Li Fang, Zhou Ya-Dong, Liu Jiao, Cai Jiao-Di, Liao Zhi-Ming, Chen Guo-Qun
Department of Pathology, The Fourth Hospital of Changsha City, Changsha 410006, Hunan Province, PR China.
Department of Pathology, The Fourth Hospital of Changsha City, Changsha 410006, Hunan Province, PR China.
Cell Signal. 2021 Nov;87:110103. doi: 10.1016/j.cellsig.2021.110103. Epub 2021 Jul 31.
RBP-J is involved in number of cellular processes. However, the potential mechanisms of RBP-J on colorectal cancer (CRC) development have not been clearly defined. In this study, we aimed to investigate the role and molecular mechanism of RBP-J in CRC.
The expression levels of RBP-J and Tiam1 in CRC tissues and cells were evaluated by RT-qPCR or western blot. RBP-J was knocked down with sh-RBP-J or overexpressed by pcDNA3.1-RBP-J in CRC cells. Cell proliferation, migration and invasion abilities were analyzed by MTT, wound healing, and transwell assay, respectively. CHIP-qPCR, RIP and dual luciferase reporter assays were performed to confirm the interaction between miR-182-5p and RBP-J or Tiam1. Expression levels of p-p38 MAPK, p38 MAPK, Slug-1, Twist1 and MMP-9 were analyzed by western blot. G-LISA test was used to detect Rac1 activity.
Our results showed that the expression of RBP-J and Tiam1 was significantly up-regulated in CRC tissues and cells. RBP-J overexpression promoted proliferation, migration and invasion of CRC cells. Moreover, RBP-J was found to directly target miR-182-5p promoter and positively regulate the Tiam1/Rac1/p38 MAPK signaling pathway in CRC cells. It was also proved that miR-182-5p can bind Tiam1 directly. Furthermore, experiments revealed that RBP-J could promote CRC cell proliferation, migration and invasion via miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis. In addition, knockdown of RBP-J reduced tumor growth and metastasis in CRC mice.
RBP-J regulates CRC cell growth and metastasis through miR-182-5p mediated Tiam1/Rac1/p38 MAPK signaling pathway, implying potential novel therapeutic targets for CRC patients.
RBP-J参与多种细胞过程。然而，RBP-J在结直肠癌（CRC）发生发展中的潜在机制尚未明确。在本研究中，我们旨在探讨RBP-J在CRC中的作用及分子机制。
通过RT-qPCR或蛋白质免疫印迹法评估CRC组织和细胞中RBP-J和Tiam1的表达水平。在CRC细胞中，用sh-RBP-J敲低RBP-J表达，或用pcDNA3.1-RBP-J过表达RBP-J。分别通过MTT法、伤口愈合实验和Transwell实验分析细胞增殖、迁移和侵袭能力。进行染色质免疫沉淀-定量聚合酶链反应（CHIP-qPCR）、RNA免疫沉淀（RIP）和双荧光素酶报告基因实验，以证实miR-182-5p与RBP-J或Tiam1之间的相互作用。通过蛋白质免疫印迹法分析磷酸化p38丝裂原活化蛋白激酶（p-p38 MAPK）、p38 MAPK、锌指蛋白Slug-1（Slug-1）、 Twist家族蛋白1（Twist1）和基质金属蛋白酶9（MMP-9）的表达水平。采用G-LISA检测法检测Rac1活性。
我们的数据表明，CRC组织和细胞中RBP-J和Tiam1的表达显著上调。RBP-J过表达促进了CRC细胞的增殖、迁移和侵袭。此外，发现RBP-J直接靶向miR-182-5p启动子，并正向调节CRC细胞中Tiam1/Rac1/p38 MAPK信号通路。还证实miR-182-5p可直接结合Tiam1。此外，实验表明RBP-J可通过miR-182-5p介导的Tiam1/Rac1/p38 MAPK轴促进CRC细胞的增殖、迁移和侵袭。此外，敲低RBP-J可减少CRC小鼠的肿瘤生长和转移。
RBP-J通过miR-182-5p介导的Tiam1/Rac1/p38 MAPK信号通路调节CRC细胞的生长和转移，这为CRC患者提供了潜在的新型治疗靶点。
