TY - JOUR

T1 - Identification of BLNK and BTK as mediators of rituximab-induced programmed cell death by CRISPR screens in GCB-subtype diffuse large B-cell lymphoma

AU - Thomsen, Emil Aagaard

AU - Rovsing, Anne Bruun

AU - Anderson, Mads Valdemar

AU - Due, Hanne

AU - Huang, Jinrong

AU - Luo, Yonglun

AU - Dybkær, Karen

AU - Mikkelsen, Jacob Giehm

PY - 2020

Y1 - 2020

N2 - Diffuse large B-cell lymphoma (DLBCL) is characterized by extensive genetic heterogeneity, and this results in unpredictable responses to the current treatment, R-CHOP, which consists of a cancer drug combination supplemented with the humanized CD20-targeting monoclonal antibody rituximab. Despite improvements in the patient response rate through rituximab addition to the treatment plan, up to 40% of DLBCL patients end in a relapsed or refractory state due to inherent or acquired resistance to the regimen. Here, we employ a lentiviral genome-wide clustered regularly interspaced short palindromic repeats library screening approach to identify genes involved in facilitating the rituximab response in cancerous B cells. Along with the CD20-encodingMS4A1gene, we identify genes related to B-cell receptor (BCR) signaling as mediators of the intracellular signaling response to rituximab. More specifically, the B-cell linker protein (BLNK) and Bruton's tyrosine kinase (BTK) genes stand out as pivotal genes in facilitating direct rituximab-induced apoptosis through mechanisms that occur alongside complement-dependent cytotoxicity (CDC). Our findings demonstrate that rituximab triggers BCR signaling in a BLNK- and BTK-dependent manner and support the existing notion that intertwined CD20 and BCR signaling pathways in germinal center B-cell-like-subtype DLBCL lead to programmed cell death.

AB - Diffuse large B-cell lymphoma (DLBCL) is characterized by extensive genetic heterogeneity, and this results in unpredictable responses to the current treatment, R-CHOP, which consists of a cancer drug combination supplemented with the humanized CD20-targeting monoclonal antibody rituximab. Despite improvements in the patient response rate through rituximab addition to the treatment plan, up to 40% of DLBCL patients end in a relapsed or refractory state due to inherent or acquired resistance to the regimen. Here, we employ a lentiviral genome-wide clustered regularly interspaced short palindromic repeats library screening approach to identify genes involved in facilitating the rituximab response in cancerous B cells. Along with the CD20-encodingMS4A1gene, we identify genes related to B-cell receptor (BCR) signaling as mediators of the intracellular signaling response to rituximab. More specifically, the B-cell linker protein (BLNK) and Bruton's tyrosine kinase (BTK) genes stand out as pivotal genes in facilitating direct rituximab-induced apoptosis through mechanisms that occur alongside complement-dependent cytotoxicity (CDC). Our findings demonstrate that rituximab triggers BCR signaling in a BLNK- and BTK-dependent manner and support the existing notion that intertwined CD20 and BCR signaling pathways in germinal center B-cell-like-subtype DLBCL lead to programmed cell death.

KW - B-cell receptor

KW - CD20

KW - CRISPR

KW - CRISPR library screen

KW - lentiviral vectors

KW - rituximab

KW - IMPAIR ANTITUMOR-ACTIVITY

KW - CALCIUM INFLUX

KW - TYROSINE PHOSPHORYLATION

KW - INDUCED APOPTOSIS

KW - ANTIGEN RECEPTOR

KW - CD20 EXPRESSION

KW - IN-VITRO

KW - ANTIBODY

KW - COMPLEMENT

KW - GENE

U2 - 10.1002/1878-0261.12753

DO - 10.1002/1878-0261.12753

M3 - Journal article

C2 - 32585766

VL - 14

SP - 1978

EP - 1997

JO - Molecular Oncology

JF - Molecular Oncology

SN - 1574-7891

IS - 9

ER -