tRNA-derived fragments (tRFs) as key non-coding players in the tumor transcriptome of colorectal cancer: introducing a new suspect responsible for the remaining unknowns of tumor pathology.

Colorectal cancer (CRC) is the third most common cancer globally, and the prognosis of this cancer is still not promising. As a result, a deeper investigation of CRC diagnosis biomarkers and a better knowledge of cancer carcinogenesis is still required. Otherwise, RNAs have the ability to modulate gene expression, which makes them potentially useful as novel markers. tRNA fragments (tRFs) are one of the novel emerging classes of non-coding RNA (ncRNA) produced from tRNAs under the influence of sex hormones and other stress situations. tRFs are crucial regulators of gene silencing, RNA processing, and protein translation. A growing number of studies have shown that tRFs are important in human cancers and can be used as diagnostic markers and potential therapeutic targets. Proliferation, cell cycle, and migration of tumor cells are all regulated by tRFs. Differentially expressed tRFs have been found in the epithelial-mesenchymal transition (EMT), proliferation, or metastasis process of CRC and are highly expressed in CRC tissues. They may be potential biomarkers and targets for interventions in the clinical treatment of CRC, and have a significant function in the metastasis of CRC. So, we aim to review the role of tRFs in the progression of CRC in order to know more about the functions of tRFs. Although much has been discovered about tRFs, what we currently know is probably only the beginning. So, more research is needed to determine the precise pathways in which tRFs are involved in CRC.