Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Desmoplastic small round cell tumor (DSRCT) is a unique, highly aggressive neoplasm that chiefly affects male adolescents and young adults. This tumor is characterized by nests of small undifferentiated cells that show immunohistochemical evidence of epithelial, mesenchymal, and neural differentiation. We report two cases of DSRCT that lacked immunohistochemical evidence of epithelial differentiation, but were found to have the fusion transcripts characteristic of this tumor. Both patients (a 41-year-old male and a 31-year-old female) presented with large intra-abdominal masses. After diagnostic biopsy, both were treated with multi-agent chemotherapy. One patient expired 18 days after diagnosis, and the other is currently alive 28 months later. Histologically, both tumors had the characteristic features of DSRCT and were composed of small round cells with hyperchromatic nuclei and scanty cytoplasm. In one of the cases, perinuclear intracytoplasmic hyaline inclusions were seen. Immunohistochemically, neither case expressed any of the epithelial markers tested, including AE1/AE3, CAM 5.2 and EMA. Both tumors were diffusely immunoreactive for desmin with a prominent globoid "dot-like" pattern of staining in one case. Both tumors stained for vimentin, neuron specific enolase, and synaptophysin, but were negative for CD99, muscle-specific actin, and myogenin. Reverse transcriptase-polymerase chain reaction revealed EWS-WT1 fusion transcripts characteristic of this neoplasm. In conclusion, we describe two cases of DSRCT that lacked immunohistochemical evidence of epithelial differentiation but had histologic and other immunohistochemical features which suggested this diagnosis. The ability to confirm the diagnosis of this rare tumor using molecular genetic techniques is particularly useful in those cases with unusual histologic or immunophenotypic features.
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PMID:Cytokeratin-negative desmoplastic small round cell tumor: a report of two cases emphasizing the utility of reverse transcriptase-polymerase chain reaction. 1049 92

Anion exchangers (AE) are transmembrane proteins catalyzing electroneutral exchange of Cl(-) for HCO3-. To date, three different genes coding for this protein, AE1, AE2 and AE3, have been identified in many species. AE1 is considered to be the unique anion exchanger expressed in erythrocytes. In this paper we propose the presence of three different AEs in skate erythrocytes, a skAE1, a skAE2 and a skAE3, cloned by RT-PCR (reverse-transcriptase polymerase chain reaction). These three skAE have a similar predicted secondary structure. All three skAE are divided in two main domains: a hydrophilic cytoplasmic N-terminal domain and a C-terminal domain crossing the lipid bilayer at least 12 times. The greatest similarity is found in the membrane-spanning domain of the three skAE. The size as well as the amino-acid sequence of the cytoplasmic domain differ significantly among three anion exchangers. Functional expression studies in Xenopus oocytes led to the conclusion that skAE-1 and -2 share some functional features (Cl-dependence and DIDS sensitivity). The skAE3 could not be expressed in Xenopus oocytes. These data are in agreement with expression data obtained with AEs of different species utilizing the oocyte system. It is highly probable that these three new AE sequences come from three different genes, thus suggesting for the first time the presence of the three AE genes in Chondrichthyes.
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PMID:Evidence for the presence of three different anion exchangers in a red cell. Functional expression studies in Xenopus oocytes. 1287 59

This paper discusses the diversity of synovial sarcomas (SSs) [biphasic (BSS), monophasic fibrous (MFSS), and poorly differentiated (PDSS)] and tissue microarray (TMA) evaluation of the immunophenotypic and histological progression of SSs in nude mice using three TMAs comprising 11 primary SSs (8 MFSSs, 2 BSSs, and 1 PDSS) and their xenografts. BSS and MFSS progressively transformed to a similar undifferentiated phenotype with loss of glandular component in the xenografts. Epidermal growth factor receptor and SALL2 were expressed in primary tumors and xenografts. Enhanced bcl-2 and bax expression were noted in xenografts. Ki-67 overexpression in xenografts correlated with high mitotic index. Epithelial membrane antigen (EMA) and cytokeratin AE1/AE3 were detected in all original and xenografted SSs. Hierarchical clustering differentiated original MFSS and BSS, but their xenografts clustered together due to similar immunoexpression profile. Our study demonstrates definite phenotypic variability of BSS and MFSS in the xenografts. Differences in immunoexpression for various markers existed between primary tumor and xenografts but not between subtypes. Hierarchical clustering grouped TMA immunostaining data and confirmed immunophenotypic variability; however, it failed to reveal any immunophenotypic differences between SYT-SSX1 and SYT-SSX2 type tumors. Nonetheless, reverse-transcriptase-polymerase chain reaction detected SYT-SSX transcripts in all primary SSs and their xenografts, thereby demonstrating their genetic stability.
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PMID:Tissue microarray profiling of primary and xenotransplanted synovial sarcomas demonstrates the immunophenotypic similarities existing between SYT-SSX fusion gene confirmed, biphasic, and monophasic fibrous variants. 1695 34