Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast cancer has never had any good serum tumor markers. Therefore, we developed and evaluated a proteomics approach to searching for new biomarkers and building diagnostic models. SELDI-TOF-MS ProteinChip was used to detect the serum protein patterns of 49 breast cancer patients, 51 patients with benign breast diseases, and 33 healthy women. The diagnostic models were developed and validated using bioinformatics tools such as artificial neural networks and discriminant analysis. In total, four models were built and their sensitivities and specificities were satisfactory. The abilities of these models to diagnose stage I breast cancer were not worse than for stages II-IV (P>0.05). Four candidate biomarkers of breast cancer were found. The high sensitivity and specificity achieved by this method show great potential for the early detection of breast cancer and facilitation of discovering new and improved biomarkers.
 ...
PMID:SELDI-TOF-MS: the proteomics and bioinformatics approaches in the diagnosis of breast cancer. 1608 30

Identification of major histocompatibility complex (MHC)-associated peptides recognized by T-lymphocytes is a crucial prerequisite for the detection and manipulation of specific immune responses in cancer, viral infections, and autoimmune diseases. Unfortunately immunogenic peptides are less abundant species present in highly complex mixtures of MHC-extracted material. Most peptide identification strategies use microcapillary LC coupled to nano-ESI MS/MS in a challenging on-line approach. Alternatively MALDI PSD analysis has been applied for this purpose. We report here on the first off-line combination of nanoscale (nano) LC and MALDI TOF/TOF MS/MS for the identification of naturally processed MHC peptide ligands. These peptides were acid-eluted from human leukocyte antigen (HLA)-A2, HLA-A3, and HLA-B/-C complexes separately isolated from a renal cell carcinoma cell lysate using HLA allele-specific antibodies. After reversed-phase HPLC, peptides were further fractionated via nano-LC. This additional separation step provided a substantial increase in the number of detectable candidate species within the complex peptide pools. MALDI MS/MS analysis on nano-LC-separated material was then sufficiently sensitive to rapidly identify more than 30 novel HLA-presented peptide ligands. Peptide sequences contained perfect anchor amino acid residues described previously for HLA-A2, HLA-A3, and HLA-B7. The most promising candidate for a T-cell epitope is an HLA-B7-binding nonamer peptide derived from the tumor-associated gene NY-BR-16. To demonstrate the sensitivity of our approach we characterized peptides binding to HLA-C molecules that are usually expressed at the cell surface at approximately only 10% the levels of HLA-A or HLA-B. In fact, multiple renal cell carcinoma peptides were identified that contained anchor amino acid residues of HLA-Cw5 and HLA-Cw7. We conclude that the nano-LC MALDI MS/MS approach is a sensitive tool for the rapid and automated identification of MHC-associated tumor peptides.
 ...
PMID:Rapid and sensitive identification of major histocompatibility complex class I-associated tumor peptides by Nano-LC MALDI MS/MS. 1611 85

Platinum compounds are the most effective drugs in the fight against ovarian cancer. Unfortunately, many ovarian tumors are not eradicated by chemotherapy due to the emergence of drug-resistant clones during therapy, and hence 5-year survival rate of women afflicted with this disease is just 18%. In the continued absence of an effective early detection test for ovarian cancer, there is a considerable need to develop treatment strategies that can either circumvent (e.g. gene therapy) or prevent the development of platinum resistance. A prerequisite for the development of such treatments is a detailed knowledge of factors that confer tumor cell resistance to platinum compounds. We have used surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS or SELDI) to identify low mass proteins that are uniquely expressed in ovarian tumor cells that are platinum-resistant. Only two polypeptide peaks (m/z 5041 and 7324) were consistently altered following the induction of cisplatin resistance in the OAW42 and 2780 cell lines. These peaks appear to be specific to cisplatin resistance as they are not altered in the same manner in a melphalan-resistant variant of OAW42. The exact identity of the polypeptide peaks is unknown, but appears to be unrelated to changes in several proteins that have been historically associated with cisplatin resistance. These data suggest that SELDI-based proteomic profiling may be useful in monitoring the emergence of cisplatin-resistant tumor cell clones.
 ...
PMID:Identification of reproducible low mass SELDI protein profiles specific to cisplatin resistance in human ovarian cancer cells. 1621 4

