Cell Leukemia Patients Research Articles

Survival Outcomes of Patients with Primary Plasma Cell Leukemia in the Era of Proteasome Inhibitors and Immunomodulatory Agents: A Real-Life Multicenter Analysis.

In this study, we aimed to obtain real-life data on the use of antimyeloma agents, which significantly increase overall survival (OS) in multiple myeloma (MM) patients, in primary plasma cell leukemia (pPCL) patients with a poor prognosis. Data from 53 patients who were diagnosed with pPCL between 2011-2020 and who used at least one proteasome inhibitor (PI) and/or immunomodulatory (IMID) agent were analyzed retrospectively. Depending on the year of pPCL diagnosis, 20% leukocytes or ≥2×109/L plasma cells in the peripheral blood were used. The median age of the patients was 58 years, and 23 (43.4%) patients were over 65 years of age. For first-line treatment, PI or IMID alone was used in 31 (58.5%) patients, and PI and IMID were used simultaneously in 15 (28.3%) patients. Additionally, 21 (39.6%) patients received transplantation, and 13 (24.5%) patients received maintenance treatment. The median progression-free survival was 4 (1-42) months. When patients whose primary disease was refractory to first-line therapy were excluded, the duration of treatment was 6.5 months. The median OS was 15 months, with a median follow-up of 15 months. Only 7 (13.2%) of the patients were alive at the last follow-up visit. Those with higher beta-2 microglobulin levels and ISS stage 3 and nontransplant patients receiving first-line treatment had shorter OS (p=0.005, p=0.02 and p=0.008, respectively). Otherwise, the concomitant use of PIs and IMIDs, the addition of chemotherapy to induction therapy, and the response to induction therapy or maintenance therapy did not affect OS. In our study, as in previous similar studies, we could not see the increased survival trend in pPCL which is observed in MM. New studies are needed for pPCL patients, which is likely to increase with the new diagnostic criteria, based on current agents and information in MM.

Development of a clinical prognostic model for primary plasma cell leukemia patients treated with novel agents: a multicenter retrospective cohort study.

The prognosis of primary plasma cell leukemia (pPCL) is poor, and the relevant prognostic factors are incompletely understood. We aimed to explore the prognostic factors and develop a validated prognostic prediction model for pPCL patients in the new era. This multicenter retrospective study was conducted across 16 hospitals in China. Cox proportional hazards regression analysis was used to develop a prediction model. The predictive performance of the model was assessed using multiple metrics. Internal validation was conducted using bootstrap resampling. A total of 102 pPCL patients were included in this study, and 57 (55.9%) were male. The 12-month, 24-month, and 36-month OS rates for pPCL patients were 75.4%, 58.3%, and 47.6%, respectively. An overall survival prognostic nomogram for pPCL patients was established by integrating independent prognostic factors, including age, B2MG, and del17p. The nomogram exhibited good performance, with a C-index of 0.720 (95% CI 0.642-0.797) and an AUC of 0.653. Bootstrap validation yielded a C-index of 0.721 (95% CI 0.629-0.787) and an AUC of 0.653 (95% CI 0.546-0.759), indicating a relatively good fit of the calibration curve. A nomogram incorporating age, B2MG grade, and del17p were developed and validated to accurately and consistently predict the prognosis of pPCL patients.

A Qualitative Analysis of Leukemia Fractional Order SICW Model

Using a series of fundamental differential equations, including the Caputo derivative, which makes it easier to specify the initial conditions of the differential equations, we present a fractional order concept of leukemia in this study. The universality, positivity, and boundedness of solutions are first established. The local stability properties of the equilibrium are studied using the fractional Routh-Hurwitz stability criteria. The differential equation system has been solved using unconventional finite difference techniques. The Leukemia Fractional Order SICW model introduces several innovative elements compared to traditional epidemiological and disease models. This stands out due to its integration of fractional-order differential equations, inclusion of leukemic cells and immune cells compartments, simulation of treatment strategies, consideration of waning immunity, and its application to leukemia-specific scenarios. These elements collectively make it a valuable tool for studying leukemia dynamics, exploring treatment options, and improving our understanding of how the immune system interacts with cancer cells in leukemia patients. Numerical simulations of the model are shown at the conclusion to interpret our theoretical outcomes in support of various fractional orders of derivative options. From there, we can observe how the evolution of the system components is impacted by the fractional derivative .

