Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The t(2;5)(p23;q35) translocation is associated with a high percentage of anaplastic large-cell lymphomas (ALCL) of T- or null-cell phenotype. This translocation was recently cloned and results in the fusion of the nucleophosmin gene (NPM) on chromosome 5q35 to a novel tyrosine kinase-encoding gene designated anaplastic lymphoma kinase (ALK) on chromosome 2p23. Using a sensitive and specific reverse transcription-polymerase chain reaction (RT-PCR) assay to detect the NPM/ALK fusion transcript, we assessed the involvement of NPM/ALK in a series of histologically and immunohistochemically confirmed ALCL, in non-ALCL aggressive non-Hodgkin's lymphomas of T-cell phenotype, and in Hodgkin's disease (HD) to better define the morphologic spectrum of disease associated with this translocation. Twenty-four cases of ALCL were selected on the basis of CD30 positivity and histologic features. Seventeen cases presented as classical nodal and extranodal disease, four cases presented as primary cutaneous disease, and three were associated with human immunodeficiency virus (HIV) infection. As ALCL may show overlapping histology with both HD and other aggressive non-Hodgkin's lymphomas, particularly of T-cell phenotype (T-NHL), we also studied 34 cases of HD and 19 of T-NHL. NPM/ALK chimeric transcripts of identical size were detected in 11 of the 24 (46%) cases of ALCL. NPM/ALK fusion transcripts were found in 11 of 17 (65%) classical ALCL cases but were not detected in the four primary cutaneous cases of ALCL or in the three HIV-related ALCL cases. In addition, NPM/ALK transcripts were not detected in any of the 34 cases of HD or in the 19 cases of T-NHL. These data indicate that NPM/ALK fusion transcripts occur in a high percentage of classical nodal ALCL (65%). In addition, these data strongly suggest that ALCL, as defined in this study, is not pathogenetically related to either HD disease or the majority of other types of aggressive T-NHL. This is a US government work. There are no restrictions on its use.
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PMID:Analysis of the t(2;5)(p23;q35) translocation by reverse transcription-polymerase chain reaction in CD30+ anaplastic large-cell lymphomas, in other non-Hodgkin's lymphomas of T-cell phenotype, and in Hodgkin's disease. 766 79

The t(2;5)(p23;q35) translocation was initially identified in cases of anaplastic large-cell lymphoma (ALCL) that expressed the Ki-1 (CD30) antigen. We have recently cloned this translocation and shown it to encode a chimeric product consisting of the N-terminal portion of a nonribosomal nucleolar phosphoprotein, nucleophosmin (NPM), from chromosome 5, fused to the kinase domain of a novel transmembrane tyrosine-specific protein kinase, anaplastic lymphoma kinase (ALK), from chromosome 2. To better define the spectrum of lymphomas that contain this translocation, we have analyzed 70 cases of non-Hodgkin's lymphoma (NHL) for expression of the t(2;5)-derived NPM/ALK chimeric message by reverse transcriptase-polymerase chain reaction (RT-PCR). Using a previously described set of oligonucleotide primers, NPM/ALK chimeric transcripts were detected in 21 of 22 cases that contained the t(2;5) by cytogenetic analysis and in 10 of 48 cases that either lacked evidence of the t(2;5) or had unsuccessful cytogenetics. In all but 1 case, the NPM/ALK PCR products were of identical size and sequence, suggesting that the genomic chromosome breaks are clustered in a single intron in both NPM and ALK. The NPM/ALK-expressing cases were not confined to NHLs with anaplastic morphology and included 15 ALCLs, 6 immunoblastic lymphomas, and 10 diffuse large-cell lymphomas. Moreover, only slightly greater than half of the cases with anaplastic morphology and 59% of CD30-expressing cases were NPM/ALK positive. Thus, neither anaplastic morphology nor the expression of CD30 accurately predicted the presence of this molecular genetic subtype of lymphoma.
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PMID:Molecular detection of the (2;5) translocation of non-Hodgkin's lymphoma by reverse transcriptase-polymerase chain reaction. 778 Jan 28

