title: Detection of miR-34a and miR-34b/c in stool sample as potential screening biomarkers for noninvasive diagnosis of colorectal cancer.
abstract: Explore potential screening biomarkers for noninvasive diagnosis of colorectal cancer (CRC) by testing methylation of the miR-34a and miR-34b/c promoter in CRC patients' tissue and stool samples. Methylation-specific PCR analyses were performed on sample DNAs: 82 pairs of normal/cancer samples, 82 CRC patients' stool samples, 40 healthy volunteer stool samples, and 20 healthy volunteer blood samples were recruited. miR-34a has been found methylated in 65 of 82 (79.3%) the CRC tissue samples, but only 36 of 82 (43.9%) in corresponding normal samples. And when testing miR-34a in stool, 63 of 82 (76.8 %) CRC stool samples were observed methylated, and 2 of 40 (5%) healthy samples were observed methylated. The methylation for miR-34b/c has been found in 80 of 82 (97.5%) CRC tissue samples, 49 of 82 (59.8%) corresponding CRC normal samples, and 74 of 79 (93.6%) CRC stool samples. Yet we did not detect any methylation from healthy volunteers stool samples or healthy adult blood samples. Results indicated 76.8 % sensitivity and 93.6% specificity of the miR-34a methylation test for detecting CRC using stool samples. Meanwhile, the sensitivity and specificity of miR-34b/c were 95 and 100%, respectively. Moreover, our results revealed that abnormal DNA methylation of miR-34a was correlated with lymph metastasis (P = 0.010). Abnormal methylation of miR-34a and miR-34b/c genes might be regarded as potential biomarkers for noninvasive screening and diagnosis of colorectal cancer.
authors.affiliation: The Department of Surgical Oncology, The First Affiliated Hospital, Xi'an Jiaotong University College of Medicine, 277W. Yanta Road, Xi'an, 710061, Shaanxi, China.
authors.forename: Xuan-di
authors.initials: XD
authors.lastname: Wu
authors.forename: Yong-Chun
authors.initials: YC
authors.lastname: Song
authors.forename: Pei-Long
authors.initials: PL
authors.lastname: Cao
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Guo
authors.forename: Rong
authors.initials: R
authors.lastname: Yan
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Diao
authors.forename: Yao
authors.initials: Y
authors.lastname: Cheng
authors.forename: Cheng-Xue
authors.initials: CX
authors.lastname: Dang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism*; D019175:DNA Methylation; D005243:Feces; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D064368:Healthy Volunteers; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA
chemical_list: D014408:Biomarkers, Tumor; C522425:MIRN34 microRNA, human; D035683:MicroRNAs