title: MicroRNA-143 suppresses gastric cancer cell growth and induces apoptosis by targeting COX-2.
abstract: OBJECTIVE
  To investigate the function of microRNA-143 (miR-143) in gastric cancer and explore the target genes of miR-143.
  
  
  METHODS
  A quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed to evaluate miR-143 expression in gastric cancer cell lines. After transfecting gastric cancer cells with miR-143-5p and miR-143-3p precursors, Alamar blue and apoptosis assays were used to measure the respective proliferation and apoptosis rates. Cyclooxygenase-2 (COX-2) expression was determined by real-time RT-PCR and Western blot assays after miR-143 transfection. Reporter plasmids were constructed, and a luciferase reporter assay was used to identify the miR-143 binding site on COX-2.
  
  
  RESULTS
  Both miR-143-5p and miR-143-3p were significantly downregulated in multiple gastric cancer cell lines. Forced miR-143-5p and miR-143-3p expression in gastric cancer cells produced a profound cytotoxic effect. MiR-145-5p transfection into gastric cancer cells resulted in a greater growth inhibitory effect (61.23% ± 3.16% vs. 46.58% ± 4.28%, P < 0.05 in the MKN-1 cell line) and a higher apoptosis rate (28.74% ± 1.93% vs. 22.13% ± 3.31%, P < 0.05 in the MKN-1 cell line) than miR-143-3p transfection. Further analysis indicated that COX-2 expression was potently suppressed by miR-143-5p but not by miR-143-3p. The activity of a luciferase reporter construct that contained the 3'-untranslated region (UTR) of COX-2 was downregulated by miR-143-5p (43.6% ± 4.86%, P < 0.01) but not by miR-143-3p. A mutation in the miR-145-5p binding site completely ablated the regulatory effect on luciferase activity, which suggests that there is a direct miR-145-5p binding site in the 3'-UTR of COX-2.
  
  
  CONCLUSIONS
  Both miR-143-5p and miR-143-3p function as anti-oncomirs in gastric cancer. However, miR-143-5p alone directly targets COX-2, and it exhibits a stronger tumor suppressive effect than miR-143-3p.
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Wu
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Cheng
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Pei-Yuan
authors.initials: PY
authors.lastname: Li
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Huan-Jun
authors.initials: HJ
authors.lastname: Huang
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Zi-Li
authors.initials: ZL
authors.lastname: Dan
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: De-An
authors.initials: DA
authors.lastname: Tian
authors.affiliation: Xiao-Li Wu, Bin Cheng, Pei-Yuan Li, Huan-Jun Huang, Qiu Zhao, Zi-Li Dan, De-An Tian, Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
mesh_terms: D020413:3' Untranslated Regions; D017209:Apoptosis; D001665:Binding Sites; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D009154:Mutation; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D013997:Time Factors; D014162:Transfection; D047368:Tumor Burden
chemical_list: D020413:3' Untranslated Regions; C542359:MIRN143 microRNA, human; D035683:MicroRNAs; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human
keywords: Anti-oncomir; Apoptosis; Cyclooxygenase-2; Gastric cancer; MicroRNA-143