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)

The PAX5 gene encodes the BSAP (B-cell-specific activator protein) which is a key regulator of B-cell development and differentiation. A recurring translocation t(9;14)(p13;q32) in non-Hodgkin's lymphoma moves the PAX5 on 9p13 within close proximity of the immunoglobulin heavy chain gene (IGH). KIS-1 cell line was established from a patient with diffuse large cell lymphoma of B-cell type carrying t(9;14). We analysed PAX5/BSAP expression by Northern and Western blotting in a panel of haematological tumour cell lines with other chromosome abnormalities in comparison with that of KIS-1. PAX5 mRNA and BSAP expression were detected in all B-cell lines tested, and the high level in KIS-1 was confirmed. However, a diffuse large B-cell lymphoma cell line and an acute B-lymphoid/myeloid leukaemia cell line expressed the PAX5/BSAP at levels comparable with KIS-1. PAX5 transcripts were readily detectable in clinical materials with a wide variety of B-cell neoplasms by reverse transcriptase-mediated polymerase chain reaction (PCR). Thus, PAX5/BSAP activation in haematological tumour cells is not necessarily associated with t(9;14). Although binding sites for BSAP have been identified in the promoters of CD19, this study failed to find clear correlation between the level of PAX5/BSAP expression and that of CD19. In contrast to KIS-1 in which the E mu enhancer of IGH was juxtaposed to PAX5, cloning of t(9; 14) from another case by long-distance PCR revealed that the PAX5 promoter was linked to a Cgamma constant region in divergent orientation, suggesting that the mechanism of PAX5 activation through recombination with IGH varies among individual cases. Breakpoints on 9p13 of the two translocations were clustered upstream of PAX5, leaving the PAX5 coding region intact.
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PMID:Expression of the PAX5/BSAP transcription factor in haematological tumour cells and further molecular characterization of the t(9;14)(p13;q32) translocation in B-cell non-Hodgkin's lymphoma. 972 95

The p73 gene, a member of the p53 family, is a new candidate tumor suppressor gene. To investigate the possibility of genetic alteration of p73 in leukemia and lymphoma, we examined 55 cell lines and 39 patient samples together with 17 nonhematopoietic cancer cell lines. Gene expression of p73 was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in cell lines (5 of 7 pre B/B-acute lymphoblastic leukemia [ALL], 13 of 21 T-ALL/lymphoblastic lymphomas [LBL], 9 of 10 B-non-Hodgkin's lymphomas [B-NHL], 8 of 9 acute myelogenous leukemias [AML], 2 of 2 T-NHL, 3 of 3 multiple myeloma), and in patient samples (16 of 23 pre B-ALL, 5 of 8 T-ALL/LBL, 5 of 8 B-NHL). PCR-single-strand conformation polymorphism (SSCP) of cDNAs showed no mutation in 43 p73-expressing cell lines within the regions that corresponded to the 5 mutational hotspots of the p53 gene. Neither homologous deletion nor rearrangement of the p73 gene were found by Southern blot analysis in any of the cell lines that lack expression of p73. In contrast to prior published data, analysis of a polymorphic site showed that the p73 gene was expressed biallelically in cell lines and normal peripheral blood. Notably, the p73-negative cell lines were hypermethylated at a CpG island in the 5' untranslated region of the p73 mRNA, and treatment of these cell lines with 5-azacytidine (5-AC), a demethylation reagent, induced p73 expression. Taken together, we found that a sizable proportion (32%) of ALL/B-NHL cell lines and primary tumors had negligible or limited expression of the p73 gene associated with hypermethylation of the gene. These findings suggest that silencing of the p73 gene by hypermethylation may contribute to development and/or progression of lymphoid neoplasms.
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PMID:Loss of p73 gene expression in leukemias/lymphomas due to hypermethylation. 1041 5

