Exploring the diagnostic potential of serum 5'tRF-Lys as a novel gastric cancer biomarker.

[OBJECTIVES] Gastric cancer (GC) is a global health challenge due to its asymptomatic early stages, low sensitivity of traditional serum biomarkers, and the invasiveness of endoscopy, resulting in delayed diagnosis and poor prognosis. The expression levels of tRNA-derived small RNAs (tsRNAs) significantly influence the emergence and development of malignancies. This study focused on the potential of tsRNAs as serum biomarkers for diagnosing GC.

[METHODS] Quantitative real-time PCR was used to measure 5'tRF-Lys expression levels, validated by agarose gel electrophoresis and Sanger sequencing. Kaplan-Meier survival curves assessed the association between 5'tRF-Lys expression levels and patient outcomes, while receiver operating characteristic (ROC) curves evaluated diagnostic accuracy. ROC curves showed that 5'tRF-Lys outperformed traditional serum biomarkers, and combining these markers can enhance diagnostic accuracy.

[RESULTS] The expression level of 5'tRF-Lys effectively differentiated GC patients from gastritis patients and healthy subjects. 5'tRF-Lys expression is negatively correlated with the T stage, lymph node metastasis, tumor-node-metastasis stage, neuro/vascular invasion, and positively correlated with tumor differentiation. Patients with low serum 5'tRF-Lys had a lower survival rate.

[CONCLUSIONS] 5'tRF-Lys shows promise as a sensitive and specific biomarker for GC, including early-stage detection and survival prognosis, offering potential clinical applications.