title: Targeting miR-29 induces apoptosis of osteosarcoma MG-63 cells via regulation of TGF-β1/PUMA signal.
abstract: Recent studies have shown that high miR-29 expression was associated with poor prognosis in patients with osteosarcoma (OS). However, the exact role and mechanisms of miR-29 in human OS remains speculative. Here, we identify a connection between miR-29 and TGF-β1/PUMA signaling in this context.
  
  
  
  MG-63 cells were treated with anti-miR-29 for 48 h. Cell growth and apoptosis in vitro were detected by MTT, colony formation and flow cytometry assay. The effect of the miR-29 inhibitor on the growth of MG-63 cells was also evaluated in a MG-63 mouse model. Human recombinant TGF-β1 (rh TGF-β1) and PUMA siRNA transfection were used to assess the signal pathway. miR-29, TGF-β1, PUMA, and caspase-3 protein expression were detected by Western blotting assay and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays.
  
  
  
  Knockdown of miR-29 resulted in 80% decrease of miR-29 compared to the negative control. Knockdown of miR-29 significantly downregulated TGF-β1 and upregulated PUMA expression, and decreased MG-63 cell growth by 70%, impaired colony formation by approximately 80%, and increased MG-63 cell apoptosis by 40%. Knockdown of PUMA reversed miR-29 silencing-induced proliferation and apoptosis of MG-63 cells. Restoration of TGF-β1 decreased PUMA expression. In murine engraftment models of MG-63, we showed that knockdown of miR-29 was able to reduce tumor growth. This was accompanied by decreased levels of TGF-β1 and increased levels of PUMA in these tumors.
  
  
  
  Targeting miR-29 exhibits significant in vivo and in vitro anti-tumor activities in OS through a novel mechanism resulting in inhibition of TGF-β1 expression and inducing PUMA expression.
authors.affiliation: Department of Orthopaedics, the Affiliated Hospital of Qingdao University, Qingdao, Shandong, China. blooddoc@126.com.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Wang
authors.forename: J-B
authors.initials: JB
authors.lastname: Ren
authors.forename: M
authors.initials: M
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Yu
mesh_terms: D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D001859:Bone Neoplasms; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics; D012516:Osteosarcoma; D011518:Proto-Oncogene Proteins; D015398:Signal Transduction / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; C438378:BBC3 protein, human; D035683:MicroRNAs; D011518:Proto-Oncogene Proteins; D053773:Transforming Growth Factor beta1