title: PPM1D silencing by RNA interference inhibits the proliferation of lung cancer cells.
abstract: BACKGROUND
  PPM1D (protein phosphatase, Mg2+/Mn2+ dependent, 1D) has been reported to be involved in multiple human tumors. This study was designed to investigate the functional role of PPM1D in lung cancer cells.
  
  
  METHODS
  Expression levels of PPM1D were analyzed in A549 and H1299 cells by real-time PCR and Western blotting. Lentivirus-mediated short hairpin RNA (shRNA) was used to knock down PPM1D expression in both cell lines. The effects of PPM1D on lung cancer cell growth were investigated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), colony formation and flow cytometry assays.
  
  
  RESULTS
  Knockdown of PPM1D in lung cancer cells resulted in decreased cell proliferation and impaired colony formation ability. Moreover, flow cytometry analysis showed that knockdown of PPM1D arrested cell cycle at the G0/G1 phase. Furthermore, PPM1D silencing downregulated the expression of cyclin B1 in H1299 cells. Therefore, it is reasonable to speculate that the mechanisms by which PPM1D knockdown alleviates cell growth may be partly via the induction of cell cycle arrest due to the suppression of cyclin B1.
  
  
  CONCLUSIONS
  These results suggest that PPM1D silencing by RNA interference (RNAi) may be a potential therapeutic approach for the treatment of lung cancer.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.forename: Yuanzhuo
authors.initials: Y
authors.lastname: Chen
authors.forename: Mingsong
authors.initials: M
authors.lastname: Wang
authors.forename: Xianzhen
authors.initials: X
authors.lastname: Chen
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Li
authors.forename: E
authors.initials: E
authors.lastname: Song
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Liu
authors.affiliation: Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China. sknkim@pknu.ac.kr.
authors.forename: Sekwon
authors.initials: S
authors.lastname: Kim
authors.forename: Hu
authors.initials: H
authors.lastname: Peng
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D002453:Cell Cycle; D049109:Cell Proliferation; D003114:Colony-Forming Units Assay; D005434:Flow Cytometry; D020868:Gene Silencing; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000071636:Protein Phosphatase 2C; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; C000607458:PPM1D protein, human; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C