Fifty-six cases of anaplastic large cell lymphoma (ALCL), 23 cases of Hodgkin's disease, and 16 cases of diffuse large cell lymphoma were investigated for the t(2;5)(p23;q35) translocation. The translocation was detected by using cytogenetic analysis, reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry with P80 antibody directed against the kinase domain of anaplastic lymphoma kinase (ALK) of the chimeric NPM/ALK protein. In all but three cases of ALCL, we found an agreement between cytogenetic analysis, RT-PCR, and P80 staining. However, in one case, the t(2;5) translocation was detected with cytogenetic analysis, but RT-PCR and P80 staining were found to be negative. Conversely, in another case the karyotype was normal, but the hybrid mRNA and P80 staining were found to be positive. In one case, malignant cells showed a translocation involving chromosomes 1q25 and 2p23 and were strongly positive for P80 staining. Such a result could be expected because P80 antibody detects the kinase domaine of the ALK protein encoded by chromosome 2p23. Overall 73.2% (41 of 56) of cases were found to be positive. However, the highest percentage (23 of 26 cases; 88.5%) of P80 positive cases was found in children compared with 60% (18 of 30 cases) in adult ALCL (P < .05). In Hodgkin's disease, Reed-Sternberg cells were found to be clearly negative by RT-PCR and with P80 antibody. The latter results suggest that Hodgkin's disease and t(2;5)-positive ALCL are distinct biological entities and that the demonstration of the t(2;5) translocation is of diagnostic importance in differentiating these two entities. The results of the present study indicate that immunohistochemistry with P80 antibody is a reliable method for detecting NPM/ALK chimeric protein.
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PMID:High incidence of the t(2;5)(p23;q35) translocation in anaplastic large cell lymphoma and its lack of detection in Hodgkin's disease. Comparison of cytogenetic analysis, reverse transcriptase-polymerase chain reaction, and P-80 immunostaining. 854 53

The CD30+ anaplastic large cell lymphoma (ALCL) represents a new lymphoma entity thought to be related to Hodgkin'S disease (HD), but displaying also its own unique features. Cytogenetic studies of ALCL have demonstrated the presence of a (2;5)(p23;q35) translocation in a substantial number of these cases. Recently, the t(2;5) has been cloned and described to represent fusion of the NPM gene with the ALK gene on chromosome 5. To better define the spectrum of lymphomas containing this abnormality we have analyzed 50 continuous human cell lines established from various types of non-Hodgkin's lymphoma, ALCL and HD. In a first step, the expression of the NPM-ALK fusion gene was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). In a second step, the t(2;5)-carrying cells were tested for the translation of functional chimeric mRNA into a fusion protein by immuno-staining of single cells with a polyclonal antibody. The NPM-ALK fusion transcript and the p80 protein were detected in eight of nine ALCL cell lines. We were unable to find PCR evidence for the t(2;5) in any of the non-ALCL cell lines including other CD30+ cell lines. As all seven bona fide HD cell lines were NPM-ALK-negative, these results do not support the notion that the t(2;5) represents a chromosomal aberration common to both ALCL and HD.
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PMID:The (2;5)(p23;q35) translocation in cell lines derived from malignant lymphomas: absence of t(2;5) in Hodgkin-analogous cell lines. 855 20

