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MEF2B is a member of the BCL6 gene transcriptional complex and induces its expression in diffuse large B-cell lymphoma of the germinal center B-cell-like type

Laboratory Investigation (2018) | Download Citation


Myocyte enhancer-binding factor 2B (MEF2B) has been implicated as a transcriptional regulator for BCL6. However, details about the interaction between MEF2B and BCL6 during expression, as well as the relationship of MEF2B to the expression of other germinal center (GC) markers, have not yet been fully explained. Using germinal center B-cell-like diffuse large B-cell lymphoma (GC-DLBCL) and activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell lines, we analyzed the expression of MEF2B and its associations with BCL6, CD10, and ERK. Furthermore, small interfering RNA (siRNA) was used to study the possible effects of MEF2B knockdown on these proteins and cell growth. Analysis of the BCL6 transcriptional complex was performed using electrophoretic mobility shift assay. The correlation between MEF2B expression and the genetic type of DLBCL was assessed using immunohistochemistry on 111 patient samples, and via in silico analysis of publicly available microarray (Gene Expression Omnibus (GEO)) datasets. Our results indicate that the expression of MEF2B protein is important for the growth of GC-DLBCL cells, as evidenced by MEF2B knockdown inhibition of cell growth and the subsequent suppression of BCL6, CD10, and ERK phosphorylation. Analysis of BCL6 transcription factors in nuclear extracts of MEF2-expressing DLBCL cells showed involvement of MEF2B with AP-2α and BCL6 proteins in the formation of the BCL6 gene transcriptional complex. Indeed, differential expression of MEF2B in the GC-DLBCL is statistically significant compared to the ABC-DLBCL in the GEO datasets, as well as in tissue microarray, as indicated via immunohistochemistry (Visco–Young algorithm). Our findings indicate that MEF2B is an essential component of the BCL6 gene transcriptional complex for the regulation of DLBCL growth via the promotion of BCL6 expression. Beyond its regulatory role in DLBCL growth, MEF2B expression correlated positively with BCL6 and CD10 expression, and was preferentially expressed in the GBC-DLBCL group.

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  1. 1.

    Swerdlow S, Campo E, Lee Harris N, et al. WHO classification of tumors of haematopoietic and lymphoid tissues. Lyon: IARC Press; 2008.

  2. 2.

    Alizadeh AA, Eisen MB, Davis RE, et al. Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling. Nature. 2000;403:503–11.

  3. 3.

    Cattoretti G, Chang CC, Cechova K, et al. BCL-6 protein is expressed in germinal-center B cells. Blood. 1995;86:45–53.

  4. 4.

    Ye BH, Cattoretti G, Shen Q, et al. The BCL-6 proto-oncogene controls germinal-centre formation and Th2-type inflammation. Nat Genet. 1997;16:161–70.

  5. 5.

    Ding J, Dirks WG, Ehrentraut S, et al. BCL6—regulated by AhR/ARNT and wild-type MEF2B—drives expression of germinal center markers MYBL1 and LMO2. Haematologica. 2015;100:801–9.

  6. 6.

    Ying CY, Dominguez-Sola D, Fabi M, et al. MEF2B mutations lead to deregulated expression of the oncogene BCL6 in diffuse large B cell lymphoma. Nat Immunol. 2013;14:1084–92.

  7. 7.

    Basso K, Saito M, Sumazin P, et al. Integrated biochemical and computational approach identifies BCL6 direct target genes controlling multiple pathways in normal germinal center B cells. Blood. 2010;115:975–84.

  8. 8.

    Pon JR, Marra MA. MEF2 transcription factors: developmental regulators and emerging cancer genes. Oncotarget. 2016;7:2297–312.

  9. 9.

    Basso K, Brescia P, Schneider C, et al. MEF2B instructs germinal center development and acts as an oncogene in B cell lymphomagenesis. Chantilly, VA: ASH Meeting on Lymphoma Biology; 2018.

  10. 10.

