NT157 exhibits antineoplastic effects by targeting IRS and STAT3/5 signaling in multiple myeloma.

Multiple myeloma (MM) is a prevalent hematological malignancy with high recurrence and no definitive cure. The current study revisits the role of the IGF1/IGF1R axis in MM, introducing a novel inhibitor, NT157. The IGF1/IGF1R pathway is pivotal in MM, influencing cell survival, proliferation, and migration and impacting patient survival outcomes. NT157 targets intracellular proteins such as IRS and STAT proteins and demonstrates antineoplastic potential in hematological malignancies and solid tumors. In the present study, we assessed IGF1R signaling-related gene expression in MM patients and healthy donors, unveiling significant distinctions. MM cell lines displayed varying expression patterns of IGF1R-related proteins. A gene dependence analysis indicated the importance of targeting receptor and intracellular elements over autocrine IGF1. NT157 exhibited inhibitory effects on MM cell viability, clonal growth, cell cycle progression, and survival. Moreover, NT157 reduced IRS2 expression and STAT3, STAT5, and RPS6 activation and modulated oncogenes and tumor suppressors, fostering a tumor-suppressive molecular profile. In summary, our study demonstrates that the IGF1/IGF1R/IRS signaling axis is differentially activated in MM cells and the NT157's capacity to modulate crucial molecular targets, promoting antiproliferative effects and apoptosis in MM cells. NT157 may offer a multifaceted approach to enhance MM therapy.

Antineoplastic effects of pharmacological inhibitors of aurora kinases in CSF3RT618I-driven cells.

Myeloproliferative neoplasms (MPN) are consolidated as a relevant group of diseases derived from the malfunction of the hematopoiesis process and have as a particular attribute the increased proliferation of myeloid lineage. Among these, chronic neutrophilic leukemia (CNL) is distinguished, caused by the T618I mutation of the CSF3R gene, a trait that generates ligand-independent receptor activation and downstream JAK2/STAT signaling. Previous studies reported that mutations in BCR::ABL1 and JAK2V617F increased the expression of the aurora kinase A (AURKA) and B (AURKB) in Ba/F3 cells and their pharmacological inhibition displays antineoplastic effects in human BCR::ABL1 and JAK2V617F positive cells. Delimiting the current scenario, aspects related to the AURKA and AURKB as a potential target in CSF3RT618I-driven models is little known. In the present study, the cellular and molecular effects of pharmacological inhibitors of aurora kinases, such as aurora A inhibitor I, AZD1152-HQPA, and reversine, were evaluated in Ba/F3 expressing the CSF3RT618I mutation. AZD1152-HQPA and reversine demonstrated antineoplastic potential, causing a decrease in cell viability, clonogenicity, and proliferative capacity. At molecular levels, all inhibitors reduced histone H3 phosphorylation, aurora A inhibitor I and reversine reduced STAT5 phosphorylation, and AZD1152-HQPA and reversine induced PARP1 cleavage and γH2AX expression. Reversine more efficiently modulated genes associated with cell cycle and apoptosis compared to other drugs. In summary, our findings shed new insights into the use of AURKB inhibitors in the context of CNL.

Telomeric repeat-containing RNA is dysregulated in acute myeloid leukemia.

TERRA (telomeric repeat-containing RNA) is a class of long noncoding RNAs transcribed from subtelomeric and telomeric regions. TERRA binds to the subtelomeric and telomeric DNA-forming R-loops (DNA-RNA hybrids), which are involved in telomere maintenance and telomerase function, but the role of TERRA in human cells is not well characterized. Here, we comprehensively investigated for the first time TERRA expression in primary human hematopoietic cells from an exploratory cohort of patients with acute myeloid leukemia (AML), patients with acute lymphoblastic leukemia (ALL), patients with telomere biology disorder (TBD), and healthy subjects. TERRA expression was repressed in primary human hematopoietic cells, including healthy donors, patients with ALL, and patients with TBD, irrespective of their telomere length, except for AML. A second cohort comprising 88 patients with AML showed that TERRA was overexpressed in an AML subgroup also characterized by higher R-loop formation, low TERT and RNAseH2 expression, and a paucity of somatic splicing factor mutations. Telomere length did not correlate with TERRA expression levels. To assess the role of TERRA R-loops in AML, we induced R-loop depletion by increasing RNAseH1 expression in 2 AML cell lines. Decreased TERRA R-loops in AML cell lines resulted in increased chemosensitivity to cytarabine. Our findings indicate that TERRA is uniformly repressed in primary human hematopoietic cells but abnormally expressed in an AML subset with low telomerase.

