Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, P.R. China.
Lab Invest. 2022 Apr;102(4):411-421. doi: 10.1038/s41374-021-00638-x. Epub 2021 Nov 13.
Acute lymphoblastic leukemia (ALL) is a common malignancy in children. In this study, we aimed to explore putative mechanisms of microRNA-155-5p (miR-155-5p) involvement in childhood ALL (cALL) via interactions with casitas B-lineage lymphoma (CBL), interferon regulatory factor 4 (IRF4), and cyclin-dependent kinase 6 (CDK6). Bioinformatic analysis was performed initially to identify differentially expressed genes in cALL. The expression levels of miR-155-5p, CBL, IRF4, and CDK6 in peripheral blood lymphocytes from clinical ALL samples were determined using RT-qPCR and Western blot assays. A dual-luciferase reporter gene assay was used to ascertain a possible targeting relationship between miR-155-5p and CBL, CCK-8 assay and flow cytometry were used to measure cell activity and apoptosis of ALL cells. Co-IP was performed to investigate the interaction between CBL and IRF4 and the ubiquitination level of IRF4. Furthermore, in vivo validation was performed inducing xenograft tumor models with ALL cells in nude mice. As indicated by bioinformatic analysis, miR-155-5p and CDK6 were upregulated and CBL was downregulated in ALL. miR-155-5p was found to target CBL to inhibit CBL expression. miR-155-5p promoted the proliferation of ALL cells and inhibited their apoptosis by inhibiting the expression of CBL, which otherwise degraded IRF4 protein through ubiquitination, leading to inhibited CDK6 expression. Collectively, the results show that miR-155-5p can promote the development of cALL via the regulation on CBL-mediated IRF4/CDK6 axis.
急性淋巴细胞白血病（ALL）是儿童常见的恶性肿瘤。在这项研究中，我们旨在通过与 Casitas B 细胞淋巴瘤（CBL）、干扰素调节因子 4（IRF4）和细胞周期蛋白依赖性激酶 6（CDK6）的相互作用，探讨 microRNA-155-5p（miR-155-5p）在儿童 ALL（cALL）中的潜在作用机制。首先进行了生物信息学分析，以确定 cALL 中差异表达的基因。使用 RT-qPCR 和 Western blot 检测临床 ALL 样本外周血淋巴细胞中 miR-155-5p、CBL、IRF4 和 CDK6 的表达水平。双荧光素酶报告基因检测用于确定 miR-155-5p 与 CBL 之间可能的靶向关系，CCK-8 检测和流式细胞术用于测量 ALL 细胞的活性和凋亡。Co-IP 用于研究 CBL 和 IRF4 之间的相互作用以及 IRF4 的泛素化水平。此外，通过在裸鼠中用 ALL 细胞诱导异种移植肿瘤模型进行体内验证。生物信息学分析表明，miR-155-5p 和 CDK6 在 ALL 中上调，而 CBL 下调。miR-155-5p 被发现靶向 CBL 以抑制 CBL 表达。miR-155-5p 通过抑制 CBL 的表达促进 ALL 细胞的增殖并抑制其凋亡，否则 CBL 通过泛素化降解 IRF4 蛋白，从而抑制 CDK6 的表达。总之，这些结果表明，miR-155-5p 可以通过调节 CBL 介导的 IRF4/CDK6 轴促进 cALL 的发展。