Evaluation of lipopolymer as therapeutic siRNA delivery agents in non-malignant and malignant primary cells.

e15189 Background: Targeting leukemia-driving oncogenes via short interfering RNA (siRNA) offers an alternative approach to leukemia treatment that can overcome the limitations of current therapies. Low molecular weight polyethyleneimine grafted with lipids (lipopolymers) have emerged as promising carriers for siRNA delivery to leukemia cells. Lipopolymers harboring select lipids were recently shown to downregulate target oncogene leading to significant anti-leukemic activity in both in vitro and in vivo cell line-based leukemia models. The goal of this study was to evaluate these lipopolymers in (i) PBMCs obtained from healthy donors to determine the potential impact on non-malignant cells, and (ii) primary leukemia patient cells to assess therapeutic efficacy. Methods: Target gene levels were determined by RT-qPCR and the effect of treatment on progenitor cells was assessed by measuring changes in colony forming ability. Results: At day 1 post-treatment, no changes in FLT3 mRNA levels were observed in all 6 PBMC samples with the 2 candidate lipopolymers (LeuFectB and LeuFectC) tested. Among 11 PBMC samples evaluated at day 2, only one sample showed a significant reduction in oncogene transcript levels on treatment with LeuFectB. The impact of lipopolymer/siRNA complex treatment on progenitor cells in the PBMC population was then assessed. Of the 7 PBMC samples tested, significant reduction in colony numbers was observed in one sample with LeuFectB and two samples with LeuFectC. On an average, the lipopolymer/siRNA complexes were well tolerated by normal healthy cells as changes observed in oncogene expression and colony forming ability were not consistent across the whole pool. Primary acute lymphoblastic leukemia (ALL) patient cells treated with complexes targeting STAT5A showed marked reduction in STAT5A transcript levels in 4 out of 7 samples with both the lipopolymers tested. The subsequent impact of STAT5A downregulation on the clonogenicity of leukemia stem cells was observed in the significant decrease in colony numbers seen in 3 samples (out of 8) with LeuFects. Additionally, combined downregulation of STAT5A and BCR-ABL genes in BCR-ABL+ ALL patient samples led to a notable decrease in cell proliferation and viability. Moreover,2 out of 3 acute myeloid leukemia (AML) patient samples harboring the FLT3-ITD mutation showed significant retardation in their colony forming ability on treatment with FLT3-targeting siRNA complexes. Collectively, the ALL and AML primary samples demonstrated promising preliminary results, suggesting a therapeutic effect on the stem cell population which is critical for mitigating relapse or prolonging remission. Conclusions: These findings provide further proof-of-concept for clinical translation of lipopolymer mediated siRNA therapy of leukemia, showing relative safety and selectivity of these lipopolymer/siRNA complexes.

Human serum albumin-based drug-free macromolecular therapeutics induce apoptosis in chronic lymphocytic leukemia patient cells by crosslinking of CD20 and/or CD38 receptors.

This study explores the efficacy of human serum albumin (HSA)-based Drug-Free Macromolecular Therapeutics (DFMT) in treating Chronic Lymphocytic Leukemia (CLL), a prevalent adult leukemia subtype. DFMT, a novel strategy, employs biomimetic crosslinking of CD20 and CD38 receptors on malignant B cells without the need for low molecular weight drugs. Apoptosis is initiated via a two-step process: i) Recognition of a bispecific engager, Fab' fragment conjugated with morpholino oligonucleotide (Fab'-MORF1), by a cell surface antigen; followed by ii) crosslinking of the MORF1-decorated cells with a multivalent effector, HSA holding multiple copies of complementary MORF2, HSA-(MORF2)x. Herein we evaluated the efficacy of HSA-based DFMT in the treatment of 56 samples isolated from patients diagnosed with CLL. Fab' fragments from Obinutuzumab (OBN) and Isatuximab (ISA) were employed in the synthesis of anti-CD20 (Fab'OBN-MORF1) and anti-CD38 (Fab'ISA-MORF1) bispecific engagers. The efficacy of DFMT was significantly influenced by the expression levels of CD20 and CD38 receptors. Dual-targeting DFMT strategies (CD20 + CD38) were more effective than single-target approaches, particularly in samples with elevated receptor expression. Pretreatment of patient cells with gemcitabine or ricolinostat markedly increased cell surface CD20 and CD38 expression, respectively. Apoptosis was effectively initiated in 62.5% of CD20-targeted samples and in 42.9% of CD38-targeted samples. Our findings demonstrate DFMT's potential in personalized CLL therapy. Further research is needed to validate these outcomes in a larger number of patient samples and to explore DFMT's applicability to other malignancies.

