Circulating micro-RNAs as biomarkers for detection of cervical cancer

Abstract

Objectives: Circulating micro-RNAs have great potential as biomarkers for various pathological conditions including cancers. The serum miR-21 and miR-125b expressions were assessed for their potential clinical significance in cervical cancer. Methods: Serum samples were collected from 303 cervical cancer patients before the surgery or radio/chemotherapy and after the completion of the treatment with no evidence of the disease. Normal control serum samples were obtained from 335 healthy volunteers and individuals with benign diseases. Total RNAs were extracted from sera and reverse transcribed, and the expressions of miR-21 and miR-125b were measured by real-time quantitative PCR. Results: The expression levels of miR-21 and miR-125b were assessed in matched pre-treatment and post-treatment sera of cervical cancer patients. Compared to the normal control individuals, the expressions of both miR-21 and miR-125b were significantly down-regulated in pre- and post-treatment sera of cancer patients (p<0.0001). There was no significant difference in both miRNA expressions between pre- and post-treatment sera. The ROC curve analysis revealed that serum expression levels of miR-21 and miR-125b were able to differentiate cancer patient from normal controls (AUC 0.65 and 0.61 for miR-21 and miR-125b, respectively, p<0.0001). Clinical correlation analysis showed that patients with late stage cancer had significantly lower expressions of both miRNAs than patients with early stage disease (miR-21: p=0.025; miR-125b: p=0.001). Conclusions: Serum miR-21 and miR-125b may be the potential biomarkers for early detection of cervical cancer.