title: Over- and under-expressed microRNAs in human colorectal cancer.
abstract: MicroRNAs (miRNAs) constitute a class of small (21-23 nucleotides) noncoding RNAs that function as post-transcriptional gene regulators. It is becoming increasingly clear that altered miRNA expression correlates with the pathogenesis of cancers. The purpose of this study was to determine the up-regulated miRNAs in human colorectal cancer. Total RNA was isolated from cancer tissues and corresponding noncancerous tissues from surgically resected colorectal cancers. The expression profiles of miRNAs were determined using a miRNA microarray containing 455 human miRNA probes. The expression status of selected miRNAs in paired clinical samples was then investigated by real-time RT-PCR. Twenty-one miRNAs were identified by miRNA array analysis as overexpressed in colorectal cancer tissues compared to normal epithelial tissues. Among them, the expression of miR-31, miR-183, miR-17-5p, miR-18a, miR-20a and miR-92 were confirmed to be significantly higher in cancer tissues than in normal tissues (P<0.05). In contrast, the expression of miR-143 and miR-145 in cancer tissues were significantly lower than in normal tissues (P<0.05). The miR-18a overexpression group tended to have a poorer clinical prognosis than the low expression group (P=0.07). We identified miRNAs that were overexpressed or under-expressed in colorectal cancers and which may be correlated with colorectal carcinogenesis.
authors.affiliation: Department of Molecular and Surgical Oncology, Medical Institute of Bioregulation, Kyushu University, Beppu 874-0838, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Motoyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takatsuno
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Tanaka
authors.forename: Koshi
authors.initials: K
authors.lastname: Mimori
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uetake
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
authors.forename: Masaki
authors.initials: M
authors.lastname: Mori
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D035683:MicroRNAs