SMARCA5 reprograms AKR1B1-mediated fructose metabolism to control leukemogenesis

A significant variation in chromatin accessibility is an epigenetic feature of leukemia. The cause of this variation in leukemia, however, remains elusive. Here, we identify SMARCA5, a core ATPase of the imitation switch (ISWI) chromatin remodeling complex, as being responsible for aberrant chromatin accessibility in leukemia cells. We find that SMARCA5 is required to maintain aberrant chromatin accessibility for leukemogenesis and then promotes transcriptional activation of AKR1B1, an aldo/keto reductase, by recruiting transcription co-activator DDX5 and transcription factor SP1. Higher levels of AKR1B1 are associated with a poor prognosis in leukemia patients and promote leukemogenesis by reprogramming fructose metabolism. Moreover, pharmacological inhibition of AKR1B1 has been shown to have significant therapeutic effects in leukemia mice and leukemia patient cells. Thus, our findings link the aberrant chromatin state mediated by SMARCA5 to AKR1B1-mediated endogenous fructose metabolism reprogramming and shed light on the essential role of AKR1B1 in leukemogenesis, which may provide therapeutic strategies for leukemia.

Differential Expression of LMNA/C and Insulin Receptor Transcript Variants in Peripheral Blood Mononuclear Cells of Leukemia Patients.

Background: Recent research has identified alternative transcript variants of LMNA/C (LMNA, LMNC, LMNAΔ10, and LMNAΔ50) and insulin receptors (INSRs) as potential biomarkers for various types of cancer. The objective of this study was to assess the expression of LMNA/C and INSR transcript variants in peripheral blood mononuclear cells (PBMCs) of leukemia patients to investigate their potential as diagnostic biomarkers. Methods: Quantitative TaqMan reverse transcriptase polymerase chain reaction (RT-qPCR) was utilized to quantify the mRNA levels of LMNA/C (LMNA, LMNC, LMNAΔ10, and LMNAΔ50) as well as INSR (IR-A and IR-B) variants in PBMCs obtained from healthy individuals (n = 32) and patients diagnosed with primary leukemias (acute myeloid leukemia (AML): n = 17; acute lymphoblastic leukemia (ALL): n = 8; chronic myeloid leukemia (CML): n = 5; and chronic lymphocytic leukemia (CLL): n = 15). Results: Only LMNA and LMNC transcripts were notably present in PBMCs. Both exhibited significantly decreased expression levels in leukemia patients compared to the healthy control group. Particularly, the LMNC:LMNA ratio was notably higher in AML patients. Interestingly, IR-B expression was not detectable in any of the PBMC samples, precluding the calculation of the IR-A:IR-B ratio as a diagnostic marker. Despite reduced expression across all types of leukemia, IR-A levels remained detectable, indicating its potential involvement in disease progression. Conclusions: This study highlights the distinct expression patterns of LMNA/C and INSR transcript variants in PBMCs of leukemia patients. The LMNC:LMNA ratio shows promise as a potential diagnostic indicator for AML, while further research is necessary to understand the role of IR-A in leukemia pathogenesis and its potential as a therapeutic target.