The translocation of chromosome 11, long arm, region 2, band 1, to chromosome 18, long arm, region 2, band 1 (t(11;18)(q21;q21)) represents a recurrent chromosomal abnormality in extranodal marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue (MALT) type and leads to a fusion of the apoptosis inhibitor-2 (API2) gene on chromosome 11 and the MALT lymphoma-associated translocation (MLT) gene on chromosome 18. A 2-color fluorescence in situ hybridization (FISH) assay, which can be used for the detection of t(11;18) in interphase nuclei and metaphase chromosomes on fresh and archival tumor tissue, was developed. The P1 artificial chromosome (PAC) clone located immediately telomeric to the MLT gene and the PAC clone spanning the API2 gene were differentially labeled and used to visualize the derivative chromosome 11 resulting from t(11;18), as evident by the overlapping or juxtaposed red and green fluorescent signals. The assay was applied to interphase nuclei of 20 cases with nonmalignant conditions and 122 B-cell non-Hodgkin's lymphomas (NHLs). The latter group comprised 20 cases of nodal follicle center cell lymphoma and diffuse large B-cell NHL, 10 cases of gastric diffuse large B-cell lymphoma, 10 cases of hairy cell leukemia, and 82 cases of MZBCL (41 extranodal from various locations, 19 nodal, and 22 splenic MZBCL) including 35 cases with an abnormal karyotype, 2 of which revealed t(11;18). By interphase FISH, t(11;18) was detected in 8 gastrointestinal low-grade MALT-type lymphomas including the 2 cytogenetically t(11;18)(+) cases. In the 8 t(11;18)(+) cases, the FISH results were confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) using API2 and MLT specific primers. Our results indicate that t(11;18)(q21;q21) specifically characterizes a subgroup of low-grade MZBCL of the MALT-type and that the FISH assay described here is a highly specific and rapid test for the detection of this translocation.
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PMID:Detection of t(11;18)(q21;q21) by interphase fluorescence in situ hybridization using API2 and MLT specific probes. 1097 68

Mucin1 (MUCI) is a class of high molecular weight glycoproteins found in the cell membranes of human epithelial cells. Epithelial glycoprotein 40 (EGP40) is a homophilic cell-cell adhesion molecule and expressed on the surface of most simple epithelial cells and the majority of carcinomas. We analyzed the expression of MUC1 and EGP40 in human bone marrow (BM) and peripheral blood (PB) by reverse transcriptase polymerase chain reaction (RT-PCR) and immunocytochemistry (ICC). Eight BM and 95 PB samples from healthy donors, 39 BM and 17 PB samples from patients with haematological malignancies and 45 BM samples from patients with breast cancer were analyzed. MUC1 mRNA and EGP40 mRNA and protein were detected in BM samples and PB samples from healthy donors and from patients with multiple myeloma (MM), non-Hodgkin's lymphoma (NHL) and chronic myelogenous leukaemia (CML). The positive cells showed erythroblast-like and plasmacell-like morphology by immunocytochemistry. The MUC1 and EGP40 nested PCR were positive in 83.3% (10/12) and in 100% (33/33) respectively of BM from patiens with breast cancer who had no evidence of distant metastases. It is concluded that MUC1 and EGP40 is expressed in haematopoietic tissues and haematological malignancies. Therefore, MUC1 and EGP40 expression as a marker for detection of breast cancer cells and micrometastatic epithelial cells in BM and PB is not specific using RT-PCR technique and immunocytochemistry.
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PMID:Evaluation of MUC1 and EGP40 in bone marrow and peripheral blood as a marker for occult breast cancer. 1120 3

