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.

Asciminib stands out as the superior tyrosine kinase inhibitor to combine with anti-CD20 monoclonal antibodies for the treatment of CD20 Philadelphia-positive B-cell precursor acute lymphoblastic leukemia in preclinical models.

Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (Ph+ BCP-ALL) is a high-risk subtype of acute lymphoblastic leukemia characterized by the presence of the BCR::ABL1 fusion gene. Tyrosine kinase inhibitors (TKI) combined with chemotherapy are established as the first-line treatment. Additionally, rituximab, an anti-CD20 monoclonal antibody is administered to adult BCP-ALL patients with ≥20% CD20+ blasts.

Concomitant inhibition of the thioredoxin system and nonhomologous DNA repair potently sensitizes Philadelphia-positive lymphoid leukemia to tyrosine kinase inhibitors.

Breakpoint cluster region-Abelson () gene fusion is an essential oncogene in both chronic myeloid leukemia (CML) and Philadelphia-positive (Ph) B-cell acute lymphoblastic leukemia (B-ALL). While tyrosine kinase inhibitors (TKIs) are effective in up to 95% of CML patients, 50% of Ph B-ALL cases do not respond to treatment or relapse. This calls for new therapeutic approaches for Ph B-ALL.

Efficient chimeric antigen receptor targeting of a central epitope of CD22.

Chimeric antigen receptor (CAR) T-cell therapy has had considerable success in the treatment of B-cell malignancies. Targeting the B-lineage marker CD19 has brought great advances to the treatment of acute lymphoblastic leukemia and B-cell lymphomas. However, relapse remains an issue in many cases.

CAR-T Cells Shoot for New Targets: Novel Approaches to Boost Adoptive Cell Therapy for B Cell-Derived Malignancies.

Chimeric antigen receptor (CAR)-T cell therapy is undeniably a promising tool in combating various types of hematological malignancies. However, it is not yet optimal and a significant number of patients experience a lack of response or relapse after the treatment. Therapy improvement requires careful analysis of the occurring problems and a deeper understanding of the reasons that stand behind them.

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.

Potent, p53-independent induction of NOXA sensitizes MLL-rearranged B-cell acute lymphoblastic leukemia cells to venetoclax.

The prognosis for B-cell precursor acute lymphoblastic leukemia patients with Mixed-Lineage Leukemia (MLL) gene rearrangements (MLLr BCP-ALL) is still extremely poor. Inhibition of anti-apoptotic protein BCL-2 with venetoclax emerged as a promising strategy for this subtype of BCP-ALL, however, lack of sufficient responses in preclinical models and the possibility of developing resistance exclude using venetoclax as monotherapy. Herein, we aimed to uncover potential mechanisms responsible for limited venetoclax activity in MLLr BCP-ALL and to identify drugs that could be used in combination therapy.

Mechanisms of Immune Evasion in Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) results from a clonal expansion of abnormal lymphoid progenitors of B cell (BCP-ALL) or T cell (T-ALL) origin that invade bone marrow, peripheral blood, and extramedullary sites. Leukemic cells, apart from their oncogene-driven ability to proliferate and avoid differentiation, also change the phenotype and function of innate and adaptive immune cells, leading to escape from the immune surveillance. In this review, we provide an overview of the genetic heterogeneity and treatment of BCP- and T-ALL.

Philadelphia Chromosome-Positive Leukemia in the Lymphoid Lineage-Similarities and Differences with the Myeloid Lineage and Specific Vulnerabilities.

Philadelphia chromosome (Ph) results from a translocation between the breakpoint cluster region () gene on chromosome 9 and ABL proto-oncogene 1 () gene on chromosome 22. The fusion gene, , is a constitutively active tyrosine kinase which promotes development of leukemia. Depending on the breakpoint site within the gene, different isoforms of BCR-ABL1 exist, with p210 and p190 being the most prevalent.

Inhibition of IDO leads to IL-6-dependent systemic inflammation in mice when combined with photodynamic therapy.

It was previously reported that the activation of antitumor immune response by photodynamic therapy (PDT) is crucial for its therapeutic outcome. Excessive PDT-mediated inflammation is accompanied by immunosuppressive mechanisms that protect tissues from destruction. Thus, the final effect of PDT strongly depends on the balance between the activation of an adoptive arm of immune response and a range of activated immunosuppressive mechanisms.

Harnessing altered oxidative metabolism in cancer by augmented prooxidant therapy.

Deregulated metabolism of oxygen with increased generation of reactive oxygen species (ROS) is characteristic for a majority of cancers. The elevated ROS levels are in part responsible for further progression of cancer, but when produced in large excess, they endanger the viability of the cancer cells. To protect themselves from ROS-mediated toxicity, many types of cancers enhance the intrinsic antioxidant defenses, which make them dependent on the efficacy of a given ROS-detoxifying system.

Targeting the thioredoxin system as a novel strategy against B-cell acute lymphoblastic leukemia.

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a genetically heterogeneous blood cancer characterized by abnormal expansion of immature B cells. Although intensive chemotherapy provides high cure rates in a majority of patients, subtypes harboring certain genetic lesions, such as MLL rearrangements or BCR-ABL1 fusion, remain clinically challenging, necessitating a search for other therapeutic approaches. Herein, we aimed to validate antioxidant enzymes of the thioredoxin system as potential therapeutic targets in BCP-ALL.

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.

Typical and Atypical Inducers of Lysosomal Cell Death: A Promising Anticancer Strategy.

Lysosomes are conservative organelles with an indispensable role in cellular degradation and the recycling of macromolecules. However, in light of recent findings, it has emerged that the role of lysosomes in cancer cells extends far beyond cellular catabolism and includes a variety of cellular pathways, such as proliferation, metastatic potential, and drug resistance. It has been well described that malignant transformation leads to alterations in lysosomal structure and function, which, paradoxically, renders cancer cells more sensitive to lysosomal destabilization.

Long-lasting reduction in clonogenic potential of colorectal cancer cells by sequential treatments with 5-azanucleosides and topoisomerase inhibitors.

Background: The currently approved therapies fail in a substantial number of colorectal cancer (CRC) patients due to the molecular heterogeneity of CRC, hence new efficient drug combinations are urgently needed. Emerging data indicate that 5-azanucleosides are able to sensitize cancer cells to the standard chemotherapeutic agents and contribute to overcoming intrinsic or acquired chemoresistance.

Methods: CRC cells with different genetic backgrounds (HCT116, DLD-1, HT-29) were sequentially treated with 5-azanucleosides and topoisomerase inhibitors.

β-caryophyllene and β-caryophyllene oxide-natural compounds of anticancer and analgesic properties.

Natural bicyclic sesquiterpenes, β-caryophyllene (BCP) and β-caryophyllene oxide (BCPO), are present in a large number of plants worldwide. Both BCP and BCPO (BCP(O)) possess significant anticancer activities, affecting growth and proliferation of numerous cancer cells. Nevertheless, their antineoplastic effects have hardly been investigated in vivo.