Generation and characteristics of a novel “double-hit” high grade B-cell lymphoma cell line DH-My6 with MYC/IGH and BCL6/IGH gene arrangements and potential molecular targeted therapies

Abstract

“Double-hit” lymphoma (DHL) is a high-grade B-cell lymphoma that harbors concurrent MYC and BCL2 or BCL6 rearrangements. Because cases of MYC/BCL6 DHL are uncommon, most reported conclusions have been based on cases of MYC/BCL2 DHL. Lack of experimental MYC/BCL6 DHL models continues to hinder the pathophysiologic and therapeutic investigations of this disorder. We herein describe a novel MYC/BCL6 DHL cell line, designated DH-My6, carrying both the MYC–IGH and BCL6–IGH fusion genes. Interruptions of MYC and BCL6 expressions using short interfering RNAs and chemical inhibitors led to significant attenuation of DH-My6 cell growth. Greater antitumor effects were found when the cells were treated with a combination of MYC and BCL6 inhibitors. Moreover, the PLK1 inhibitor volasertib and the HDAC inhibitor vorinostat synergized strongly when combined with the bromodomain inhibitor JQ1. DH-My6 is a new well-validated MYC/BCL6 DHL cell line that will provide a useful model for studies of the pathogenesis and therapeutics for the less common DHL tumor type. The rationale for approaches targeting both MYC and BCL6, and in combination with PLK1 or HDAC inhibitors for superior suppression of the aggressive MYC/BCL6 DHL warrants further in vivo testing in a preclinical model.

Development of a novel cell line‐derived xenograft model of primary herpesvirus 8‐unrelated effusion large B‐cell lymphoma and antitumor activity of birabresib in vitro and in vivo

“…Also, we did not observe tumor cells invading tissues or organs in the thoracic cavity including the diaphragm or lungs. The xenotransplantation experiments were also performed using the “double‐hit” high‐grade B‐cell lymphoma cell line DH‐My6 22 . DH‐My6 cells (3 × 10 7 per mouse) also induced massive multiple solid tumors in all irradiated mice ( n = 3) 5 weeks after injection, but they spread outside the abdominal cavity (data not shown).…”

“…Cells were fixed with 4% paraformaldehyde, treated with blocking reagents, and reacted with rabbit monoclonal anti‐human c‐MYC (clone D84C12; Cell Signaling Technology) and mouse monoclonal anti‐human CD20 (clone L26; Nichirei Biosciences). Chromosomal analysis and spectral karyotyping (SKY) analysis were performed as described 22,23 . c‐MYC rearrangements were detected in interphase nuclei by FISH analysis using dual‐color, break‐apart rearrangement probes flanking the breakpoint regions of the genes 24 .…”

EBV‐positive pyothorax‐associated lymphoma expresses CXCL9 and CXCL10 chemokines that attract cytotoxic lymphocytes via CXCR3

“…OPL‐1, OPL‐2, OPL‐5, and OPL‐7 were obtained from Dr. Katsuyuki Aozasa (Osaka University Medical School, Japan), 25,26 and Pal‐1 and Pal‐2 were established by our group 27,28 . Nine of the 10 EBV‐negative DLBCL cell lines used here, HT, MHH‐PREB‐1, Nu‐DHL‐1, Nu‐DUL‐1, Su‐DHL‐5, Su‐DHL‐6, Su‐DHL‐10, Su‐DHL‐16, and WSu‐DLCL‐2, were obtained from Deutsche Sammlung von Migroorganismen und Zellkulturen (Leibniz Institute DSMZ), and DH‐My6 has been described elsewhere 29 . Human PBMCs were isolated from heparinized blood samples obtained from healthy adult donors using Ficoll–Paque (GE Healthcare).…”

“…27,28 Nine of the 10 EBV-negative DLBCL cell lines used here, HT, MHH-PREB-1, Nu-DHL-1, Nu-DUL-1, Su-DHL-5, Su-DHL-6, Su-DHL-10, Su-DHL-16, and WSu-DLCL-2, were obtained from Deutsche Sammlung von Migroorganismen und Zellkulturen (Leibniz Institute DSMZ), and DH-My6 has been described elsewhere. 29 Human PBMCs were isolated from heparinized blood samples obtained from healthy adult donors using Ficoll-Paque (GE Healthcare). The mouse pre-B-cell line B300-19 clone that stably expresses human CXCR3 (B300-CXCR3) was generated as previously described.…”

Itgb3-integrin-deficient mice may not be a sufficient model for patients with Glanzmann thrombasthenia

“…The spleen tissue sections were stained sequentially with hematoxylin and eosin at room temperature for 2–3 min. The immunohistochemical procedure was performed on paraffin sections or frozen sections according to a previous study ( 16 ). The slides were incubated with monoclonal anti-CD3 (1:50), anti-CD19 (1:200) or anti-CD71 (1:100) antibodies at 4°C overnight followed by goat anti-rat IgG (H+L) HRP (1:1,000) or goat anti-rabbit IgG (H+L) HRP (1:1,000) at 37°C for 1 h and diaminobenzidine substrate with hematoxylin counterstaining (n=3 mice/group).…”