title: The impact of COX-2 on invasion of osteosarcoma cell and its mechanism of regulation.
abstract: BACKGROUND
  Recently, cyclooxygenase-2 (COX-2) has become an important new target in the field of tumor metastasis. However, the relationship between COX-2 gene expression and the behavior of osteosarcoma metastasis is largely unknown. The study is to investigate how antisense oligonucleotides (ODNs) of COX-2 inhibit the invasion of human osteosarcoma cell line OS-732 and their mechanism of regulation.
  
  
  METHODS
  A COX-2 antisense oligonucleotide was designed, synthesized, and transfected into OS-732 human osteosarcoma cells. RT-PCR and western blotting were performed to determine the transfection efficiency. A modified Boyden-transwell assay was used to measure the inhibition rate of tumor cell invasion. In OS-732 cells transfected with COX-2 antisense ODNs, RT-PCR was used to examine the mRNA expression of urokinase-type plasminogen activator (uPA) and that of its receptor, uPAR.
  
  
  RESULTS
  Both the mRNA and protein expression levels of COX-2 were significantly reduced when cells were transfected with COX-2 antisense ODNs, which significantly reduced the invasive ability of OS-732 cells in a dose-dependent manner. The expression levels of uPA and uPAR were also significantly reduced (p < 0.01).
  
  
  CONCLUSIONS
  COX-2 antisense ODNs significantly inhibited the invasion of OS-732 cells, primarily by decreasing the mRNA expression of uPA and uPAR.
authors.affiliation: Department of Orthopaedics, Shanghai tenth People's Hospital, Tongji University School of Medicine, No.301 Middle Yanchang Road, Shanghai 200072, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Orthopaedics, Shanghai tenth People's Hospital, Tongji University School of Medicine, No.301 Middle Yanchang Road, Shanghai 200072, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Cai
authors.affiliation: Department of Orthopaedics, Shanghai tenth People's Hospital, Tongji University School of Medicine, No.301 Middle Yanchang Road, Shanghai 200072, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Ji
authors.affiliation: Department of Orthopaedics, Shanghai tenth People's Hospital, Tongji University School of Medicine, No.301 Middle Yanchang Road, Shanghai 200072, China.
authors.forename: Lie-Ming
authors.initials: LM
authors.lastname: Lou
keywords: Antisense oligonucleotide; COX-2; Invasion; Osteosarcoma