Abstract
The tsRNAs (tRNA-derived small RNAs) are a novel class of small non-coding RNAs derived from transfer-RNAs. Colon adenocarcinoma (COAD) is the most malignant intestinal tumor. This study focused on the identification and characterization of tsRNA biomarkers in colon adenocarcinomas. Data processing and bioinformatic analyses were performed with the packages of R and Python software. The cell proliferation, migration and invasion abilities were determined by CCK-8 and transwell assays. Luciferase reporter assay was used to test the binding of tsRNA with its target genes. With computational methods, we identified the tRNA fragments profiles within COAD datasets, and discriminated forty-two differentially expressed tsRNAs between paired colon adenocarcinomas and non-tumor controls. Among the fragments derived from the 3' end of tRNA-His-GUG (a histidyl-transfer-RNA), tRFdb-3013a and tRFdb-3013b (tRFdb-3013a/b) were notably decreased in colon and rectum adenocarcinomas, especially, tRFdb-3013a/b might tend to be down-regulated in patients with lymphatic or vascular invasion present. The clinical survival of colorectal adenocarcinoma patients with low tRFdb-3013a/b expression was significantly worse than that of high expression patients. In colon adenocarcinoma cells, tRFdb-3013a could have inhibited cell proliferations, and reduced cell migration and invasion abilities. The enrichment analyses showed that most of tRFdb-3013a correlated-genes were enriched in the extracellular matrix associated GO terms, phagosome pathway, and a GSEA molecular signature pathway. Additionally, the 3'UTR of ST3GAL1 mRNA was predicted to contain the binding site of tRFdb-3013a/b, tRFdb-3013a/b might directly target and regulate ST3GAL1 expression in colon adenocarcinomas. These results suggested that tRFdb-3013a/b might serve as novel biomarkers for diagnosis and prognosis of colon adenocarcinomas, and act a key player in the progression of colon adenocarcinomas.