Abstract | BACKGROUND: METHODS: Two types of 5-FU-resistant colon cancer cells were derived from the DLD-1 and KM12C cell lines. The expressions of microRNAs were profiled with a microarray containing 723 microRNAs and validated by quantitative real-time polymerase chain reaction (qRT-PCR). To survey the downstream mediators of microRNA, we used a microRNA: mRNA immunoprecipitation (RIP)-Chip and pathway analysis tool to identify potential direct targets of microRNA. RESULTS: In response to 5-FU, miR-19b and miR-21 were over-expressed in 5-FU-resistant cells. Of note, miR-19b was up-regulated 3.47-fold in the DLD-1 resistant cells, which exhibited no alteration in cell cycle profiles despite exposure to 5-FU. After transfection of miR-19b, specific mRNAs were recruited to microRNA: mRNA complexes isolated with Ago2 antibody and subjected to whole-genome transcriptional analysis. In this analysis, 66 target mRNAs were enriched by at least 5.0-fold in the microRNA: mRNA complexes from DLD-1 resistant cells. Ingenuity pathway analysis of mRNA targets significantly (P < 0.05) indicated the category "Cell Cycle" as a probable area of the molecular and cellular function related with 5-FU resistance. Among candidate mRNA targets, SFPQ and MYBL2 have been linked to cell cycle functions. CONCLUSIONS: We revealed up-regulation of miR-19b in response to 5-FU and potential targets of miR-19b mediating the cell cycle under treatment with 5-FU. Our study provides an important insight into the mechanism of 5-FU resistance in colorectal cancers.
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Authors | Ken Kurokawa, Toshihito Tanahashi, Tsutomu Iima, Yuta Yamamoto, Yoko Akaike, Kensei Nishida, Kiyoshi Masuda, Yuki Kuwano, Yoshiki Murakami, Masakazu Fukushima, Kazuhito Rokutan |
Journal | Journal of gastroenterology
(J Gastroenterol)
Vol. 47
Issue 8
Pg. 883-95
(Aug 2012)
ISSN: 1435-5922 [Electronic] Japan |
PMID | 22382630
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antimetabolites, Antineoplastic
- MIRN19 microRNA, human
- MIRN21 microRNA, human
- MicroRNAs
- RNA, Messenger
- Fluorouracil
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Topics |
- Antimetabolites, Antineoplastic
(therapeutic use)
- Cell Line, Tumor
- Colonic Neoplasms
(drug therapy, genetics, metabolism)
- Drug Resistance, Neoplasm
- Fluorouracil
(therapeutic use)
- Gene Expression Regulation, Neoplastic
- Humans
- MicroRNAs
(drug effects, genetics, metabolism)
- Microarray Analysis
- RNA, Messenger
(metabolism)
- Real-Time Polymerase Chain Reaction
- Transfection
- Up-Regulation
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