TY - JOUR
T1 - IRF8 is a transcriptional activator of CD37 expression in diffuse large B-cell lymphoma
AU - Elfrink, Suraya
AU - ter Beest, Martin
AU - Janssen, Luuk
AU - Baltissen, Marijke P.
AU - Jansen, Pascal W.T.C.
AU - Kenyon, Angelique N.
AU - Steen, Raymond M.
AU - de Windt, Daynelys
AU - Hagemann, Philipp M.
AU - Hess, Corine
AU - van Spronsen, Dick Johan
AU - Hoevenaars, Brigiet
AU - van der Spek, Ellen
AU - Xu-Monette, Zijun Y.
AU - Young, Ken H.
AU - Kaffa, Charlotte
AU - Bervoets, Sander
AU - van Heek, Jolien
AU - Hesius, Eva
AU - de Winde, Charlotte M.
AU - Vermeulen, Michiel
AU - van den Brand, Michiel
AU - Scheijen, Blanca
AU - van Spriel, Annemiek B.
N1 - Funding Information: S.E. is supported by a Radboudumc grant; A.B.v.S. is supported by the Netherlands Organization for Scientific Research NWO Gravitation Programme 2013 grant (ICI 000-23), the Dutch Cancer Society (KWF) (11618/2018 and 12949/2020), and was awarded a European Research Council Consolidator Grant (Secret Surface, 724281); B.S. is a recipient of a Dutch Cancer Society grant (11137/2017); and the Vermeulen laboratory is part of the Oncode Institute, which is partly funded by the Dutch Cancer Society. Publisher Copyright: © 2022 by The American Society of Hematology.
PY - 2022/4/12
Y1 - 2022/4/12
N2 - Diffuse large B-cell lymphoma (DLBCL) represents the most common form of non-Hodgkin lymphoma (NHL) that is still incurable in a large fraction of patients. Tetraspanin CD37 is highly expressed on mature B lymphocytes, and multiple CD37-targeting therapies are under clinical development for NHL. However, CD37 expression is nondetectable in ∼50% of DLBCL patients, which correlates with inferior treatment outcome, but the underlying mechanisms for differential CD37 expression in DLBCL are still unknown. Here, we investigated the regulation of the CD37 gene in human DLBCL at the (epi-)genetic and transcriptional level. No differences were observed in DNA methylation within the CD37 promoter region between CD37-positive and CD37-negative primary DLBCL patient samples. On the contrary, CD37-negative DLBCL cells specifically lacked CD37 promoter activity, suggesting differential regulation of CD37 gene expression. Using an unbiased quantitative proteomic approach, we identified transcription factor IRF8 to be significantly higher expressed in nuclear extracts of CD37-positive as compared with CD37-negative DLBCL. Direct binding of IRF8 to the CD37 promoter region was confirmed by DNA pulldown assay combined with mass spectrometry and targeted chromatin immunoprecipitation (ChIP). Functional analysis indicated that IRF8 overexpression enhanced CD37 protein expression, while CRISPR/Cas9 knockout of IRF8 decreased CD37 levels in DLBCL cell lines. Immunohistochemical analysis in a large cohort of primary DLBCL (n 5 206) revealed a significant correlation of IRF8 expression with detectable CD37 levels. Together, this study provides new insight into the molecular mechanisms underlying differential CD37 expression in human DLBCL and reveals IRF8 as a transcriptional regulator of CD37 in B-cell lymphoma.
AB - Diffuse large B-cell lymphoma (DLBCL) represents the most common form of non-Hodgkin lymphoma (NHL) that is still incurable in a large fraction of patients. Tetraspanin CD37 is highly expressed on mature B lymphocytes, and multiple CD37-targeting therapies are under clinical development for NHL. However, CD37 expression is nondetectable in ∼50% of DLBCL patients, which correlates with inferior treatment outcome, but the underlying mechanisms for differential CD37 expression in DLBCL are still unknown. Here, we investigated the regulation of the CD37 gene in human DLBCL at the (epi-)genetic and transcriptional level. No differences were observed in DNA methylation within the CD37 promoter region between CD37-positive and CD37-negative primary DLBCL patient samples. On the contrary, CD37-negative DLBCL cells specifically lacked CD37 promoter activity, suggesting differential regulation of CD37 gene expression. Using an unbiased quantitative proteomic approach, we identified transcription factor IRF8 to be significantly higher expressed in nuclear extracts of CD37-positive as compared with CD37-negative DLBCL. Direct binding of IRF8 to the CD37 promoter region was confirmed by DNA pulldown assay combined with mass spectrometry and targeted chromatin immunoprecipitation (ChIP). Functional analysis indicated that IRF8 overexpression enhanced CD37 protein expression, while CRISPR/Cas9 knockout of IRF8 decreased CD37 levels in DLBCL cell lines. Immunohistochemical analysis in a large cohort of primary DLBCL (n 5 206) revealed a significant correlation of IRF8 expression with detectable CD37 levels. Together, this study provides new insight into the molecular mechanisms underlying differential CD37 expression in human DLBCL and reveals IRF8 as a transcriptional regulator of CD37 in B-cell lymphoma.
UR - http://www.scopus.com/inward/record.url?scp=85128307165&partnerID=8YFLogxK
U2 - https://doi.org/10.1182/bloodadvances.2021004366
DO - https://doi.org/10.1182/bloodadvances.2021004366
M3 - Article
C2 - 35086136
SN - 2473-9529
VL - 6
SP - 2254
EP - 2266
JO - Blood advances
JF - Blood advances
IS - 7
ER -