The chromosomal aberration t(2:5) resulting in the juxtaposition of NPM and ALK genes is a well-known feature of several Ki-1+ anaplastic large cell lymphomas (ALCL) of the T-cell type. However, conflicting results have been reported concerning the presence of this gene rearrangement in other ALCL and Hodgkin's disease (HD), respectively. We performed NPM/ALK RT-PCR on 14 cases of ALCL expressing distinct myelomonocytic markers, e.g. CD11c, CD13, CD14 or CD68, but neither T-cell nor B-cell associated antigens (null cell phenotype). The specific translocation was found exclusively in six childhood tumours previously diagnosed as malignant histiocytosis (MH), whereas all adult lymphomas (three ALCL without characteristics of MH, three secondary ALCL following HD) and two paediatric cases of secondary ALCL following HD did not show NPM/ALK gene fusion products. By Southern blotting, the status of T-cell receptor (TCR) and immunoglobulin heavy chain genes (IgH) were investigated; two patients with initially diagnosed MH had the TCRdelta-chain gene rearranged (Ddelta2-Ddelta3 and Vdelta1-Jdelta1, respectively). IgH rearrangements were detected in only one patient with secondary ALCL. Our data indicate a high association of previously diagnosed MH and NPM/ALK gene rearrangements. In one case, this specific translocation was demonstrated at an early stage of development; in another, a mature TCRdelta-chain gene rearrangement was detected. These data support the hypothesis of a lymphoid origin of this subgroup of Ki-1 positive ALCL previously diagnosed as MH.
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PMID:NPM/ALK gene fusion transcripts identify a distinct subgroup of null type Ki-1 positive anaplastic large cell lymphomas. 861 79

We have molecularly cloned a cDNA encoding a protein uniquely expressed and hyperphosphorylated at tyrosine residues in a Ki-1 lymphoma cell that contained chromosomal translocation t(2;5). The encoded protein p80 was shown to be generated by fusion of a protein-tyrosine kinase and a nucleolar protein B23/nucleophosmin (NPM). The coding sequence of this cDNA turned out to be virtually identical to that of the fusion cDNA for NPM-anaplastic lymphoma kinase (ALK) previously cloned from the transcript of the gene at the breakpoint of the same translocation. Overexpression of p80 in NIH 3T3 cells induced neoplastic transformation, suggesting that the p80 kinase is aberrantly activated. The normal form of p80 was predicted to be a receptor-type tyrosine kinase on the basis of its sequence similarity to the insulin receptor family of kinases. However, an immunofluorescence study using COS cells revealed that p80 was localized to the cytoplasm. Thus, subcellular translocation and activation of the tyrosine kinase presumably by its structural alteration would cause the malignant transformation. We also showed that a mutant p80 lacking the NPM portion was unable to transform NIH 3T3 cells. Thus, the NPM sequence is essential for the transforming activity, suggesting that the chromosomal translocation is responsible for the oncogenesis. Finally, Shc and insulin receptor substrate 1 (IRS-1) were tyrosine-phosphorylated and bound to p80 in p80-transformed cells. However, mutants of p80 that were defective for binding to and phosphorylation of Shc and insulin receptor substrate 1 could transform NIH 3T3 cells. Association of these mutants with GRB2 was still observed, suggesting that interaction of p80 with GRB2 but not with Shc or IRS-1 was relevant for cell transformation.
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PMID:Characterization of the transforming activity of p80, a hyperphosphorylated protein in a Ki-1 lymphoma cell line with chromosomal translocation t(2;5). 863 37

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

The revised European-American lymphoma classification recognizes a subtype of anaplastic large-cell lymphoma (ALCL), termed lympho-histiocytic because of its peculiar cytological composition. As in the case of classical ALCL, this tumor usually occurs in young patients and shows an excellent response to chemotherapy, but some authors have suggested that in reality this is a nonanaplastic T-cell lymphoma rich in histiocytes. In this paper, we show that three of five cases of lympho-histiocytic ALCL stain with anti-ALK antibodies and can therefore be presumed to express the chimeric NPM/ALK protein secondary to (2;5) translocation. These findings further support the inclusion of this as a type of ALCL and not among the nonanaplastic peripheral T-cell lymphomas. Furthermore, they indicate that staining for ALK proteins is a powerful tool for the diagnosis of lympho-histiocytic ALCL, the recognition of which may be difficult on morphological grounds.
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PMID:Frequent expression of the NPM-ALK chimeric fusion protein in anaplastic large-cell lymphoma, lympho-histiocytic type. 909 77

