PO.MCB06.03 · 分子与细胞生物学
SETD4 调控儿童急性淋巴细胞白血病的细胞增殖和甲氨蝶呤反应
SETD4 regulates cell proliferation and methotrexate response in pediatric acute lymphoblastic leukemia
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
急性淋巴细胞白血病（ALL）是儿童人群中最常见的恶性肿瘤，缓解率较高。然而，复发仍是一个主要问题，该疾病仍是儿童和青少年死亡的主要原因之一。甲氨蝶呤（MTX）广泛用于 ALL 治疗，但在复发患者中经常观察到耐药性。白血病发生和治疗反应受基因表达改变和表观遗传调控的影响。SETD4 是一种组蛋白赖氨酸甲基转移酶，可调节染色质结构和与肿瘤发生相关的转录程序。在本研究中，我们研究了其在白血病发生中的作用。在我们由 83 例巴西儿童 ALL 患者组成的队列中，我们观察到 SETD4 过表达，这一发现得到了 BloodSpot Leukemia MILE Study 队列的支持，其中 SETD4 上调在具有 t(12;21) 易位的患者中尤为明显。我们进一步分析了来自 TARGET-ALL Phase II 研究的 TCGA RNA-seq 数据，按 SETD4 表达水平对患者进行分层。高 SETD4 与增殖相关通路的富集相关，包括 E2F、MYC、G2M 检查点和 DNA 修复，这些通路驱动加速的细胞周期进程并增加白血病细胞存活。为验证这些发现，我们在低表达的 Nalm-6 细胞系中上调 SETD4，并使用 siRNA 在高表达的 REH 细胞系中敲低 SETD4。SETD4 过表达在 24 小时（FC= 1.7，p < 0.01）、48 小时（FC= 1.6，p < 0.01）和 72 小时（FC= 2.0，p < 0.001）增加了 Nalm-6 的增殖，而 SETD4 沉默在 24 小时（FC= 0.8，p < 0.05）和 48 小时（FC= 0.7，p < 0.05）降低了 REH 的增殖。两个系统均显示 SETD4 水平与白血病细胞增殖之间存在直接关联。由于甲氨蝶呤靶向增殖过程，我们研究了 SETD4 是否也影响治疗敏感性。较高的 SETD4 水平增加了对 MTX 的敏感性（FC= 1.4，p < 0.0001），而 SETD4 沉默则降低了敏感性（FC= 0.7，p < 0.001）。总之，这些结果突显 SETD4 作为儿童 ALL 白血病负荷和治疗反应的有前景的候选生物标志物。
查看英文原文 English abstract
Acute lymphoblastic leukemia (ALL) is the most common malignancy in the pediatric population and presents high remission rates. However, relapse persists as a major concern and the disease remains a leading cause of mortality among children and adolescents. Methotrexate (MTX) is widely used in ALL treatment, although resistance is frequently observed in relapsed patients. Leukemogenesis and treatment response are influenced by alterations in gene expression and epigenetic regulation. SETD4 is a histone lysine methyltransferase that modulates chromatin structure and transcriptional programs linked to oncogenesis. In this study, we investigated its role in leukemogenesis. In our cohort of 83 Brazilian pediatric ALL patients, we observed SETD4 overexpression, a finding supported by the BloodSpot Leukemia MILE Study cohort, in which SETD4 upregulation was particularly evident among patients with the t(12;21) translocation. We further analyzed TCGA RNA-seq data from the TARGET-ALL Phase II study, stratifying patients by SETD4 expression levels. High SETD4 was associated with enrichment of proliferation-related pathways, including E2F, MYC, G2M checkpoint and DNA repair, which drive accelerated cell-cycle progression and increased leukemic cell survival. To validate these findings, we upregulated SETD4 in the low-expressing Nalm-6 cell line and knocked down SETD4 in the high-expressing REH line using siRNA. SETD4 overexpression increased proliferation in Nalm-6 at 24h (FC= 1.7, p < 0.01), 48h (FC= 1.6, p < 0.01) and 72h (FC= 2.0, p < 0.001), whereas SETD4 silencing reduced proliferation in REH at 24h (FC= 0.8, p < 0.05) and 48h (FC= 0.7, p < 0.05). Both systems demonstrated direct association between SETD4 levels and leukemic cell proliferation. Since methotrexate targets proliferative processes, we investigated whether SETD4 also influences treatment sensitivity. Higher SETD4 levels increased sensitivity to MTX (FC= 1.4, p < 0.0001), whereas SETD4 silencing reduced sensitivity (FC= 0.7, p < 0.001). Together, these results highlight SETD4 as a promising biomarker candidate for leukemic burden and treatment response in pediatric ALL.
利益披露 Disclosure
M. B. de Loyola, None..
A. M. Gualberto, None.