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)

The recombination activating gene, RAG-1, which is supposed to encode a molecule regulating V(D)J recombination, has been isolated. In the current study, the distribution of RAG-1 expression in human neoplastic hematopoietic cells was compared with the phenotypic and genotypic status of differentiation. Thirty-one hematopoietic cell lines (16 B-lineage, 9 T-lineage, 2 Hodgkin's disease, and 4 nonlymphoid cell lines) were investigated for the expression of human RAG-1 using the reverse-transcriptase polymerase chain reaction (RT-PCR). RAG-1 was not expressed in nonlymphoid, Hodgkin's disease, or mature-stage lymphoid cell lines, but was present in some acute lymphoblastic leukemia (ALL)/lymphoblastic lymphoma (LBL) cell lines. The investigation was extended to 45 cases of fresh ALL/LBL cells. The patterns of RAG-1 expression found in the cell lines and fresh ALL/LBL cells were similar. In B-lineage cells, the product of RAG-1 RT-PCR was detected in CD19+ CD10- CD20- CD5- stage (stage II, Nadler's classification) and was at the highest level in CD19+ CD10+ CD20- CD5- stage (stage III), but was absent or limited in CD19+ CD10+ CD20-+ CD5- (stage IV) or CD19+ CD10+ (or CD10-) CD5+. In stage II, monoclonal gene rearrangements of only the immunoglobulin heavy chain (IgH) were found, whereas monoclonal gene rearrangements of both IgH and T-cell receptor (TCR)-beta chain were frequently noted in stages III and IV. The expression of CD20 or CD5 antigen apparently correlated with the decline of RAG-1 expression. In T-lineage cells, RAG-1 was highly expressed in CD3- CD4+ CD8+/CD3+ CD4+ CD8+ thymic stages, but was negative or only weakly expressed in the CD3- CD4- CD8- prothymic or early thymic stage, in which the TCR-beta gene was often germline, or the CD3+ CD4+ CD8- mature thymic stage. The relative levels of RAG-1 mRNA give an additional delineating frame to the schemes of lymphoid differentiation based on phenotypic and genotypic status. RAG-1 is exhibited by cells of the thymic stage capable of synthesizing TCR or expressing it on the cell surface. The weak or absent expression of RAG-1 in the prothymic or early thymic stage suggests that the contribution of RAG-1 to the gene rearrangement may differ quantitatively between TCR-delta/TCR-gamma and TCR-beta.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Human recombination activating gene-1 in leukemia/lymphoma cells: expression depends on stage of lymphoid differentiation defined by phenotype and genotype. 839 73

T-cell lymphoma in patients infected with HIV is much less common than B-cell lymphoma. We describe two cases of HIV-associated extranodal lymphoma that showed Toutonlike tumor giant cells and mononuclear large lymphoma cells. Both cell types expressed T-cell-associated antigens, including CD3, CD5, CD43, and CD45RO, and were CD4- and CD30-positive and negative for all B-lineage-associated antigens. Both cases showed T-cell receptor gamma chain gene rearrangements using the polymerase chain reaction and were negative for the Epstein-Barr virus by in situ hybridization. Despite the expression of CD30 by the multinucleated cells, both cases were negative for ALK1 by immunohistochemistry and failed to show evidence of the nucleophosmin-anaplastic lymphoma kinase fusion product characteristic of t(2;5) using the reverse-transcriptase polymerase chain reaction. Although rare, CD4-positive, T-cell lymphoma with Toutonlike giant cells may be a distinct type of HIV-associated malignant lymphoma.
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PMID:Peripheral T-cell lymphoma with Toutonlike tumor giant cells associated with HIV infection: report of two cases. 1032 82

Successful implantation is a highly coordinated process involving changes in cytokines, adhesion molecules, hormones, enzymes and growth factors. This study examines the expression of key cytokines and vascular surface molecules in the pregnant uterus of sheep around the time of implantation. Uterine tissues and uterine washings were collected from non-pregnant and pregnant sheep at 17-19 days post-coitus (dpc), 26-27 and 34-36 dpc. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of caruncular/placentomal tissues revealed that cytokines IL-2, IL-4 and IL-8, which were not detected in non-pregnant uterus, were induced more strongly at 26-27 dpc than at other stages of pregnancy tested. Cytokines LIF, IL-6, IL-10, TNF-alpha were also most highly expressed at 26-27 dpc, expression of them being lower at other time-points during early pregnancy and non-pregnancy. The cytokines IL-1beta, IFN-gamma and TGF-beta were expressed in all non-pregnant and pregnant tissues examined. Enzyme-linked immunosorbent assay (ELISA) performed on uterine washings clearly detected the presence of IL-1alpha protein at 26-27 and 34-36 dpc. Immunohistochemistry revealed that expression of vascular adhesion molecule VCAM-1 in endometrial endothelium was strongly induced at 26-27 dpc in the pregnant endometrium. Expression of CD5 on vascular endothelium was not induced in placentomal tissues until 26-27 dpc and was further increased by 34-36 dpc. These results demonstrate a dynamic change in a wide range of cytokines during early stages of pregnancy, with a critical period around 26-27 dpc. In addition, at 26-27 dpc, expression of the surface/adhesion molecules, CD5 and VCAM-1, is induced on vascular endothelium of the sheep endometrium, possibly as a direct consequence of the changed cytokine environment, and may be involved in directing the changes in leucocyte migration observed during pregnancy.
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PMID:Effects of implantation and early pregnancy on the expression of cytokines and vascular surface molecules in the sheep endometrium. 1559 26