    Pon JR, Wong J, Saberi S, et al. MEF2B mutations in non-Hodgkin lymphoma dysregulate cell migration by decreasing MEF2B target gene activation. Nat Commun. 2015;6:7953.

  11. 11.

    Moore EM, Swerdlow SH, Gibson SE. Comparison of myocyte enhancer factor 2B versus other germinal center-associated antigens in the differential diagnosis of B-cell non-Hodgkin lymphomas. Am J Surg Pathol. 2018;42:342–50.

  12. 12.

    Krenács D, Borbényi Z, Bedekovics J, et al. Pattern of MEF2B expression in lymphoid tissues and in malignant lymphomas. Virchows Arch. 2015;467:345–55.

  13. 13.

    Schuetz JM, Johnson NA, Morin RD, et al. BCL2 mutations in diffuse large B-cell lymphoma. Leukemia. 2012;26:1383–90.

  14. 14.

    Yang Y, Shaffer AL, Emre NC, et al. Exploiting synthetic lethality for the therapy of ABC diffuse large B cell lymphoma. Cancer Cell. 2012;21:723–37.

  15. 15.

    Camicia R, Bachmann SB, Winkler HC, et al. BAL1/ARTD9 represses the anti-proliferative and pro-apoptotic IFNÂ-STAT1-IRF1-p53 axis in diffuse large B-cell lymphoma. J Cell Sci. 2013;126:1969–80.

  16. 16.

    Hassan M, Mirmohammadsadegh A, Selimovic D, et al. Identification of functional genes during Fas-mediated apoptosis using a randomly fragmented cDNA library. Cell Mol Life Sci. 2005;62:2015–26.

  17. 17.

    Negi AK, Kansal S, Bhatnagar A, et al. Alteration in apoptosis and cell cycle by celecoxib and/or fish oil in 7,12-dimethyl benzene (α) anthracene-induced mammary carcinogenesis. Tumour Biol. 2013;34:3753–64.

  18. 18.

    El Jamal SM, Taylor EB, Abd Elmageed ZY, et al. Interferon gamma-induced apoptosis of head and neck squamous cell carcinoma is connected to indoleamine-2,3-dioxygenase via mitochondrial and ER stress-associated pathways. Cell Div. 2016;11:11.

  19. 19.

    Selimovic D, Porzig BB, El-Khattouti A, et al. Bortezomib/proteasome inhibitor triggers both apoptosis and autophagy-dependent pathways in melanoma cells. Cell Signal. 2013;25:308–18.

  20. 20.

    Selimovic D, Sprenger A, Hannig M, et al. Apoptosis related protein-1 triggers melanoma cell death via interaction with the juxtamembrane region of p75 neurotrophin receptor. J Cell Mol Med. 2012;16:349–61.

  21. 21.

    El-Khattouti A, Selimovic D, Hannig M, et al. Imiquimod-induced apoptosis of melanoma cells is mediated by ER stress-dependent Noxa induction and enhanced by NF-κB inhibition. J Cell Mol Med. 2016;20:266–86.

  22. 22.

    Hassan M, Selimovic D, Ghozlan H, et al. Induction of high-molecular-weight (HMW) tumor necrosis factor(TNF) alpha by hepatitis C virus (HCV) non-structural protein 3 (NS3) in liver cells is AP-1 and NF-kappaB-dependent activation. Cell Signal. 2007;19:301–11.

  23. 23.

    Visco C, Li Y, Xu-Monette ZY, et al. Comprehensive gene expression profiling and immunohistochemical studies support application of immunophenotypic algorithm for molecular subtype classification in diffuse large B-cell lymphoma: a report from the International DLBCL Rituximab-CHOP Consortium Program Study. Leukemia. 2012;26:2103–13.

  24. 24.

    Scott DW, Wright GW, Williams PM, et al. Determining cell-of-origin subtypes of diffuse large B-cell lymphoma using gene expression in formalin-fixed paraffin-embedded tissue. Blood. 2014;123:1214–7.