Combined highly active anti-retroviral therapy (HAART) with protease and reverse transcriptase inhibitors has modified the natural history of opportunistic infections and neoplasms in human immunodeficiency virus (HIV)-infected patients. We analysed the influence of HAART on the response to treatment and survival in a series of 58 patients with acquired immune deficiency syndrome (AIDS)-related non-Hodgkin's lymphoma (NHL) treated with CHOP (cyclophosphamide, hydroxydoxorubicin, vincristine and prednisone). Two groups of patients were included: (i) forty-one patients diagnosed with NHL between 1988 and 1996 who were not treated with HAART; (ii) seventeen patients diagnosed since 1996, who were receiving or commenced HAART when NHL was diagnosed. The response rate to CHOP was higher in group 2 (13 out of 17 cases; 75%) than in group 1 (14 out of 41 cases; 34%) (P = 0.003). The 2-year probability of event-free survival (EFS) [95% confidence interval (CI)] for group 1 was 0.5 (0.24-0.74), whereas for group 2 it was 0.85 (0.61-0.90) (P = 0.024). The lymphoma-free survival (LFS) was also significantly different for both groups (2-year LFS probability 0.53 vs. 1.0, P = 0.04). The median (95% CI) overall survival (OS) for group 1 was 7 months (range, 3-10.8 months), whereas it was not reached in group 2 (P = 0.0015). In the multivariate analysis for remission attainment, the only variables with a higher probability to achieve complete remission (CR) were HAART (P = 0.01) and International Prognostic Index score 1 (P = 0.02). The only statistically significant variable in the multivariate analysis for EFS was HAART (P = 0.049) and the variables with prognostic value for OS in the multivariate analysis were B symptoms (P = 0.01) and HAART (P = 0.003). Patients with AIDS-related NHL treated with CHOP and HAART had a higher CR rate than those treated only with CHOP. In this study, HAART was an independent prognostic factor for CR, OS and EFS in patients with AIDS-related NHL.
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PMID:Influence of highly active anti-retroviral therapy on response to treatment and survival in patients with acquired immunodeficiency syndrome-related non-Hodgkin's lymphoma treated with cyclophosphamide, hydroxydoxorubicin, vincristine and prednisone. 1129 85

A nondifferentiating mouse myeloid leukemia cell line produces differentiation-inhibiting factors. One of these factors was purified as a homologue of nm23. The nm23 gene was isolated as a metastasis-suppressor gene that exhibits low expression in high-level metastatic cancer cells. The nm23 gene was overexpressed in acute myelogenous leukemia (AML) cells and a higher level of nm23-H1 expression was correlated with a poor prognosis in AML. Multivariate analysis of putative prognostic factors revealed that elevated nm23-H1 mRNA levels significantly contributed to the prognosis of patients with AML. The overexpression of nm23-H1 was also observed in various hematological neoplasms. To use nm23 overexpression to determine the prognosis for lymphoma, we established an enzyme-linked immunosorbent assay (ELISA) technique to determine the serum level of nm23-H1 protein. This assay is far simpler than that used to determine nm23 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). Using this system, we measured nm23-H1 protein levels in many hematological malignancies. Serum nm23-HI levels were significantly higher in patients with all of the hematological neoplasms tested (AML, chronic myelogenous leukemia, acute lymphoblastic leukemia, (ALL) myelodysplastic syndrome (MDS) and malignant lymphomas) than in normal controls. An elevated serum nm23-H1 protein concentration predicted a poor outcome for AML and non-Hodgkin's lymphoma. Especially in diffuse large B-cell lymphoma (DLBCL), seram nm23-H1 protein levels were an important prognostic factor in planning an appropriate treatment strategy for DLBCL. The serum nm23-H I protein levels probably depend on the total mass of malignant cells overexpressing nm23-H1.
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PMID:Serum nm23-H1 protein as a prognostic factor in hematological malignancies. 1215 76

