OBJECTIVE: To search for the differentially expressed proteins of nasopharyngeal carcinoma (NPC),and provide scientific evidence for identifying molecular biomarkers for NPC. METHODS: Laser capture microdissection (LCM) was used to purify the target cells from NPC and normal nasopharyngeal epithelial tissues (NNET). Two-dimensional gel electrophoresis (2-DE) was used to separate the total proteins of microdissected NPC and NNET, PDQuest software was applied to analyze 2-DE images,and the differential proteins between the 2 types of tissues were identified by both MALDI-TOF-MS and ESI-Q-TOF-MS. Western blot and immunohistochemistry of tissue microarray were used to detect the expression of the differential protein SCCA1 in NPC and NNET. RESULTS: 2-DE patterns of microdissected NPC and NNEC were established,and 36 differential proteins in the NPC and NNEC were identified,20 of which only expressed or up-regulated in NPC and 16 only expressed or up-regulated in NNET. The differentially expressed level of SCCA1 in the NPC and NNET was confirmed by Western blot and immunohistochemistry of tissue microarray. CONCLUSION Thirty-six differentially expressed proteins identified in this study may be associated with the carcinogenesis of NPC,and may be candidate molecular biomarkers for NPC.
Amino Acid Sequence ; Antigens, Neoplasm ; isolation & purification ; Biomarkers, Tumor ; isolation & purification ; Carcinoma, Squamous Cell ; chemistry ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Lasers ; Microdissection ; methods ; Molecular Sequence Data ; Nasopharyngeal Neoplasms ; chemistry ; Neoplasm Proteins ; isolation & purification ; Proteomics ; methods ; Serpins ; isolation & purification

Three different chemical carcinogens, 2-acetylaminofluorene (AAF), diethylnitrosamine(DENA), and 3'-methyl-4dimethylaminoazobenzene (3'-Me DAB) were used to induce hepatomas in rats. Plasma membrane surface proteins of normal rat liver cells and rat hepatomas were extracted with 3M KCI. From the analysis of the proteins of normal rat liver and rat hepatoma induced by 3'-Me DAB by discontinuous polyacrylamide gel electrophoresis(Disc-PAGE), under nonreducing and nondenaturing conditions polyacrylamide gel electrophoresis in the presence of SDS and 2-mercaptoethanol (SDS-PAGE), Sephadex G-200 gel permeation chromatography, DEAE-A50 ion-exchange chromatography and two-dimensional gel electrophoresis, at least three tumor specific antigens were identified. One had a molecular weigh of 66,000 (pl=6.79) while the other two had the same molecular weight 73,000 but differed in their isoelectric points (7.58 and 7.81). For immunological analysis of tumor specific antigens, the absorbed antiserum was prepared. Plasma membrane surface proteins of rat hepatoma induced by 3'-Me DAB were used to obtain New Zealand White male rabbit antiserum. Rabbit antiserum was then reacted with the proteins isolated from the plasma membrane surface of normal rat liver and the absorbed antiserum reacting specifically with the tumor specific antigens derived by 3'-Me DAB was obtained. Using the absorbed antiserum, the immunoreactivities of plasma membrane surface proteins isolated from rat hepatomas induced by 3'-Me DAB, AAF, and DENA were compared by Ouchterlony double immunodiffusion analysis and immunoelectrophoresis. To characterize the proteins reacting to the absorbed antiserum, immunoglobulin G was separated from the absorbed antiserum and coupled to cyanogen bromide-activated Sepharose CL-4B. The isolated proteins from the plasma membrane surface proteins of 3'-Me DAB-induced hepatoma using this immunoaffinity chromatography had molecular weights of 66,000 and 73,000. The localization of these proteins on surface plasma membranes of rat hepatomas induced by 3'-Me DAB was confirmed by an immunofluorescence technique. The experimental results revealed the existence of cross-reacting common antigens on the plasma membrane surface of rat hepatomas induced by different hepatocarcinogens.
2-Acetylaminofluorene ; Animal ; Antigens, Neoplasm/*isolation and purification ; Antigens, Surface/isolation and purification ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/*immunology ; Methyldimethylaminoazobenzene ; Rats ; Rats, Inbred Strains ; Support, Non-U.S. Gov't

