RESUMO
Long non-coding RNAs have been proposed as biomarkers for the detection, prevention and screening of various malignancies. In this study, two lncRNAs (ANRIL and BANCR) were assessed for biomarker application in the early detection of colorectal cancer (CRC) through stool specimen testing, as a non-invasive and cost-effective methodology. A total of 40 stool samples were collected from patients referred to the hospital with colorectal cancer or adenomatous polyps as pre-cancerous lesions; patients were diagnosed using colonoscopy and pathology reports were available. Twenty control samples were also obtained from healthy subjects for comparison. RNA extraction and cDNA synthesis were followed by real-time PCR to evaluate lncRNA expression. The up-regulation of ANRIL in 20% of samples taken from polyp patients, combined with up-regulation in 65% of patients with CRC, confirmed the potential usefulness of ANRIL as a prognostic biomarker (AUC 0.95; P < 0.0001). BANCR relative expression analysis illustrated significant up-regulation in polyp (P < 0.04) and tumoural participants (P < 0.03) compared with normal control individuals. The expression patterns of ANRIL and BANCR in polyp cases were significantly correlated according to correlation analysis (r = 0.45, P < 0.045). ANRIL expression patterns in stool specimens of polyp and tumour cases supported the use of ANRIL as a prognostic biomarker for screening patients in the early stages of CRC. Up-regulation of BANCR in pre-cancerous lesions as well as down-regulation of ANRIL may also be a specific marker pair for easy, convenient and fast CRC prognosis.