Monoe Yuya, Jingushi Kentaro, Taniguchi Kohei, Hirosuna Kensuke, Arima Jun, Inomata Yosuke, Takano Yoshiaki, Hamamoto Hiroki, Komura Kazumasa, Tanaka Tomohito, Hase Hiroaki, Lee Sang-Woong, Tsujikawa Kazutake
Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
Center for Medical Research & Development, Division of Translational Research, Osaka Medical and Pharmaceutical University, Takatsuki, Osaka, Japan.
J Extracell Vesicles. 2025 May;14(5):e70083. doi: 10.1002/jev2.70083.
RNA modifications are crucial in cellular processes, and their dysregulation is linked to diseases like cancer. Extracellular vesicles (EVs) contain various RNAs and might be susceptible to modifications, but detecting these modifications has been challenging due to the small amount of RNA in EVs. We successfully detected 22 RNA modifications in EVs using a proprietary ultra-HPLC MS/MS system. We identified reduced levels of N6-methyladenosine (m6A) in EVs derived from colon cancer tissues, which correlated with cancer recurrence. Increasing m6A levels via m6A demethylase Alkbh5 knockout suppressed the tumour-promoting effects of colorectal cancer EVs. Mechanistically, colorectal cancer-derived EVs increased tumour necrotic factor α and interleukin-6 secretion by macrophages via Toll-like receptor 8 in an m6A-dependent manner, promoting cancer cell proliferation. RNA-sequencing analysis showed that the levels of 5'-half-tRNA fragment (5'-half)-GlyGCC as well as those of m6A-modified 5'-half-GlyGCC were higher and lower, respectively, in colorectal cancer EVs than in normal colon tissue EVs. Cancer-derived EVs containing 5'-half-GlyGCC significantly promoted tumour growth, which was impeded by macrophage depletion. These findings provide evidence that cancer-specific RNA modifications are present in EVs, promoting tumour progression by regulating immune cells.
RNA修饰在细胞过程中至关重要，其失调与癌症等疾病相关。细胞外囊泡（EVs）含有多种RNA，可能易于发生修饰，但由于EVs中RNA含量少，检测这些修饰具有挑战性。我们使用专有的超高效液相色谱串联质谱系统成功检测到了EVs中的22种RNA修饰。我们发现来自结肠癌组织的EVs中N6-甲基腺苷（m6A）水平降低，这与癌症复发相关。通过敲除m6A去甲基化酶Alkbh5提高m6A水平可抑制结直肠癌EVs的促肿瘤作用。机制上，结直肠癌来源的EVs通过Toll样受体8以m6A依赖的方式增加巨噬细胞分泌肿瘤坏死因子α和白细胞介素-6，促进癌细胞增殖。RNA测序分析表明，结直肠癌EVs中5'-半tRNA片段（5'-half）-GlyGCC以及m6A修饰的5'-half-GlyGCC的水平分别高于和低于正常结肠组织EVs。含有5'-half-GlyGCC的癌症来源的EVs显著促进肿瘤生长，巨噬细胞耗竭可阻碍这一过程。这些发现提供了证据，表明癌症特异性RNA修饰存在于EVs中，通过调节免疫细胞促进肿瘤进展。
