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Clinical Significance of Screening Serum Protein Fingerprint in Gastric Cancer

Objective To detect the serum protein fingerprint in gastric cancer patients by using the surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and protein chip array technology, screen biomarker candites, build diagnostic models and evaluate its clinical significance. Methods The serum proteomic patterns were detected in 40 patients with gastric cancer, 20 patients with gastric ulcer and 20 healthy blood donors. The diagnostic models were developed and valited by discriminant analysis. Results The peak intensity of differential expression proteins was not found in healthy blood donors, and 1 case was found in patient with gastric ulcer (m/z: 5 910,4 095). The peak intensity of 5 329, 4 095, 5 910, 8 691 and 3 300 (m/z) proteins were significantly higher in 40 gastric cancer patients than those in 20 gastric ulcer patients and 20 healthy blood donors ( P ＜0.05）. Three differential expression proteins were set up a diagnostic model together to diagnose gastric cancer. The diagnostic model made up of the differential expression proteins of 4 095, 5 910 and 8 691 had a sensitivity of 92.5% and a specificity of 97.5% . Conclusion Using SELDI-TOF-MS shows great potential to detect, and screen novel and better biomarkers for gastric cancer.

Comparative Proteome Analysis of the Serum before and after Cardiopulmonary Bypass

Abstract： Objective To study the molecular mechanism of pathologic states related to cardiopulmonary bypass (CPB) and screen the differential proteins from the serum before and after CPB in the open heart surgery patients. Methods By the twodimensional gel electrophoresis (2DE), we took the blood samples from each of the sixteen open heart surgery patients 30 minutes before CPB, 1 hour after CPB, and 24 hours after CPB. The protein spots were analyzed by the PDQuest image analysis software and the differential protein spots were identified by matrixassisted laser desorption/ionizationtime of flightmass spectrometry (MALDITOF-MS). Then, enzymelinked immunosorbent assay (ELISA) was used to determine the expression level of serum amyloid A protein (SAA) in the serum of healthy people and the enrolled patients before and after CPB. Results Through 2DE in combination with massspectrometry, 7 proteins altered in expression were identified, including SAA, haptoglobin (HPT), leucinerich alpha2-glycoprotein (A2GL), hemoglobin subunit beta (HBB), serine/threonineprotein phosphatase 2A -regulatory subunit B″ subunit gamma (P2R3C), transthyretin (TTHY), and T-complex protein 11-like protein2 (T11L2). ELISA analysis showed that SAA levels in healthy people and the open heart surgery patients 30 minutes before CPB were not statistically different (t=-1.955, P=0.056), while the SAA level rose from 54.47±48.32 μg/ml 30 min before CPB to 1 017.78±189.92 μg/ml 24 hours after CPB in the serum of open heart surgery patients． Conclusion The results of this pilot study illustrate that SAA, HPT, A2GL, HBB, P2R3C, TTHY and T11L2 may be the molecule markers of pathologic state related to CPB. Acute phase reaction happens intensively after CPB in human body.

Follow-up Analysis of Postoperative Serum Proteomic Patterns in Patients of Lung Adenocarcinoma

Objective To select relatively specific biomarkers in serum from lung adenocarcinoma patients using surface-enhanced laser desorption ionization time of flight mass spectrometry （SELDI-TOF-MS） Protein Chip technology, and study the follow-up results of postoperative serum proteomic patterns. Methods Serum samples from 71 lung adenocarcinoma patients. 71 healthy volunteers with matched gender, age and history of smoking were analyzed by using weak cation exchange 2（WCX2） Protein Chip to select potentially biomarkers. Seventy-one patients were followed-up till 9 months after surgery. Compare the serum proteomic patterns 3,6 and 9 months after surgery. Results Five highly expressed potential biomarkers were identified with the relative molecular weights of 4 047.79, 4 203. 99, 4 959. 81, 5 329. 30 and 7 760. 12 Da. The postoperative serum proteomic patterns changed among individuals, and correlated with patients＇ clinical stage. Conclusions SELDI-TOF-MS Protein Chip technology is a quick, easy, convenient, and high-throughout analyzing method capable of selecting relatively specific, potential biomarkers from the serum of lung adenocarcinoma patients and may have attractive clinical value.

