title: Silencing of miR-1-1 and miR-133a-2 cluster expression by DNA hypermethylation             in colorectal cancer.
abstract: MicroRNAs are small non-coding RNA molecules that play important roles in             the multistep process of colorectal carcinoma (CRC) development. The present study             evaluated the relationship between miR-1-1 and miR-133a-2 expression and DNA methylation,             and its putative biological role in CRC. The results indicated that DNA methylation             regulated the expression of the miR-1-1 and miR-133a-2 cluster in CRC cell lines.             Expression of miR-1 and miR-133a was further evaluated in 64 paired tissue samples             (CRC tumor and adjacent normal mucosa) using the stem-loop real-time polymerase             chain reaction. The miR-1-133a cluster displayed significantly lower expression             in CRC tissue compared to adjacent normal mucosa (P<0.001). The results also             indicated frequent hypermethylation of the CpG islands upstream of miR-1-133a             (54.6%). Liver metastatic tissues exhibited significantly lower miR-1 (P<0.001)             and miR-133a (P<0.001) expression compared to adjacent normal mucosa. Expression             of the miR-1-133a cluster inversely correlated with TAGLN2 in the tumor specimens.             In conclusion, epigenetic repression of the miR-1-133a cluster may play a critical             role in colorectal cancer metastasis by silencing TAGLN2.
authors: Department of Surgery, Veterans General Hospital, Taipei, Taiwan, ROC.
authors: Wei-Shone
authors: WS
authors: Chen
authors: Chung-Man
authors: CM
authors: Leung
authors: Hung-Wei
authors: HW
authors: Pan
authors: Ling-Yueh
authors: LY
authors: Hu
authors: Sung-Chou
authors: SC
authors: Li
authors: Meng-Ru
authors: MR
authors: Ho
authors: Kuo-Wang
authors: KW
authors: Tsai
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018899:CpG Islands; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D060588:LIM Domain Proteins / Q000235:genetics / Q000378:metabolism; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D003598:Cytoskeletal Proteins; C096353:LASP1 protein, human; D060588:LIM Domain Proteins; C544547:MIRN1 microRNA, human; C548234:MIRN133 microRNA, human; D035683:MicroRNAs; D008840:Microfilament Proteins; D009124:Muscle Proteins; C051615:transgelin