title: The role of microRNA-133b and its target gene FSCN1 in gastric cancer.
abstract: BACKGROUND
  Increasing evidences have documented that microRNAs (miRNAs) act as oncogenes or tumor suppressors in gastric cancer (GC). In this study, we aimed to investigate the expression of miR-133b in a large number of GC samples and elucidate its role in GC carcinogenesis and the detailed mechanism.
  
  
  METHODS
  We used Taqman probe stem-loop real-time PCR to accurately measure the levels of miR-133b in 100 pairs of gastric cancer tissues and the adjacent non-neoplastic tissues. miR-133b mimics were overexpressed in GC cell lines, miR-133b inhibitors were also introduced in GES cells to investigate its role on regulating cell proliferation, cell migration and cell invasion. The target of miR-133b was identified by luciferase reporter assay and western blot. Fascin actin-bundling protein 1 (FSCN1) siRNA was used to achieve the knockdown of FSCN1 in GC cells and to investigate its role on modulating GC cell proliferation and invasion.
  
  
  RESULTS
  miR-133b was significantly down-regulated in GC cell lines and in GC tissues compared with adjacent normal tissues. Moreover, lower-level of miR-133b was also associated with venous invasion and a more aggressive tumor phenotype. Re-introduction of miR-133b in GC cells can inhibit cell proliferation, cell migration and invasion. In contrary, knockdown of miR-133b in GES cells can promote cell proliferation and invasion. Further investigation indicated that miR-133b targeted FSCN1 in GC cells and knockdown of FSCN1 can also inhibit GC cell growth and invasion.
  
  
  CONCLUSIONS
  Our findings demonstrated that miR-133b was significantly down-regulated in GC tissues and exerted its tumor suppressor role in GC cells. The investigation of the detailed mechanism showed that miR-133b directly targeted FSCN1 which functioned as an oncogenic gene in GC cells. These results suggested that miR-133b can be developed as a new diagnostic marker or therapeutic target for GC.
authors.affiliation: School of Computer and Information Technology, Shangyuan Residence, Haidian District, Beijing, 100044, China. lihuaguo@bjtu.edu.cn.|College of Life Sciences and Bioengineering, Beijing Jiaotong University, Shangyuan Residence, Haidian District, Beijing, 100044, China. lihuaguo@bjtu.edu.cn.
authors.forename: Lihua
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Ophthalmology, General Hospital of Bei Jing Command of PLA, #5 Nanmencang, DongCheng District, Beijing, 100700, China. paihoo@163.com.
authors.forename: Hua
authors.initials: H
authors.lastname: Bai
authors.affiliation: Department of Gynecologic Oncology, Chongqing Cancer Institute, Chongqing, 400030, China. zdl19811026@aliyun.com.
authors.forename: Dongling
authors.initials: D
authors.lastname: Zou
authors.affiliation: College of Life Sciences and Bioengineering, Beijing Jiaotong University, Shangyuan Residence, Haidian District, Beijing, 100044, China. hongt@cae.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Hong
authors.affiliation: School of Computer and Information Technology, Shangyuan Residence, Haidian District, Beijing, 100044, China. jieliu@bjtu.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Life Sciences and Bioengineering, Beijing Jiaotong University, Shangyuan Residence, Haidian District, Beijing, 100044, China. jqhuang@bjtu.edu.cn.
authors.forename: Jiaqiang
authors.initials: J
authors.lastname: Huang
authors.affiliation: National Institutes for Food and Drug Control, No.2 Tiantan Xi Li, Beijing, 100050, China. pengfeihe@foxmail.com.
authors.forename: Pengfei
authors.initials: P
authors.lastname: He
authors.affiliation: Department of Gynecologic Oncology, Chongqing Cancer Institute, Chongqing, 400030, China. qizhou9128@163.com.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: College of Life Sciences and Bioengineering, Beijing Jiaotong University, Shangyuan Residence, Haidian District, Beijing, 100044, China. jshhe@bjtu.edu.cn.
authors.forename: Jinsheng
authors.initials: J
authors.lastname: He
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D014162:Transfection
chemical_list: D002352:Carrier Proteins; C502658:FSCN1 protein, human; C548234:MIRN133 microRNA, human; D035683:MicroRNAs; D008840:Microfilament Proteins