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.