Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the expression of three cell proliferation-associated antigens: DNA polymerase alpha, Ki-67 antigen, and transferrin receptor, in 35 T-cell lymphomas of nodal origin (T-NL) and 40 cutaneous T-cell lymphomas (CTCL). Immunohistochemical staining was carried out on frozen tissue sections of these specimens using three monoclonal antibodies, DAKO-PC, CL22-2-42B (DNA polymerase alpha), and OKT9. The proportion of cells positive for CL22-2-42B, DAKO-PC, or OKT9 among all tumor cells was correlated with four histologic subtypes: malignant lymphoma (ML), diffuse, small; mixed; large; and large cell immunoblastic in both T-NL and CTCL. A strong correlation was noted between positivity for CL22-2-42B and that for DAKO-PC or OKT9. On the other hand, no difference in the expression of these three antigens was noted between T-NL and CTCL in the high, intermediate or low grade-malignancy group. In CTCL as well as in T-NL, cells positive for CL22-2-42B, DAKO-PC or OKT9 were significantly more numerous in the high-grade group than the intermediate-grade group, and in the intermediate-grade group than the low-grade group. Furthermore, a significant correlation between survival period and the number of CL22-2-42B-positive cells was noted when the T cell malignancies, CTCL and T-NL were considered (t value = 2.015, p less than 0.05). Thus, the expression of DNA-polymerase alpha, Ki-67 antigen or OKT9 seems to well reflect the biological behavior and/or clinical prognosis of T-cell lymphoma.
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PMID:Expression of three cell proliferation-associated antigens, DNA polymerase alpha, Ki-67 antigen and transferrin receptor in nodal and cutaneous T-cell lymphomas. 175 49

To detect the proliferating cells in situ, a monoclonal antibody against human DNA polymerase alpha (pol alpha) was employed because this enzyme is known to be present in the nucleus of the cells in G1, S, and G2 phases. In addition, the surface phenotype of pol alpha-positive proliferating lymphocytes in diseased lymph nodes was determined by double staining consisting of immunoperoxidase and immunoalkaline phosphatase methods with various monoclonal antibodies against lymphocyte membrane antigens. In the paracortical area of lymph nodes with reactive changes, proliferating cells were 17% or less, and most of them were helper T-cells, although suppressor T-cells and B-cells also proliferate to a certain extent. In contrast, the proliferating cell population in malignant lymphomas was generally more than 40%, and it showed a single surface phenotype, indicating monoclonal proliferation. In addition, an unusual T-cell antigen phenotype of proliferating cells was observed in some cases of peripheral T-cell lymphomas. Thus, this double staining provided the authors with valuable information regarding the proportion, localization, and surface phenotype of proliferating cells, which should be useful for diagnosis of the diseases of lymphoid system.
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PMID:Double immunoenzymatic detection of surface phenotype of proliferating lymphocytes in situ with monoclonal antibodies against DNA polymerase alpha and lymphocyte membrane antigens. 243 27

Terminal deoxynucleotidyl transferase (TdT) is a DNA polymerase located in the cell nucleus which catalyses the polymerization of deoxynucleotides at the 3'hydroxyl ends of oligo- or polydeoxynucleotide initiators without a template. TdT is known as a useful marker for the diagnosis of acute lymphoblastic leukaemia/lymphoma, but its detection usually requires fresh tissue specimens or cell suspensions, using either an enzyme analysis or immuno-fluorescence or -peroxidase staining. Until the recent development of the use of microwave-treated paraffin sections for immunoperoxidase staining, detection of TdT in paraffin sections required rather complicated processes. This new simple technique was applied to paraffin sections from the tumour tissue specimens of 16 patients with lymphoblastic lymphoma and of seven patients with non-endemic Burkitt's lymphoma, which is sometimes difficult to differentiate from lymphoblastic lymphoma because of their similar clinicopathological characteristics. In addition, as a control, ten cases each were examined of adult T-cell leukaemia/lymphoma (ATLL) and angioimmunoblastic lymphoma (AILD), which are both peripheral T-cell lymphomas. The tumour cells from 15 of the 16 (94 per cent) patients with lymphoblastic lymphoma were found to be TdT-positive. The specificity of the anti-TdT antibody used was confirmed by immunoblot and the specific 60 kD band was detected only in a specimen of lymphoblastic lymphoma. These results show that the immunostaining of TdT on paraffin-embedded sections is a useful method for differentiating lymphoblastic lymphoma from other lymphomas. This method is applicable to a routine diagnostic service.
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PMID:Terminal deoxynucleotidyl transferase staining of malignant lymphomas in paraffin sections: a useful method for the diagnosis of lymphoblastic lymphoma. 922 46