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: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To evaluate whether the expression of T-cell receptor (TCR) V beta families in eight cases of malignant T-cell lymphomas took place in a preferential manner, we analyzed four cases of mycosis fungoides (MF), the most common form of primary cutaneous T-cell non-Hodgkin's lymphomas (NHL), and four cases of primary nodal T-cell NHL. The usage of V beta families in T-cell populations was investigated on mRNA that was transcribed to cDNA using a C beta primer and reverse transcriptase. Subsequently, the specific usage of the families was analyzed by polymerase chain reaction (PCR) using combinations of the selected C beta-oligonucleotide primer and one of the family-specific V beta primers. Peripheral blood lymphocytes from four healthy volunteers and 1 "reactive" lymph node served as a control and expressed all 20 V beta families tested for. In T-cell lines, with restricted V beta expression, and in three patients with advanced MF, only one or two V beta families were expressed at the mRNA level. In an early MF lesion this monoclonal expression was absent: several V beta families were expressed with a weak intensity. This may indicate either a polyclonal origin of MF, or that too few monoclonal neoplastic cells were present in the tissue specimen. In the four nodal T-cell NHL, only one family could be clearly distinguished, whereas some of the other V beta families showed only a weak expression. These latter families represent the reactive T-cell component in the nodal T-cell NHL. Both in nodal T-cell NHL and in MF there was no preferential expression of a particular V beta family. There was a good correlation between PCR data and the expression of V beta-family protein products observed by immunohistochemistry on tissue sections of the T-cell lymphomas. All T-cell lines, three cases of MF, and three cases of nodal T-cell NHL showed a rearrangement of the TCR beta chain on DNA level.
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PMID:T-cell receptor V beta-family usage in primary cutaneous and primary nodal T-cell non-Hodgkin's lymphomas. 796 67

A highly purified thyroglobulin mRNA was isolated from human nodal euthyroid goiter. A full-length cDNA was synthesized from 33S RNA by using reverse transcriptase in the presence of human placenta ribonuclease inhibitor. A DNA complementary to human Tg mRNA was used in liquid hybridization experiments to quantify Tg mRNA. The amount of Tg mRNA in euthyroid nodal and congenital goiter was reduced. In thyroid cancer Tg specific mRNA was absent. Direct correlation between Tg gene expression in thyroid cells and DNAase-I hypersensitivity of chromatin from the thyroid gland nucleus was revealed.
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PMID:[Changes in the chromatin structure of the thyroid cells related to the expression of the thyroglobulin gene]. 197 92

A highly purified thyroglobulin (Tg) mRNA was isolated from human nodal euthyroid goiter. Ultracentrifugation in a 5-20% sucrose density gradient revealed that the protein has a sedimentation coefficient of 33S. cDNA was synthesized from the 33S RNA, using reverse transcriptase in the presence of a human placental ribonuclease inhibitor. In order to detect the polymorphism of restriction fragment length, screening of high molecular weight DNA from normal human thyroid gland and from nodal euthyroid and diffuse toxic goiters was carried out, using Tg cDNA probes and plasmid DNA containing a Tg cDNA fragment. After restriction with endonuclease Hind III, three Tg-containing fragments were identified both in the normal and nodal euthyroid goiters, whereas restriction with endonuclease Bam HI revealed two Tg-containing fragments in nodal euthyroid and diffuse toxic goiters.
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PMID:[Mapping of the thyroglobulin gene in high molecular weight DNA from the human thyroid in normal conditions and in thyroid pathology]. 256 30

Highly purified thyroglobulin mRNA was isolated from human nodal euthyroid goiter. Full length cDNA was synthesized from 33S RNA by using reverse transcriptase in the presence of human placenta ribonuclease inhibitor. DNA complementary to human Tg mRNA was used in liquid hybridization experiments to determine the quantity of Tg mRNA. The amount of Tg mRNA in euthyroid nodal and congenital goiter was reduced. Tg specific mRNA was absent in thyroid cancer cells.
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PMID:[Thyroglobulin gene expression in human thyroid cells in various types of thyroid pathology]. 258 2

