastic Lymphoma or T-Cell Acute Lymphoblastic Leukemia

T-cell lymphoblastic lymphoma (T-LBL) and lymphoblastic leukemia (T-ALL) arise from the transformation of precursor T-cells sharing common morphological and immunophenotypic features. Despite this, T-LBL and T-ALL show different genomic/transcriptomic profiles and whether they represent two distinct disease entities or variant manifestations of the same disease is still a matter of debate. In this work, we performed a Reverse Phase Protein Array study on T-LBL and T-ALL samples and demonstrated that they are characterized by a different phosphoproteomic profile. Indeed, T-LBLs showed the hyperactivation of FAK/ERK1/2 and AKT/mTOR pathways, whereas JAK/STAT pathway was significantly hyperphosphorylated in T-ALLs. Moreover, since the only criteria for discriminating T-LBL from T-ALL is blasts’ infiltration below 25% in the bone marrow and lymphoma patients can present with a percentage of blasts close to this cut-off, a biomarker that could help distinguishing the two diseases would be of great help for the clinical diagnosis and treatment decision. Pursuing this aim, we identified a proteomic signature of six proteins whose expression/activation was able to discriminate stage IV T-LBL from T-ALL. Moreover, we demonstrated that AKT hyperphosphorylation alone was able to distinguish stage IV T-LBL from both T-ALL and stage III T-LBL. Concluding, these data demonstrate that T-ALL and T-LBL bear different phosphoproteomic profiles, further sustaining the hypothesis of the two disease as different entities and paving the way for the identification of new biomarkers able to distinguish stage IV T-LBL from T-ALL disease, so far based only on BM involvement criteria.

High-sensitivity next-generation sequencing MRD assessment in ALL identifies patients at very low risk of relapse

Measurable residual disease (MRD) is highly prognostic for relapse and overall survival (OS) in acute lymphoblastic leukemia (ALL), although many patients with apparent "MRD negativity" by standard assays still relapse. We evaluated the clinical impact of a highly sensitive next-generation sequencing (NGS) MRD assay in 74 adults with ALL undergoing frontline therapy. Among remission samples that were MRD negative by multiparameter flow cytometry (MFC), 46% were MRD positive by the NGS assay. After one cycle of induction chemotherapy, MRD negativity by MFC at a sensitivity of 1x10-4 and NGS at a sensitivity of 1x10-6 was achieved in 66% and 23% of patients, respectively. The 5-year cumulative incidence of relapse (CIR) among patients who achieved MRD negativity by MFC at CR was 29%; in contrast, no patients who achieved early MRD negativity by NGS relapsed, and their 5-year OS was 90%. NGS MRD negativity at CR was associated with significantly decreased risk of relapse compared with MRD positivity (5-year CIR: 0% versus 45%, respectively, P=0.04). Among patients who were MRD negative by MFC, detection of low levels of MRD by NGS identified patients who still had a significant risk of relapse (5-year CIR: 39%). Early assessment of MRD using a highly sensitive NGS assay adds clinically relevant prognostic information to standard MFC-based approaches and can identify patients with ALL undergoing frontline therapy who have a very low risk of relapse and excellent long-term survival.

Prognostic Significance of Comprehensive Gene Mutations and Clinical Characteristics in Adult T-Cell Acute Lymphoblastic Leukemia Based on Next-Generation Sequencing

Background

Adult T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous malignant tumor with poor prognosis. However, accurate prognostic stratification factors are still unclear.

Methods

Data from 90 adult T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) patients were collected. The association of gene mutations detected by next-generation sequencing and clinical characteristics with the outcomes of T-ALL/LBL patients were retrospectively analyzed to build three novel risk stratification models through Cox proportional hazards model.

Results

Forty-seven mutated genes were identified. Here, 73.3% of patients had at least one mutation, and 36.7% had ≥3 mutations. The genes with higher mutation frequency were NOTCH1, FBXW7, and DNMT3A. The most frequently altered signaling pathways were NOTCH pathway, transcriptional regulation pathway, and DNA methylation pathway. Age (45 years old), platelet (PLT) (50 G/L), actate dehydrogenase (LDH) (600 U/L), response in D19-BMR detection, TP53 and cell cycle signaling pathway alterations, and hematopoietic stem cell transplantation (HSCT) were integrated into a risk stratification model of event-free survival (EFS). Age (45 years old), white blood cell (WBC) count (30 G/L), response in D19-BMR detection, TP53 and cell cycle signaling pathway alterations, and HSCT were integrated into a risk stratification model of overall survival (OS). According to our risk stratification models, the 1-year EFS and OS rates in the low-risk group were significantly higher than those in the high-risk group.

