Theotoki Eleni I, Kakoulidis Panos, Nikolakopoulos Konstantinos-Stylianos, Vlachou Eleni N, Tsitsilonis Ourania E, Voutsinas Gerassimos E, Anastasiadou Ema, Stravopodis Dimitrios J
Section of Cell Biology and Biophysics, Department of Biology, School of Science, National and Kapodistrian University of Athens, Athens 15701, Greece.
Department of Cancer Genetics, Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens 11527, Greece.
Mol Med Rep. 2025 Sep;32(3). doi: 10.3892/mmr.2025.13609. Epub 2025 Jul 11.
Argonaute RNA‑induced silencing complex catalytic component 2 (AGO2) is an evolutionary conserved protein involved in microRNA‑dependent gene expression regulation via the RNA interference (RNAi) mechanism. Nevertheless, AGO2 may also be involved in other key processes, such as histone modification, DNA methylation and alternative splicing. Its role in the proper development of organisms is key and no homologue is able to compensate for its loss. Therefore, using advanced immunofluorescence, transient transfection and molecular bioinformatics, the present study aimed to investigate novel, non‑canonical, RNAi‑dependent functions of AGO2 protein in mRNA/protein local homeostasis. The data revealed microtubule network‑dependent, localization of AGO2 in both centrosome and mitotic spindle assemblies during cell division and in the cytokinetic bridge formed during the last stage of mitosis (cytokinesis). Detection of AGO2 protein in these mitosis‑specific compartments, regardless of the presence of malignant phenotypes or multiple centrosomes/mitotic spindles in liver cells, indicates the cardinal role of AGO2 in centrosome biosynthesis, mitotic spindle formation and function, potentially controlling locality‑dependent homeostasis, in a novel non‑canonical, RNAi‑dependent manner. This novel AGO2/centrosome/mitotic spindle/cytokinetic bridge pathway may serve as a versatile molecular 'toolbox' for targeted therapy of human malignancy, including liver cancer.
AGO2蛋白是一种进化保守蛋白，通过RNA干扰（RNAi）机制参与微小RNA依赖性基因表达调控。然而，AGO2也可能参与其他关键过程，如组蛋白修饰、DNA甲基化和可变剪接。它在生物体正常发育中的作用至关重要，没有同源物能够弥补其缺失。因此，本研究利用先进的免疫荧光、瞬时转染和分子生物信息学技术，旨在研究AGO2蛋白在mRNA/蛋白质局部稳态中新型的、非经典的、RNAi依赖性功能。数据显示，在细胞分裂过程中，AGO2在中心体和有丝分裂纺锤体组件中以及在有丝分裂最后阶段（胞质分裂）形成的胞质分裂桥中呈微管网络依赖性定位。在这些有丝分裂特异性区室中检测到AGO2蛋白，无论肝细胞中是否存在恶性表型或多个中心体/有丝分裂纺锤体，这表明AGO2在中心体生物合成、有丝分裂纺锤体形成和功能中起关键作用，可能以一种新型的、非经典的、RNAi依赖性方式控制局部依赖性稳态。这种新型的AGO2/中心体/有丝分裂纺锤体/胞质分裂桥途径可能作为一种通用的分子“工具箱”用于包括肝癌在内的人类恶性肿瘤的靶向治疗。