ANALYSIS OF PROTEIN BAND IN PERIPHERAL NERVE REGENERATION CONDITIONEDFLUID BY SHOTGUN TECHNIQUE

Objective To study the biological activities ofthe nerve regeneration conditioned fluid (NRCF), especially to further separateand identify the protein bands of the relative molecular mass of (232-440)×103. Methods The silicone nerve regeneration chambers were implanted between the cut ends of the sciatic nerve in 6 New Zealand white rabbits (weight, 1.8-2.5 kg). The proteins in NRCF were separated by the native-polycrylamide gel electrophoresis (Native-PAGE), the protein bands of the relative molecular mass of (232-440)×103 were analyzed by the Shotgun technique, liquid chromatography, and mass spectrometry. Results The Native-PAGE result showed that there was 1 protein band of the relative molecular mass over 669×103, (232-440)×103 and (140-232)×103,respectively, and 6 bands of the relative molecular mass of (67-140)×103.Besides, 54 proteins were identified with at least 2 distinct peptides in 1 protein band of the relative molecular mass of (232-440)×103, including 4 unnamed protein products, mainly at the isoelectric points of 5.5-8.0 and of the relative molecular mass of (10-40)×103. Based on their functions in the protein database, allthe identified proteins in this study were classified into the following 5 groups: conjugated protein (43%), transport protein (30%), enzyme (6%), signal transducer (4%), and molecular function-unknown protein (17%). At the subcellular localization of the identified proteins, there was mainly a secreted protein (63%), and the remaining proteins were localized in the membrane and cytoplasm. Conclusion Native-PAGE and the Shotgun technique can effectively separate and identify proteins from NRCF, and can identify the components of the protein band of the relative molecular mass of (232-440)×103 and provide basicinformation on the unnamed protein products in NRCF.

C57小鼠视网膜蛋白质组的初步研究

Effect of Ginkgo biloba extract on protein expression in light-damaged retinal pigment epithelial cells

　　Objective　To investigate the effect and mechanism of Ginkgo biloba extract EGb761 on protein expression in lightdamaged retinal pigment epithelial (RPE) cells. Methods　The human RPE cells (ARPE19) were divided into normal control group, light damage group and EGb761 treatment group; the cells of latter 2 groups were exposed to the cold white light ［(2200 ± 300) lx］ to induce light damage responses. The lightdamaged RPE cells were treated with or without EGb761 (100 g/ml). The soluble protein of those cells were extracted and separated by twodimension electrophoresis and stained by silverstaining. Different proteins in the gel were analyzed by ImageMaster and identified by MALDITOFMS, and were further analyzed by mass spectrometry and bioinformatics.Results　ImageMaster and MALDITOFMS identified 25, 33 and 11 different proteins between light damage group and EGb761 treatment group, between normal control and light damage group, between normal control and EGb761 treatment group of RPE cells respectively. Mass spectrometry and bioinformatics analysis successfully identified 16 proteins, including metabolic enzymes, cytoskeleton proteins, antioxidation protein and other types of proteins expressed differentially．Conclusion　Protein expression profiles are different between normal control group, light damage group and Ginkgo biloba extract treatment group of RPE cells. The mechanism of protective effect of EGb761 may involve cathepsin B, heat shock protein, cytochrome C reductase, and other proteins.

Human retinal proteomics study of adults and two-month old infants

　　Objective 　To identify proteins that have expressed in human eyes from adults and two-month old infants by proteomics approach, so as to build a two-dimensional gel electrophoresis (two-DE) reference map for human retina. The difference of proteomics between the retinas of adults and two-month old infants are also studied. Methods 　Human retina tissues were collected from donor eyes (nine adults and two infants). Proteins were separated by two-DE. The gels were analyzed by image software. Protein spots were excised from the gels and detected by matrix assisted laser desorption ionization time off light mass spectrometry (MALDI-TOF-MS). Results 　A total of 1179 spots and 1295 spots were detected respectively on two-DE gels of Coomassie-stained adults and two-month old infants retina, of which 1039 spots were matched in the position. Five spots up-regulated were successfully identified. Human serum albumin and 4 guanylate kinase 1 (GUK1) were identified in adult retina. beta;2-tubulin, transaldolase1 and alpha A-crystallin were identified in infant retina. Conclusion　 The two-DE reference map for retina proteomics is successfully established. This study provides an evidence of changes in retinal protein levels between adults and infants and biochemical pathways for future studies of human retina development.

A preliminary study on the expression of proteins in light-injured retinal pigment epithelial cells by two dimensional electrophoresis

Objective To observe the expression of proteins in light-injured retinal pigment epithelial (RPE) cells. Methods ARPE19 cells were exposed to the cool white light at the intensity of (2200plusmn;300) Lx for 6 hours to set up the light injured model. Cellular soluble proteins was extracted and analyzed by means of twodimensional electrophoresis to find out the changes of protein map of lightinjured RPE cells. Results Cellular soluble proteins had (390plusmn;10) spots on the map, in which 11 spots had obvious difference between the light injured group and the normal control group. In the lightinjured cells, the expressio of 8 proteins increased, 1 decreased, and 2 disappeared. Conclusion Twodimensional electrophoresis can find out the difference of expression of proteins in lightinjured and normal RPE cells.