Anaplastic large cell lymphoma (ALCL) is a heterogeneous group of diseases by morphology, phenotype, genotype, and clinical presentation. Using a new monoclonal antibody (ALK1) that recognizes the native anaplastic lymphoma kinase (ALK) protein as well as the fusion product of the t(2;5)(p23;q35), nucleophosmin (NPM)/ALK, we investigated for ALK expression cases diagnosed as ALCL as well as lympho-proliferative disorders possessing overlapping features with ALCL. Thirteen cases showed cytoplasmic staining of the neoplastic cells. These cases were characterized by a fairly uniform morphology and occurred in children and young adults as a systemic disease. All other cases comprising T or null ALCL (17 cases), B ALCL (8 cases), Hodgkin's disease (HD) (15 cases), HD-like ALCL (23 cases), and lymphomatoid papulosis (9 cases), were negative for ALK expression. Translocation t(2;5)(p23;q35) was found by classical cytogenetics or interphase fluorescence in situ hybridization in 8 of the ALK1-positive cases and by reverse transcription-polymerase chain reaction in 1 other case. Two additional ALK1-positive cases with an abnormal karyotype, but without t(2;5)(p23;q35), showed by fluorescence in situ hybridization analysis a cryptic NPM/ALK gene fusion caused by an insertion of ALK near NPM in one case and a translocation of ALK to 2q35 as a result of an indiscernible inv(2)(p23q35) in the other. The latter variant translocation points to a localization of an unknown gene at 2q35 that, like NPM, might deregulate ALK and be involved in the pathogenesis of ALCL. In summary, immunohistochemistry with ALK1 antibody allows the identification of a distinct subgroup within the ALCL of T or null phenotype that is associated with 2p23 abnormalities and lacks the marked histological pleomorphism described in ALCL in general. Whereas immunostaining is the most sensitive method to identify this group, it does not help to additionally clarify the relationship among ALCL, HD, and HD-like ALCL.
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PMID:The monoclonal antibody ALK1 identifies a distinct morphological subtype of anaplastic large cell lymphoma associated with 2p23/ALK rearrangements. 925 Jan 48

In 20%-50% of the advanced cutaneous T-cell lymphomas (CTCL), malignant T cells undergo large cell transformation (LCT). The malignant T cells of LCT in CTCL can share morphologic and immunophenotypic similarities with CD30 (Ki-1)-positive anaplastic large cell lymphoma (ALCL), suggesting a common mechanism of pathogenesis. The t(2;5) (p23;q35) translocation, resulting in the fusion of the nucleophosmin (NPM) gene and the anaplastic lymphoma kinase (ALK) gene, is associated with primary CD30+ ALCL. To determine whether acquisition of this chromosomal translocation is involved in the pathogenesis of LCT in CTCL, we examined 12 tumor samples from 9 CTCL patients, including 8 with LCT-CTCL and one with concurrent CTCL and Hodgkin's disease, for the presence of the t(2;5) translocation. Numerous CD30+ large cells were present in 4 LCT-CTCL consistent with secondary CD30+ ALCL; CD30 was expressed by <10% of the large cells in another case and was negative in the other 3 lymphomas. Using primers spanning the NPM/ALK fusion junction, PCR amplification following reverse transcription (RT) of mRNA failed to show the products of NPM/ALK fusion in all samples tested. Thus, the t(2;5) (p23;q35) translocation does not appear to be involved in the molecular pathogenesis of LCT in CTCL, including CD30+ cases.
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PMID:The pathogenesis of large cell transformation in cutaneous T-cell lymphoma is not associated with t(2;5)(p23;q35) chromosomal translocation. 927 57


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