Potassium/sodium cation carriers robustly up-regulate CD20 antigen by targeting MYC, and synergize with anti-CD20 immunotherapies to eliminate malignant B cells.

Our investigation uncovers that nanomolar concentrations of salinomycin, monensin, nigericin, and narasin (a group of potassium/sodium cation carriers) robustly enhance surface expression of CD20 antigen in B-cell-derived tumor cells, including primary malignant cells of chronic lymphocytic leukemia and diffuse large B-cell lymphoma. Experiments in vitro, ex vivo, and animal model reveal a novel approach of combining salinomycin or monensin with therapeutic anti-CD20 monoclonal antibodies or anti-CD20 CAR-T cells, significantly improving non- Hodgkin lymphoma (NHL) therapy. The results of RNA-seq, genetic editing, and chemical inhibition delineate the molecular mechanism of CD20 upregulation, at least partially, to the downregulation of MYC, the transcriptional repressor of the MS4A1 gene encoding CD20.

CD20 expression regulates CD37 levels in B-cell lymphoma - implications for immunotherapies.

Rituximab (RTX) plus chemotherapy (R-CHOP) applied as a first-line therapy for lymphoma leads to a relapse in approximately 40% of the patients. Therefore, novel approaches to treat aggressive lymphomas are being intensively investigated. Several RTX-resistant (RR) cell lines have been established as surrogate models to study resistance to R-CHOP.

Targeting arginase-1 exerts antitumor effects in multiple myeloma and mitigates bortezomib-induced cardiotoxicity.

Multiple myeloma (MM) remains an incurable malignancy of plasma cells despite constantly evolving therapeutic approaches including various types of immunotherapy. Increased arginase activity has been associated with potent suppression of T-cell immune responses in different types of cancer. Here, we investigated the role of arginase 1 (ARG1) in Vκ*MYC model of MM in mice.

CRL4 E3 Ligase Complex as a Therapeutic Target in Multiple Myeloma.

Multiple myeloma (MM) is the second most common hematological malignancy with a recurrent clinical course. The introduction of immunomodulatory drugs (IMiDs) was one of the milestones in MM therapy leading to a significant improvement in patients' prognosis. Currently, IMiDs are the backbone of MM therapy in newly diagnosed and relapsed/refractory settings.

SARS-CoV-2 Infection in Patients Treated with Azacitidine and Venetoclax for Acute Leukemia: A Report of a Case Series Treated in a Single Institution.

Introduction: Venetoclax combined with azacitidine (AZA-VEN) constitutes an option for the treatment of acute myeloid leukemia. There are, however, no data on the COVID-19 incidence and outcome in patients treated with AZA-VEN.

Methods: Patients with acute leukemia treated with AZA-VEN at a single institution were included in this prospective observational study.

Immune checkpoint inhibition improves antimyeloma activity of bortezomib and STING agonist combination in Vk*MYC preclinical model.

Unlabelled: Multiple myeloma (MM), a hematological malignancy of plasma cells, has remained incurable despite the development of novel therapies that improve patients' outcome. Recent evidence indicates that the stimulator of interferon genes (STING) pathway may represent a novel target for induction of antitumor immune response in multiple myeloma. Here, we investigated antitumor effects of STING agonist with bortezomib with or without checkpoint inhibitor in the treatment of MM.

Bing-Neel Syndrome, a Rare Presentation of Waldenström Macroglobulinemia-A Multicenter Report by the Polish Lymphoma Research Group.

Bing-Neel syndrome (BNS) is a rare presentation of Waldenström macroglobulinemia (WM). BNS is a consequence of the central nervous system (CNS) involvement by lymphoplasmacytic lymphoma (LPL) and, rarely, the peripheral nervous system. The data on BNS are extremely scarce.

Tracking Clonal Evolution of Multiple Myeloma Using Targeted Next-Generation DNA Sequencing.

Clonal evolution drives treatment failure in multiple myeloma (MM). Here, we used a custom 372-gene panel to track genetic changes occurring during MM progression at different stages of the disease. A tumor-only targeted next-generation DNA sequencing was performed on 69 samples sequentially collected from 30 MM patients.

A Specific CD44lo CD25lo Subpopulation of Regulatory T Cells Inhibits Anti-Leukemic Immune Response and Promotes the Progression in a Mouse Model of Chronic Lymphocytic Leukemia.

