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  1. TARC, a CC chemokine, is frequently expressed in classic Hodgkin's lymphoma but not in NLP Hodgkin's lymphoma, T-cell-rich B-cell lymphoma, and most cases of anaplastic large cell lymphoma
    Peh SC, Kim LH, Poppema S
    Am. J. Surg. Pathol., 2001 Jul;25(7):925-9.
    PMID: 11420464
    Thymus and activation-regulated chemokine (TARC) has been identified as a lymphocyte-directed CC chemokine that attracts activated T-helper type 2 (Th2) cells in humans. Recent studies showed that the T cells surrounding Reed-Sternberg cells in Hodgkin's lymphomas (HL) are Th2 type. Anaplastic large cell lymphomas (ALCL), T-cell-rich B-cell lymphoma (TCRBCL) can mimic HL in some instances. This study aimed to establish the pattern of TARC expression in these diseases. Immunohistochemical stain using a polyclonal goat anti-human antibody to TARC was performed on 119 cases of confirmed HL; 99 were classical type (43 mixed cellularity, 43 nodular sclerosis, 5 lymphocyte depleted, 4 lymphocyte rich, 4 unclassifiable) and 20 lymphocyte predominant HL. Additional 27 ALCL (9 T-, 18 null-cell phenotype), 16 T-cell and 8 B-cell non-Hodgkin's lymphoma (NHL) were studied. A total of 85.8% of the classical HL, one case of ALCL, and one case of large cell B-cell lymphoma with anaplastic morphology showed positive TARC expression in the tumor cells. The expression was paranuclear and/or diffuse in the cell cytoplasm. The tumor cells in all cases of lymphocyte predominant HL, TCRBCL, null ALCL, and T-NHL did not express TARC. The high frequency of TARC expression in the Reed-Sternberg cells of classical HL may explain the characteristic T-cell infiltrate in this disease. The absence in other types that may be morphologically similar indicates that staining for TARC may aid in differential diagnosis.
    Matched MeSH terms: Lymphoma, Large B-Cell, Diffuse/virology
  2. pSTAT3 and MYC in Epstein-Barr virus-positive diffuse large B-cell lymphoma
    Teoh SH, Khoo JJ, Abdul Salam DSD, Peh SC, Cheah SC
    Malays J Pathol, 2019 Dec;41(3):273-281.
    PMID: 31901912
    INTRODUCTION: Epstein-Barr Virus (EBV) is associated with several B-cell non-Hodgkin's lymphoma (NHL), but the role of EBV in diffuse large B-cell lymphoma (DLBCL) is poorly defined. Several studies indicated the expression of phosphorylated STAT3 (pSTAT3) is predominant in EBV(+)- DLBCL, of which its activated form can promote the downstream oncogenes expression such as c-MYC. c-MYC gene rearrangements are frequently found in aggressive lymphoma with inferior prognosis. Furthermore, EBV is a co-factor of MYC dysregulation. JAK1/STAT3 could be the downstream pathway of EBV and deregulates MYC. To confirm the involvement of EBV in JAK1/ STAT3 activation and MYC deregulation, association of EBV, pSTAT3 and MYC in EBV(+)- DLBCL cases were studied. The presence of pSTAT3 and its upstream proteins: pJAK1 is identify to delineate the role of EBV in JAK1/STAT3 pathway.

    MATERIALS AND METHODS: 51 cases of DLBCL paraffin-embedded tissue samples were retrieved from a single private hospital in Kuala Lumpur, Malaysia. EBER-ISH was performed to identify the EBV expression; ten EBV(+)-DLBCL cases subjected to immunohistochemistry for LMP1, pJAK1, pSTAT3 and MYC; FISH assay for c-MYC gene rearrangement.

    RESULTS: Among 10 cases of EBV(+)-DLBCL, 90% were non-GCB subtype (p=0.011), 88.9% expressed LMP1. 40% EBV(+)-DLBCL had pJAK1 expression.

    CONCLUSION: 66.7% EBV(+)-DLBCL showed the positivity of pSTAT3, which implies the involvement of EBV in constitutive JAK/STAT pathway. 44.5% EBV(+)-DLBCL have co-expression of pSTAT3 and MYC, but all EBV(+)-DLBCL was absence with c-MYC gene rearrangement. The finding of clinical samples might shed lights to the lymphomagenesis of EBV associated with non-GCB subtypes, and the potential therapy for pSTAT3-mediated pathway.

    Matched MeSH terms: Lymphoma, Large B-Cell, Diffuse/virology*
  3. Fulltext Regulation of S1PR2 by the EBV oncogene LMP1 in aggressive ABC-subtype diffuse large B-cell lymphoma
    Vockerodt M, Vrzalikova K, Ibrahim M, Nagy E, Margielewska S, Hollows R, et al.
    J Pathol, 2019 06;248(2):142-154.
    PMID: 30666658 DOI: 10.1002/path.5237
    The Epstein-Barr virus (EBV) is found almost exclusively in the activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL), yet its contribution to this tumour remains poorly understood. We have focused on the EBV-encoded latent membrane protein-1 (LMP1), a constitutively activated CD40 homologue expressed in almost all EBV-positive DLBCLs and which can disrupt germinal centre (GC) formation and drive lymphomagenesis in mice. Comparison of the transcriptional changes that follow LMP1 expression with those that follow transient CD40 signalling in human GC B cells enabled us to define pathogenic targets of LMP1 aberrantly expressed in ABC-DLBCL. These included the down-regulation of S1PR2, a sphingosine-1-phosphate (S1P) receptor that is transcriptionally down-regulated in ABC-DLBCL, and when genetically ablated leads to DLBCL in mice. Consistent with this, we found that LMP1-expressing primary ABC-DLBCLs were significantly more likely to lack S1PR2 expression than were LMP1-negative tumours. Furthermore, we showed that the down-regulation of S1PR2 by LMP1 drives a signalling loop leading to constitutive activation of the phosphatidylinositol-3-kinase (PI3-K) pathway. Finally, core LMP1-PI3-K targets were enriched for lymphoma-related transcription factors and genes associated with shorter overall survival in patients with ABC-DLBCL. Our data identify a novel function for LMP1 in aggressive DLBCL. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
    Matched MeSH terms: Lymphoma, Large B-Cell, Diffuse/virology
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