Conclusions

Our risk stratification models exhibited good prognostic roles in adult T-ALL/LBL patients and might guide individualized treatment and ultimately improve their outcomes.

Animal models of acute lymphoblastic leukemia: Recapitulating the human disease to evaluate drug efficacy and discover therapeutic targets

Acute lymphoblastic leukemia (ALL) is a malignant hematologic tumor with highly aggressive characteristics, which is prone to relapse, has a poor prognosis and few clinically effective drugs. It is meaningful to gain a better understanding of its pathogenesis in order to discover and evaluate potential therapeutic drugs and new treatment targets. The goal of developing novel targeted drugs and treatment methods is to increase complete remission, reduce toxicity and morbidity, and that is also the most important prerequisite for modern leukemia treatment. However, the process of new drugs from research and development to clinical application is long and difficult. Many promising drugs were rejected by the USFoodandDrugAdministration(FDA) due to serious adverse drug reactions (ADR) in clinical phase I trials. Animal models provide us with an excellent tool to understand the complex pathological mechanisms of human diseases, to evaluate the potential of new targeted drugs and therapeutic approaches to treat ALL in vivo and, more importantly, to assess the potential ADR they may have on healthy organs. In this article we review ALL animal models' progression, their roles in revealing the pathogenesis of ALL and drug development. Additionally, we mainly focus on the mouse models, especially xenotransplantation and transgenic models that more closely reproduce the human phenotype. In conclusion, we summarize the advantages and limitations of each model, thereby facilitating further understanding the etiology of ALL, and eventually contributing to the effective management of the disease.

Early T-Cell Precursor Acute Lymphoblastic Leukemia: Diagnosis, Updates in Molecular Pathogenesis, Management, and Novel Therapies

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a distinct subtype of T lymphoblastic leukemia (T-ALL) identified in 2009, due to its unique immunophenotypic and genomic profile. The outcome of patients was poor in earlier studies, and they were prone to have induction failure, with more frequent relapse/refractory disease. Recent advances had been made in discoveries of genetic aberrations and molecular pathogenesis of ETP-ALL. However, the diagnosis and management of ETP-ALL is still challenging. There are limited choices of novel therapies so far. In this review article, it highlighted the diagnostic issue of ETP-ALL, pitfall in diagnosis, and strategy of accurate diagnosis. The review also summarized current understanding of molecular mechanism of leukemogenesis. The emerging role of risk-adapted therapy and allogenic stem cell transplant in optimizing the outcome of patients with ETP-ALL was discussed. Finally, some potential novel therapies were proposed based on the current understanding of molecular pathogenesis.

T-cell lymphoblastic lymphoma with extensive thrombi and cardiac thrombosis: A case report and review of literature

BACKGROUND

T-lymphoblastic lymphoma (T-LBL), a neoplasm of immature T-cell precursors or lymphoblasts, is a clinically aggressive disease. In general, patients with T-LBL have a poor prognosis and often have high-risk clinical features, such as mediastinal masses, central nervous system infiltration, or other indications of high tumor burden; however, extensive thrombi are not common.

CASE SUMMARY

A 27-year-old woman presented to the Department of General Surgery with cervical lymph node enlargement accompanied by cough, wheezing, and palpitation for 3 mo. A complete blood count showed a white blood cell count of 1.6 × 10⁹/L, a hemoglobin concentration of 135 g/L, and a platelet count of 175 × 10⁹/L. A biopsy sample of the lymph node mass indicated T-cell lymphoblastic lymphoma, and the bone marrow immunophenotype indicated early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). Abdominal and chest enhanced computed tomography showed thrombi in the superior vena cava, inferior vena cava, right hepatic vein, azygos vein, and right atrium. The ultrasonic cardiogram showed a thrombus in the right atrium of 5.23 cm × 4.21 cm. The patient was first treated with low-dose dexamethasone and low-molecular-weight heparin followed by 2 cycles of chemotherapy. Then, the ultrasonic cardiogram showed that thrombus in the right atrium had disappeared and the patient had achieved complete cytological remission. The maintenance therapy of the patient included chidamide 30 mg/wk, and she survived for 6 mo.

