Brief Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Nov 14, 2011; 17(42): 4711-4717
Published online Nov 14, 2011. doi: 10.3748/wjg.v17.i42.4711
miR-93 suppresses proliferation and colony formation of human colon cancer stem cells
Xiao-Feng Yu, Jian Zou, Zhi-Jun Bao, Jie Dong
Xiao-Feng Yu, Jian Zou, Zhi-Jun Bao, Jie Dong, Department of Gastroenterology, Huadong Hospital, Fudan University, Shanghai 200040, China
Author contributions: Yu XF and Zou J contributed equally to this work; Zou J designed the research; Zou J, Yu XF, Bao ZJ and Dong J performed the majority of the experiments; Dong J, Bao ZJ and Zou J analyzed data; and Yu XF and Zou J wrote the paper.
Supported by Medical guidance projects of Shanghai Science Committee, No. 10411961800; Youth Science Foundation of Fudan University, No. 08FQ49
Correspondence to: Dr. Jian Zou, Department of Gastroenterology, Huadong Hospital, Fudan University, 221 Yan an Xi Road, Shanghai 200040, China.
Telephone: +86-21-62483180 Fax: +86-21-62484981
Received: March 20, 2011
Revised: June 23, 2011
Accepted: June 30, 2011
Published online: November 14, 2011

AIM: To identify differentially expressed microRNAs (miRNAs) in human colon cancer stem cells (SW1116csc) and study their function in SW1116csc proliferation.

METHODS: SW1116csc were isolated from the human colon cancer cell line, SW1116 and cultured in serum-free medium. A miRNA microarray was used to detect differential expression profiles of miRNAs in SW1116csc and SW1116 cells. Real-time quantitative polymerase chain reaction (PCR) was performed to verify the differential expression of candidate miRNAs obtained from the microarray. Target mRNAs of differentially expressed miRNAs were predicted with target prediction tools. miRNA expression plasmids were transfected into SW1116csc using Lipofectamine 2000 reagent. Cell proliferation curves were generated with trypan blue staining, and the colony formation rate of transfected cells was measured with the soft agar colony formation assay. Expression of target mRNAs and proteins from differentially expressed miRNAs were detected using reverse transcription (RT)-PCR and western blotting.

RESULTS: Compared with expression in SW1116 cells, 35 miRNAs (including hsa-miR-192, hsa-miR-29b, hsa-miR-215, hsa-miR-194, hsa-miR-33a and hsa-miR-32) were upregulated more than 1.5-fold, and 11 miRNAs (including hsa-miR-93, hsa-miR-1231, hsa-miRPlus-F1080, hsa-miR-524-3p, hsa-miR-886-3p and hsa-miR-561) were downregulated in SW1116csc. The miRNA microarray results were further validated with quantitative RT-PCR. miR-93 was downregulated, and its predicted mRNA targets included BAMBI, CCND2, CDKN1A, HDAC8, KIF23, MAP3K9, MAP3K11, MYCN, PPARD, TLE4 and ZDHHC1. Overexpressed miR-93 significantly inhibited cell proliferation and colony formation by SW1116csc. Furthermore, miR-93 negatively regulated the mRNA and protein levels of HDAC8 and TLE4.

CONCLUSION: Some miRNAs were differentially expressed during differentiation of SW1116csc into SW1116 cells. miR-93 may inhibit SW1116csc proliferation and colony formation.

Keywords: miR-93, Stem cell, Colon cancer, Expression profile