title: Let-7a inhibits migration, invasion and epithelial-mesenchymal transition by targeting HMGA2 in nasopharyngeal carcinoma.
abstract: BACKGROUND
  Let-7a has been shown to play important roles in nasopharyngeal carcinoma (NPC) cell proliferation and apoptosis, but little is known about the function and mechanism of let-7a in nasopharyngeal carcinoma metastasis. We aimed to investigate the function and mechanism of let-7a in nasopharyngeal carcinoma metastasis and clarified the regulation of high mobility group A2 (HMGA2) by let-7a.
  
  
  METHODS
  The expression levels of let-7a and HMGA2 were examined in NPC clinical specimens using quantitative reverse transcription-PCR (RT-qPCR). HMGA2 was confirmed as a target of let-7a through luciferase reporter assays, RT-qPCR, and Western blotting. Furthermore, the roles of let-7a and HMGA2 in regulating NPC cells biological properties including proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) process were analyzed with let-7a mimics and si-HMGA2 transfected cells.
  
  
  RESULTS
  Our study demonstrated that let-7a was downregulated and inversely associated with the clinical stage, T classification and N classification, and HMGA2 was upregulated and directly associated with the clinical stage and N classification in patients with NPC. Moreover, there was an inverse correlation between let-7a expression and HMGA2 expression in NPC patient. In addition, HMGA2 was negatively regulated at the posttranscriptional level by let-7a via a binding site of HMGA2-3'UTR. In addition, synthetic let-7a mimics suppressed NPC cells migration, invasion and EMT process and knockdown of HMGA2 was consistent with the effects of let-7a in NPC cells.
  
  
  CONCLUSIONS
  Let-7a directly downregulates HMGA2 protein expression, which suppress NPC cell migration, invasion and EMT process. Let-7a could serve as a potential diagnostic marker and therapeutic target for NPC.
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. wab8010016@163.com.
authors.forename: Aibing
authors.initials: A
authors.lastname: Wu
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. 67104234@163.com.
authors.forename: Kunpeng
authors.initials: K
authors.lastname: Wu
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. moon1382002@163.com.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Li
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. summeryeah158@163.com.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Mo
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. moonheart2000@163.com.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. summeryeah138@163.com.
authors.forename: Yuzhou
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. gangliu11@126.com.
authors.forename: Xiang
authors.initials: X
authors.lastname: Shen
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. weilinjin@yeah.net.
authors.forename: Shujun
authors.initials: S
authors.lastname: Li
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. wulumin@163.com.
authors.forename: Lixia
authors.initials: L
authors.lastname: Li
authors.affiliation: Oncology Center, Affiliated Hospital of Guangdong Medical College, No.57 Peoples Avenue South, Zhanjiang, Guangdong, 524002, People's Republic of China. yangzhixiong068@126.com.
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: Yang
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000368:Aged; D001483:Base Sequence; D002277:Carcinoma; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics*; D049109:Cell Proliferation; D015536:Down-Regulation / Q000235:genetics; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D025461:Feedback, Physiological; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D025743:HMGA2 Protein / Q000378:metabolism*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D008969:Molecular Sequence Data; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000473:pathology; D009361:Neoplasm Invasiveness; D011485:Protein Binding / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; D025743:HMGA2 Protein; D035683:MicroRNAs; C487931:mirnlet7 microRNA, human