Experimental Study of Serum Proteomics Patterns Detected by SELDI-TOF MS in Early Diagnosis of Hepatic Fibrosis

Objective To find a new specific marker that can be used to early diagnose hepatic fibrosis by detecting the change of serum protein in patients with hepatic fibrosis. Methods This research adopted 50 SD rats (25 males and 25 females), and from which 6 rats were selected randomly (3 males and 3 females) as control group, last 44 rates were divided into four groups according to four pathological stages as hepatic fibrosis model group (experimental group). Distinct proteins in serum were detected by surface-enhanced laser desorption/ionization-time of flight-mass spectra (SELDI-TOF-MS). Radioimmunoassay was used to measure four parameters of hepatic fibrosis which were hyaluronidase (HA), precollagen Ⅲ (PCⅢ), laminin (LN) and collagen Ⅳ (Ⅳ-C). Results Distinct proteins in serum were detected in 8 cases of stage Ⅰ of hapatic fibrosis, 5 cases of stage Ⅱ, 5 cases of stage Ⅲ, 6 cases of stage Ⅳ, and 5 cases of control by SELDI-TOF-MS. Three protein peaks were found (M/Z: 4 203, 4 658, and 7 400). The peaks of M/Z 4 658 and 4 700 proteins were obviously increased in the stage Ⅰ of hepatic fibrosis （Plt;0.05）, while the changes of hepatic fibrosis four parameters appeared in stage Ⅳ of hepatic fibrosis. Conclusion This method shows great potential for early diagnosing of hepatic fibrosis and finding better biomarkers to hepatic fibrosis.

Detection of Differential Expression of Serum Protein in Peripheral Blood by SELDI-TOF-MS Technology in Cholangiocarcinoma

Objective Toa nalyzed ifferentialp roteine xpressiono fc holangiocarcinomai np eripheralb loodb yproteomics technology, and to investigate the significance of proteomics technology in early diagnosis of bile ductmalignancy.M ethods Serum proteinf rom 58p atientsw ithc holangiocarcinomaa nd5 8c ontrols( 20p atientsw ithcholecystolithiasis and 38 healthy people) were detected by surface enhanced laser desorption/ionization-time offlight-mass spectrometry (SELDI-TOF-MS). Ciphergen protein chip software was used to identify proteinic spectra.R esults Comparedw itht hes pectrao fs erum proteini nc ontrolg roup,t herew ere1 0d ifferentiallye xpressedproteins in bile duct carcinoma group, among which three proteins with relative molecular masses of 5. 900 X 10’，9.08 0X 1 0’a nd1 1.86 3X 1 0’w ereu p-regulated( Plt;1 0-’)ands evenp roteinsw ithr elativem olecularm asseso f6.9 59X 1 0’，14.0 00X 1 0’，14.1 29X 1 0’，14.3 02X 1 0’，17.5 57X 10’，17.6 90X 1 0’a nd2 8.5 52X 1 0’w ered ownregulated(Plt; 10-’)。The average concentration of protein with the relative molecular mass of 11. 863 X 10’ incholangiocarcinoma group was eight times more than that in controls group. At the stage I of cholangiocarcinoma,thee xpressiono fp roteinp ointw itha r elativem olecularm asso f5 .90 0X1 0’w ass ignificantlyh ighert hant hosep atientsat the stage III and stage fV (Plt;10-’)，while there were no statistical difference of expression between diffeent clinical stages for the other 9 proteins points. And there were no significant expression differences of the above10 proteins between the patients with and without jaundice following cholangiocarcinoma. Instead, another threeproteinsw ithr elativem olecularm asseso f7 .25 5X 1 03，12.36 4X 1 0’a nd1 5.8 73X 1 03w ered etectedt oh aved ifferentproteine xpressions.A nda llo fth em showedh ighe xpressionsin j aundiceg roup( Plt;10-5).C onclusion Thereare remarkable differences of the expressions of serum proteins in peripheral blood in patients with cholangiocarcinoma.T hep roteinp ointw itha r elativem olecularm asso f1 1.86 3X 1 0’m ayb ea p otentialb iomarkerfo re arlyd iagnosisof cholangiocarcinoma