Treatment patterns and outcomes for Hodgkin Lymphoma patients aged 60 and older: a report from the Brazilian Prospective Hodgkin Lymphoma Registry.

The treatment of older patients with Hodgkin lymphoma (HL) remains a challenge. We sought to identify the treatment patterns and outcomes in older HL patients included in the Brazilian HL registry (NCT02589548). A total of 136 patients with HIV-negative classic HL, aged ≥ 60 years, diagnosed between 2009 and 2018, were analyzed. The median age was 66 years old (60-90), 72% had advanced disease, 62% had a high IPS, and 49% had a nodular sclerosis subtype. Median follow-up was 64 months for alive patients. ABVD was the front-line treatment in 96% of patients. Twenty-one patients (15%) died during front-line treatment. The 5-year PFS and 5-year OS rates were 55% and 59%, respectively. The 5-year OS rates in localized and advanced disease were 81% and 51% (p=0.013). Lung toxicity developed in 11% of the patients treated with ABVD. Bleomycin was administered for > 2 cycles in 65% of patients. Compared with 2009-2014, there was a decrease in the use of bleomycin for > 2 cycles in 2015-2018 (88% × 45%, p<0.0001). The impact of socioeconomic status (SES) on outcomes was studied in patients treated with ABVD. After adjusting for potential confounders, lower SES remained independently associated with poorer survival (HR 2.22 [1.14-4.31] for OS and HR 2.84 [1.48-5.45] for PFS). Treatment outcomes were inferior to those observed in developed countries. These inferior outcomes were due to an excess of deaths during front-line treatment and the excessive use of bleomycin. SES was an independent factor for shorter survival.

Isolated massive histiocytes renal interstitial infiltration: a case report of an unexpected cause of acute kidney injury in a kidney transplant recipient.

BACKGROUND: Acute kidney injury is a frequent cause of hospital readmission in kidney transplant recipients (KTR), usually associated with infections and graft rejection. Herein, we report a case of an unusual cause of acute kidney injury in a KTR (massive histiocytes renal interstitial infiltration). CASE PRESENTATION: A 40-year-old woman was submitted to a second kidney transplant. One year after surgery, she presented asthenia, myalgia, and fever, haemoglobin 6.1 g/dL; neutrophils: 1.3 × 109/µL; platelets: 143 × 109/µL; blood creatinine 11.8 mg/dL, requiring dialysis. A kidney biopsy revealed diffuse histiocytic infiltration, which was assumed due to dysregulated immunological activation triggered by infections. The patient had multiple infections, including cytomegalovirus infection (CMV), aspergillosis, bacteraemia, and urinary tract infections, which could trigger the immune response. Haemophagocytic lymphohistiocytosis (HLH) was ruled out. The present case highlights the occurrence of isolated massive renal interstitial infiltration of histiocytes that does not meet the criteria for HLH or other related pathologies. CONCLUSIONS: Renal histiocyte activation and infiltration may have been initiated by an immunological mechanism similar to what occurs in HLH and infectious processes. The present case highlights the occurrence of isolated massive renal interstitial infiltration of histiocytes that does not meet the criteria for HLH or other related pathologies.

Clinical significance of mitochondrial DNA content in acute promyelocytic leukaemia.

Although a growing body of evidence demonstrates that altered mtDNA content (mtDNAc) has clinical implications in several types of solid tumours, its prognostic relevance in acute promyelocytic leukaemia (APL) patients remains largely unknown. Here, we show that patients with higher-than-normal mtDNAc had better outcomes regardless of tumour burden. These results were more evident in patients with low-risk of relapse. The multivariate Cox proportional hazard model demonstrated that high mtDNAc was independently associated with a decreased cumulative incidence of relapse. Altogether, our data highlights the possible role of mitochondrial metabolism in APL patients treated with ATRA.

NT157 exerts antineoplastic activity by targeting JNK and AXL signaling in lung cancer cells.

