Transfer RNA-derived fragments as novel biomarkers of the onset and progression of gastric cancer.

Gastric cancer (GC) is a particularly malignant disease; thus, early diagnosis and treatment are especially important. Transfer RNA-derived small RNAs (tsRNAs) have been implicated in the onset and progression of various cancers. Therefore, the aim of this study was to explore the role of tRF-18-79MP9P04 (previously named tRF-5026a) in the onset and progression of GC. Expression levels of tRF-18-79MP9P04 were quantified in gastric mucosa specimens of healthy controls and plasma samples of patients with different stages of GC. The results showed that plasma levels of tRF-18-79MP9P04 were significantly decreased in the early and advanced stages of GC. The results of the nucleocytoplasmic separation assay found that tRF-18-79MP9P04 was localized in the nuclei of GC cells. High-throughput transcriptome sequencing identified genes regulated by tRF-18-79MP9P04 in GC cells, and the function of tRF-18-79MP9P04 was predicted by bioinformatics. Collectively, the findings of this study suggest that tRF-18-79MP9P04 would be useful as non-invasive biomarker for early diagnosis of GC and is related to cornification, the type I interferon signaling pathway, RNA polymerase II activities, and DNA binding.