We analyzed 74 cryostat sections of central gastric tumor, tumor margin, and normal gastric epithelium using ProteinChip Arrays and SELDI-TOF MS. One peak was significantly down-regulated in tumor tissue (P = 1.43 x 10(-6)) and identified as pepsinogen C using MS/MS analysis and immunodepletion. This signal was further characterized by immunohistochemistry. This work demonstrates that differentially expressed signals can be identified and assessed using a proteomic approach comprising tissue-microdissection, protein profiling, and immunohistochemistry.
 ...
PMID:Characterization of pepsinogen C as a potential biomarker for gastric cancer using a histo-proteomic approach. 1621 35

Epithelial ovarian cancer is the fourth leading cause of cancer death among women. Due to the asymptomatic nature and poor survival characteristic of the disease, screening for specific biomarkers for ovarian cancer is a major health priority. Differentially expressed proteins in the serum of ovarian cancer patients have the potential to be used as cancer-specific biomarkers. In this study, proteomic methods were used to screen 24 serum samples from women with high-grade ovarian cancer and compared to a control group of 11 healthy women. Affigel-Blue treated serum samples were processed either by linear (pH 4-7) or narrow range (pH 5.5-6.7) IEF strips for the first dimension. Proteins separated in first dimension were resolved by 8-16% gradient SDS-PAGE. Protein spots were visualized by SYPRO Ruby staining, imaged by FX-imager and compared and analyzed by PDQuest software. Twenty-two protein spots were consistently differentially expressed between normal and ovarian cancer patients by resolving proteins in a linear pH strip of 4-7 for the first dimension. Six of the protein spots, significantly up-regulated in grade 3 ovarian cancer patients (p < 0.05), were identified by MALDI-TOF MS and Western blotting as the isoforms of haptoglobin precursor. When serum proteins were resolved on narrow pH range strips (5.5-6.7), 23 spots were consistently differentially expressed between normal and grade 3 ovarian cancer patients. Of these, 4 protein spots significantly down regulated in grade 3 ovarian cancer patients (p < 0.05) were identified by MALDI-TOF MS and Western blotting, as isoforms of transferrin precursor. Increased expression of serum haptoglobin and transferrin was also identified in peritoneal tumor fluid obtained from women diagnosed with grade 2/3 ovarian cancer (n = 7). Changes in the expression of haptoglobin and transferrin in the serum of women with different pathological grades of ovarian cancer was examined by one-dimensional Western blotting method. Serum samples collected from women suffering from benign, borderline, grade 1, grade 2 and grade 3 cancer (n = 4 for haptoglobin and n = 5 for transferrin in each group) were analyzed and compared to the serum of normal healthy women. The mean serum haptoglobin expression in grade 3 ovarian cancer patients was fourfold higher than in the control subjects (p < 0.05). On the other hand, transferrin expression in grade 3 ovarian cancer patients was decreased by twofold than in normal healthy women (p < 0.05). Haptoglobin expression in the serum of cancer patients (n = 7) decreased following chemotherapy (six cycles of taxol/carboplatin). Concomitant with the decrease of haptoglobin, transferrin expression remained constant in four patients, but increased in three out of seven patients included in the study. Changes in serum expression of haptoglobin correlated with the change of CA 125 levels before and after chemotherapy. In conclusion, proteomic profiling of differentially expressed proteins in the sera of normal women compared to women with ovarian cancer can greatly facilitate the discovery of a panel of biomarkers that may aid in the detection of ovarian cancer with greater specificity.
 ...
PMID:Proteomic tracking of serum protein isoforms as screening biomarkers of ovarian cancer. 1622 May 31

