Expression Analysis of Circulating miR-21 in Iranian Patients with Hereditary Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality in the world. MicroRNAs (miRNAs) have potential as diagnostic biomarkers for various diseases including cancer. This study was undertaken to investigate expression of miR-21 before and after surgery in patients with hereditary CRC.

After collecting blood samples from 39 patients and 39 healthy controls, total RNA was extracted by the TRIzol method. Following cDNA synthesis, expression of miR-21 in serum of subjects was evaluated using real-time PCR, along with two reference genes, let-7d and let-7g. The real-time expression results and Ct values were collected and analyzed based on the 2-∆∆ct method.

In spite of tumor removal, serum miR-21 expression levels was significantly higher in hereditary CRC patients compared with controls (P=0.022).

Our results confirmed that samples from hereditary cases of CRC must not be included in experiments on the diagnostic potential of miRNAs.