Combination therapies or multi-targeted drugs have been pointed out as an option to prevent the emergence of resistant clones, which could make long-term treatment more effective and translate into better clinical outcomes for cancer patients. The NT157 compound is a synthetic tyrphostin that leads to long-term inhibition of IGF1R/IRS1-2-, STAT3- and AXL-mediated signaling pathways. Given the importance of these signaling pathways for the development and progression of lung cancer, this disease becomes an interesting model for generating preclinical evidence on the cellular and molecular mechanisms underlying the antineoplastic activity of NT157. In lung cancer cells, exposure to NT157 decreased, in a dose-dependent manner, cell viability, clonogenicity, cell cycle progression and migration, and induced apoptosis (p < 0.05). In the molecular scenario, NT157 reduced expression of IRS1 and AXL and phosphorylation of p38 MAPK, AKT, and 4EBP1. Besides, NT157 decreased expression of oncogenes BCL2, CCND1, MYB, and MYC and increased genes related to cellular stress and apoptosis, JUN, BBC3, CDKN1A, CDKN1B, FOS, and EGR1 (p < 0.05), favoring a tumor-suppressive cell signaling network in the context of lung cancer. Of note, JNK was identified as a key kinase for NT157-induced IRS1 and IRS2 phosphorylation, revealing a novel axis involved in the mechanism of action of the drug. NT157 also presented potentiating effects on EGFR inhibitors in lung cancer cells. In conclusion, our preclinical findings highlight NT157 as a putative prototype of a multitarget drug that may contribute to the antineoplastic arsenal against lung cancer.

Diagnosis and treatment of systemic mastocytosis in Brazil: Recommendations of a multidisciplinary expert panel

ABSTRACT Introduction: Systemic Mastocytosis comprises a group of neoplastic diseases characterized by clonal expansion and infiltration of mast cells into several organs. The diagnosis and treatment of this disease may be challenging for non-specialists. Objective: Make suggestions or recommendations in Systemic Mastocytosis based in a panel of Brazilian specialists. Method and results: An online expert panel with 18 multidisciplinary specialists was convened to propose recommendations on the diagnosis and treatment of Systemic Mastocytosis in Brazil. Recommendations were based on discussions of topics and multiple-choice questions and were graded using the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence Chart. Conclusion: Twenty-two recommendations or suggestions were proposed based on a literature review and graded according to the findings.

Diagnosis and treatment of systemic mastocytosis in Brazil: Recommendations of a multidisciplinary expert panel.

INTRODUCTION: Systemic Mastocytosis comprises a group of neoplastic diseases characterized by clonal expansion and infiltration of mast cells into several organs. The diagnosis and treatment of this disease may be challenging for non-specialists. OBJECTIVE: Make suggestions or recommendations in Systemic Mastocytosis based in a panel of Brazilian specialists. METHOD AND RESULTS: An online expert panel with 18 multidisciplinary specialists was convened to propose recommendations on the diagnosis and treatment of Systemic Mastocytosis in Brazil. Recommendations were based on discussions of topics and multiple-choice questions and were graded using the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence Chart. CONCLUSION: Twenty-two recommendations or suggestions were proposed based on a literature review and graded according to the findings.

Differential cytotoxic activity of pharmacological inhibitors of IGF1R-related pathways in JAK2V617F driven cells.

Myeloproliferative neoplasms (MPN) belong to a group of clonal diseases of hematopoietic stem cells characterized by aberrant proliferation of mature myeloid lineages. The constitutive activation of the JAK2/STAT signaling pathway is now well established to play a central role in MPN pathogenesis; however, accumulating evidence now indicates that the IGF1R-mediated signaling pathway contributes to the maintenance of the malignant phenotype. Studies using inhibitors of IGF1-mediated signaling have reported cytotoxic effects in cellular and murine models of MPN, but no consensus has been reached regarding the potency and efficacy of inhibitors of the IGF1R-related pathway in this context. In the present study, we compared the potency and efficacy of three inhibitors of IGF1R-related pathways in a JAK2V617F-driven cellular model. These inhibitors (NT157, OSI-906, and NVP-AEW54) present antineoplastic activity with similar efficacy in Ba/F3 JAK2V617F cells, with NT157 showing the greatest potency. Both the induction of apoptosis and reduction in cell proliferation were associated with the observed reduction in cell viability. Downregulation of JAK2/STAT signaling was an advantageous off-target effect of all three inhibitors. These preclinical studies reinforce the potential of the IGF1R-related pathway as a therapeutic target in MPN.

Phenformin increases early hematopoietic progenitors in the Jak2V617F murine model.