Ovarian cancer is most common gynecological malignancy which is difficult for early diagnostics. Development of new methods for diagnostics of ovarian cancer, especially, on early stage, is the urgent problem of modern oncology. A general approach to early diagnostics of cancer is a discovery of specific blood disease biomarkers. Ovarian cancer biomarker used in the modern art, CA125, has some drawbacks resulting in extensive research recently directed to this tumor diagnosis. In particular, it was shown the advantage of parallel use of several diagnostic biomarkers instead of the single one. Proteome techniques (two-dimensional electrophoresis, mass-spectrometry methods) in connection to bioinformatics represent a powerful tool for new biomarker discovery. In this respect, the best method of choice is shown to be SELDI-TOF (Surface-enhanced laser desorption/ionization time-of-flight) technique which combines chromatography protein chip application and mass-spectrometry-based detection. In this review, new ovarian biomarker data obtained by proteome methods are summarized.
 ...
PMID:[Molecular diagnostics of ovarian cancer using proteome techniques]. 1622 28

The search for novel molecular markers of tumor invasion is vital if strategies are to become more effective in the diagnostic and prognostic management of transitional cell carcinoma of the bladder. Up to 50% of tumors detected at stage 1 (pT1) progress to a higher grade even after endoscopic surgical resection, and there are currently no protein markers of this aggressive, invasive phenotype. We have combined SELDI-TOF-MS, ClinProt magnetic bead enrichment, Nano-LC-ESI-ion trap tandem mass spectrometry and immunohistochemical analysis to the study of 12 invasive bladder cancer tissue biopsies paired with normal bladder tissue samples obtained from the same patients for the definition and identification of proteins up-regulated in the tumors. We report the inflammation-associated calcium binding protein S100A8 (MRP-8, calgranulin A) to be highly expressed in tumor cells in contrast to normal urothelium in 50% of the samples, as well as two unidentified protein markers at 5.75 and 6.89 kDa that were differentially detected in 9/12 and 10/12 tumor samples, respectively. These new markers, when fully characterized, may contribute to new target proteins for the prediction of aggressive, invasive bladder tumors.
 ...
PMID:Differential detection of S100A8 in transitional cell carcinoma of the bladder by pair wise tissue proteomic and immunohistochemical analysis. 1625 5

The phosphatase and tensin homolog tumor suppressor (PTEN) belongs to a class of "gatekeeper" tumor suppressors together with p53, retinoblastoma and adenomatous polyposis. It is considered one of the most important tumor suppressors in the post p53 era. Previously to identify the molecules involved in the signaling network regulated by PTEN using proteomic tools, we reported global proteome profiles at different time points using the PTEN inducible NIH3T3 cells (Kim, S.-y., Kim, Y. S., Bahk, Y. Y., Mol. Cells 2003, 15, 396-405). However, the system had a critical limitation that NIH3T3 cell has endogenous wild-type PTEN and, thus to be exact, the induced PTEN could not give the answer about the real physiological roles of this tumor suppressor. Here, to find out PTEN-related protein network we have established various PTEN (wild-type, an activity inert C124G, and a lipid phosphatase deficient G129E)-expressing cell clones in U-87 MG human glioblastoma cells lacking detectable PTEN as a result of genetic lesions. In this biological context, we compared their morphological and expression patterns, and proteome images of each PTEN-expressing cell clone by 2-DE followed by identification with MALDI-TOF MS. We obtained some pieces of evidence that morphological change by PTEN expression is mediated by its protein phosphatase activity and their growth rate by the lipid phosphatase activity. The proteomic approaches showed that 30 proteins possibly correlated with PTEN's protein phosphatase activity (13 down-regulated and 17 up-regulated) and 20 with the lipid phosphatase activity (14 down-regulated and 6 up-regulated) were identified. Taken together, we conclude that the comparative analysis of proteome from various PTEN-expressing cells has yielded interpretable data to elucidate the protein network directly and/or indirectly caused by individual phosphatase activities of PTEN in vivo.
 ...
PMID:Proteome profile changes that are differentially regulated by lipid and protein phosphatase activities of tumor suppressor PTEN in PTEN-expressing U-87 MG human glioblastoma cells. 1629 7