Regulatory T cells (Tregs) are capable of inhibiting the proliferation, activation and function of T cells and play an important role in impeding the immune response to cancer. In chronic lymphocytic leukemia (CLL) a dysfunctional immune response and elevated percentage of effector-like phenotype Tregs have been described. In this study, using the Eµ-TCL1 mouse model of CLL, we evaluated the changes in the Tregs phenotype and their expansion at different stages of leukemia progression.

Inhibition of PIM Kinases in DLBCL Targets MYC Transcriptional Program and Augments the Efficacy of Anti-CD20 Antibodies.

The family of PIM serine/threonine kinases includes three highly conserved oncogenes, and , which regulate multiple prosurvival pathways and cooperate with other oncogenes such as . Recent genomic CRISPR-Cas9 screens further highlighted oncogenic functions of PIMs in diffuse large B-cell lymphoma (DLBCL) cells, justifying the development of small-molecule PIM inhibitors and therapeutic targeting of PIM kinases in lymphomas. However, detailed consequences of PIM inhibition in DLBCL remain undefined.

Cladribine Combined with Low-Dose Cytarabine as Frontline Treatment for Unfit Elderly Acute Myeloid Leukemia Patients: Results from a Prospective Multicenter Study of Polish Adult Leukemia Group (PALG).

Acute myeloid leukemia (AML) in older unfit patients is a therapeutic challenge for clinical hematologists. We evaluated the efficacy and safety of a novel low-intensity regimen consisting of low-dose cytarabine and cladribine (LD-AC+cladribine) in first-line treatment of elderly (≥60 years) AML patients not eligible for intensive chemotherapy (IC) who had either the Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 or the hematopoietic cell transplantation comorbidity index (HCT-CI) score ≥3. The induction phase included two cycles of LD-AC+cladribine.

The CRBN, CUL4A and DDB1 Expression Predicts the Response to Immunomodulatory Drugs and Survival of Multiple Myeloma Patients.

Immunomodulatory drugs (IMiDs) are effective in the treatment of multiple myeloma (MM), myelodysplastic syndrome with deletion of chromosome 5q and other haematological malignancies. Recent studies showed that IMiDs bind to cereblon (CRBN), a substrate receptor of the CRL4-CRBN complex, to induce the ubiquitination and degradation of IKZF1 and IKZF3 in MM cells, contributing to their anti-myeloma activity. We aimed to determine whether the CRL4-CRBN complex proteins' expression predicts the prognosis of MM patients treated with IMiDs.

SYK inhibition targets acute myeloid leukemia stem cells by blocking their oxidative metabolism.

Spleen tyrosine kinase (SYK) is an important oncogene and signaling mediator activated by cell surface receptors crucial for acute myeloid leukemia (AML) maintenance and progression. Genetic or pharmacologic inhibition of SYK in AML cells leads to increased differentiation, reduced proliferation, and cellular apoptosis. Herein, we addressed the consequences of SYK inhibition to leukemia stem-cell (LSC) function and assessed SYK-associated pathways in AML cell biology.

The impact of cytogenetic evolution and acquisition of del(17p) on the prognosis of patients with multiple myeloma.

Introduction: Prognosis of patients with newly diagnosed multiple myeloma (MM), a third most common hematological cancer, is dependent on baseline cytogenetics. However, little is known about the prognostic significance of cytogenetic evolution (CE) at the time between the diagnosis and relapse of MM.

Objectives: Here, we retrospectively analyzed the prognostic impact of CE detected in a routine interphase fluorescence in situ hybridization (FISH) test in a cohort of patients with MM.

Hepatitis B virus screening in patients with non-Hodgkin lymphoma in clinical practice in Poland - a report of the Polish Lymphoma Research Group.

Introduction: The risk of HBV reactivation is important in lymphoma patients receiving immunosuppressive chemotherapy containing steroids or anti-CD20 antibodies. We aimed to establish the prevalence of HBV Ag and anti-HBc serologic positive results in patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) in Poland before anti-CD20 therapy initiation; to assess the frequency of insufficient HBV screening; and to assess the association between inadequate HBV screening and diagnosis according to the WHO classification and age or gender.

Material And Methods: We retrospectively collected data from 805 patients with non-Hodgkin lymphoma and chronic lymphocytic leukemia treated in 2016-2018.