In summarizing the results of the experimental studies up to the present, it is conjectured that the pathogenicity of Entamoeba histolytica or establishment of amoebiasis is not unique but differs by strain and age of Entamoeba histolytica and the age of the host. A non-virulent strain is more likely adapt to as low a temperature as 32 . This is not so in the strains which originated form clinical cases. Iso-enzyme patterns may roughly characterize pathogenic strains from non-pathogenic, Red blood cells may contribute as nutrients for growth of Entamoeba histolytica only after they have been hemolysed, but they are toxic to the amoebae as long as they remains intact. A low protein diet and stress may facilitate the establishment of amoebiasis; male sex hormones or previous infection by enteric bacteria provide a more advantageous condition than the female; and hepatotoxic agents will accelerate amoebic hepatitis.
2-Acetylaminofluorene ; Animal ; Antigens, Neoplasm/*isolation and purification ; Antigens, Surface/isolation and purification ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/*immunology ; Methyldimethylaminoazobenzene ; Rats ; Rats, Inbred Strains ; Support, Non-U.S. Gov't

OBJECTIVETo amplify mouse prostate stem cell antigen (mPSCA) gene and construct a recombinant plasmid to obtain mPSCA protein and identify its antigenicity.

METHODSThe gene of mPSCA was amplified by RT-PCR from mouse prostate cancer cell line RM-1 with the signal peptide sequence removed. The PCR product was cloned into pET-42a prokaryotic expression vector to construct the recombinant plasmid pET-42a-mPSCA, which was transformed into BL21 (DE3) for mPSCA expression. The fusion protein was purified and identified by SDS-PAGE and Western blotting. The antigenicity of the purified protein was characterized by ELISA.

RESULTSThe mPSCA gene was obtained with an identical sequence to that retrieved in GenBank. The prokaryotic expression vector for mPSCA was successfully constructed as confirmed by enzyme digestion and DNA sequencing. Both Western blotting and ELISA demonstrated the antigenicity of the purified mPSCA protein.

CONCLUSIONThe purified mPSCA obtained possesses good antigenicity, which will facilitate further study of immunotherapy for prostate cancer targeting PSCA.

Animals ; Antigens, Neoplasm ; genetics ; immunology ; isolation & purification ; Cloning, Molecular ; Escherichia coli ; metabolism ; GPI-Linked Proteins ; genetics ; immunology ; isolation & purification ; Genetic Vectors ; Male ; Mice ; Neoplasm Proteins ; genetics ; immunology ; isolation & purification ; Plasmids ; Prostate ; cytology

r-Glutamyltranspeptidase (r-GT) from a rat hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (3'-Me DAB) was purified 833 fold. The purified enzyme had a specific activity of 15.0 U/mg protein with an overall yield of 3.8%. The molecular weight of native r-GT was estimated as about 350,000 daltons, whichs a multicomplex of a single polypetide having a M W of 59,000. Anti r-GT rabbit antiserum cross-reacted with kidney r-GT as well as liver r-GT. Tryptic digestion of r-GT followed by separation with Con A sepharose column chromatography resulted in two major glycopeptides. A tumor associated antigen was prepared by the conjugation of a tryptic glycopeptide of r-GT to keyhole limpets hemocyanin and an antibody against this antigen cross-reacted preferentially with r-GT in rat hepatoma tissue.
Animal ; Antigens, Neoplasm/isolation and purification ; Liver Neoplasms, Experimental/*enzymology/immunology ; Male ; Molecular Weight ; Rats ; Support, Non-U.S. Gov't ; gamma-Glutamyltransferase/immunology/*isolation and purification