Primary cutaneous CD30+ lymphoproliferative disorders (LPDs), including lymphomatoid papulosis (LyP), anaplastic and nonanaplastic CD30+ large-cell lymphoma, and borderline cases, comprise a clinical and histologic spectrum. Primary cutaneous and primary nodal CD30+ anaplastic large-cell lymphomas (ALCLs) are distinct clinical entities that have identical morphologic features but differ in age of onset, immunophenotype, and prognosis. It can be difficult to distinguish primary cutaneous from nodal ALCLs that secondarily involve the skin, which is important because these diseases differ significantly in response to treatment and clinical outcome. The t(2;5) chromosomal translocation is highly associated with primary CD30+ ALCL of nodal origin. The possible occurrence of t(2;5) in primary cutaneous CD30+ LPDs has not been studied extensively, and it remains to be determined if expression of this translocation can be used to distinguish primary cutaneous ALCL from nodal ALCL that secondarily involves the skin. To address these issues, we studied 43 cases of cutaneous and nodal CD30+ LPDs using reverse transcriptase-polymerase chain reaction (RT-PCR) and/or immunohistochemistry. We found no evidence for the t(2; 5) translocation in 14 cases of primary cutaneous CD30+ LPDs, which included 10 cases of LyP, three cases of primary cutaneous CD30+ ALCL, and one borderline case. These findings were in marked contrast to CD30+ ALCL of nodal origin, in which 19 of 29 (66%) cases were positive for t(2;5), including all five cases with secondary skin involvement. Our results support the hypothesis that (1) primary cutaneous CD30+ LPDs (including LyP) and primary nodal ALCL are distinct diseases that differ in clinical behavior and pathogenesis and (2) differential expression of t(2;5) can help to distinguish between primary cutaneous CD30+ LPDs and ALCL of nodal origin.
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PMID:The t(2;5) chromosomal translocation is not a common feature of primary cutaneous CD30+ lymphoproliferative disorders: comparison with anaplastic large-cell lymphoma of nodal origin. 887 25

The t(2;5) generates a chimeric NPM-ALK transcript encoded by the nucleophosmin NPM gene fused to the anaplastic lymphoma kinase gene ALK. Using a reverse transcriptase nested polymerase chain reaction assay we have detected NPM-ALK transcripts within CD30+ primary cutaneous lymphoma and lymphomatoid papulosis (LP). The t(2;5) was identified in 4 out of 9 CD30+ anaplastic lymphomas and in 1 out of 4 CD30+ pleomorphic lymphomas. Moreover, the t(2;5) was detected in 3 out of 10 LPs. All NPM-ALK-positive lymphomas and 1 NPM-ALK-positive LP exhibited a clonal rearrangement of the T cell receptor gamma-chain gene. The t(2;5) was detected in 2 cases of LP without other evidence for a clonal lymphoid population. To identify cells carrying the t(2;5) translocation, we used immunohistochemistry to detect the ALK-encoded p80 protein and in situ hybridization for the specific detection of NPM-ALK transcripts. Both p80 protein and NPM-ALK transcripts were expressed by anaplastic or large CD30+ lymphoma cells with positive NPM-ALK amplification. The presence of t(2;5) in a subset of CD30+ cutaneous lymphoma and LP may indicate a common pathogenesis with a subset of anaplastic nodal lymphoma.
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PMID:Detection of t(2;5)(p23;q35) translocation by reverse transcriptase polymerase chain reaction and in situ hybridization in CD30-positive primary cutaneous lymphoma and lymphomatoid papulosis. 870 87

This paper examines the expression of fibroblast growth factor 2 (FGF-2) in the malignant human breast. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the level of expression of FGF-2 in a series of 51 patients clinically followed up for a median of 84 months (Luqmani et al, 1992). Immunohistochemistry and Western blotting were used to show that the level of FGF-2 in breast tissues correlated with the amount of FGF-2 mRNA. FGF-2 was present in both malignant and non-malignant breast, although less was expressed in malignant tissues as determined by all three methods. Immunohistochemistry on frozen sections of breast tissue showed expression of FGF-2 in myoepithelial and epithelial cells in non-malignant samples and generally lower or undetectable levels of staining in malignant epithelial cells. The results obtained by immunohistochemistry correlated well with RT-PCR data showing similar levels of FGF-2 and FGF-2 mRNA expression in samples. No correlation was found between FGF-2 mRNA expression and T stage, nodal status or oestrogen receptor status. However, Kaplan-Meier survival plots show that higher levels of FGF-2 are associated with improved overall and disease-free survival. We suggest that FGF-2 expression may have value as a prognostic indicator in breast cancer.
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PMID:Fibroblast growth factor 2 in breast cancer: occurrence and prognostic significance. 900 May 94

