Elevated level of microRNA-21 in the serum of patients with colorectal cancer.

In patients with colorectal cancer, circulating micro RNA-21 (miR-21) is overexpressed and may act as a potential diagnostic and prognostic biomarker. In the present study, serum miR-21 level was determined in patients with colorectal cancer and control subjects in an attempt to explore its potential clinical diagnostic and prognostic value. Serum levels of miR-21 were measured in 40 patients with colorectal adenocarcinoma and 40 control subjects using a quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) assay. Serum miR-21 levels were compared in the colorectal cancer patients and control subjects. Furthermore, the association between serum miR-21 level and the clinical stages of tumors was also examined in the patients. Serum miR-21 level was significantly elevated in colorectal adenocarcinoma patients relative to control subjects (P=0.0001), and it was revealed as a potential diagnostic biomarker for differentiating the patients from control subjects. Increased levels of serum miR-21 were associated with clinical stages of tumors in the patients (P=0.01). These results indicated that serum miR-21 levels could serve as a reliable diagnostic and prognostic biomarker for colorectal adenocarcinoma.