Chinese Journal of Lung Cancer (Apr 2011)

miR-145 Inhibits Lung Adenocarcinoma Stem Cells Proliferation by Targeting OCT4 Gene

  • Shuai ZHANG,
  • Yaqin WU,
  • Dongjie FENG,
  • Zhi ZHANG,
  • Feng JIANG,
  • Rong YIN,
  • Lin XU

Journal volume & issue
Vol. 14, no. 4
pp. 317 – 322

Abstract

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Background and objective MiR-145 functions as a protective miRNA identified in tumor tissues of lung adenocarcinoma patients. The aim of this study is to investigate the relationship between miR-145 and proliferation of lung cancer stem cells and involved molecular mechanisms in human lung adenocarcinaoma A549 cell line. Methods MicroRNA microarray technology was conducted to compare miRNA signature between tumor and adjacent normal tissue of lung adenocarcinaoma. The potential target gene of miR-145 was predicted by online bioinformatic softwares. Pre-miR-145 mimics and anti-miR-145 inhibitor were transfected into A549 cell line by lipofectamine 2000. miR-145 expression in each group was detected by real time PCR. The OCT4 protein level was analyzed by Western blot. The predicted miR-145 binding site in OCT4 3’-untranslated region (UTR) was validated by dual-luciferase reporter gene assay. CCK-8 assay was employed to observe the proliferation activity of A549 cells. The ratio of CD133 positive cells in each group was analyzed by flow cytometry. Results miR-145 expression was significantly down-regulated in lung adenocarcinoma compared with ajacent normal tissue. OCT4 is a potential target gene of miR-145 predicted by miRanda. Compared with control group, miR-145 was significantly up-regulated and down-regulated in the pre-miR-145 mimics and anti-miR-145 inhibitor groups respectively. Overexpression of miR-145 inhibited the proliferation of A549 cells. Both the OCT4 protein level and CD133 positive ratio were remarkably decreased in the pre-miR-145 mimics group, whereas significantly increased in the anti-miR-145 inhibitor group. Dual-luciferase reporter gene assay validated the predicted miR-145 binding site of OCT4 3’UTR. Conclusion MiR-145 can inhibit the proliferation of lung cancer stem cells in A549 cell line via down-regulating OCT4 expression. MiR-145 is a potential protective miRNA of lung cancer.

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