  25. 25.

    Saad AG, Grada Z, Bishop B, et al. nCounter NanoString Assay shows variable concordance With Immunohistochemistry-based Algorithms in Classifying Cases of Diffuse Large B-Cell Lymphoma According to the Cell-of-Origin. Appl Immunohistochem Mol Morphol 2018.

  26. 26.

    El Jamal SM, Yaseen AA, Alatassi H, et al. Strong NFκB expression is associated with high-grade dysplasia in barrett's esophagus. Appl Immunohistochem Mol Morphol. 2016;2:329–33.

  27. 27.

    Daems C, Martin LJ, Brousseau C, et al. MEF2 is restricted to the male gonad and regulates expression of the orphan nuclear receptor NR4A1. Mol Endocrinol. 2014;28:886–98.

  28. 28.

    McCarty KS, Miller LS, Cox EB, et al. Estrogen receptor analyses. Correlation of biochemical and immunohistochemical methods using monoclonal antireceptor antibodies. Arch Pathol Lab Med. 1985;109:716–21.

  29. 29.

    Hirsch FR, Varella-Garcia M, Bunn PA, et al. Epidermal growth factor receptor in non-small-cell lung carcinomas: correlation between gene copy number and protein expression and impact on prognosis. J Clin Oncol. 2003;21:3798–807.

  30. 30.

    Budczies J, Klauschen F, Sinn BV, et al. Cutoff Finder: a comprehensive and straightforward Web application enabling rapid biomarker cutoff optimization. PLoS ONE. 2012;7:e51862.

  31. 31.

    Tzankov A, Zlobec I, Went P, et al. Prognostic immunophenotypic biomarker studies in diffuse large B cell lymphoma with special emphasis on rational determination of cut-off scores. Leuk Lymphoma. 2010;51:199–212.

  32. 32.

    Williams PM, Li R, Johnson NA, et al. A novel method of amplification of FFPET-derived RNA enables accurate disease classification with microarrays. J Mol Diagn. 2010;12:680–6.

  33. 33.

    Shaknovich R, Geng H, Johnson NA, et al. DNA methylation signatures define molecular subtypes of diffuse large B-cell lymphoma. Blood. 2010;116:e81–89.

  34. 34.

    Hummel M, Bentink S, Berger H, et al. A biologic definition of Burkitt's lymphoma from transcriptional and genomic profiling. N Engl J Med. 2006;354:2419–30.

  35. 35.

    Salaverria I, Philipp C, Oschlies I, et al. Translocations activating IRF4 identify a subtype of germinal center-derived B-cell lymphoma affecting predominantly children and young adults. Blood. 2011;118:139–47.

  36. 36.

    Kikuchi M, Miki T, Kumagai T, et al. Identification of negative regulatory regions within the first exon and intron of the BCL6 gene. Oncogene. 2000;19:4941–5.

  37. 37.

    Pasqualucci L, Migliazza A, Basso K, et al. Mutations of the BCL6 proto-oncogene disrupt its negative autoregulation in diffuse large B-cell lymphoma. Blood. 2003;101:2914–23.

  38. 38.

    Wang X, Li Z, Naganuma A, et al. Negative autoregulation of BCL-6 is bypassed by genetic alterations in diffuse large B cell lymphomas. Proc Natl Acad Sci USA. 2002;99:15018–23.

  39. 39.

    Ohashi K, Miki T, Hirosawa S, et al. Characterization of the promoter region of human BCL-6 gene. Biochem Biophys Res Commun. 1995;214:461–7.

  40. 40.

    Hans CP, Weisenburger DD, Greiner TC, et al. Confirmation of the molecular classification of diffuse large B-cell lymphoma by immunohistochemistry using a tissue microarray. Blood. 2004;103:275–82.

  41. 41.

    Bavi P, Uddin S, Ahmed M, et al. Bortezomib stabilizes mitotic cyclins and prevents cell cycle progression via inhibition of UBE2C in colorectal carcinoma. Am J Pathol. 2011;178:2109–20.