Small blue cell tumors are a group of tumors that share a common histologic characteristic with H&E staining. This makes differentiation from one another difficult as they all appear small, blue and round. Even though they all appear the same, they are vastly different from each other. Several different techniques have been developed to help further delineate and classify these tumors which include: small cell lung cancer (SCLC); non-Hodgkin's lymphoma (NHL); Ewing's sarcoma; rhabdomyosarcoma; Merkel carcinoma; neuroblastoma; carcinoid tumors; and intra-abdominal desmpolastic small round cell tumor. Using immunoperoxidase staining, reverse transcriptase polymerase chain reaction and fluorescence in situ hybridization techniques, these tumors have been successfully differentiated from one another. This separation makes staging and treatment of these tumors more effective, as not all of these tumors respond to the same modality of treatment. The following review summarizes some of the recent findings in the various small blue cell tumors and with the potential of novel therapies.
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PMID:Recent advances in the molecular biology, diagnosis and novel therapies for various small blue cell tumors. 1292 79

The Fas ligand (FasL) pathway is one of the two major effector mechanisms of T-cell-mediated cell death. FasL expression by extralymphatic tissues is thought to maintain a status of immunity. Accordingly, it has been proposed that tumor cells express FasL as a mechanism of immunologic escape. However, data regarding FasL expression in normal or neoplastic tissues remain controversial. In the present study, we investigated the expression of FasL in normal peripheral blood B lymphocytes or malignant cells of the B-lymphocyte lineage to elucidate a possible immunologic counterattack mechanism. FasL gene expression was analyzed by reverse transcriptase polymerase chain reaction in two non-Hodgkin's lymphoma (NHL) entities: the highly aggressive Burkitt's lymphoma (BL) and indolent NHL chronic lymphocytic leukemia (CLL). FasL expression was found to be consistently negative in all BL cell lines and purified samples from patients with CLL. FasL is not constitutively expressed in normal peripheral blood or neoplastic B lymphocytes making the Fas counterattack, as described for gastrointestinal cancer, unlikely as a mechanism of immunologic escape of lymphoma cells.
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PMID:Fas ligand is not constitutively expressed in low-grade B-cell lymphoma and B-lymphoblastoid cells. 1293 Mar 19

Hepatitis C virus (HCV) has been associated with several extrahepatic disorders including mixed cryoglobulinemia (MC), autoimmune thyroiditis, Sjogren's syndrome. Such associations have led to the suggestion that HCV may participate in the development of various immunmediated disorders. Recently, it has been hypothesised that HCV might act as a trigger for the development of monoclonal B-cell disorders such as non-Hodgkin's lymphoma (NHL). Discordant data have been reported in different geographic regions of the world. The aim of this prospective case-control study was to detect the prevalence of HCV in patients with NHL in southeastern Anatolia region of Turkey. In this study, HCV antibody prevalence and cryoglobulinemia were investigated in 119 patients with histologically diagnosed NHL. The control group consisted of 117 patients who visited the outpatient clinic of internal medicine. None of the patients had HCV antibody positive (0%) with the enzyme immunoassay and reverse transcriptase polymerase chain reaction (RT-PCR). One of the control patients had positive HCV antibody (0.9%). Our data does not support the association between HCV infection and NHL in southeastern Anatolia region of Turkey.
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PMID:Hepatitis C virus in patients with non-Hodgkin's lymphoma in southeastern Anatolia region of Turkey: a prospective case-control study of 119 patients. 1469 28

Osteolysis and hypercalcemia are observed in 5-15%, and 10%, respectively, of malignant lymphoma patients during their clinical course. However, both osteolysis and hypercalcemia are uncommon at onset of the disease. We encountered a 24-year-old male non-Hodgkin's lymphoma patient who had multiple osteolytic lesion from the onset of the disease and repeated episodes of hypercalcemia during the clinical course. The patient died with refractory disease. We studied the expression of chemokines which might affect bone resorption using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Increased expressions of MIP-1alpha, MIP-1beta and RANKL, which are osteoclast-activating factors, were observed in the RNA derived from the patient's lymphoma cells. The secretion of osteoclast-activating factors such as MIP-1alpha by the tumor cells (and/or bone marrow stromal cells) might be involved in the etiology of osteolysis and hypercalcemia in some malignant lymphoma cases.
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PMID:Diffuse large B-cell lymphoma presenting with hypercalcemia and multiple osteolysis. 1510 31


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