Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019829 (Hodgkin's disease)
 30,247 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The neoplastic cells in classical Hodgkin disease (Reed-Sternberg cells) are of B-lymphoid origin, but they lack many markers of this cell lineage, for example, immunoglobulin, CD20, and B-cell-associated transcription factors. In contrast, the neoplastic cells ("L&H" cells) in lymphocyte predominance Hodgkin disease retain the molecular profile of germinal center B cells. In this paper, we investigated the expression in Hodgkin disease (45 cases and 3 cell lines) of 5 intracellular signaling molecules found in B cells. The Src family kinase Syk, the B-cell adaptor protein BLNK, and phospholipase C (PLC)-gamma2 were consistently absent from Reed-Sternberg cells, whereas 2 other Src kinases (Lyn and Fyn) were heterogeneously expressed in a proportion of cases (12% and 42%, respectively). In contrast, the tumor cells in all cases of lymphocyte predominance Hodgkin disease were positive for Fyn, Syk, BLNK, and PLC-gamma2, and Lyn immunostaining was seen in a minority of biopsies. These results indicate that in Reed-Sternberg cells, the defect in B-cell lineage marker expression includes a spectrum of molecules involved in intracellular signaling, a finding in keeping with recent gene expression profiling studies. Furthermore, the clear difference in expression of signaling proteins between the 2 major subtypes of Hodgkin disease may be of diagnostic value.
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PMID:Expression of intracellular signaling molecules in classical and lymphocyte predominance Hodgkin disease. 1288 1

We have investigated whether intracellular signal transduction molecules can be used as immunohistological markers of normal and neoplastic human leucocytes in routine tissue sections. We obtained selective labelling of white cells for eight such molecules (the 'linker' molecules SLP-76 and BLNK, the Src family kinases Lyn, Fyn, Syk and Hck, and the phospholipases PLC-gamma1 and PLC-gamma2). Antibodies to SLP-76 and PLC-gamma1 selectively labelled T cells, and antibodies to BLNK, Lyn, Fyn, Syk and PLC-gamma2 labelled B cells (although Fyn immunostaining was restricted to mantle zone B cells). Antibodies to the Syk and Hck kinases labelled probable thymocyte precursors at the periphery of the thymic cortex. In addition to lymphoid cells, several other leucocyte types were immunostained (e.g. SLP-76, Lyn, Syk and Hck were found in megakaryocytes, myeloid cells and/or macrophages, and PLC-gamma2 was detected in arterial endothelium). SLP-76 and PLC-gamma1 were found in most T-cell lymphomas studied, and some B-cell lymphomas were also positive for PLC-gamma1 (e.g. diffuse large cell and Burkitt's lymphoma). The five B cell-associated markers were found in most B-cell non-Hodgkin's lymphomas, although some diffuse large B-cell lymphomas were negative (e.g. for Lyn) and anti-Fyn tended not to stain small B-cell neoplasms. The observation that a range of leucocyte signalling molecules can be detected in routine biopsies offers new possibilities for studying normal and neoplastic human white cells in diagnostic tissue samples.
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PMID:Intracellular signalling molecules as immunohistochemical markers of normal and neoplastic human leucocytes in routine biopsy samples. 1498 4

Two microarray studies of mediastinal B cell lymphoma have shown that this disease has a distinct gene expression profile, and also that this is closest to the pattern seen in classical Hodgkin's disease. We reported previously an immunohistologic study in which the loss of intracellular B cell-associated signaling molecules in Reed-Sternberg cells was demonstrated, and in this study we have investigated the expression of the same components in more than 60 mediastinal B cell lymphomas. We report that these signaling molecules are frequently present, and in particular that Syk, BLNK and PLC-gamma2 (absent from Reed-Sternberg cells) are present in the majority of mediastinal B cell lymphomas. The overall pattern of B cell signaling molecules in this disease is therefore closer to that of diffuse large B cell lymphoma than to Hodgkin's disease, and is consistent with a common cell of origin as an explanation of the similar gene expression profiles.
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PMID:Expression pattern of intracellular leukocyte-associated proteins in primary mediastinal B cell lymphoma. 1574 41

The presumed involvement of paired box gene 5 (PAX5) in B-lymphomagenesis is based largely on the discovery of Pax5-specific translocations and somatic hypermutations in non-Hodgkin lymphomas. Yet mechanistically, the contribution of Pax5 to neoplastic growth remains undeciphered. Here we used 2 Myc-induced mouse B lymphoma cell lines, Myc5-M5 and Myc5-M12, which spontaneously silence Pax5. Reconstitution of these cells with Pax5-tamoxifen receptor fusion protein (Pax5ER(TAM)) increased neoplastic growth in a hormone-dependent manner. Conversely, expression of dominant-negative Pax5 in murine lymphomas and Pax5 knockdown in human lymphomas negatively affected cell expansion. Expression profiling revealed that Pax5 was required to maintain mRNA levels of several crucial components of B cell receptor (BCR) signaling, including CD79a, a protein with the immunoreceptor tyrosine-based activation motif (ITAM). In contrast, expression of 2 known ITAM antagonists, CD22 and PIR-B, was suppressed. The key role of BCR/ITAM signaling in Pax5-dependent lymphomagenesis was corroborated in Syk, an ITAM-associated tyrosine kinase. Moreover, we observed consistent expression of phosphorylated BLNK, an activated BCR adaptor protein, in human B cell lymphomas. Thus, stimulation of neoplastic growth by Pax5 occurs through BCR and is sensitive to genetic and pharmacological inhibitors of this pathway.
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PMID:B cell activator PAX5 promotes lymphomagenesis through stimulation of B cell receptor signaling. 1771