BACKGROUND: Myeloproliferative neoplasms (MPN) are disorders characterized by an alteration at the hematopoietic stem cell (HSC) level, where the JAK2 mutation is the most common genetic alteration found in classic MPN (polycythemia vera, essential thrombocythemia, and primary myelofibrosis). We and others previously demonstrated that metformin reduced splenomegaly and platelets counts in peripheral blood in JAK2V617F pre-clinical MPN models, which highlighted the antineoplastic potential of biguanides for MPN treatment. Phenformin is a biguanide that has been used to treat diabetes, but was withdrawn due to its potential to cause lactic acidosis in patients. AIMS: We herein aimed to investigate the effects of phenformin in MPN disease burden and stem cell function in Jak2V617F-knockin MPN mice. RESULTS: In vitro phenformin treatment reduced cell viability and increased apoptosis in SET2 JAK2V67F cells. Long-term treatment with 40 mg/kg phenformin in Jak2V617F knockin mice increased the frequency of LSK, myeloid progenitors (MP), and multipotent progenitors (MPP) in the bone marrow. Phenformin treatment did not affect peripheral blood counts, spleen weight, megakaryocyte count, erythroid precursors frequency, or ex vivo clonogenic capacity. Ex vivo treatment of bone marrow cells from Jak2V617F knockin mice with phenformin did not affect hematologic parameters or engraftment in recipient mice. CONCLUSIONS: Phenformin increased the percentages of LSK, MP, and MPP populations, but did not reduce disease burden in Jak2V617F-knockin mice. Additional studies are necessary to further understand the effects of phenformin on early hematopoietic progenitors.

STMN1 is highly expressed and contributes to clonogenicity in acute promyelocytic leukemia cells.

Stathmin 1 (STMN1) is a microtubule-destabilizing protein highly expressed in hematological malignancies and involved in proliferation and differentiation. Although a previous study found that the PML-RARα fusion protein, which contributes to the pathophysiology of acute promyelocytic leukemia (APL), positively regulates STMN1 at the transcription and protein activity levels, little is known about the role of STMN1 in APL. In this study, we aimed to investigate the STMN1 expression levels and their associations with laboratory, clinical, and genomic data in APL patients. We also assessed the dynamics of STMN1 expression during myeloid cell differentiation and cell cycle progression, and the cellular effects of STMN1 silencing and pharmacological effects of microtubule-stabilizing drugs on APL cells. We found that STMN1 transcripts were significantly increased in samples from APL patients compared with those of healthy donors (all p < 0.05). However, this had no effect on clinical outcomes. STMN1 expression was associated with proliferation- and metabolism-related gene signatures in APL. Our data confirmed that STMN1 was highly expressed in early hematopoietic progenitors and reduced during cell differentiation, including the ATRA-induced granulocytic differentiation model. STMN1 phosphorylation was predominant in a pool of mitosis-enriched APL cells. In NB4 and NB4-R2 cells, STMN1 knockdown decreased autonomous cell growth (all p < 0.05) but did not impact ATRA-induced apoptosis and differentiation. Finally, treatment with paclitaxel (as a single agent or combined with ATRA) induced microtubule stabilization, resulting in mitotic catastrophe with repercussions for cell viability, even in ATRA-resistant APL cells. This study provides new insights into the STMN1 functions and microtubule dynamics in APL.

Comprehensive analysis of cytoskeleton regulatory genes identifies ezrin as a prognostic marker and molecular target in acute myeloid leukemia.

PURPOSE: Despite great advances that have been made in the understanding of the molecular complexity of acute myeloid leukemia (AML), very little has been translated into new therapies. Here, we set out to investigate the impact of cytoskeleton regulatory genes on clinical outcomes and their potential as therapeutic targets in AML. METHODS: Gene expression and clinical data were retrieved from The Cancer Genome Atlas (TCGA) AML study and used for survival and functional genomics analyses. For pharmacological tests, AML cells were exposed to ezrin (EZR) inhibitors and submitted to several cellular and molecular assays. RESULTS: High EZR expression was identified as an independent marker of worse outcomes in AML patients from the TCGA cohort (p < 0.05). Functional genomics analyses suggested that EZR contributes to responses to stimuli and signal transduction pathways in leukemia cells. EZR pharmacological inhibition with NSC305787 and NSC668394 reduced viability, proliferation, autonomous clonal growth, and cell cycle progression in AML cells (p < 0.05). NSC305787 had a greater potency and efficiency than NSC668394 in leukemia models. At the molecular level, EZR inhibitors reduced EZR, S6 ribosomal protein and 4EBP1 phosphorylation, and induced PARP1 cleavage in AML cells. NSC305787, but not NSC668394, favored a gene network involving cell cycle arrest and apoptosis in Kasumi 1 AML cells. CONCLUSIONS: From our data we conclude that EZR expression may serve as a prognostic factor in AML. Our preclinical findings indicate that ezrin inhibitors may be employed as a putative novel class of AML targeting drugs.

