title: miR-26b is downregulated in human tongue squamous cell carcinoma and regulates cell proliferation and metastasis through a COX-2-dependent mechanism.
abstract: MicroRNAs (miRNAs) are important gene regulators that play a profound role in tumorigenesis. Previous studies have revealed that miR-26b is downregulated in a wide range of malignant tumors and plays an important role in the regulation of carcinogenesis and tumor progression. In the present study, we revealed that miR-26b expression was decreased in human tongue squamous cell carcinoma and was associated with clinical stage, lymph node metastasis and survival prognosis. Ectopic expression of miR-26b suppressed the proliferation and metastasis of human tongue squamous cell carcinoma cells. Using a luciferase reporter assay, combined with western blot analysis results, we identified PTGS2 (prostaglandin-endoperoxide synthase-2, encoding COX-2) as the functional target of miR-26b. Specific inhibition of COX-2 activity by nimesulide further confirmed that miR-26b was able to regulate the cell proliferation and metastasis of the human tongue squamous cell carcinoma cells through a COX-2-dependent mechanism. Taken together, these results suggest that miR-26b serves as a tumor suppressor by targeting COX-2 and calls for the use of miR-26b as a potential therapeutic tool for human tongue squamous cell carcinoma, where COX-2 is often hyperactivated.
authors.affiliation: Department of Stomatology, The First Affiliated Hospital of the PLA General Hospital, Beijing, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department of Stomatology, The Fifth Affiliated Hospital, Xinjiang Medical University, Urumqi, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.affiliation: Department of Stomatology, Wuhan General Hospital of Guangzhou Command, People's Liberation Army, Wuhan, P.R. China.
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Dong
authors.affiliation: Department of Stomatology, The First Affiliated Hospital of the PLA General Hospital, Beijing, P.R. China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Stomatology, The First Affiliated Hospital of the PLA General Hospital, Beijing, P.R. China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Li
mesh_terms: D020413:3' Untranslated Regions; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D008207:Lymphatic Metastasis; D035683:MicroRNAs / Q000378:metabolism*; D009362:Neoplasm Metastasis; D010641:Phenotype; D013449:Sulfonamides / Q000737:chemistry; D014062:Tongue Neoplasms / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D020413:3' Untranslated Regions; D051546:Cyclooxygenase 2; D035683:MicroRNAs; D013449:Sulfonamides; C528163:MIRN26 microRNA, human; C496540:PTGS2 protein, human; C012655:nimesulide