Identification of serum biomarkers for diagnosing stage Ⅰ lung adenocarcinoma by MALDI-TOF mass spectrometry

Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 patients with stage Ⅰ lung adenocarcinoma and 17 age-and sex-matched healthy controls,and the serum proteomic profiles were obtained by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Results Compared with healthy control group,two highly expressed potential biomarkers were identified with the relative molecular weights of 6 631.64 Da and 4 964.21 Da. The two best novel protein peaks were automatically chosen for the system training and the development of the constructed model. The constructed model was then used to test an independent set of masked serum samples from 15 lung adenocarcinoma patients and 22 healthy individuals. The analysis yielded a sensitivity of 93.3%,and a specificity of 95.5%. Conclusion These results suggest that MALDI-TOF-MS ProteinChip technology is a quick,convenient,and high-output analyzing method that is capable of selecting several relatively potential biomarkers from the serum of lung adenocarcinoma patients and may have a clinical value in the future,and will provide clues to identifying new serologic biomarkers of lung adenocarcinoma.

Establishment and Preliminary Application of Two dimensional Electrophoresis and Mass Spectrometry in Ovary Study

Objective To apply two-dimensional electrophoresis and mass spectrometry in the ovary proteome researchMethods Protein extractions from mouse ovaries were run in IPGphor isoelectric focus system with 11 cm and 24 cm IPG strips respectively (pH 3～10, 0.3 mm thick), then the protein spots were identified by mass spectrometry.Results The ovary protein exactions separated by two-dimensional electrophoresis have got high resolution, and identifing protein by mass spectrometry was highly efficient and facilitly. These two techniques should facilitate further investigation of female reproduction proteome research.Conclusion These two rapid high resolutions and efficient techniques have a variety of applications foreground in female reproduction proteome pattern research.

Diagnosis of Tumor-Like Polypoid Lesions of Gallbladder by Serum Proteomic Fingerprint

Objective： To search the specific serum proteins in tumor-like polypoid lesions of the gallbladder（PLG） patients. Methods： Surface enhanced laser desorption/ionization time of flight mass spectrometry （SELDI-TOF-MS） technique and WCX Magnetic Beads were used to detect the serum proteomic fingerprint of 23 patients with tumor-like PLG, 21 patients with non tumor-like PLG and 26 normal persons. Biomarker Wizard and Biomarker Patterns Software were used in combination to analyze the data. Results： In the preliminary screening, 22 representative specific proteins for tumor-like PLG were found. Seven specific proteins showed increased expression and 15 specific proteins showed decreased expression in the tumor-like PLG patients. Three specific proteins are selected for the diagnosis of the tumor-like PLG.. Conclusion： SELDI-TOF-MS technique can be used to select specific proteins for tumor-like PLG patients, which may be useful for the diagnosis of the tumor-like PLG and the differential diagnosis with the non tumor-like PLG.

Exact Mass Measurements for α-Allenic Alcohol by Atmospheric Pressure Chemical Ionization/Time-of-flight Mass Spectrometry

The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion mode. Polyethylene glycol (PEG) was used as the internal reference. All results were obtained under the resolution of about 5000 FWHM (full width at the half maximum). Solvent effects were studied and the satisfied results were obtained in acetonitrile. Compared with the theoretical values, all absolute errors were less than 1.0 mmu. The effects of nozzle potential, push pulse potential, pull pulse potential, pull bias potential and acquisition rate on exact mass determination were also discussed. APCI/TOF MS is proven to be a very sensitive analytical technique and an alternative ionization mode in analyzing thermally labile compounds with relatively weak polarity, such as α allenic alcohol.

Comparative Analysis of the Endosperm Proteins Separated by 2-D Electrophoresis for Two Cultivars of Hybrid Rice （Oryza sativa L,）

Liangyoupeijiu is a two-parental-line, and Shanyou63 is a three-parental-line hybrid rice （Oryza sativa L.）. Although both belong to the indica subspecies, they have obvious differences with respect to morphology, physiology and grain quality. Variations in endosperm protein compositions were studied by comparing the 2-D electrophoresis （2-DE） maps for these two cultivars of hybrid rice. After matrix-assisted laser desorption/ionization time of flight mass spectrometry （MALDI-TOF/MS） analysis, a 21-kDa precursor of 19- kDa globulin was identified as the major storage protein for both cultivars. Some isoforms of peroxiredoxin and seed maturation protein were found to only exist in Shanyou63, whereas aldose reductase and starch granule-bound starch synthase were only detected in Liangyoupeijiu. These data might provide a foundation for further comparative studies of these two cultivars of hybrid rice.

Proteomics analysis of cerebral cortex in Wistar rats

To analyze the protein expression pattern of the cerebral cortex in Wistar rats using the proteomics approach,proteins were separated by two-dimensional gel electrophoresis,stained with Coomassie brilliant blue and digested with trypsin.Then,we analyzed the peptide section using a matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS)and identified the protein by indexing special database(SwissProt)according to the finger printing of the peptide quality.Eighty-four protein spots were identified,including metabolic enzymes,skeleton proteins,heat shock proteins,antioxidant proteins,signaling proteins,proteasome related proteins,neuron and glial specific proteins and serum associated proteins.The result of this study enriches the database of the proteome in the cerebral cortex of rats and lays a foundation for further research of neurological disorders in rat models.

α2,3-Sialylation with Fucosylation Associated with More Severe Anti-MDA5 Positive Dermatomyositis Induced by Rapidly Progressive Interstitial Lung Disease

Dermatomyositis(DM)is a heterogeneous autoimmune disease associated with numerous myositis specific antibodies(MSAs)in which DM with anti-melanoma differentiation-associated gene 5-positive(MDA5+DM)is a unique subtype of DM with higher risk of developing varying degrees of Interstitial lung disease(ILD).Glycosylation is a complex posttranslational modification of proteins associated with many autoimmune diseases.However,the association of total plasma N-glycome(TPNG)and DM,especially MDA5+DM,is still unknown.TPNG of 94 DM patients and 168 controls were analyzed by mass spectrometry with in-house reliable quantitative method called Bionic Glycome method.Logistic regression with age and sex adjusted was used to reveal the aberrant glycosylation of DM and the association of TPNG and MDA5+DM with or without rapidly progressive ILD(RPILD).The elastic net model was used to evaluate performance of glycans in distinguishing RPLID from non-RPILD,and survival analysis was analyzed with N-glycoslyation score by Kaplan-Meier survival analysis.It was found that the plasma protein N-glycome in DM showed higher fucosylation and bisection,lower sialylation(α2,3-notα2,6-linked)and galactosylation than controls.In MDA5+DM,more severe disease condition was associated with decreased sialylation(specificallyα2,3-sialylation with fucosylation)while accompanying elevated H6N5S3 and H5N4FSx,decreased galactosylation and increased fucosylation and the complexity of N-glycans.Moreover,glycosylation traits have better discrimination ability to distinguish RPILD from non-RPILD with AUC 0.922 than clinical features and is MDA5-independent.Survival advantage accrued to MDA5+DM with lower N-glycosylation score(p=3e-04).Our study reveals the aberrant glycosylation of DM for the first time and indicated that glycosylation is associated with disease severity caused by ILD in MDA5+DM,which might be considered as the potential biomarker for early diagnosis of RPILD and survival evaluation of MDA5+DM.