Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0027651 (tumor)
685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vascular endothelial growth factor (VEGF) expression and microvessel density were studied in cases of advanced epithelial ovarian carcinoma to evaluate their usefulness as prognostic variables. Tumor samples from 18 patients with advanced stage serous epithelial ovarian cancer were evaluated for VEGF expression by reverse-transcriptase polymerase chain reaction (RT-PCR) analysis. Immunohistochemical study of corresponding archival tissues with an antibody to von Willebrand factor (vWF; FVIII-RA) was used for tumor microvessel count determinations. The correlation of VEGF expression and mean microvessel counts was determined by an unpaired t-test. Survival analysis for known prognostic factors and VEGF expression was performed. Survival distributions were calculated by the product limit of Kaplan and Meier and significant differences between distributions were analyzed with a log rank test. From the RT-PCR analysis of tumor VEGF expression, 12 samples were found to be strongly positive, whereas six samples had low/negative VEGF expression. The median survival was 60 months for the VEGF-low/negative group and 28 months for the VEGF-positive group (P = 0.058). Other prognostic variables had minimal impact on survival, i.e. age < 65 years (P = 0.873), FIGO stage (P = 0.06), grade (P = 0.236) and debulking status (P = 0.842). Fourteen of 18 tumor specimens were suitable for microvessel counting. The mean microvessel counts of the VEGF-positive group and the VEGF-negative group were 27/hpf and 35/hpf, respectively (P = 0.16). In this preliminary analysis, high VEGF expression in epithelial ovarian carcinomas was associated with poor overall survival. Further study will be necessary to elucidate the lack of association of VEGF expression and tumor microvessel counts.
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PMID:Vascular endothelial growth factor (VEGF) expression and survival in human epithelial ovarian carcinomas. 957 Mar 55

Despite recent extensive immunohistochemical studies, the expression patterns of CD44 in testicular germ cell tumors are still controversial. In the present study, we investigated the CD44 gene expression in 40 specimens including 18 seminomas, 16 nonseminomatous germ cell tumors (NSGCT), and 6 normal testes by reverse transcriptase-polymerase chain reaction and Western blotting. Reverse transcriptase-polymerase chain reaction analysis revealed that the standard CD44 isoform (CD44s) was expressed in all of the specimens, whereas the variant CD44 isoforms were highly expressed in NSGCTs but barely detectable in seminomas and normal testes. In addition, we confirmed by direct DNA sequence analysis that the predominantly expressed variant isoform in NSGCTs was CD44v8-10. In germ cell tumors, these results were paralleled in Western blot analysis; that is, CD44s protein was expressed in all of the tumor specimens, whereas high molecular weight variant isoforms were expressed only in NSGCTs. However, at the protein level, no detectable CD44 was expressed in normal testes. These findings show that the combined assessment of CD44 expression patterns at both the RNA and protein levels enables us to distinguish among seminoma, NSGCT, and normal testis specimens; hence, it could serve as a useful practical adjunct to conventional diagnostic methods for testicular germ cell tumors.
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PMID:Expression patterns of CD44 adhesion molecule in testicular germ cell tumors and normal testes. 958 83

Fas (APO-1/CD95) is a cell surface receptor that mediates apoptosis when it reacts with Fas ligand (FasL) or Fas antibody. In this study, we analyzed Fas and FasL expression in normal esophageal mucosa and esophageal squamous cell carcinomas. Reverse transcriptase-PCR revealed that Fas, soluble Fas, and FasL were expressed in all eight esophageal squamous carcinoma cell lines analyzed. Furthermore, it was demonstrated that FasL expressed in esophageal carcinoma cells is functional because coculture experiments using FasL-expressing TE-15 esophageal carcinoma cells resulted in apoptosis of Jurkat T leukemia cells, which are sensitive to Fas-mediated apoptosis. Immunohistochemistry of Fas and FasL showed that they are constitutively expressed in normal esophageal mucosa, FasL being predominantly in the basal and suprabasal layers, whereas Fas is in more differentiated layers, i.e., rows of polyhedral cells of the intermediate layers and squamous cells forming the outer layers. In 18 of 19 invasive esophageal squamous cell carcinomas, FasL expression was found in >50% of tumor cells. In contrast, most tumors (15 of 19, 79%) either showed no Fas expression or showed expression in <5% of tumor cells. These alterations were already detected in dysplasia and carcinoma in situ. These results suggest that up-regulation of FasL and down-regulation of Fas expression are early and frequent events associated with the evolution of esophageal squamous cell carcinomas.
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PMID:Up-regulation of Fas (APO-1/CD95) ligand and down-regulation of Fas expression in human esophageal cancer. 960 41

