Proteomic landscape of extracellular vesicles for diffuse large b‐cell lymphoma subtyping

Funding Information: R.M. is supported by Funda??o para a Ci?ncia e a Tecnologia (CEEC position, 2019?2025 investigator). This article is a result of the projects (iNOVA4Health?UID/Multi/04462/2013), supported by Lisboa Portugal Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work is also funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT?Portuguese Foundation for Science and Technology under the projects number PTDC/BTM?TEC/30087/2017 and PTDC/BTM?TEC/30088/2017. B.C.S. is supported by the Cham-palimaud Foundation and the EMBO Installation Grant 3921. Funding Information: Funding: R.M. is supported by Fundação para a Ciência e a Tecnologia (CEEC position, 2019–2025 investigator). This article is a result of the projects (iNOVA4Health—UID/Multi/04462/2013), sup‐ ported by Lisboa Portugal Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work is also funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT—Portuguese Foundation for Science and Technology under the projects number PTDC/BTM‐TEC/30087/2017 and PTDC/BTM‐TEC/30088/2017. B.C.S. is supported by the Cham‐ palimaud Foundation and the EMBO Installation Grant 3921. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The role of extracellular vesicles (EVs) proteome in diffuse large B‐cell lymphoma (DLBCL) pathology, subclassification, and patient screening is unexplored. We analyzed by state‐of‐the‐art mass spectrometry the whole cell and secreted extracellular vesicles (EVs) proteomes of different molecular subtypes of DLBCL, germinal center B cell (GCB subtype), and activated B cell (ABC subtype). After quality control assessment, we compared whole‐cell and secreted EVs proteomes of the two cell‐of‐origin (COO) categories, GCB and ABC subtypes, resulting in 288/1115 significantly differential expressed proteins from the whole‐cell proteome and 228/608 proteins from EVs (adjust p‐value < 0.05/p‐value < 0.05). In our preclinical model system, we demonstrated that the EV prote-ome and the whole‐cell proteome possess the capacity to separate cell lines into ABC and GCB sub-types. KEGG functional analysis and GO enrichment analysis for cellular component, molecular function, and biological process of differential expressed proteins (DEP) between ABC and GCB EVs showed a significant enrichment of pathways involved in immune response function. Other enriched functional categories for DEPs constitute cellular signaling and intracellular trafficking such as B‐cell receptor (BCR), Fc_gamma R‐mediated phagocytosis, ErbB signaling, and endocyto-sis. Our results suggest EVs can be explored as a tool for patient diagnosis, follow‐up, and disease monitoring. Finally, this study proposes novel drug targets based on highly expressed proteins, for which antitumor drugs are available suggesting potential combinatorial therapies for aggressive forms of DLBCL. Data are available via ProteomeXchange with identifier PXD028267.publishersversionpublishe

Evaluating the Proliferation of Human PeripheralBlood Mononuclear Cells Using MTT Assay

Introduction: 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay is a safe, convenient, and low-cost technique with high applications for the measurement of cell proliferation rate in researches and clinical laboratories. Our aim was to evaluate the proliferation rate of human peripheral blood mononuclear cells (PBMCs) and production rate of Tumor necrosis factor alpha (TNF-α) by these cells after various mitogens stimulation in different situations. Methods: The MTT test was performed with various concentrations of mitogens including concanavalin A (ConA), lipopolysaccharide (LPS) and phytohemagglutinin (PHA) on the PBMCs. The cells were incubated for 24, 48, 72, and 96 hours in the culture medium and TNF-α cytokine assay was performed on the supernatant of the cultured splenocytes using the enzyme-linked immunosorbent assay (ELISA) method. Results: The optimal time and incubation of the PBMCs with the mixture of PHA-ConA were 5 μg/mL and 72 hours, respectively. The TNF-α level increased significantly after PHA-ConA and PHA stimulation. Conclusion: The results showed that the mixture of PHA-ConA (at the concentration of 5 μg/mL) can give rise to the optimal results on stimulation of the PBMcs using the MTT assay after 72 hours incubation

The Effects of Hypoxia on U937 Cell Line in Mesenchymal Stem Cells Co-Culture System

Purpose: Mesenchymal Stem Cells (MSCs) are the most important members of Bone Marrow (BM) milieu. MSCs affect different kinds of cells, particularly malignant cells of hematologic malignancies, but the effects of MSCs are unclear exactly. Here we analyzed the effects of derived Umbilical Cord Blood-MSCs on proliferation, cell death and some surface markers of U937 cell line in a Co-culture system with MSCs. Methods: Here we designed Co-culture systems as a model of BM milieu. We cultured U937 cells on UCB-MSCs and MSCs Conditioned Medium (C.M) driven and then treated U937 cells with optimum concentration of chloride cobalt (CoCl2) as a hypoxia-mimetic agent. In addition, we applied suitable concentrations of H2O2 to induce cell death. Proliferation rate, cell death rate and some surface markers of hypoxic U937 cells were analyzed by MTT assay, flow cytometry and Real Time-PCR were flown respectively. Results: UCB-MSCs showed supportive effects on U937 proliferation rate in normoxia and hypoxia. Lethal effect of H2O2 suppressed in the presence of UCB-MSCs in hypoxia and normoxia. Among CD11a, CD14, CD49d, CD54 and CD116 markers, CD49d was down regulated in presence of UCB-MSCs and CD116 was up regulated in hypoxia. Other markers didn’t show any significant changes. Conclusion: This work provides evidences that MSCs play critical roles in U937 cells biology. These observations shed new light on MSCs roles and demonstrated that MSCs should be regarded as an important member of BM milieu in several clinical applications such as BM transplantation prognosis and treatment of hematologic malignancies