4-Hydrazinobenzoic acid, an ingredient of mushroom Agaricus bisporus, is carcinogenic to rodents. To clarify the mechanism of carcinogenesis, we investigated DNA damage by 4-hydrazinobenzoic acid using (32)P-labeled DNA fragments obtained from the human p53 and p16 tumor suppressor genes. 4-Hydrazinobenzoic acid induced Cu(II)-dependent DNA damage especially piperidine-labile formation at thymine and cytosine residues. Typical hydroxyl radical scavengers showed no inhibitory effects on Cu(II)-mediated DNA damage by 4-hydrazinobenzoic acid. Bathocuproine and catalase inhibited the DNA damage, indicating the participation of Cu(I) and H(2)O(2) in the DNA damage. These findings suggest that H(2)O(2) generated by the autoxidation of 4-hydrazinobenzoic acid reacts with Cu(I) to form reactive oxygen species, capable of causing DNA damage. Interestingly, catalase did not completely inhibit DNA damage caused by a high concentration of 4-hydrazinobenzoic acid (over 50 microM) in the presence of Cu(II). 4-Hydrazinobenzoic acid induced piperidine-labile sites frequently at adenine and guanine residues in the presence of catalase. 4-Hydrazinobenzoic acid increased formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a characteristic oxidative DNA lesion, in calf thymus DNA, whereas 4-hydrazinobenzoic acid did not increase the formation of 8-oxodG in the presence of catalase. ESR spin-trapping experiments showed that the phenyl radical was formed during the reaction of 4-hydrazinobenzoic acid in the presence of Cu(II) and catalase. Matrix-assisted laser desorption/ionization time-of-flight mass (MALDI-TOF/mass) spectrometry analysis showed that phenyl radical formed adduct with adenosine and guanosine. These results suggested that 4-hydrazinobenzoic acid induced DNA damage via not only H(2)O(2) production but also phenyl radical production. This study suggests that both oxidative DNA damage and DNA adduct formation play important roles in the expression of carcinogenesis of 4-hydrazinobenzoic acid.
 ...
PMID:Radical production and DNA damage induced by carcinogenic 4-hydrazinobenzoic acid, an ingredient of mushroom Agaricus bisporus. 1629 57

Chronic infection of hepatitis virus B (HBV) has been proven to be one of the most important risk factors of hepatocellular carcinoma (HCC). HBx has been shown to function in the viral life cycle and the development of HCC. Recently, we have reported that HBx transgenic mice (p21-HBx), generated by gene knockin, develop HCC at the age of 18 months. To further study the function of HBx during the development of HCC in vivo, we performed proteomic analysis of the transgenic and wild-type control mice. The combination of 2-DE and MALDI-TOF MS revealed that proteasome subunits (PSMA6, PSMB4, PSMC2 and PSMD12) were up-regulated in tumor tissues of the p21-HBx transgenic mice. Cathepsin B, ubiquinol-cytochrome C reductase core protein 1 and an ATP-dependent caseinolytic protease, which were involved in the cellular proteolytic process, were also found increased in tumors. The results were confirmed in tumors of transgenic mice and HCCs of human using RT-PCR. All these results suggested that the strengthened ubiquitin-proteasome and lysosomal pathway might contribute to the development of HBx-related HCC.
 ...
PMID:The up-regulation of proteasome subunits and lysosomal proteases in hepatocellular carcinomas of the HBx gene knockin transgenic mice. 1631 74


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>