MLL5 improves ATRA driven differentiation and promotes xenotransplant engraftment in acute promyelocytic leukemia model.

Although the mixed lineage leukemia 5 (MLL5) gene has prognostic implications in acute promyelocyte leukemia (APL), the underlying mechanism remains to be elucidated. Here, we demonstrate the critical role exerted by MLL5 in APL regarding cell proliferation and resistance to drug-induced apoptosis, through mtROS regulation. Additionally, MLL5 overexpression increased the responsiveness of APL leukemic cells to all-trans retinoic acid (ATRA)-induced differentiation, via regulation of the epigenetic modifiers SETD7 and LSD1. In silico analysis indicated that APL blasts with MLL5high transcript levels were associated with retinoic acid binding and downstream signaling, while MLL5low blasts displayed decreased expression of epigenetic modifiers (such as KMT2C, PHF8 and ARID4A). Finally, APL xenograft transplants demonstrated improved engraftment of MLL5-expressing cells and increased myeloid differentiation over time. Concordantly, evaluation of engrafted blasts revealed increased responsiveness of MLL5-expressing cells to ATRA-induced granulocytic differentiation. Together, we describe the epigenetic changes triggered by the interaction of MLL5 and ATRA resulting in enhanced granulocytic differentiation.

New germline GATA1 variant in females with anemia and thrombocytopenia.

Familial forms of bone marrow defects are rare disorders and description of new cases are valuable opportunities to clarify the molecular machinery that triggers hematopoiesis and blood formation, as well as risk to malignant transformation. We investigated the genetic scenario and possible patterns of transmission in a rare case of familial myeloid disorder with a history of exposure to pesticides. Blood counts of two proband sisters, age 41 and 42, revealed mild anemia, neutrophilia and thrombocytopenia with bone marrow finding mimicking primary myelofibrosis in the cellular phase. We analyzed the coding regions of 78 myeloid neoplasms-related genes and 16 encoding xenobiotic metabolizing genes using Next-Generation Sequencing. The GATA1 variant c.788C > T, p.T263M, located in the C-terminal zinc finger domain of GATA1, was detected in the DNA of the two sisters. The screening of the other kindreds also revealed the p.T263M variant in the mother and two daughters with the same bone marrow disorder. This is the first report of an alteration in the GATA1 CF domain causing anemia, thrombocytopenia and megakaryocyte proliferation with mild myelofibrosis, correlating a new GATA1 germline variant with myeloid disorder.

Molecular-Based Score inspired on metabolic signature improves prognostic stratification for myelodysplastic syndrome.

Deregulated cellular energetics is formally incorporated as an emerging hallmark of cancer, however little is known about its processes in myelodysplastic syndromes (MDS). Using transcriptomic data of CD34+ cells from 159 MDS patients and 17 healthy donors, we selected 37 genes involved in cellular energetics and interrogated about its clinical and prognostic functions. Based on the low expression of ACLY, ANPEP, and PANK1, as well as high expression of PKM and SLC25A5, we constructed our Molecular-Based Score (MBS), that efficiently discriminated patients at three risks groups: favourable risk (n = 28; 3-year overall survival (OS): 100%); intermediate (n = 60; 76% [62-93%]) and adverse (n = 71; 35% [17-61%]). Adverse MBS risk was independently associated with inferior OS (HR = 10.1 [95% CI 1.26-81]; P = 0.029) in multivariable analysis using age, gender and the revised international prognostic score system as confounders. Transcriptional signature revealed that Favourable- and intermediate-risk patients presented enriched molecular programs related to mature myeloid progenitors, cell cycle progression, and oxidative phosphorylation, indicating that this cells differs in their origin, metabolic state, and cell cycle regulation, in comparison to the adverse-risk. Our study provides the first evidence that cellular energetics is transcriptionally deregulated in MDS CD34+ cells and establishes a new useful prognostic score based on the expression of five genes.