Expression of facilitative glucose transporter (Glut) isoforms was studied immunohistochemically in lung carcinomas. Glut-1 was expressed in 45 (74%) of 61 lung carcinomas, including 19 (100%) of 19 squamous cell carcinomas. No Glut-1 staining was seen in normal lung epithelium surrounding the tumors. In squamous cell carcinomas and small cell carcinomas, Glut-1 immunostaining was stronger in the central area of tumor cell nests corresponding to the hypoperfused region. Focal staining was seen in 14 (58%) of 24 adenocarcinomas, and positive staining was correlated to lesser differentiation, larger tumor size, and positive lymph node metastasis. Glut-2 was detected in normal airway epithelium, but no positive staining was seen in lung carcinomas. Glut-3 and Glut-4 were not positively stained in normal lung epithelia, but a few lung carcinoma samples showed positive reaction (9 of 61 in Glut-3; 4 of 61 in Glut-4). Glut-4 immunoexpression was seen in regenerating alveolar and bronchiolar epithelia around and in cancer tissues. Glut-5 expression was not detected in normal and tumor tissues. Reverse transcriptase-polymerase chain reaction for Glut-1, Glut-3, and Glut-4 confirmed the expression revealed by immunohistochemical analysis. Overexpression of Glut could enhance uptake of glucose into lung carcinoma cells, and the increased glucose influx could be involved in cell biologic activities.
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PMID:Expression of facilitative glucose transporter isoforms in lung carcinomas: its relation to histologic type, differentiation grade, and tumor stage. 983 Dec 15

Conjunctival melanomas, which have a relatively good prognosis as compared to other mucosal melanomas, have been investigated morphologically and pathologically. We examined the gene expression of several cytokines in a patient with conjunctival melanoma and compared them to those of other pigment cells of the eye, because no reports have discussed cytokine expression in melanoma of the eye. Samples were collected from a 64-year-old woman with conjunctival melanoma and mRNAs were extracted and reverse-transcriptase polymerase chain reaction was performed. We found that potent inhibitors of tumor cell growth such as interleukin 2, 4, 6 and gamma-interferon were expressed in the tumor. These inhibitors were not expressed in other pigment cells of the eye, in blood, in conjunctival melanosis or in choroidal melanomas. The basic fibroblast growth factor gene, which has also been known to stimulate melanoma cell growth, was not expressed in the conjunctival melanoma, and it showed +/- or weak expression in choroidal melanomas, but it was expressed in the pigment cells in the eye and in conjunctival melanosis. Although only limited cytokine expression was examined here, these results may suggest an influence of these cytokines to the growth of conjunctival melanoma.
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PMID:Expression of cytokine genes in a patient with conjunctival melanoma compared with other pigment cells. 966 56

We studied the beta-1,3-galactosyltransferase (GalT) and alpha-1,2-fucosyltansferase (FT) involved in the biosynthesis of type-1-chain carbohydrate antigens in human colon adenocarcinoma cell lines. We detected a GalT activity able to use GlcNAc as acceptor and found that lacto-N-biose I (Galbeta1-3GlcNAc) is the only reaction product. Such beta1,3GalT is kinetically similar to a pig trachea enzyme involved in mucin synthesis. The specific activity is high in cells that react strongly with anti-Lewis a and anti-Lewis b antibodies, and undetectable in a cell line that lacks antibody reaction. Reverse-transcriptase-mediated PCR analysis followed by DNA sequencing indicated that secretor-type alpha1,2FT is expressed in the cells, while the H type alpha1,2FT is not. The apparent Km values for donor and acceptor substrates determined for alpha1,2FT are similar to those of secretor-type alpha1,2FT and the specific activity measured correlates with Lewis b antigen expression on the cell surface. Moreover, some of the cell lines express Lewis y and H type 2 antigens, indicating that secretor type alpha1,2FT is responsible for their synthesis. Results suggest that biosynthesis of type-1-chain tumor-associated antigens in human colon carcinoma cells is operated by secretor-type alpha1,2FT, as reported in normal mucosa, and that beta1,3GalT activity may play a relevant role in its control.
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PMID:Beta-1,3-galactosyltransferase and alpha-1,2-fucosyltransferase involved in the biosynthesis of type-1-chain carbohydrate antigens in human colon adenocarcinoma cell lines. 976 Jan 91

