title: Microrna-124 targets flotillin-1 to regulate proliferation and migration in breast cancer.
abstract: BACKGROUND
  MicroRNAs (miRNAs) have been documented as playing important roles in cancer development. In this study, we investigated the role of miR-124 in breast cancer and clarified the regulation of flotillin-1 (FLOT1) by miR-124.
  
  
  METHODS
  The expression levels of miR-124 were examined in breast cancer cell lines and patient specimens using quantitative reverse transcription-PCR. The clinicopathological significance of the resultant data was later analyzed. Next, we explored the function of miR-124 to determine its potential roles on cancer cell growth and migration in vitro. A luciferase reporter assay was conducted to confirm the target gene of miR-124, and the results were validated in cell lines and patient specimens.
  
  
  RESULTS
  We found that miR-124 expression was significantly downregulated in breast cancer cell lines and patient specimen compared with normal cell lines and paired adjacent normal tissues (P < 0.0001), respectively. MiR-124 was also associated with tumor node metastasis (TNM) stage (P = 0.0007) and lymph node metastasis (P = 0.0004). In breast cancer cell lines, the ectopic expression of miR-124 inhibited cell growth and migration in vitro. Moreover, we identified the FLOT1 gene as a novel direct target of miR-124, and miR-124 ectopic expression significantly inhibited FLOT1. Luciferase assays confirmed that miR-124 could directly bind to the 3' untranslated region of FLOT1 and suppress translation. Moreover, FLOT1 was widely upregulated, and inversely correlated with miR-124 in breast cancer tissues. Consistent with the effect of miR-124, the knockdown of FLOT1 significantly inhibited breast cancer cell growth and migration. We also observed that the rescue expression of FLOT1 partially restored the effects of miR-124.
  
  
  CONCLUSIONS
  Our study demonstrated that miR-124 might be a tumor suppressor in breast cancer via the regulation of FLOT1. This microRNA could serve as a potential diagnostic marker and therapeutic target for breast cancer.
authors: Laisheng
authors: L
authors: Li
authors: Jinmei
authors: J
authors: Luo
authors: Bo
authors: B
authors: Wang
authors: Dong
authors: D
authors: Wang
authors: Xinhua
authors: X
authors: Xie
authors: Linjing
authors: L
authors: Yuan
authors: Jiaoli
authors: J
authors: Guo
authors: Shaoyan
authors: S
authors: Xi
authors: Jie
authors: J
authors: Gao
authors: Xiaoti
authors: X
authors: Lin
authors: Yanan
authors: Y
authors: Kong
authors: Xiangdong
authors: X
authors: Xu
authors: Hailing
authors: H
authors: Tang
authors: Xiaoming
authors: X
authors: Xie
authors: Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, People's Republic of China. 13711694565@163.com.
authors: Min
authors: M
authors: Liu
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged
chemical_list: C509207:MIRN124 microRNA, human; D008565:Membrane Proteins; D035683:MicroRNAs; C106354:flotillins