Exosomal tsRNA-Gly-5-0007 may be used as a diagnostic marker for colorectal cancer.

Colorectal cancer is one of the common malignant tumors nowadays, with the highest mortality rate among cancers, and most patients have metastasis when diagnosed. Exosomes contain bioactive molecules such as RNA, which can participate in signal transduction between cells. tRF is a new type of non-coding small RNA, which plays an important role in the progression of cancer. The purpose of this study is to explore the value of exosomal tRF as a biological diagnostic marker for colorectal cancer. Through the use of transmission electron microscopy (TEM), qNano, and western blot, exosomes obtained from the serum of both healthy people and patients with colorectal cancer were characterized; the expression of tRNA-Gly-5-0007 was validated by real-time quantitative PCR (qRT-PCR) in the exosome of 172 colorectal cancer patients and 164 healthy people. The diagnostic efficacy of tsRNA-Gly-5-0007 as a diagnostic marker for colorectal cancer was evaluated by receiver operating characteristic curve (ROC) analysis. We further conducted a preliminary verification of how tsRNA-Gly-5-0007 participates in the malignant phenotype of tumors through transwell experiments and cell adhesion experiments. The TCGA database shows that tsRNA-Gly-5-0007 is an RNA fragment derived from tsRNA-Gly-CCC-2-1. The expression of tsRNA-Gly-CCC-2-1 is down-regulated in colorectal cancer tissues and may be involved in Wnt, mTOR and other signaling pathways. tsRNA-Gly-5-0007 can inhibit the adhesion and motor capacity of colorectal cancer cells. Compared with healthy people, the expression of exosomal tsRNA-Gly-5-0007 was significantly down-regulated in patients with colorectal cancer, especially in patients with early colorectal cancer. The diagnostic efficacy of exosomal tsRNA-Gly-5-0007 for the diagnosis of colorectal cancer was 0.7812, and the diagnostic efficacy for the diagnosis of early colorectal cancer was 0.7726. tsRNA-Gly-5-0007 may affect the adhesion and motor capacity of colorectal cancer cells through Wnt signaling pathway, and then participate in the malignant process of colorectal cancer cells. Moreover, the expression of exosomal tsRNA-Gly-5-0007 is down-regulated in colorectal cancer patients and can be used as a promising biomarker for the biological diagnosis of colorectal cancer.