CONCLUSION

The incidence of venous thromboembolism is high in lymphoma; however, extensive thrombi with heart thrombosis is rare. Chemotherapy is the major method of treatment for lymphoma with thrombosis. We successfully treated a patient with T-LBL complicated by extensive thrombi, including a large right atrial thrombus, with combined chemotherapy containing liposomal doxorubicin, and the patient achieved complete remission. Maintenance therapy with chidamide was also effective.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is one of the most dangerous hematological malignancies, with high tumor heterogeneity and poor prognosis. More than 60% of T-ALL patients carry NOTCH1 gene mutations, leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways. We found that chidamide, an HDAC inhibitor, exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity. In particular, chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1 (NICD1) as well as MYC, partly through their ubiquitination and degradation by the proteasome pathway. We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease (MRD) in patients and is well tolerated. Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients, including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

A Chinese Child Presented with Early T Cell Precursor Lymphoblastic Lymphoma

T cell lymphoblastic lymphoma (T-LBL) is regarded as the leukemic phase of T cell acute lymphoblastic leukemia (T-ALL). The early T cell precursors ALL/LBL (ETP-LBL/ALL) are derived from thymic cells at the ETP differentiation stage and recognized as a high-risk subgroup of T-ALL/LBL. Most of these cases presented with ALL at the disease onset, but the ETP-LBL phase is uncommon. Here, we report a patient who presented with ETP-LBL at the disease onset. In this case, ALL developed even despite receiving chemotherapy, but the patient achieved a complete remission with intensive chemotherapy.

MicroRNA-211 attenuates cell proliferation in T-cell lymphoblastic lymphoma through targeting TCF12

T-cell lymphoblastic lymphoma (T-LBL) is a class of highly aggressive hematologic neoplasms originating from progenitor T-lymphocytes. MicroRNA (miRNA) is an endogenous RNA molecule with 22 nucleotides in length. Accumulated evidence suggests that miRNA functions as a key regulator in human cancer. Herein, by in silico analysis, we found that miR-211 was a decreased miRNA in T-LBL in high-throughput sequencing data, which was subsequently verified in our cohort. Low miR-211 was closely correlated with bulky disease, high ann arbor stage, relapse and poor prognosis. miR-211 was regulated by N6-methyladenosine (m⁶A) modification, specifically, m6A methyltransferase METTL14 methylated primary miR-211 (pri-miR-211), expediting pri-miR-211 processing via recruiting DGCR8. Functionally, miR-211 overexpression significantly reduced T-LBL cell viability, DNA synthesis rate and spheroid formation ability, whereas silencing of miR-211 had the opposite effects. In addition, we established the xenograft tumor model and found that miR-211 remarkably inhibited tumor growth in vivo. Further, TCF12 was the direct target of miR-211, miR-211 bound to TCF12 mRNA 3`-untranslated region (UTR) and increased its decay, overexpression of TCF12 could effectively rescue the weakened malignant behavior of T-LBL cells caused by miR-211 overexpression. Collectively, our data clearly demonstrate that miR-211 is a novel tumor suppressor in T-LBL, targeting of miR-211/TCF12 axis may be a potential treatment for T-LBL patients.

T-Cell Lymphoblastic Lymphoma Arising in the Setting of Myeloid/Lymphoid Neoplasms with Eosinophilia: LMO2 Immunohistochemistry as a Potentially Useful Diagnostic Marker

Simple Summary

Rarely, T-lymphoblastic lymphoma (T-LBL) may develop in the setting of myeloid/lymphoid neoplasms with eosinophilia. Given important therapeutic implications, it is crucial to identify T-LBL arising in this particular context. LIM domain only 2 (LMO2) is known to be overexpressed in almost all sporadic T-LBL and not in immature TdT-positive T-cells in the thymus and in indolent T-lymphoblastic proliferations. We retrospectively evaluated the clinical, morphological, immunohistochemical and molecular features of 11 cases of T-LBL occurring in the setting of myeloid/lymphoid neoplasms with eosinophilia and investigated the immunohistochemical expression of LMO2 in this setting of T-LBL. Interestingly, 9/11 cases were LMO2 negative, with only 2 cases showing partial expression. In our study, we would suggest that LMO2 immunostaining, as part of the diagnostic panel for T-LBL, may represent a useful marker to identify T-LBL developing in the context of myeloid/lymphoid neoplasms with eosinophilia.

