2'-O-methylation and N6-methyladenosine enhance the oral delivery of small RNAs in mice

Shaoting Guo; Zhen Li; Xiaobei Li; Zhu Liang; Dandan Zhao; Na Sun; Jiaqi Liu; Xiaona Wang; Song Mei; Xiangyu Qiao; Chengyu Jiang

doi:10.1016/j.omtn.2025.102574

2'-O-methylation and N6-methyladenosine enhance the oral delivery of small RNAs in mice

Mol Ther Nucleic Acids. 2025 May 24;36(3):102574. doi: 10.1016/j.omtn.2025.102574. eCollection 2025 Sep 9.

Authors

Shaoting Guo¹, Zhen Li¹, Xiaobei Li¹, Zhu Liang¹, Dandan Zhao¹, Na Sun¹, Jiaqi Liu¹, Xiaona Wang¹, Song Mei¹, Xiangyu Qiao¹, Chengyu Jiang¹

Affiliation

¹ State Key Laboratory of Common Mechanism Research for Major Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 10000, China.

Abstract

Studies have demonstrated that small RNAs originating from plants can be taken up by the human digestive system and play a role in regulating gene expression. However, the impact of naturally occurring RNA modifications in these small RNAs on their absorption has been underexplored. Here, we show that 2'-O-methylation (2'-O-Me), N6-methyladenosine (m⁶A), and 5-methylcytidine (m⁵C) exhibit high abundance in small RNAs (18-30 nt) derived from herbal decoction. 2'-O-Me and m⁶A promote the oral delivery of small RNAs in vitro and in vivo, whereas m⁵C did not show the same enhancement. To study the underlying mechanism of this enhancement, we used liposomes to simulate the negatively charged cell membrane and investigated the influence of these modifications on RNA-biomembrane interaction, independent of RNA stability. Our findings provide a novel perspective on the role of modifications in small RNAs, offering insights into their potential applications in oral delivery for oligonucleotides.

Keywords: 2′-O-methylation; 5-methylcytidine; MT: Oligonucleotides: Therapies and Applications; N6-methyladenosine; RNA modifications; RNA-biomembrane interaction; oligonucleotide; oral delivery; plant-derived; small RNA.