Zhou Jianbiao, Chooi Jing-Yuan, Ching Ying Qing, Quah Jessie Yiying, Toh Sabrina Hui-Min, Ng Yvonne, Tan Tuan Zea, Chng Wee-Joo
Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore.
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074, Singapore.
World J Stem Cells. 2018 Apr 26;10(4):34-42. doi: 10.4252/wjsc.v10.i4.34.
To examine whether nuclear factor kappa B (NF-κB) activity regulates LIN28B expression and their roles in leukemia stem cell (LSC)-like properties.
We used pharmacological inhibitor and cell viability assays to examine the relation between NF-κB and LIN28B. Western blot and qRT-PCR was employed to determine their protein and mRNA levels. Luciferase reporter was constructed and applied to explore the transcriptional regulation of LIN28B. We manipulated LIN28B level in acute myeloid leukemia (AML) cells and investigated LSC-like properties with colony forming and serial replating assays.
This study revealed the relationship between NF-κB and LIN28B in AML cells through drug inhibition and overexpression experiments. Notably, inhibition of NF-κB by pharmacological inhibitors reduced LIN28B expression and decreased cell proliferation. We demonstrated that NF-κB binds to the -819 to -811 region of LIN28B promoter, and transcriptionally regulates LIN28B expression. LIN28B protein was significantly elevated in NFκB1 transfected cells compared to vector control. Importantly, ectopic expression of LIN28B partially rescued the self-renewal capacity impaired by pharmacological inhibition of NF-κB activity.
These results uncover a regulatory signaling, NF-κB/LIN28B, which plays a pivotal role in leukemia stem cell-like properties and it could serve as a promising intervening target for effective treatment of AML disease.
研究核因子κB(NF-κB)活性是否调节LIN28B的表达及其在白血病干细胞(LSC)样特性中的作用。
我们使用药理学抑制剂和细胞活力测定法来研究NF-κB与LIN28B之间的关系。采用蛋白质免疫印迹法和定量逆转录聚合酶链反应(qRT-PCR)来测定它们的蛋白质和mRNA水平。构建荧光素酶报告基因并用于探索LIN28B的转录调控。我们在急性髓系白血病(AML)细胞中调控LIN28B水平,并通过集落形成和连续传代试验研究LSC样特性。
本研究通过药物抑制和过表达实验揭示了AML细胞中NF-κB与LIN28B之间的关系。值得注意的是,药理学抑制剂抑制NF-κB可降低LIN28B表达并减少细胞增殖。我们证明NF-κB与LIN28B启动子的-819至-811区域结合,并转录调节LIN28B的表达。与载体对照相比,在转染NFκB1的细胞中LIN28B蛋白显著升高。重要的是,LIN28B的异位表达部分挽救了因NF-κB活性的药理学抑制而受损的自我更新能力。
这些结果揭示了一种调节信号通路,即NF-κB/LIN28B,其在白血病干细胞样特性中起关键作用,并且它可能成为有效治疗AML疾病的有前景的干预靶点。