Новая коронавирусная инфекция COVID-19 у пациентов с волосатоклеточным лейкозом

Aim. To analyze the characteristics of novel coronavirus infection COVID-19 in hairy cell leukemia (HCL) patients and to assess humoral immune response in those of them who had COVID-19 and/or were vaccinated against SARS-CoV-2.
 Materials & Methods. This paper documents the retrospective analysis of the data from 118 HCL patients followed-up at the National Research Center for Hematology from March 2020 to October 2021. Within this period, 99 out of 118 patients had novel coronavirus infection COVID-19; 17 out of 99 COVID-19 patients were vaccinated against SARS-CoV-2 (3 of them prior to being infected and 14 of them after that). The rest of 19 HCL patients without COVID-19 were vaccinated against SARS-CoV-2 during the period from January to October 2021. By the time of HCL diagnosis, the patients were aged 23–74 years (median 47 years), whereas by the time of COVID-19 diagnosis, the age range was 25–82 years (median 55 years). There were 63 men and 36 women.
 Results. Severe CT 3–4 lung lesions were diagnosed in 22 (22 %) patients and detected more often (55 %) prior to therapy for advanced-stage HCL. In patients on therapy for advanced-stage HCL and those in remission, the rate of severe lung lesions (CT 3–4) was 17 % in each group. COVID-19 therapy was administered to 49 (49 %) patients in a special hospital. Mortality in the total cohort was 6 % (n = 6) and differed in patients with advanced-stage HCL (n = 4) and those in remission (n = 2). The patients who received anti-CD20 monoclonal antibodies for < 12 months prior to COVID-19 infection, in 42 % (n = 5) of cases showed seronegativity vs. 5 % (n = 1) of patients who received the same therapy > 12 months before COVID-19 was diagnosed.
 Conclusion. The most severe COVID-19 was observed in chemotherapy-free patients with advanced-stage HCL compared to patients on therapy or in HCL remission. When anti-CD20 monoclonal antibodies were administered for < 12 months prior to COVID-19 diagnosis, the number of patients with negative anti-SARS-CoV-2-IgG immune response increased 15-fold. Mortality in novel coronavirus infection COVID-19 differed at various HCL stages (in remission and at advanced stage).

Long term follow-up of refractory/relapsed hairy cell leukaemia patients treated with low-dose vemurafenib between 2013 and 2022 at the Department of Internal Medicine and Oncology, Semmelweis University.

Introduction: Hairy cell leukemia (HCL) is an indolent B-cell lymphoproliferative disease. BRAF V600E mutation is detected in nearly all classical HCL cases which offers the possibility of targeted therapy. Objective: The aim of our study was to assess the efficacy of low-dose vemurafenib as well as to assess the long term outcome of HCL patients treated with this drug at the Department of Internal Medicine and Oncology at Semmelweis University. Methods: We report on 10 patients with classical HCL treated with low-dose vemurafenib at our Department between 2013 and 2022. Results: As a result of fixed time low-dose vemurafenib treatment, 5 of 10 patients (5/10) achieved partial remission, 4 (4/10) had stable disease, and 1 (1/10) had MRD positivity. No patients achieved complete remission. The median progression-free survival was 28.5months while the overall survival was 82months. Conclusion: We confirm that low dose of vemurafenib is effective and safe in the vast majority of patients with HCL. This small-molecule oral treatment allows to gain valuable time-months or even years-before further, usually parenteral treatment options have to be given or before previous treatment has to be repeated. There are also promising data supporting the combination of vemurafenib with other drugs for the treatment of HCL patients which could provide even further possibility to bridge treatment.

Evaluation of the safety and efficiency of cytotoxic T cell therapy sensitized by tumor antigens original from T-ALL-iPSC in vivo.

Since RNA sequencing has shown that induced pluripotent stem cells (iPSCs) share a common antigen profile with tumor cells, cancer vaccines that focus on iPSCs have made promising progress in recent years. Previously, we showed that iPSCs derived from leukemic cells of patients with primary T cell acute lymphoblastic leukemia (T-ALL) have a gene expression profile similar to that of T-ALL cell lines. Mice with T-ALL were treated with dendritic and T (DC-T) cells loaded with intact and complete antigens from T-ALL-derived iPSCs (T-ALL-iPSCs). We evaluated the safety and antitumor efficiency of autologous tumor-derived iPSC antigens by flow cytometry, cytokine release assay, acute toxicity experiments, long-term toxicity experiments, and other methods. Our results indicate that complete tumor antigens from T-ALL-iPSCs could inhibit the growth of inoculated tumors in immunocompromised mice without causing acute and long-term toxicity. T-ALL-iPSC-based treatment is safe and can be used as a potential strategy for leukemia immunotherapy.