Abstract

Background: Rarely, T-lymphoblastic lymphoma (T-LBL) may develop in the setting of myeloid/lymphoid neoplasms with eosinophilia (M/LNs-Eo), a group of diseases with gene fusion resulting in overexpression of an aberrant tyrosine kinase or cytokine receptor. The correct identification of this category has relevant therapeutic implications. LIM domain only 2 (LMO2) is overexpressed in most T-LBL, but not in immature TdT-positive T-cells in the thymus and in indolent T-lymphoblastic proliferations (iT-LBP). Methods and Results: We retrospectively evaluated 11 cases of T-LBL occurring in the context of M/LNs-Eo. Clinical, histological, immunohistochemical and molecular features were collected and LMO2 immunohistochemical staining was performed. The critical re-evaluation of these cases confirmed the diagnosis of T-LBL with morphological, immunohistochemical and molecular features consistent with T-LBL occurring in M/LNs-Eo. Interestingly, LMO2 immunohistochemical analysis was negative in 9/11 cases, whereas only 2 cases revealed a partial LMO2 expression with a moderate and low degree of intensity, respectively. Conclusions: LMO2 may represent a potentially useful marker to identify T-LBL developing in the context of M/LNs-Eo. In this setting, T-LBL shows LMO2 immunohistochemical profile overlapping with cortical thymocytes and iT-LBP, possibly reflecting different molecular patterns involved in the pathogenesis of T-LBL arising in the setting of M/LNs-Eo.

CD2 and CD7 are sensitive flow cytometry screening markers for T-lineage acute leukemia(s): a study of 465 acute leukemia cases

T-lymphoblastic leukemia/lymphoma (T-ALL/LBL) is a rare acute leukemia that expresses cytoplasmic CD3 (cCD3) and frequently lacks surface CD3. Given that routine flow cytometric testing for cCD3 may not be feasible and cCD3 interpretation may be difficult, we investigate if surface CD2 and/or CD7 expression on blasts can be used by flow cytometry to screen for T-lineage acute leukemia. We retrospectively reviewed flow cytometric data from 233 acute leukemias (36 T-ALL/LBL, 8 mixed-phenotype acute leukemia T/myeloid, 80 acute myeloid leukemia, 97 B-ALL/LBL, 8 mixed-phenotype acute leukemia B/myeloid, and 4 acute undifferentiated leukemia cases). Uniform expression (≥75% of blasts) of CD2 and/or CD7 was seen in all 44 cCD3-positive cases but in only 11% (20/189) of cCD3-negative acute leukemias, thus demonstrating 100% sensitivity and 89% specificity in the identification of cCD3-positive (T-lineage) acute leukemia. To avoid selection bias, we prospectively studied 232 consecutive acute leukemias for which cCD3, CD2, and CD7 were automatically performed in all cases. Similar to the retrospective study, uniform expression of CD2 and/or CD7 on blasts showed 100% sensitivity and 88% specificity in the screening for cCD3-positive (T-lineage) acute leukemia. Therefore, acute leukemias with uniform expression of CD2 and/or CD7 warrant further testing for cCD3 to evaluate for T-lineage acute leukemia. Blasts that lack both uniform CD2 and CD7 expression do not require additional cCD3 testing. We propose that CD2 and CD7 could be utilized in a limited antibody flow cytometry panel as a sensitive, robust, and cost-effective way to screen for T-lineage acute leukemia.

LINC00511 exacerbated T-cell acute lymphoblastic leukemia via miR-195-5p/LRRK1 axis

T-cell acute lymphoblastic leukemia (T-ALL) is a malignant disease arising from the abnormal proliferation of T lymphocyte in marrow. Long non-coding RNAs (lncRNAs) are one kind of non-coding RNAs (ncRNAs), which were reported to modulate the initiation or progression of diverse cancers. However, the role of LINC00511 in T-ALL was unknown. To figure out the function and mechanism of LINC00511 in T-ALL, a series of experiments were carried out. Based on the experimental results, we discovered that LINC00511 boosted cell proliferation and invasion, but hindered cell apoptosis in T-ALL cells. Besides, based on bio-informatics tool, miR-195-5p was selected for further exploration. Then, miR-195-5p was validated to bind with LINC00511. Hereafter, LRRK1 was testified to serve as a target gene of miR-195-5p. At last, rescue assays suggested that LRRK1 overexpression restored sh-LINC00511#1-mediated effects on cell proliferation and apoptosis. All in all, LINC00511 exacerbated T-ALL progression via miR-195-5p/LRRK1 axis, implying a potential therapeutic clue for the patients with T-ALL.

