Detection of circulating tumor cells in peripheral blood from patients with gastric cancer using piRNAs as markers

ObjectiveTo investigate the feasibility of detecting circulating cancer cells in peripheral blood from gastric cancer patients using Piwi-interacting RNAs (piRNAs) as markers.Design and methodsReal-time quantitative reverse transcription-polymerase chain reaction was used to analyze piR-651 and piR-823 levels in the peripheral blood of 93 patients with gastric cancer and 32 healthy volunteers. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic values.ResultsThe peripheral blood levels of piR-651 and piR-823 in the patients with gastric cancer were significantly lower than those from controls (P < 0.001). The piR-651 level in gastric adenocarcinoma was higher than that in gastric signet ring cell carcinoma (P = 0.003). The piR-823 level was positively associated with tumor-node-metastasis stage (P = 0.027) and distant metastasis (P = 0.026). The areas under the ROC curve were 0.841, 0.812 and 0.860 for piR-651, piR-823 and the combination, respectively.ConclusionspiRNAs may be valuable biomarkers for detecting circulating gastric cancer cells.

Research Highlights
► piRNAs play important roles in gene expression control.
► piRNA level in peripheral blood from gastric cancer patients was not clearly defined.
► piR-651 and piR-823 levels in gastric cancer blood were lower than those in controls.
► piR-823 level was associated with tumor-node-metastasis stage and distant metastasis.
► piR-651 and piR-823 were valuable biomarkers for detecting circulating cancer cells.