Single-agent rituximab is an effective salvage therapy in pretreated patients with hairy cell leukemia

Single-agent rituximab can be a suitable treatment in hairy cell leukemia (HCL) patients relapsing after repeated courses of purine analogs, if purine analogs are contraindicated (e.g. in case of poor marrow cellularity, high disease infiltration predicting long-lasting aplasia) and if newer agents (moxetumomab or vemurafenib) are not easily available. Our institutional series of patients receiving single-agent rituximab as salvage therapy was reviewed. Patients received rituximab at the standard dose of 375 mg/m2 weekly for 4 weeks. The main study objectives were overall response rate (ORR), time-to-next treatment (TTNT), progression-free survival (PFS) and overall survival (OS). Responses have been categorized according to the Consensus Resolution Criteria. Thirty-three patients received 39 courses of rituximab (4 patients received it twice, one patient three times), as a median third line of therapy (range 2-8). Out of 39 courses, a complete response was obtained in 28.2% of cases, a partial response in 23.1% and a minimal response in 20.5%. In 28.2% of patients, we observed no response. Median TTNT was 33 months (65% at 2 years), median PFS was 24 months (51% at 2 years) and median OS resulted of 154 months (22% at 20 years). To our knowledge, this is the widest series of HCL patients receiving single-agent rituximab for disease relapse. Rituximab is an effective salvage therapy in pretreated HCL patients after failure of purine analogs. It may be repeated if no alternatives are available.

GPER1 Activation Exerts Anti-Tumor Activity in Multiple Myeloma.

G protein-coupled estrogen receptor 1 (GPER1) activation is emerging as a promising therapeutic strategy against several cancer types. While GPER targeting has been widely studied in the context of solid tumors, its effect on hematological malignancies remains to be fully understood. Here, we show that GPER1 mRNA is down-regulated in plasma cells from overt multiple myeloma (MM) and plasma cell leukemia patients as compared to normal donors or pre-malignant conditions (monoclonal gammopathy of undetermined significance and smoldering MM); moreover, lower GPER1 expression associates with worse overall survival of MM patients. Using the clinically applicable GPER1-selective agonist G-1, we demonstrate that the pharmacological activation of GPER1 triggered in vitro anti-MM activity through apoptosis induction, also overcoming the protective effects exerted by bone marrow stromal cells. Noteworthy, G-1 treatment reduced in vivo MM growth in two distinct xenograft models, even bearing bortezomib-resistant MM cells. Mechanistically, G-1 upregulated the miR-29b oncosuppressive network, blunting an established miR-29b-Sp1 feedback loop operative in MM cells. Overall, this study highlights the druggability of GPER1 in MM, providing the first preclinical framework for further development of GPER1 agonists to treat this malignancy.

Single‐agent rituximab as an effective salvage therapy in pre‐treated hairy cell leukemia

Introduction: Hairy cell leukemia (HCL) patients usually experience multiple disease relapses during the course of their disease. The CD20 antigen is highly expressed on the surface of hairy cells. Single-agent rituximab can be a suitable treatment options in patients relapsing after repeated courses of purine analogs, if purine analogs are contraindicated (e.g., in case of poor bone marrow cellularity, high disease infiltration predicting long-lasting aplasia), especially if newer agents (such as moxetumomab or vemurafenib) are not easily available (as it happens in several countries). Methods: Our institutional series of HCL patients receiving single-agent rituximab as salvage therapy was retrospectively reviewed. Patients received rituximab at the standard dose of 375 mg/m2 weekly for 4 weeks. The main study objectives were overall response rate (ORR), time-to-next treatment (TTNT), progression-free survival (PFS) and overall survival (OS). Responses have been categorized according to the Consensus Resolution Criteria. Results: Thirty-three patients received 39 courses of rituximab (4 patients received it twice, one patient three times), in median as third line of therapy (range 2–8). First rituximab was given at a median age of 61 years and at a median time from disease diagnosis of 65 months. Out of 39 courses, a complete response was obtained in 28.2% of cases, a partial response in 23.1% and a minimal response in 20.5%, yielding an ORR of 71.8%. In 28.2% of patients, we observed no response. Median TTNT was reached at 33 months (65% at 2 years), while median PFS was reached at 24 months (51% at 2 years). Median OS resulted of 154 months (22% at 20 years). Among the 5 patients receiving rituximab more than once, all responded after the first course, although the ORR after the second or later course was only 50%. Median TTNT following the first rituximab was 38.5 months in these patients, ranging from 15 to 205 months. Keywords: Immunotherapy, Lymphoid Cancers No conflicts of interests pertinent to the abstract.