FZD6 triggers Wnt-signalling driven by WNT10BIVS1 expression and highlights new targets in T-cell acute lymphoblastic leukemia

Wnt/Fzd signaling has been implicated in hematopoietic stem cell maintenance and in acute leukemia establishment. In our previous work, we described a recurrent rearrangement involving the WNT10B locus (WNT10B^R), characterized by the expression of WNT10B^IVS1 transcript variant, in acute myeloid leukemia. To determine the occurrence of WNT10B^R in T‐cell acute lymphoblastic leukemia (T‐ALL), we retrospectively analyzed an Italian cohort of patients (n = 20) and detected a high incidence (13/20) of WNT10B^IVS1 expression. To address genes involved in WNT10B molecular response, we have designed a Wnt‐targeted RNA sequencing panel. Identifying Wnt agonists and antagonists, it results that the expression of FZD6, LRP5, and PROM1 genes stands out in WNT10B^IVS1 positive patients compared to negative ones. Using MOLT4 and MUTZ‐2 as leukemic cell models, which are characterized by the expression of WNT10B^IVS1, we have observed that WNT10B drives major Wnt activation to the FZD6 receptor complex through receipt of ligand. Additionally, short hairpin RNAs (shRNAs)‐mediated gene silencing and small molecule‐mediated inhibition of WNTs secretion have been observed to interfere with the WNT10B/FZD6 interaction. We have therefore identified that WNT10B^IVS1 knockdown, or pharmacological interference by the LGK974 porcupine (PORCN) inhibitor, reduces WNT10B/FZD6 protein complex formation and significantly impairs intracellular effectors and leukemic expansion. These results describe the molecular circuit induced by WNT10B and suggest WNT10B/FZD6 as a new target in the T‐ALL treatment strategy.

Lymphoma versus thymoma: A diagnostic challenge

T-cell acute lymphoblastic lymphoma is a common hematological malignancy of childhood. It can involve the bone marrow, blood, or tissues like the thymus, lymph nodes as well as extra-nodal sites. Two aspects of the disease make early diagnosis critical - the clinically aggressive nature of the neoplasm, and availability of effective chemotherapy against the disease. Diagnosis is largely based on clinical suspicion and confirmation by histopathological examination of the affected tissue. However, biopsy results may not always be helpful in establishing the diagnosis. We describe the case of an 18-year old patient presenting with fever and an anterior mediastinal mass suspected to have a T-cell lymphoma where an initial biopsy from the mass had features of a thymoma. The patient was kept in close follow up for 2 months when there was a recurrence of symptoms and a repeat bone marrow evaluation revealed a T-cell lymphoma.

New Approaches to Treating Challenging Subtypes of ALL in AYA Patients

PURPOSE OF REVIEW

The treatment of acute lymphoblastic leukemia (ALL) in adolescent and young adult (AYA) patients has markedly improved with the adoption of pediatric-inspired protocols. However, there remain several subtypes of ALL that represent significant therapeutic challenges. Here, we review the current evidence guiding treatment of Philadelphia chromosome-positive (Ph+), Philadelphia chromosome-like (Ph-L), and early T-precursor (ETP) ALL in the AYA population.

RECENT FINDINGS

Clinical trials in Ph + ALL have demonstrated the superior efficacy of second- and third-generation tyrosine kinase inhibitors (TKIs) to induce and maintain remission. Current efforts now focus on determining the durability of these remissions and which patients will benefit from transplant. For Ph-like and ETP ALL, recent studies are investigating the addition of novel agents to standard treatment. The treatment of Ph + ALL has significantly improved with the addition of potent TKIs. However, the treatment of Ph-like and ETP ALL remains a challenge. At this time, the judicious use of allogenic transplant is the only current approach to modify this increased risk.