The L265P mutation may be helpful for understanding the pathogenesis of immune-privileged site-associated DLBCLs. The presence of the mutation, together with its protein overexpression, could also be used as a prognostic marker in advanced stage DLBCLs.

No abstract

General Control Non-derepressible 5 (GCN5) and Alteration/Deficiency in Activation 2 and 3 proteins (ADA2 and ADA3, respectively) are subunits of the Histone AcetylTransferase (HAT) module of SAGA- and ATAC-type co-activators. We previously reported four new interacting partners of human ADA3 identified by screening a human fetal brain cDNA library using yeast two hybrid technology. One of these partners was Apoptosis-Antagonizing Transcription Factor (AATF), also known as Che-1, an RNA polymerase II-binding protein with a number of roles in different cellular processes including regulation of transcription, cell proliferation, cell cycle control, DNA damage responses and apoptosis. Che-1/AATF is a potential therapeutic target for cancer treatments. In this study, we aimed to identify whether besides ADA3, other components of the HAT modules of SAGA and ATAC complexes, human ADA2 and GCN5 also interact with Che-1/AATF. Co-immunoprecipitation and co-localization experiments were used to demonstrate association of AATF both with two ADA2 isoforms, ADA2A and ADA2B and with GCN5 proteins in human cells and yeast two-hybrid assays to delineate domains in the ADA2 and GCN5 proteins required for these interactions. These findings provide new insights into the pathways regulated by ADA-containing protein complexes.

BACKGROUND: Due to the heterogeneous nature of Diffuse Large B-cell Lymphoma (DLBCL), the mechanisms underlying tumor development and progression have not yet been fully elucidated. OBJECTIVE: This study aimed to compare the characteristics of plasma exosomes of DLBCL patients and healthy individuals and to evaluate the exosomal interactions between DLBCL cell lines and normal B-cells. METHODS: Exosome isolation was performed using an ultracentrifugation-based protocol from plasma of 20 patients with DLBCL and 20 controls. The expression of miRNAs from exosome samples was analyzed using a miRNA expression microarray. The presence of exosome-mediated communication between the lymphoma cells and normal B-cells was determined by the co-culture model. RESULTS: A significant increase in plasma exosome concentrations of DLBCL patients was observed. There was also a significant decrease in the expression of 33 miRNAs in plasma exosomes of DLBCL patients. It was determined that normal B-cells internalize DLBCL-derived exosomes and then miRNA expression differences observed in normal B-cells are specific to lymphoma-subtypes. CONCLUSIONS: MiR-3960, miR-6089 and miR-939-5p can be used as the miRNA signature in DLBCL diagnosis. We suppose that the exosomes changed the molecular signature of the target cells depending on the genomic characterization of the lymphoma cells they have originated.

No abstract