  42. 42.

    Gualco G, Bacchi LM, Domeny-Duarte P, et al. The contribution of HGAL/GCET2 in immunohistological algorithms: a comparative study in 424 cases of nodal diffuse large B-cell lymphoma. Mod Pathol. 2012;25:1439–45.

  43. 43.

    Jovanovic MP, Mihaljevic B, Jakovic L, et al. BCL2 positive and BCL6 negative diffuse large B cell lymphoma patients benefit from R-CHOP therapy irrespective of germinal and non germinal center B cell like subtypes. J BUON. 2015;20:820–8.

  44. 44.

    Hideshima T, Mitsiades C, Ikeda H, et al. A proto-oncogene BCL6 is up-regulated in the bone marrow microenvironment in multiple myeloma cells. Blood. 2010;115:3772–5.

  45. 45.

    Bhalla S, Evens AM, Dai B, et al. The novel anti-MEK small molecule AZD6244 induces BIM-dependent and AKT-independent apoptosis in diffuse large B-cell lymphoma. Blood. 2011;118:1052–61.

  46. 46.

    Bernieh A, El Dinali M, Abulsayen H, et al. The incorporation of MEF2B in DLBCL immunostains algorithms: a tissue microarray comparative study. In Laboratory Investigation (Vol. 97, pp. 339A–339A) New York: Nature Publishing Group; 2017.

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This work was supported by grants from the German Research Foundation (HA 5081/3-1) and German Cancer Research Foundation (10-2202-Ha1) to M Hassan. We would like to thank Dr. Carols Cordon-Cardo at the Icahn School of Medicine at Mount Sinai for his support to this study. We would like to thank Dr. Francisco Vega at the University of Miami and Dr. Katia Basso at the Columbia University for providing some of the reagents, nuclear extracts, and MEF2B vectors required for this study. We would also like to thank Ms. Barbara Bishop, Ms. Denise Kelley, and Ms. Melissa Peak at Special Procedures Lab at the University of Louisville for performing the IHC stains.

Author information


  1. Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, USA

    • Siraj M. El Jamal
    • , Julie Teruya-Feldstein
    •  & Adolfo Firpo-Betancourt
  2. Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA

    • Zakaria Grada
  3. Department of Medicine, University of Miami, Miami, FL, USA

    • Mohamed H. El Dinali
  4. Department of Surgery, Tulane University School of Medicine, New Orleans, LA, USA

    • He Zhou
    • , Helmi S. Khadra
    • , Jessica Friedman
    • , Hosam Shalaby
    •  & Mohamed Hassan
  5. Clinic of Dermatology, University Hospital of Aachen, Aachen, Germany

    • Sofie-Yasmin Hassan
    •  & Mosaad Megahed
  6. Department of Pathology, University of Tennessee Health Science Center and Le Bonheur Children’s Hospital, Memphis, TN, USA

    • Ali G. Saad
  7. Department of Pathology, University of Louisville, Louisville, KY, USA

    • Bradley Gibson
    •  & Mostafa Fraig
  8. Department of Pathology, University of Mississippi Medical Center, Jackson, MS, USA

    • Xinchun Zhou
  9. Department of Pediatrics, SUNY Downstate School of Medicine, Brooklyn, NY, USA

    • Hend A. Abulsayen
  10. Department of Pathology, Tulane University School of Medicine, New Orleans, LA, USA

    • Abida Kadi
  11. The Cancer and Blood Diseases Institute, Cincinnatti Children Hospital, Cincinnatti, OH, USA

    • Myesa Emberesh
  12. INSERM UMR 1121, University of Strasbourg, 67000, Strasbourg, France

    • Youssef Haikel
    •  & Mohamed Hassan
  13. Department of Operative Dentistry and Endodontics, Dental Faculty, University of Strasbourg, 67000, Strasbourg, France

    • Youssef Haikel


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The authors declare that they have no conflict of interest.

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Correspondence to Siraj M. El Jamal.

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