Hepatitis C virus (HCV) infection may be complicated by non-Hodgkin's lymphoma. We describe eight cases of B-cell extranodal non-Hodgkin's lymphoma occurring during the course of chronic HCV-related hepatic disease (low-grade of mucosa-associated lymphoid tissue [MALT]-type; diffuse large cell; Burkitt; diffuse small cell). Some were localized to the liver (2), liver and spleen (1), spleen (1), peritoneal cavity (1), parotid gland (1); others manifested in the nasopharynx (1) and eyelid (1) but were accompanied by nodal disease. Four lymphomatous specimens available for molecular analysis exhibited clonal immunoglobulin gene rearrangements, lacked bcl-2, bcl-6, c-myc genes and p53 alterations, and did not contain replicative intermediate HCV RNA, as documented by a strand-specific reverse transcriptase-polymerase chain reaction. Low levels of positive-strand HCV RNA were detected in a single hepatic lymphoma, suggesting the presence of the virus in residual hepatocytes. The antigen-driven properties of HCV-associated B-cell malignant neoplasms may be considered for hepatic MALT-type lymphoma, which probably originated from lymphoid tissue acquired during long-standing HCV infection.
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PMID:Extranodal lymphomas associated with hepatitis C virus infection. 957 65

To determine the significance of the t(2;5)(p23;q35) translocation in nodal and extranodal anaplastic large cell lymphoma (ALCL), we performed cytogenetic, molecular genetic, and immunohistochemical analyses of tumor tissues from 11 patients with CD30+ ALCL. Three of five patients with nodal ALCL had additional infiltration of the skin. Six patients had extranodal ALCL, two had primary intestinal ALCL, three had a primary cutaneous ALCL, and one had osseous ALCL. Cytogenetic investigation detected the t(2;5) in all patients with nodal ALCL but not extranodal ALCL. Tumor cells in t(2;5)+ lesions also stained immunohistochemically for p80NPM/ALK, whereas no staining for p80NPM/ALK was detected in extranodal ALCL. Two extranodal lesions had NPM/ALK fusion transcripts detected by nested reverse transcriptase-polymerase chain reaction. Fluorescence in situ hybridization analysis of these two lymphomas showed in one case a significant number (4%) of cells with a split hybridization signal, indicative of disruption of the NPM gene. Additional recurrent breakpoints observed in extranodal ALCL were 1p36, 6p25, and 8q24. Loss of genetic material occurred at 6q in one extranodal ALCL. Our results suggest that the t(2;5) more frequently plays a pathogenetic role in primary nodal than in extranodal ALCL and that this translocation may not be the primary event in some CD30+ ALCL.
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PMID:Chromosomal abnormalities in nodal and extranodal CD30+ anaplastic large cell lymphomas: infrequent detection of the t(2;5) in extranodal lymphomas. 959 98

To evaluate the clinical significance of drug resistance mechanisms in breast cancer, we examined the expression of MDR1 and MRP in primary breast carcinoma and normal adjacent tissue using a highly quantitative and reproducible reverse transcription-PCR assay. Expression of both genes was observed in all specimens examined, both tumor (n = 74) and normal adjacent tissue (n = 55). The expression of MDR1, however, was low, with the level of expression being 25 times less than the drug-resistant control cell line KB 8-5. Immunohistochemical analysis of P-glycoprotein corroborated the PCR results; only 6% (2 of 31) were positive for JSB1 staining, and 0 of 32 were positive for for UIC2. MRP expression did not exceed control cell line levels, and immunohistochemistry detected moderate levels of expression. MDR1 expression was independent of grade, stage, tumor size, nodal status, metastasis, and estrogen receptor and progesterone receptor status. There was, however, a significant correlation of MDR1 expression with age and histology. Approximately twice the expression of MDR1 was observed in the < 50 age group compared to the > 50 age group, and lobular carcinoma had 4 times the expression of MDR1 of other histological types. MRP expression was independent of all other clinical parameters. Thus, these results show that although MDR1 expression is detectable in primary breast carcinoma by PCR, this expression as measured by quantitative reverse transcriptase-PCR is extremely low. The significance of these low levels is yet to be determined. MDR1 expression was higher in < 50 age group and lobular carcinoma, which may contribute to poor prognosis associated with young age and lobular histology.
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PMID:Quantitative reverse transcriptase-polymerase chain reaction measured expression of MDR1 and MRP in primary breast carcinoma. 962 74


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