title: MicroRNA-216b is Down-Regulated in Human Gastric Adenocarcinoma and Inhibits Proliferation and Cell Cycle Progression by Targeting Oncogene HDAC8.
abstract: Accumulating evidence indicates that micro (mi)RNAs play a critical role in carcinogenesis and cancer progression; however, their role in the tumorigenesis of gastric adenocarcinoma remains unclear so the present study investigated this in gastric cancer (GC) tissues and cell lines.
  
  
  
  Human GC specimens (n = 57) and patient-paired non-cancerous specimens were obtained from patients at the First Affiliated Hospital, Henan University of Science and Technology. The AGS and GC9811 gastric cancer cell lines were also used. Expression levels of miR-216b and HDAC8 were examined by quantitative real-time PCR and the expression of HDAC8 was also examined by Western blotting and immunohistochemistry assay. The cell cycle progression was determined by FACS. MiR-216b inhibitor, mimics, and siRNA-HDAC8 transfections were performed to study the loss and gain of function.
  
  
  
  We reported a significantly decreased expression of miR-216b in GC clinical specimens compared with paired non-cancerous tissues. We also observed a significant down-regulation of miR-216b expression in GC cell lines AGS and GC9811 (p < 0.0001). The introduction of miR-216b suppressed GC cell proliferation and cell cycle progression by targeting HDAC8, an oncogene shown to promote malignant tumor development with a potential miR-216b binding site in its 3' untranslated region. HDAC8 expression was shown to be significantly increased in AGS and GC9811 cell lines (p < 0.0001) and GC tissues compared with controls. Moreover, HDAC8 inhibition suppressed cell cycle progression compared with control groups (22 % ± 1.6 % vs 34 % ± 2.1), indicating that HDAC8 may function as an oncogene in the development of GC. Furthermore, HDAC8 expression was negatively correlated (p < 0.0001), while miR-216b expression was positively correlated with the clinical outcome of GC patients (p < 0.0001).
  
  
  
  Our data suggest that miR-216b functions as a tumor suppressor in human GC by, at least partially, targeting HDAC8.
authors.affiliation: Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China. yingw_215@163.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Urology Surgery Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China.
authors.forename: Po
authors.initials: P
authors.lastname: Xu
authors.affiliation: Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.affiliation: Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China.
authors.forename: Ruina
authors.initials: R
authors.lastname: Yang
authors.affiliation: Urology Surgery Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China.
authors.forename: Zhenguo
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China. 1471511798@qq.com.
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Feng
authors.affiliation: Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, 471003, China. 949898789@qq.com.
authors.forename: Shegan
authors.initials: S
authors.lastname: Gao