Heat shock protein gp96 is a glycoprotein which was found several years ago. Besides its function as a molecular chaperone, it is also reported to play important roles both in innate immunity and adaptive immunity. Gp96 can stimulate the maturation of antigen presenting cells (especially dendritic cells) and the secretion of cytokines. Gp96 and its associated peptides could stimulate peptide specific cytotoxic T lymphocyte reaction (CTL), which was very promising in the designing of anti-virus and anti-tumor vaccines. However the expression level of whole length gp96 was relatively low in E. coli and the purity of gp96 are not very suitable for further study. We successfully cloned the carboxy terminal fragment (560aa-751aa) of murine gp96 into the pGEX-6p-1 vector and expressed in BL21 strain. This fragment contains the peptide binding domain and the dimerization domain. After purification, the recombinant fusion protein was cleaved with the PreScission Protease and analyzed by Gelfiltration. The results show that this fragment may be related to the dimerization of gp96 and make an foundation for further investigations of the protein.
Animals ; Antigens, Neoplasm ; genetics ; Blotting, Western ; Chromatography, Gel ; Cloning, Molecular ; Mice ; Peptide Fragments ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; isolation & purification

This study was aimed to investigate the expression of GST-CML28 in Escherichia Coli and to prepare its antibody. The constructed recombinant expression vectors CML28-pGEX-3X were transformed into Escherichia Coli BL21 under IPTG induction. The protein was abstracted from the transformers, and purified by a GSTrap FF column. The rabbits were immunized by the purified fusion protein to produce serum with anti-CML28 antibody. The serum was purified by chromatographic column stuffed with glutathione Sephamse 4B to get the antibody. The specific antibody against CML28 was further identified by ELISA, Western blot, immunohistochemistry and quantum dot luminescence. The results indicated that GST-CML28 fusion protein was expressed in Escherichia coli and its specific polyclonal antibody was obtained. It is concluded that the anti-CML28 polyclonal antibodies with high titer and specificity are successfully prepared. These antibodies provide an useful experimental tool to profoundly research the physiological significance and biological function of the CML28 gene.
Animals ; Antibodies ; immunology ; isolation & purification ; metabolism ; Antigens, Neoplasm ; biosynthesis ; immunology ; isolation & purification ; Cells, Cultured ; Escherichia coli ; metabolism ; Exosome Multienzyme Ribonuclease Complex ; biosynthesis ; immunology ; isolation & purification ; Genetic Vectors ; Glutathione Transferase ; biosynthesis ; isolation & purification ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; RNA-Binding Proteins ; biosynthesis ; immunology ; isolation & purification ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; isolation & purification

OBJECTIVETo screen and obtain the validate immunogenic membrane antigens in pancreatic cancer.

METHODSPancreatic cancer cell line SW1990 membrane protein was extracted and separated by two-dimensional gel electrophoresis (2-DE). One of the three parallel 2-DE gels underwent Coomassie blue staining while the other two underwent immunoblot. Serum IgG was purified from clinically collected sera of 66 pancreatic cancer patients and 24 chronic pancreatitis patients and used as the primary antibody of the immunoblot. Positive dots of immunoblot were identified by MALDI-TOF mass spectrometry and PMF matching. The candidate membrane antigens were further validated respectively in cell lines and tissues by RT-PCR, real-time PCR, Western blot, and their different expression level of gene and protein between pancreatic cancer cell line and normal pancreatic tissue were compared studied.

RESULTSThe immunoblot of SW1990 membrane protein with serum IgG from cancer patients showed nine positive dots which were not the same as those from immunoblot with serum IgG from chronic pancreatitis patients. One talent dot was identified with MALDI and PMF as VDAC2. RT-PCR and real-time PCR showed that the gene of VDAC2 was expressed in the pancreatic cancer cell line. Western blot showed that the expression of protein level of VDAC2 in the pancreatic cancer cell line was obviously higher than in normal pancreatic tissue.

