Department of Hematology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Department of Hematology, Jingzhou Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Immun Inflamm Dis. 2020 Dec;8(4):672-683. doi: 10.1002/iid3.356. Epub 2020 Oct 4.
The underlying cause of relapsed and refractory (r/r) diffuse large B-cell lymphoma (DLBCL) is usually related to apoptosis resistance to antitumor drugs. The recent years have provided lots of evidence that tumor cells may undergo stress-induced premature senescence (SIPS) in response to chemotherapy, but how SIPS affects lymphoma cells remains inconclusive.
Fifty-two DLBCL patients, including 6 newly diagnosed (ND), 17 complete remissions (CR), and 29 (r/r), were enrolled in this study. We used a senescence-associated-β-galactosidase (SA-β-Gal) staining kit for senescence staining. Suppressive immune cells including regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) were detected by flow cytometry (FCM). Secreted cytokines were measured by ELISA Kit and SENEX gene expression was detected by a quantitative real-time polymerase chain reaction. We used 40 nM doxorubicin to induce the SIPS model of DLBCL in vitro. Apoptosis and proliferation activity of senescent LY8 cells were respectively detected by FCM and CCK8. SENEX gene was silenced by RNA interference.
The proportion of senescent lymphoma cells was significantly increased in r/r DLBCL patients, concomitant with increased Treg, MDSC, and various secreted cytokines with proinflammatory and immunosuppressive effects. The SENEX gene was significantly elevated in the SIPS model. Senescent DLBCL cells had good antiapoptotic ability and proliferative activity accompanied by increased immunosuppressive cytokines. Interestingly, when we silenced the SENEX gene in the DLBCL cell line, the results were the opposite to the above.
SIPS activated by the SENEX gene mediates apoptosis resistance of r/r DLBCL via promoting immunosuppressive cells and cytokines.
复发/难治性（r/r）弥漫性大 B 细胞淋巴瘤（DLBCL）的根本原因通常与抗肿瘤药物的凋亡抵抗有关。近年来有大量证据表明，肿瘤细胞在化疗时可能会因应激而发生过早衰老（SIPS），但 SIPS 如何影响淋巴瘤细胞仍存在争议。
本研究纳入了 52 例 DLBCL 患者，包括 6 例初诊（ND）、17 例完全缓解（CR）和 29 例（r/r）。我们使用衰老相关-β-半乳糖苷酶（SA-β-Gal）染色试剂盒进行衰老染色。通过流式细胞术（FCM）检测抑制性免疫细胞，包括调节性 T 细胞（Treg）和髓系来源的抑制性细胞（MDSC）。通过 ELISA 试剂盒测量分泌细胞因子，通过实时定量聚合酶链反应检测 SENEX 基因表达。我们用 40nM 多柔比星诱导体外 DLBCL 的 SIPS 模型。通过 FCM 和 CCK8 分别检测衰老 LY8 细胞的凋亡和增殖活性。用 RNA 干扰沉默 SENEX 基因。
r/r DLBCL 患者中衰老淋巴瘤细胞的比例显著增加，同时伴有 Treg、MDSC 以及各种具有促炎和免疫抑制作用的分泌细胞因子增加。SIPS 模型中 SENEX 基因明显上调。衰老的 DLBCL 细胞具有良好的抗凋亡能力和增殖活性，同时伴有免疫抑制细胞因子的增加。有趣的是，当我们在 DLBCL 细胞系中沉默 SENEX 基因时，结果与上述相反。
SENEX 基因激活的 SIPS 通过促进免疫抑制细胞和细胞因子介导 r/r DLBCL 的凋亡抵抗。
