Differences in Protein Secretion by Multipotent Mesenchymal Stromal Cells Effective and Ineffective in the Prevention of Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation.

Multipotent mesenchymal stromal cells (MSC) were administered to patients after allogeneic hematopoietic stem cell transplantation to prevent the development of acute graft-versus- host disease (GVHD). The injection of MSC did not always prevent the development of GVHD. The aim of the work was to compare the secretome of MSC effective and ineffective in the prevention of GVHD. MSC were obtained from the bone marrow of hematopoietic stem cells donors. The secretome was studied using a TripleTOF 5600+ mass spectrometer with a NanoSpray III ion source coupled to a NanoLC Ultra 2D Plus nano-HPLC System. A total of 1,965 proteins were analyzed. Analysis of the secretome of effective and ineffective MSC samples revealed significant differences in the secretion of 1,119 proteins associated with ribosomes, exosomes, focal contacts, and others. Analysis of proteins secreted by MSC can be used to identify prognostically effective samples.

Expression and Intracellular Localization of Paraoxonase 2 in Different Types of Malignancies.

PON2 belongs to the paraoxonase protein family that consists of lactone hydrolyzing enzymes with different substrate specificities. Unlike other members of the family, PON2 exhibits substantial antioxidant activity, is localized predominantly inside the cell, and is ubiquitously expressed in all human tissues. Previously, it was proffered that defense against pathogens, such as Pseudomonas aeruginosa, is the main function of paraoxonases. However, recent findings have highlighted the important role played by PON2 in protection against oxidative stress, inhibition of apoptosis, and progression of various types of malignancies. In the current study, we performed a bioinformatic analysis of RNA and DNA sequencing data extracted from tumor samples taken from more than 10,000 patients with 31 different types of cancer and determined expression levels and mutations in the PON2 gene. Next, we investigated the intracellular localization of PON2 in multiple cancer cell lines and identified the proteins interacting with PON2 using the LC-MS/MS technique. Our data indicate that a high PON2 expression level correlates with a worse prognosis for patients with multiple types of solid tumors and suggest that PON2, when localized on the nuclear envelope and endoplasmic reticulum, may protect cancer cells against unfavorable environmental conditions and chemotherapy.

[Proteomic technologies for identification of serum potential biomarkers of autoimmune demyelinating polyneuropathies].

Time-of-flight MALDI mass spectrometry (MALDI-TOF-MS) profiling of blood serum of patients with Guillain-Barré syndrome (GBS, 36 samples), chronic inflammatory demyelinating polyneuropathy (CIDP, 24 samples) and practically healthy donors (HD) (35 samples) was carried out in order to identify potential biomarkers of autoimmune demyelinating polyneuropathies (ADP). To simplify the peptide-protein mixture of serum prior to MALDI-TOF-MS analysis samples were pre-fractionated on magnetic microparticles with a weak cation-exchange (MB-WCX) surface. Comparative analysis of mass spectrometric data using the classification algorithms (genetic and neural network-controlled) revealed a characteristic set of peaks, agreed change area with a high specificity and sensitivity of the differentiated mass spectrometry profiles of the blood serum of patients with DPNP and healthy donors (for GBS values of these characteristics reached 100 and 100, and for CIDP 94.1 and 100% respectively). Comparative analysis of mass spectrometric profiles of serum samples obtained from patients with GBS and CIDP, allowed to build a classification model to differentiate these diseases from each other, with a specificity of 88.9 and a sensitivity of 80%.

[Serum proteome profiling for ovarion cancer diagnosis using ClinProt magnetic bead technique and MALDI-TOF-mass-spectrometry].

Using reverse-phase (MB-HIC 8 and HB-HIC 18) weak cation exchange (MB-WCX) and metal affinity ClinProt magnetoc beads peptides and protein factions were obtained from human sera for their profiling by MALDI-TOF mass spectrometry. Proteome profiling of sera from I-IV stage ovarian cancer patients (47 women, average age 51) and from healthy women (47 subjects, average age 49) using MB-WCX beads allowed calculation of the best diagnostic models based on the Genetic Algorithm and Supervised Neural Network classifiers; these model generated 100% sensitivity and specificity when the test set of subjects was analyzed. Introduction of additional sera from patients with colorectal cancer (19) and ulcerous colitis (5) to the statistical model confirmed 100% ovarian cancer recognition. Statistical mass-spectrometry analysis of mass-spectrometry peak areas included to the diagnostic classifiers showed 3 peaks distinctive for ovarian cancer and 4 peaks distinctive for ovarian and colorectal cancer.