title: miR-93 suppresses proliferation and colony formation of human colon cancer stem cells.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  Some miRNAs were differentially expressed during differentiation of SW1116csc into SW1116 cells. miR-93 may inhibit SW1116csc proliferation and colony formation.
authors.affiliation: Department of Gastroenterology, Huadong Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Yu
authors.forename: Jian
authors.initials: J
authors.lastname: Zou
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Bao
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D020869:Gene Expression Profiling; D006801:Humans; D035683:MicroRNAs / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014411:Neoplastic Stem Cells / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: C543350:MIRN93 microRNA, human; D035683:MicroRNAs