Although hepatitis C virus (HCV) mainly affects hepatocytes, infection is widespread and involves immunologically privileged sites. Whether lymphoid cells represent further targets of early HCV infection, or whether other cells in the hematopoietic microenvironment may serve as a potential virus reservoir, is still unclear. We studied whether pluripotent hematopoietic CD34(+) cells support productive HCV infection and can be used to establish an in vitro infection system for HCV. Six patients were selected as part of a cohort of HCV chronic carriers who developed a neoplastic disease. Reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA signal amplification assays were used to detect and quantitate HCV RNA in extracted nucleic acids from purified bone marrow and peripheral blood CD34(+) cells. Direct in situ RT-PCR, flow cytometry analysis, and immunocytochemistry were applied to demonstrate specific viral genomic sequences and structural and nonstructural virus-related proteins in intact cells. Results indicated that both positive and negative HCV RNA strands and viral proteins were present in CD34(+) cells from all HCV-positive patients and in none of the controls. Additional experiments showed that a complete viral cycle took place in CD34(+) cells in vitro. Spontaneous increases in viral titers indicated that virions were produced by infected hematopoietic progenitor cells. To further define the cellular tropism, we attempted to infect CD34(+) cells in vitro. We were unable to demonstrate viral uptake by cells. These findings suggest that HCV replication can occur in the early differentiation stages of hematopoietic progenitor cells, and that they may be an important source of virus production.
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PMID:Hepatitis C virus infection involves CD34(+) hematopoietic progenitor cells in hepatitis C virus chronic carriers. 978 70

We report here a 15-year-old boy with an intraabdominal desmoplastic small round cell tumor (DSRCT). Cytogenetic analysis of the tumor cells showed the chromosomal translocation (11;22). Reverse-transcriptase polymerase chain reaction and sequencing analysis revealed a chimeric transcriptional message of the EWS gene exon 10 fused to the WT1 gene exon 8. The typical chimeric transcript seen in DSRCT is an in-frame fusion of EWS exon 7 to WT1 exon 8. The tumor in this case had a novel and longer chimeric transcript, which should be a potent transcription factor. Genetic analysis is a very powerful and specific aid in the differential diagnosis of small round cell tumors.
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PMID:Novel breakpoints of the EWS gene and the WT1 gene in a desmoplastic small round cell tumor. 979 82

In more than 95% of patients, the Ewing family of tumors (ET) has chimeric transcripts caused by fusion of the EWS gene to either FLI1 or ERG. The presence of specific EWS-FLI1 or EWS-ERG transcripts in peripheral blood (PB) samples of patients being treated for ET was prospectively evaluated, and these data were correlated to their clinical status. The authors studied 113 PB samples from 28 patients with ET. Treatment included chemotherapy, radiotherapy, and surgical excision of tumor after induction therapy. PB samples were taken prospectively at least 2 weeks after resection of tumor. Nested reverse-transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot was performed in all samples. Resected tumors were reviewed for the degree of response to chemotherapy and volume. Seventy-seven PB samples from 28 patients had EWS-FLI1/ERG transcripts. In 11 patients, PB samples became negative with treatment, and, in 5 of them, the samples remained negative throughout the study. Samples taken during progression were always positive and, in 4 patients, became positive before progression was clinically evident. All patients with transcripts other than EWS-FLI1 type 1 (n = 3) died from tumor progression. This is a sensitive assay to monitor circulating tumor cells in Ewing tumors. The preliminary data suggest that progression is preceded by positive samples and may be related to specific transcript types.
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PMID:Ewing family tumors: potential prognostic value of reverse-transcriptase polymerase chain reaction detection of minimal residual disease in peripheral blood samples. 983 70

The WT1 gene is normally expressed in fetal kidney and mesothelium, and its expression has been suggested as a marker for Wilms tumor and mesothelioma. We examined WT1 expression levels by reverse-transcriptase polymerase chain reaction (RT-PCR) in 38 childhood small-cell tumors including Wilms tumor, embryonal and alveolar rhabdomyosarcoma, Ewing sarcoma, lymphoma, desmoplastic small round-cell tumor (DSRCT), synovial sarcoma, extrarenal rhabdoid tumor, and two tumors that were atypical for this group of tumors. WT1 expression was only detected in Wilms tumor, rhabdoid tumor, and in these two cases of uncertain histogenesis. Both arose in the peritoneal cavity and by immunohistochemistry were diffusely positive for vimentin, keratin, and desmin. Tonofilaments were identified by electron microscopy in one of the cases. RT-PCR failed to detect the t(11;22) translocation associated with DSRCT in either case. Our results suggest that WT1 expression is an unusual feature of childhood non-Wilms tumors and, in the right setting, it may indicate a mesothelial origin. The expression of WT1 may play a role in mesodermal cells acquiring epithelial characteristics, a concept supported by the mixed epithelial and mesenchymal phenotype of these two cases.
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PMID:Expression of WT1 in pediatric small cell tumors: report of two cases with a possible mesothelial origin. 984 4


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