NSUN3‐Associated m5C Modification of tRF5‐GlyTCC Suppresses Colorectal Cancer Progression via RPL23‐Linked Nucleolar Stress and p53‐Associated Autophagy and Enhances 5‐FU Sensitivity

Abstract

ABSTRACT tRNA‐derived small RNAs (tsRNAs) regulate gene expression and cellular stress responses in cancer, but their roles in colorectal cancer (CRC) progression and chemotherapy response remain incompletely understood. Dysregulated tsRNAs in CRC were identified by RNA sequencing. The functions of tRF5‐GlyTCC were evaluated using in vitro assays and an in vivo xenograft model. Its targets and molecular effects were investigated by bioinformatic analyses, luciferase reporter assays, western blotting, and immunofluorescence. m5C modification was assessed by MeRIP‐qPCR. tRF5‐GlyTCC was downregulated in CRC tissues and associated with advanced disease and poor prognosis. Restoration of tRF5‐GlyTCC suppressed CRC cell growth and migration in vitro and tumor growth in vivo. tRF5‐GlyTCC interacted with the RPL23 3′UTR and was associated with altered ribosomal homeostasis, nucleolar stress, p53 signaling, and autophagy. Restoration of tRF5‐GlyTCC enhanced 5‐FU sensitivity, while its agomir increased the antitumor effect of 5‐FU in vivo. NSUN3‐mediated m5C modification contributed to tRF5‐GlyTCC stability. NSUN3‐mediated m5C modification contributes to tRF5‐GlyTCC stability, which is associated with ribosomal homeostasis, nucleolar stress responses, and p53 signaling. This network contributes to tumor suppression and chemotherapy response in CRC.