MicroRNA-21 is a new marker of circulating tumor cells in gastric cancer patients

The detection of circulating tumor cells (CTCs) has received great attention. MicroRNA-21 (miR-21) plays crucial roles in carcinogenesis and is considered as one of the most studied oncomiRNAs. We determined if miR-21 could be used a marker for the detection of CTCs in gastric cancer patients. Peripheral blood samples were collected from 53 preoperative patients with gastric cancer and 20 healthy volunteers. Real-time reverse transcription-polymerase chain reaction was used to detect the level of miR-21. Receiver operator characteristic curves (ROC) were constructed. Patients with gastric cancer display a significantly higher level of miR-21 in peripheral blood than those from controls. The miR-21 level was associated with the tumor node metastasis (TNM) stage, tumor size and tissue categories. The area under ROC curve was up to 0.853 +/- 0.086. This study highlights the potential of the detection of miR-21 in peripheral blood as a novel tool for monitoring CTCs in gastric cancer patients.