Neural cell adhesion molecule (CD56)-positive B cell lymphoma of the urinary bladder

Re-Expression of Poly/Oligo-Sialylated Adhesion Molecules on the Surface of Tumor Cells Disrupts Their Interaction with Immune-Effector Cells and Contributes to Pathophysiological Immune Escape

Glycans linked to surface proteins are the most complex biological macromolecules that play an active role in various cellular mechanisms. This diversity is the basis of cell-cell interaction and communication, cell growth, cell migration, as well as co-stimulatory or inhibitory signaling. Our review describes the importance of neuraminic acid and its derivatives as recognition elements, which are located at the outermost positions of carbohydrate chains linked to specific glycoproteins or glycolipids. Tumor cells, especially from solid tumors, mask themselves by re-expression of hypersialylated neural cell adhesion molecule (NCAM), neuropilin-2 (NRP-2), or synaptic cell adhesion molecule 1 (SynCAM 1) in order to protect themselves against the cytotoxic attack of the also highly sialylated immune effector cells. More particularly, we focus on α-2,8-linked polysialic acid chains, which characterize carrier glycoproteins such as NCAM, NRP-2, or SynCam-1. This characteristic property correlates with an aggressive clinical phenotype and endows them with multiple roles in biological processes that underlie all steps of cancer progression, including regulation of cell-cell and/or cell-extracellular matrix interactions, as well as increased proliferation, migration, reduced apoptosis rate of tumor cells, angiogenesis, and metastasis. Specifically, re-expression of poly/oligo-sialylated adhesion molecules on the surface of tumor cells disrupts their interaction with immune-effector cells and contributes to pathophysiological immune escape. Further, sialylated glycoproteins induce immunoregulatory cytokines and growth factors through interactions with sialic acid-binding immunoglobulin-like lectins. We describe the processes, which modulate the interaction between sialylated carrier glycoproteins and their ligands, and illustrate that sialic acids could be targets of novel therapeutic strategies for treatment of cancer and immune diseases.

CD56-positive diffuse large B-cell lymphoma/leukemia with BCL6/MYC double-hit and multiple gene mutations: an indicator of poor prognosis?

Diffuse large B-cell lymphoma (DLBCL) is the most common adult non-Hodgkin lymphoma (NHL) and is highly invasive, with a poor prognosis. The main clinical treatment for DLBCL involves chemotherapy or a combination of chemotherapy and targeted drugs. CD56 expression is considered as an indicator of poor prognosis in patients with acute myeloid leukemia and anaplastic large cell lymphoma; however, its role in DLBCL remains unclear. We report on a patient with CD56-positive DLBCL/leukemia with BCL6/MYC double-hit, and DDX3X, LRP1B, SIN3A, and GNA13 gene mutations (stage IVA, prognostic index aaIPI = 2 points). The patient was treated with cyclophosphamide and prednisone pre-chemotherapy plus R-Hyper-CVAD AB and DA-EPOCH regimens. Lumbar puncture combined with intrathecal injection was performed to prevent central nervous system infiltration during hospitalization, and complete remission was confirmed. We also reviewed the literature to clarify the relevance of the unique clinical features associated with this case.