Decreased Activity of Blood Acid Sphingomyelinase in the Course of Multiple Myeloma.

Acid sphingomyelinase (aSMase) is involved in the generation of metabolites that function as part of the sphingolipid signaling pathway. It catalyzes the breakdown of sphingomyelin into ceramide, a bioactive lipid that, among other roles, is involved in regulation of apoptosis. Dry drop blood test (DBS) and colorimetric 2-step enzymatic assay were used to assess the activity of human blood aSMase, beta-galactosidase, and beta-glucosidase, these enzymes are lysosomal hydrolases that catalyze the degradation of related sphingolipids, of sphingolipid signaling molecules.

Inhibition of thioredoxin-dependent HO removal sensitizes malignant B-cells to pharmacological ascorbate.

L-ascorbate (L-ASC) is a widely-known dietary nutrient which holds promising potential in cancer therapy when given parenterally at high doses. The anticancer effects of L-ASC involve its autoxidation and generation of HO, which is selectively toxic to malignant cells. Here we present that thioredoxin antioxidant system plays a key role in the scavenging of extracellularly-generated HO in malignant B-cells.

FOXO1 promotes resistance of non-Hodgkin lymphomas to anti-CD20-based therapy.

Diminished overall survival rate of non-Hodgkin lymphoma (NHL) patients treated with a combination regimen of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) has been recently linked to recurrent somatic mutations activating FOXO1. Despite of the clinical relevance of this finding, the molecular mechanism driving resistance to R-CHOP therapy remains largely unknown. Herein, we investigated the potential role of FOXO1 in the therapeutic efficacy of rituximab, the only targeted therapy included in the R-CHOP regimen.

HDAC6 inhibition upregulates CD20 levels and increases the efficacy of anti-CD20 monoclonal antibodies.

Downregulation of CD20, a molecular target for monoclonal antibodies (mAbs), is a clinical problem leading to decreased efficacy of anti-CD20-based therapeutic regimens. The epigenetic modulation of CD20 coding gene () has been proposed as a mechanism for the reduced therapeutic efficacy of anti-CD20 antibodies and confirmed with nonselective histone deacetylase inhibitors (HDACis). Because the use of pan-HDACis is associated with substantial adverse effects, the identification of particular HDAC isoforms involved in CD20 regulation seems to be of paramount importance.

Selection of an optimal promoter for gene transfer in normal B cells.

Gene transfer into normal quiescent human B cells is a challenging procedure. The present study aimed to investigate whether it is possible to increase the levels of transgene expression by using various types of promoters to drive the expression of selected genes‑of‑interest. To produce lentiviral particles, the present study used the 2nd generation psPAX2 packaging vector and the vesicular stomatitis virus ‑expressing envelope vector pMD2.

Low dose of GRP78-targeting subtilase cytotoxin improves the efficacy of photodynamic therapy in vivo.

Photodynamic therapy (PDT) exerts direct cytotoxic effects on tumor cells, destroys tumor blood and lymphatic vessels and induces local inflammation. Although PDT triggers the release of immunogenic antigens from tumor cells, the degree of immune stimulation is regimen-dependent. The highest immunogenicity is achieved at sub-lethal doses, which at the same time trigger cytoprotective responses, that include increased expression of glucose-regulated protein 78 (GRP78).

Dimeric peroxiredoxins are druggable targets in human Burkitt lymphoma.

Burkitt lymphoma is a fast-growing tumor derived from germinal center B cells. It is mainly treated with aggressive chemotherapy, therefore novel therapeutic approaches are needed due to treatment toxicity and developing resistance. Disturbance of red-ox homeostasis has recently emerged as an efficient antitumor strategy.

Adenanthin targets proteins involved in the regulation of disulphide bonds.

Adenanthin has been recently shown to inhibit the enzymatic activities of peroxiredoxins (Prdx) I and II through its functional α,β-unsaturated ketone group serving as a Michael acceptor. A similar group is found in SK053, a compound recently developed by our group to target the thioredoxin-thioredoxin reductase (Trx-TrxR) system. This work provides evidence that next to Prdx I and II adenanthin targets additional proteins including thioredoxin-thioredoxin reductase system as well as protein disulfide isomerase (PDI) that contain a characteristic structural motif, referred to as a thioredoxin fold.