ag-879 and Lymphoma--Large-B-Cell--Diffuse

Neurotrophin receptor signaling has been increasingly recognized as an important factor in the development and progression of a variety of malignancies. In order to analyze the potential contribution of neurotrophin signaling to lymphoma cell survival, we investigated the role of a neurotrophin axis in promoting survival and proliferation of non-Hodgkin lymphoma (NHL) cells.. The role of neurotrophins in the survival and proliferation of NHL cells was determined by exposing cells to the Trk-specific inhibitor, K252a, and then performing (3)H-thymidine incorporation and Annexin-V/propidium iodide staining. The involvement of nuclear factor-kappaB (NF-kappaB) in this process was studied using Western blot, electrophoretic mobility shift assay, and immunofluorescence assays.. Here we demonstrate that both primary NHL cells and diffuse large B-cell lymphoma cell lines express Trk receptors and their neurotrophin ligands. Furthermore, these cells are sensitive to the Trk-specific inhibitor, K252a, as evidenced by the inhibition of proliferation and/or induction of apoptosis. Analysis of the mechanism into the effects of K252a revealed that, in the OCI-LY3 cell line, K252a induced a subnuclear distribution of NF-kappaB resulting in the sequestration of RelA in the nucleolus, thereby inhibiting NF-kappaB-dependent gene transcription. This results in the loss of interleukin-6 production; a known survival-promoting signal for OCI-LY3, as well as many primary diffuse large B-cell lymphomas.. Thus, Trk receptors represent a novel therapeutic target for the treatment of NHL.

Topics: Apoptosis; Autocrine Communication; B-Lymphocytes; Brain-Derived Neurotrophic Factor; Carbazoles; Cell Division; Cell Line, Tumor; Culture Media, Conditioned; DNA Replication; Humans; Indole Alkaloids; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Neoplasm Proteins; Nerve Growth Factor; Nerve Growth Factors; NF-kappa B; Receptors, Nerve Growth Factor; RNA, Messenger; RNA, Neoplasm; Signal Transduction; Tyrphostins