title: Downregulation of microRNA 99a in oral squamous cell carcinomas contributes             to the growth and survival of oral cancer cells.
abstract: MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression by either translational inhibition or mRNA degradation. miRNAs play pivotal roles in physiological functioning and pathological progression. The function of microRNA-99a (miR-99a) in oral squamous cell carcinoma (OSCC) remains unclear. In the present study, we investigated the roles of miR-99a in OSCC development and the underlying mechanisms in 25 cases of primary OSCC tissues and Tca-8113 cells. The cells were analyzed using FACS analysis and western blotting. Results showed that the expression levels of miR-99a were markedly decreased in OSCC tissues compared with the adjacent non-tumor tissues (n=25). The results of in vitro experiments showed that miR-99a mimics significantly inhibited the proliferation of Tca-8113 cells, a tongue squamous carcinoma cell line, and that miR-99a mimics markedly induced the apoptosis of Tca-8113 cells. Furthermore, we demonstrated that mammalian target of rapamycin (mTOR) was directly targeted by miR-99a, as the overexpression of miR-99a in Tca-8113 cells downregulated the protein expression level of mTOR. Thus, our findings suggest that the downregulation of miR-99a in OSCC tissues is associated with tumor development. miR-99a regulates the growth and survival of OSCC cells and may be exploited as a biomarker and therapeutic target for patients with OSCC.
authors: Department of Oral and Maxillofacial Surgery, Ningbo First Hospital, Ningbo 315000, PR China.
authors: Bin
authors: B
authors: Yan
authors: Qihong
authors: Q
authors: Fu
authors: Lihua
authors: L
authors: Lai
authors: Xinran
authors: X
authors: Tao
authors: Yanghonghong
authors: Y
authors: Fei
authors: Jiangen
authors: J
authors: Shen
authors: Zuodong
authors: Z
authors: Chen
authors: Qingqing
authors: Q
authors: Wang
mesh_terms: D020413:3' Untranslated Regions; D017209:Apoptosis / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015536:Down-Regulation; D057809:HEK293 Cells; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism* / Q000494:pharmacology; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; C561679:MIRN99 microRNA, human; D035683:MicroRNAs; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases