title: Exosome-derived microRNA-29c induces apoptosis of BIU-87 cells by down regulating BCL-2 and MCL-1.
abstract: BACKGROUND
  Aberrant expression of the microRNA-29 family is associated with tumorigenesis and cancer progression. As transport carriers, tumor-derived exosomes are released into the extracellular space and regulate multiple functions of target cells. Thus, we assessed the possibility that exosomes could transport microRNA- 29c as a carrier and correlations between microRNA-29c and apoptosis of bladder cancer cells.
  
  
  METHODS
  A total of 28 cancer and adjacent tissues were examined by immunohistochemistry to detect BCL-2 and MCL-1 expression. Disease was Ta-T1 in 12 patients, T2-T4 in 16, grade 1 in 8, 2 in 8 and 3 in 12. The expression of microRNA-29c in cancer tissues was detected by quantitative reverse transcriptase PCR (QRT- PCR). An adenovirus containing microRNA-29c was used to infect the BIU-87 human bladder cancer cell line. MicroRNA-29c in exosomes was measured by QRT-PCR. After BIU-87 cells were induced by exosomes-derived microRNA-29c, QRT-PCR was used to detect the level of microRNA-29c. Apoptosis was examined by flow cytometry and BCL-2 and MCL-1 mRNA expressions were assessed by reverse transcription-polymerase chain reaction. Western blotting was used to determine the protein expression of BCL-2 and MCL-1.
  
  
  RESULTS
  The expressions of BCL-2 and MCL-1 protein were remarkably increased in bladder carcinoma (p<0.05), but was found mainly in the basal and suprabasal layers in adjacent tissues. The expression of microRNA-29c in cancer tissues was negatively correlated with the BCL-2 and MCL-1. The expression level of microRNA-29c in exosomes and BIU-87 cells from the experiment group was higher than that in control groups (p<0.05). Exosome-derived microRNA-29c induced apoptosis (p<0.01). Although only BCL-2 was reduced at the mRNA level, both BCL-2 and MCL-1 were reduced at the protein level.
  
  
  CONCLUSIONS
  Human bladder cancer cells infected by microRNA- 29c adenovirus can transport microRNA-29c via exosomes. Moreover, exosome-derived microRNA29c induces apoptosis in bladder cancer cells by down-regulating BCL-2 and MCL-1.
authors.affiliation: Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China E-mail : 414939334@qq.com.
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Xu
authors.forename: Xiao-Hou
authors.initials: XH
authors.lastname: Wu
authors.forename: Yan-Ru
authors.initials: YR
authors.lastname: Fan
authors.forename: Bing
authors.initials: B
authors.lastname: Tan
authors.forename: Zhen
authors.initials: Z
authors.lastname: Quan
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Luo
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D002295:Carcinoma, Transitional Cell / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000235:genetics*; D055354:Exosomes; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000235:genetics* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism
chemical_list: C579095:MCL1 protein, human; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger