title: Involvement of human micro-RNA in growth and response to chemotherapy in human cholangiocarcinoma cell lines.
abstract: OBJECTIVE
  Micro-RNA (miRNA) are endogenous regulatory RNA molecules that modulate gene expression. Alterations in miRNA expression can contribute to tumor growth by modulating the functional expression of critical genes involved in tumor cell proliferation or survival. Our aims were to identify specific miRNA involved in the regulation of cholangiocarcinoma growth and response to chemotherapy.
  
  
  METHODS
  miRNA expression in malignant and nonmalignant human cholangiocytes was assessed using a microarray. Expression of selected miRNA and their precursors was evaluated by Northern blots and real-time polymerase chain reaction, respectively. The effect of selected miRNA on cell growth and response to chemotherapy was assessed using miRNA-specific antisense oligonucleotides to decrease miRNA expression or with precursor miRNA to increase cellular expression.
  
  
  RESULTS
  miRNA expression was markedly different in malignant cholangiocytes, with decreased expression of many miRNA compared with nonmalignant cells. A cluster of miRNA, including miR-320, miR-200b, miR-21, miR-23a, miR-141, miR-27a, and miR-34a, were expressed in all cell lines. MiR-21, miR-141, and miR-200b were highly over-expressed in malignant cholangiocytes. Inhibition of miR-21 and miR-200b increased sensitivity to gemcitabine, whereas inhibition of miR-141 decreased cell growth. Treatment of tumor cell xenografts with systemic gemcitabine altered the expression of a significant number of miRNA. miR-21 modulates gemcitabine-induced apoptosis by phosphatase and tensin homolog deleted on chromosome 10 (PTEN)-dependent activation of PI 3-kinase signaling. Potential target genes that were modulated by selected miRNA were identified.
  
  
  CONCLUSIONS
  Alterations in miRNA expression contribute to tumor growth and response to chemotherapy. Aberrantly expressed miRNA or their targets will provide mechanistic insight and therapeutic targets for cholangiocarcinoma.
authors.affiliation: Department of Internal Medicine, Scott and White Clinic, Texas A&M University System Health Science Center College of Medicine, Temple, Texas 76508, USA.
authors.forename: Fanyin
authors.initials: F
authors.lastname: Meng
authors.forename: Roger
authors.initials: R
authors.lastname: Henson
authors.forename: Molly
authors.initials: M
authors.lastname: Lang
authors.forename: Hania
authors.initials: H
authors.lastname: Wehbe
authors.forename: Shail
authors.initials: S
authors.lastname: Maheshwari
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Mendell
authors.forename: Jinmai
authors.initials: J
authors.lastname: Jiang
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Schmittgen
authors.forename: Tushar
authors.initials: T
authors.lastname: Patel
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015152:Blotting, Northern; D015153:Blotting, Western; D045744:Cell Line, Tumor / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D018281:Cholangiocarcinoma / Q000188:drug therapy / Q000473:pathology; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000032:analysis / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011336:Probability; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D014162:Transfection; D014183:Transplantation, Heterologous; D000093542:Gemcitabine
chemical_list: C531388:MIRN27 microRNA, human; D035683:MicroRNAs; D003841:Deoxycytidine; D000093542:Gemcitabine