Circulating serum exosomes 5'Leader ArgTCG and 3'tRF SerGCT combined with tumor biomarkers as non-invasive diagnostic and monitoring indicators for colorectal cancer.

OBJECTIVES: Colorectal cancer (CRC) has one of the highest incidence and mortality rates among cancers, particularly concerning the rates of diagnosis. Serum exosomes (Exos) are crucial mediators for the intercellular transmission of genetic information. These vesicles contain various tRNA-derived fragments (tRFs) that play a role in the noncoding regulation of tumor genes. Consequently, they are anticipated to become valuable non-invasive diagnostic and predictive biomarkers for CRC. METHODS: At the Affiliated Taian City Central Hospital of Qingdao University, we isolated and extracted serum Exos from 201 healthy donors and 205 patients with CRC. To measure Exo physical morphology, we utilized qNano, transmission electron microscopy, and a particle size analyzer. Western blotting was conducted to confirm the expression of surface and nuclear proteins in the Exos. Gene chips were employed to screen for differentially expressed tRF RNAs. The quantitative PCR technology was deployed to ascertain 5'Leader-ArgTCG and 3'tRF-SerGCT differential expression. CRC diagnostic efficiency was assessed utilizing the area under the curve. RESULTS: We compared 5'Leader-ArgTCG and 3'tRF-SerGCT expression in 205 patients with CRC and 201 healthy donors. Among them, 5'Leader-ArgTCG was significantly downregulated, while 3'tRF-SerGCT was significantly upregulated. The diagnostic efficiency of predicting 5'Leader-ArgTCG and 3'tRF-SerGCT in serum Exos using survival curves was 0.659 and 0.659, respectively. Meanwhile, the diagnostic efficiency of combining the two tumor markers was 0.954. CONCLUSION: Serum Exos 5'Leader-ArgTCG and 3'tRF-SerGCT were differentially expressed in patients with CRC. Combining these two tumor markers may serve as a predictive indicator for the non-invasive diagnosis of CRC, demonstrating notable statistical significance.