CONCLUSIONSVDAC2 might be the candidate immunogenic membrane antigens of pancreatic cancer, and its gene is all expressed in the pancreatic cancer cell line SW1990, AsPc and P3. The protein level of VDAC2 is significantly overexpressed in pancreatic cancer cell line than in normal pancreatic tissue.

Adult ; Aged ; Antigens, Neoplasm ; isolation & purification ; Cell Line, Tumor ; Female ; Humans ; Male ; Membrane Proteins ; immunology ; isolation & purification ; Middle Aged ; Pancreatic Neoplasms ; immunology ; Proteomics ; Voltage-Dependent Anion Channel 2 ; metabolism ; Young Adult

This study was to establish the method of purifying heat shock protein GP96 from K562 cells and explore the differentiation and function of human DC influenced by heat shock prolein (HSP). Using ammonium sulfate precipitation, conA-sepharose affinity chromatography and DEAE-sephacel anion exchange chromatography GP96 from K562 cells lysate was isolated and purified. The identification of the purified protein was controlled by Western blot with anti-human GP96 IgG. Human dendritic cell derived from peripheral blood mononuclear cell were cultured with purified GP96. The phenotype changes of DC were analyzed by flow cytometry and MLR was detected by MTT. The results showed that 60-80 microg GP96 was purified successfully from 1 x 10(10) K562 cells. DC stimulated with HSP-GP96 had higher expression rates of CD83, CD86, HLA-DR and lower expression rates of CD1a and had stronger ability to induce T cells proliferation. It is concluded that heat shock protein GP96 can be isolated and purified from K562 cells and could induce maturation of dendritic cell. HSP-DC vaccine show stronger ability to induce T cell proliferation than DC.
Antigens, Neoplasm ; isolation & purification ; pharmacology ; Cancer Vaccines ; immunology ; Cell Differentiation ; drug effects ; Dendritic Cells ; cytology ; drug effects ; immunology ; Humans ; Immunophenotyping ; K562 Cells ; chemistry

OBJECTIVETo identify a naturally presented HLA-A2-restricted epitope of MAGE-A3 antigen, FLWGPRALV (MAGE-A3(271 - 279)), on the surface of a human hepatocellular carcinoma (HCC) cell line HLE.

METHODSSynthetic peptide FLWGPRALV, served as positive control target, was analyzed by HPLC and HPLC-ESI-TOF-MSMS, in order to determine its HPLC elution time, mass-spectrometric characteristics and the lowest detection limitation by the two approaches. 3 x 10(9) HLE cells were collected, peptides naturally presented by major histocompatibility complex (MHC) molecules on the cell surface were isolated by mild acid elution, and concentrated by lyophilization, then the mixtures of peptides were fractioned by HPLC. The ingredient ranged from 2 min before the elution time determined by the synthetic peptide to 2 min after that was collected, concentrated by lyophilization, and analyzed by HPLC-ESI-TOF-MSMS, to identify the existence of the MAGE-A3(271 - 279) peptide.

RESULTSThe HPLC-ESI-TOF-MSMS detection provided an evidence for the existence of a doubly charged ion of (m/z)(2) 529.9, which was further analyzed by collision induced dissociation. The doubly charged ion was ultimately identified as the MAGE-A3(271 - 279) peptide, its amino sequence was FLWGPRALV and its molecular weight was 1058.4 Da.

CONCLUSIONSMAGE-A3(271 - 279) epitope could be naturally presented by HLA-A2 molecules to the surface of HCC cell line and MAGE-A3(271 - 279) peptide may have potential immunotherapeutic value in HCC patients.

Amino Acid Sequence ; Antigen Presentation ; Antigens, Neoplasm ; analysis ; isolation & purification ; Carcinoma, Hepatocellular ; immunology ; pathology ; Cell Line, Tumor ; Chromatography, High Pressure Liquid ; Epitopes, T-Lymphocyte ; analysis ; isolation & purification ; HLA-A2 Antigen ; immunology ; Humans ; Liver Neoplasms ; immunology ; pathology ; Mass Spectrometry ; Neoplasm Proteins ; analysis ; isolation & purification