Targeting MYC in combination with epigenetic regulators induces synergistic anti-leukemic effects in MLLr leukemia and simultaneously improves immunity

MLL rearranged (MLLr) leukemias are associated with a poor prognosis and a limited response to conventional therapies. Moreover, chemotherapies result in severe side effects with significant impairment of the immune system. Therefore, the identification of novel treatment strategies is mandatory.Recently, we developed a human MLLr leukemia model by inducing chromosomal rearrangements in CD34+ cells using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9. This MLLr model authentically mimics patient leukemic cells and can be used as a platform for novel treatment strategies. RNA sequencing of our model revealed MYC as one of the most important key drivers to promote oncogenesis. However, in clinical trials the BRD4 inhibitor JQ-1 leading to indirect blocking of the MYC pathway shows only modest activity. We and others previously reported that epigenetic drugs targeting MAT2A or PRMT5 promote cell death in MLLr cells. Therefore, we use these drugs in combination with JQ-1 leading to augmented anti-leukemic effects. Moreover, we found activation of T, NK and iNKT cells, release of immunomodulatory cytokines and downregulation of the PD-1/PD-L1 axis upon inhibitor treatment leading to improved cytotoxicity.In summary, the inhibition of MYC and MAT2A or PRMT5 drives robust synergistic anti-leukemic activity in MLLr leukemia. Moreover, the immune system is concomitantly activated upon combinatorial inhibitor treatment, hereby further augmenting the therapeutic efficiency.

B cell leukemia elicits a suppressive Tr1-like CD4 T cell response that can be reversed with anti-PDL1-blockade

Abstract CD4 T cell exhaustion is associated with relapse in B cell leukemia (B-ALL) patients. However, checkpoint blockade is not effective in treating B-ALL. Using a murine model of B-ALL, we demonstrate that leukemia induced CD4 T cells had a unique regulatory-cytotoxic phenotype (T rctx) with preferential expression of exhaustion markers (PD1/TIM3) as well as IL10 and c-Maf, which are markers of immunosuppressive Tr1 cells. Leukemia cells acting as APCs elicited CD4 T cells with a similar Tr1 phenotype that suppressed bystander T cells. This process mimics the mechanism by which hematopoietic stem cells (HSC) enforce an immunosuppressive niche in the bone marrow that protects the HSC compartment. Anti-PDL1 ornilotinib (targeted therapy) treatment alone had a minimal impact on survival; concurrent treatment with anti-PDL1 andnilotinib had a significant synergistic effect that was dependent on CD4 and CD8 T cells. Nilotinib treatment increased markers of helper and regulatory function in the T rctxcells. In contrast, treatment with nilotinib andanti-PDL1 induced expansion of a leukemia-specific CD4 T cell clone with lower expression of Tr1 markers and higher expression of helper molecules that facilitate recruitment and activation of anti-tumor immune cells. Expansion of the helper-cytotoxic (T hctx) CD4 T cell clone was associated with increased GzmB +CD8 T cells. We propose that leukemia coopts a naturally occurring process designed to protect the HSC niche, thereby inducing T rctxcells that drive escape from immune surveillance. Combining nilotinib and anti-PDL1 alters the balance between immunosuppressive T rctxand immune-activating T hctx, thereby inducing a protective anti-leukemia immune response that prevents relapse. Spatial Transcriptomics Award from the University of Minnesota, Children's Cancer Research Fund

Subcutaneous and Intravenous Cladribine Treatment of Hairy Cell Leukemia Patients: Do We Still Need Intravenous Cladribine?

Background Hairy cell leukemia (HCL) is an uncommon neoplasm representing approximately 2% leukemias and

Abstract NG14: Dissecting immune microenvironment of T-cell acute lymphoblastic leukemia

Abstract NG14: Dissecting immune microenvironment of T-cell acute lymphoblastic leukemia

CLL stereotyped B-cell receptor immunoglobulin sequences are recurrent in the B-cell repertoire of healthy individuals: Apparent lack of central and early peripheral tolerance censoring.