The anti-CD20 monoclonal antibody (mAb) rituximab is now routinely used for the treatment of non-Hodgkins lymphoma and is being examined in a wide range of other B-cell disorders, such as rheumatoid arthritis. Despite intensive study, the mechanism of action still remains uncertain. In the current study, anti-CD20 mAb-induced calcium signaling was investigated. Previously, we grouped anti-CD20 mAbs into Type I (rituximab-like) and Type II (B1-like) based upon various characteristics such as their ability to induce complement activation and redistribute CD20 into detergent-insoluble membrane domains. Here we show that only Type I mAbs are capable of inducing a calcium flux in B cells and that this is tightly correlated with the expression of the B-cell antigen receptor (BCR). Inhibitor analysis revealed that the signaling cascade employed by CD20 was strikingly similar to that utilized by the BCR, with inhibitors of Syk, Src, and PI3K, but not EGTA, p38, or ERK1/2, completely ablating calcium flux. Furthermore, binding of Type I but not Type II mAbs caused direct association of CD20 with the BCR as measured by FRET and resulted in the phosphorylation of BCR-specific adaptor proteins BLNK and SLP-76. Crucially, variant Ramos cells lacking BCR expression but with unchanged CD20 expression were completely unable to induce calcium flux following ligation of CD20. Collectively, these data indicate that CD20 induces cytosolic calcium flux through its ability to associate with and "hijack" the signaling potential of the BCR.
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PMID:Induction of cytosolic calcium flux by CD20 is dependent upon B Cell antigen receptor signaling. 1842 2

Although the latent membrane protein-1 (LMP1) of the Epstein-Barr virus (EBV) is believed to be important for the transformation of germinal centre (GC) B cells, the precise contribution of this viral oncogene to lymphoma development is poorly understood. In this study, we used a non-viral vector-based method to express LMP1 in primary human GC B cells. Gene expression profiling revealed that LMP1 induced in GC B cells transcriptional changes characteristic of Hodgkin's lymphoma cell lines. Strikingly, LMP1 down-regulated the expression of B-cell-specific genes including B-cell receptor components such as CD79A, CD79B, CD19, CD20, CD22, and BLNK. LMP1 also induced the expression of ID2, a negative regulator of B-cell differentiation. Our data suggest that in EBV-positive cases, LMP1 is likely to be a major contributor to the altered transcriptional pattern characteristic of Hodgkin/Reed-Sternberg cells, including the loss of B-cell identity.
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PMID:The Epstein-Barr virus oncoprotein, latent membrane protein-1, reprograms germinal centre B cells towards a Hodgkin's Reed-Sternberg-like phenotype. 1856 61

RSK2 is a serine/threonine kinase downstream signaling mediator in the RAS/ERK signaling pathway and may be a therapeutic target in mantle cell lymphoma (MCL), an almost incurable disease subtype of non-Hodgkin lymphoma. In this study, serine-227 (RSK2Ser227 ) in the N-terminal kinase domain (NTKD) of RSK2 was found to be ubiquitously active in five MCL-derived cell lines and in tumor tissues derived from five MCL patients. BI-D1870, an inhibitor specific to RSK2-NTKD, caused RSK2Ser227 dephosphorylation, and thereby, induced dose-dependent growth inhibition via G2 /M cell cycle blockade and apoptosis in four of the five cell lines, while one cell line showed only modest sensitivity. In addition, RSK2 gene knockdown caused growth inhibition in the four BI-D1870-sensitive cell lines. Comparative gene expression profiling of the MCL-derived cell lines showed that inhibition of RSK2Ser227 by BI-D1870 caused downregulation of oncogenes, such as c-MYC and MYB; anti-apoptosis genes, such as BCL2 and BCL2L1; genes for B cell development, including IKZF1, IKZF3, and PAX5; and genes constituting the B cell receptor signaling pathway, such as CD19, CD79B, and BLNK. These findings show that targeting of RSK2Ser227 enables concomitant blockade of pathways that are critically important in B cell tumorigenesis. In addition, we found favorable combinatory growth inhibitory effects of BI-D1870 with inhibitors of BTK (ibrutinib), AKT (ipatasertib), and BCL2 (venetoclax) in cell characteristic-dependent manners. These results provide a rationale for RSK2Ser227 in the NTKD as a potential therapeutic target in MCL and for future development of a novel bioavailable RSK2 NTKD-specific inhibitor.
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PMID:Serine-227 in the N-terminal kinase domain of RSK2 is a potential therapeutic target for mantle cell lymphoma. 3242 Jun 99