Expression Of Serum Proteins In Patients Research Articles

MGMT ProFWise: Unlocking a New Application for Combined Feature Selection and the Rank-Based Weighting Method to Link MGMT Methylation Status to Serum Protein Expression in Patients with Glioblastoma.

Glioblastoma (GBM) is a fatal brain tumor with limited treatment options. O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status is the central molecular biomarker linked to both the response to temozolomide, the standard chemotherapy drug employed for GBM, and to patient survival. However, MGMT status is captured on tumor tissue which, given the difficulty in acquisition, limits the use of this molecular feature for treatment monitoring. MGMT protein expression levels may offer additional insights into the mechanistic understanding of MGMT but, currently, they correlate poorly to promoter methylation. The difficulty of acquiring tumor tissue for MGMT testing drives the need for non-invasive methods to predict MGMT status. Feature selection aims to identify the most informative features to build accurate and interpretable prediction models. This study explores the new application of a combined feature selection (i.e., LASSO and mRMR) and the rank-based weighting method (i.e., MGMT ProFWise) to non-invasively link MGMT promoter methylation status and serum protein expression in patients with GBM. Our method provides promising results, reducing dimensionality (by more than 95%) when employed on two large-scale proteomic datasets (7k SomaScan® panel and CPTAC) for all our analyses. The computational results indicate that the proposed approach provides 14 shared serum biomarkers that may be helpful for diagnostic, prognostic, and/or predictive operations for GBM-related processes, given further validation.

Proteomic analysis of differentially expressed proteins in the serum of patients with acute renal allograft rejection using iTRAQ labelling technology.

Transplantation is currently the best treatment for patients with end-stage renal disease. However, acute rejection (AR) is the major source of failure in renal transplantation. The current best practice for the diagnosis of AR involves renal biopsy, but it is invasive, time-consuming, costly and inconvenient. Sensitive and less invasive detection of AR episodes in renal transplant patients is essential to preserve allograft function. The present study applied isobaric tags for relative and absolute quantitation (iTRAQ) mass spectrometry to analyze serum protein expression in patients with AR and healthy controls. Overall, 1,399 proteins were identified. Using a cut-off of Q<0.05 and a fold change of >1.2 for the variation in expression, 109 proteins were identified to be differentially expressed between the AR and control groups, 72 of which were upregulated and 37 were downregulated. Several proteins, including properdin, keratin 1, lipoprotein(a) and vitamin D-binding protein, may have roles in the pathogenesis of AR. The present study focused on iTRAQ-based proteomic profiling of serum samples in AR. Insight from the present study may help advance the understanding of the molecular mechanisms of AR and identify potential novel biomarkers of AR for further characterization.

P129 Differential serum protein expression in patients with clinical vs subclinical antibody-mediated rejection

P129 Differential serum protein expression in patients with clinical vs subclinical antibody-mediated rejection

Application of protein chip combined with SELDI-TOF-MS detection to investigate serum protein expression in patients with silicosis fibrosis.

The present study aimed to observe the identification of biomarkers of silicosis based on the differentially expressed serum proteins between normal healthy individuals and patients with silicosis fibrosis. A total number of 20 patients with clinically diagnosed silicosis were screened, which were designated as the foundation treatment group. In addition, 20 age-matched healthy patients attending a check-up at the physical examination department were selected. Serum samples were obtained and a combined protein chip with surface-enhanced laser desorption ionization flight mass spectrometry was applied to perform serum analysis. Data preprocessing, screening differences in peak, hierarchical cluster analysis, Principal Component Analysis, construction of a decision tree model, and prediction based on the differences between peaks corresponding to proteins were performed to analyze the data. The results revealed differences in the proteins in serum between the normal group and the group prior to foundation treatment prediction. The corresponding names of the protein peak, predicted protein, and gene name were as follows: M1948_00, complement c3 frag, C3; M2017_02, amyloid-βa4 protein, APP; and M2879_56, hepcidin, HAMP. Differentially expressed serum proteins in the normal group and the basis treatment group were predicted, including M2017_02, amyloid-βa4 protein, APP; M2879_56, hepcidin, HAMP; and M3224_97, fibrinogen-α chain frags, FGA. The differentially expressed serum proteins in the group prior to basis treatment and the group following basis treatment were predicted, including M2001_69, amyloid-βa4 protein, APP; M2017_02, amyloid-βa4 protein, APP, M4144_81, plasma protease c1 inhibitor frag, and SERPING1. In conclusion, there were differences in the proteins in serum between the patients with silicosis fibrosis and healthy individuals.

Serum proteomic analysis after laparoscopic gastrointestinal surgery for the treatment of type 2 diabetes mellitus

Objective To investigate the impact of laparoscopic gastrointestinal surgery on serum protein expression in patients with type 2 diabetes mellitus(T2DM).Methods Twelve patients with T2DM received gastrointestinal surgery at Changhai Hospital of the Second Medical University from June 2008 to September 2010.Their serum samples were collected at different time points(before surgery,1 week and 1 month after surgery).Total proteins were seperated by two-dimensional(2D)gel electrophoresis.The differentially expressed proteins were analyzed by mass spectrometry and bioinformatics.Results Protein extracts of the serum samples were separated on 2D gels successfully.Twenty differentially expressed proteins in the serum after surgery were screened out.Eight proteins were successfully identified,in which the expression of 5 proteins(Rho GDP-dissociation inhibitor 1,Prohibitin,Alpha-1-anfitrypsin precursor,Serotransferrin precursor and Fibrinogen gamma chain precursor)was increased after operation,and the expression of 3 proteins(MAP3K12-binding inhibitory protein 1,Coronin-1A and Isovalery1-COA dehydrogenase) was decreased.Conclusions The expression of 20 proteins have been changed significantly in serum samples after laparoscopic gastrointestinal surgery in patients with T2DM,and 8 proteins were successfully identified. Key words: Diabetes mellitus,type 2; Gastrointestinal surgery; Laparoscopy; Proteome; Twodimensional gel electrophoresis