Expression profile of circulating microRNAs as a promising fingerprint for cervical cancer diagnosis and monitoring

Sensitive and specific biomarkers for the early detection of cervical cancer are urgently required to reduce the high morbidity and mortality of this disease. We previously demonstrated that circulating microRNAs (miRNAs) are correlated with certain types of human cancer. The aim of this study was to investigate the altered profile of serum miRNAs in cervical cancer patients in order to predict cervical cancer at a relative early stage. Serum samples were collected from 213 cervical cancer patients and 158 age- and ethnicity-matched controls. An initial screening of miRNA expression was performed by Solexa sequencing. Differential expression was validated using the stem-loop miRNA quantitative polymerase chain reaction (qPCR) assay in individual samples and the samples were arranged by two-phase selection and validation. The Solexa sequencing results revealed 12 markedly upregulated serum miRNAs in cervical cancer patients compared with controls. The reverse transcription-qPCR analysis identified a profile of 5 serum miRNAs (miR-21, -29a, -25, -200a and -486-5p) as a cervical cancer biomarker. The receiver operating characteristic curves indicated that a panel of 5 miRNAs constitutes a more sensitive and specific diagnostic test compared with any single miRNA-based assay, the squamous cell carcinoma antigen or the carbohydrate antigen 125. More importantly, miR-29a and miR-200a may indicate tumor histological grade and progression stage. Therefore, a 5-miRNA signature identified from genome-wide serum miRNA expression profiling may serve as a fingerprint for cervical cancer diagnosis.