The leukemic cells of patients with chronic lymphocytic leukemia (CLL) are often unique, expressing remarkably similar IGHV-IGHD-IGHJ gene rearrangements, "stereotyped BCRs". The B-cell receptors (BCRs) on CLL cells are also distinctive in often deriving from autoreactive B lymphocytes, leading to the assumption of a defect in immune tolerance. Using bulk and single-cell immunoglobulin heavy and light chain variable domain sequencing, we enumerated CLL stereotype-like IGHV-IGHD-IGHJ sequences (CLL-SLS) in B cells from cord blood (CB) and adult peripheral blood (PBMC) and bone marrow (BM of healthy donors. CLL-SLS were found at similar frequencies among CB, BM, and PBMC, suggesting that age does not influence CLL-SLS levels. Moreover, the frequencies of CLL-SLS did not differ among B lymphocytes in the BM at early stages of development, and only re-circulating marginal zone B cells contained significantly higher CLL-SLS frequencies than other mature B-cell subpopulations. Although we identified CLL-SLS corresponding to most of the CLL major stereotyped subsets, CLL-SLS frequencies did not correlate with those found in patients. Interestingly, in CB samples, half of the CLL-SLS identified were attributed to two IGHV-mutated subsets. We also found satellite CLL-SLS among the same normal samples, and they were also enriched in naïve B cells but unexpectedly, these were ~10-fold higher than standard CLL-SLS. In general, IGHV-mutated CLL-SLS subsets were enriched among antigen-experienced B-cell subpopulations, and IGHV-unmutated CLL-SLS were found mostly in antigen-inexperienced B cells. Nevertheless, CLL-SLS with an IGHV-mutation status matching that of CLL clones varied among the normal B-cell subpopulations, suggesting that specific CLL-SLS could originate from distinct subpopulations of normal B cells. Lastly, using single-cell DNA sequencing, we identified paired IGH and IGL rearrangements in normal B lymphocytes resembling those of stereotyped BCRs in CLL, although some differed from those in patients based on IG isotype or somatic mutation. CLL-SLS are present in normal B-lymphocyte populations at all stages of development. Thus, despite their autoreactive profile they are not deleted by central tolerance mechanisms, possibly because the level of autoreactivity is not registered as dangerous by deletion mechanisms or because editing of L-chain variable genes occurred which our experimental approach could not identify.

Promoter methylation might shift the balance of Galectin-3 & 12 expression in de novo adult acute myeloid leukemia patients.

Acute myeloid leukemia (AML) was reported as the most common type of leukemia among adults. Galectins constitute a family of galactose-binding proteins reported to play a critical role in many malignancies including AML. Galectin-3 and -12 are members of the mammalian galectin family. To understand the contribution of galectin-3 and -12 promoter methylation to their expression, we performed bisulfite methylation-specific (MSP)-PCR and bisulfite genomic sequencing (BGS) of primary leukemic cells in patients with de novo AML before receiving any therapy. Here, we show a significant loss of LGALS12 gene expression in association with promoter methylation. The lowest degree of expression was found in the methylated (M) group while the highest degree was in the unmethylated (U) group and the partially methylated (P) group expression lies in between. This was not the case with galectin-3 in our cohort unless the CpG sites analyzed were outside the frame of the studied fragment. We were also able to identify four CpG sites (CpG number 1, 5, 7& 8) in the promoter region of galectin-12; these sites must be unmethylated so that expression can be induced. As far as the authors know, these findings were not previously concluded in earlier studies.

Meta-analysis of the Prognostic Value of microRNA-22 in Leukemia Patients.

Objective: The pathogenesis of leukemia is complex and there are no effective diagnostic and prognostic indicators. Previous studies showed that microRNA-22 (miR-22) has altered expression level in multiple leukemia subtypes, which is associated with the survival outcomes of leukemia. Methods: According to the constituted retrieval strategy, eligible studies were included from January 2010 to November 2022 by searching database. The pooled Risk Ratio (RR) and 95% confidence intervals (CI) were used to study the relationship between miR-22 and survival. Stata12.0 was used for meta-analysis. Differential expression analysis was conducted based on expression profile of miRNA. Results: Four English articles were included containing a total of 215 leukemia patients. Data showed that the pooled RR for overall survival (OS) was 1.558 (95% CI: 1.197-2.028, P < .01). Subgroup analysis for OS of acute myeloid leukemia patients and the RFS of plasma cell leukemia patients were statistically significant with different expression levels of miR-22 (RR:1.495, 95%CI:1.141-1.958, P < .01 and RR:1.517, 95%CI:1.114-2.065, P < .01, respectively). Moreover, all data included had no significant heterogeneity and publication bias. Conclusions: miR-22 is associated with the survival outcome of leukemia patients suggesting that miR-22 may be a promising prognostic biomarker for this patient population, and the expression level of miR-22 in ALL patients down-regulated.