title: Gambogic acid inhibits invasion of osteosarcoma via upregulation of             TIMP-1.
abstract: Gambogic acid (GA), the natural product, has been demonstrated to be a promising             chemotherapeutic drug for osteosarcoma (OS) due to its ability to induce apoptosis             and cell cycle arrest. To date, no studies have examined the role of GA in metastatic             bone disease. Matrix metalloproteinases (MMPs) play critical roles in invasion             and metastasis, and the tissue inhibitors of metalloproteinase (TIMP) family regulates             the activity of multifunctional metalloproteinases. In this study, we investigated             the gene expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor             of matrix metalloproteinase-1 (TIMP-1) in OS cell lines treated by the GA. The             expression of MMP-9 and TIMP-1 were studied by reverse transcription-polymerase             chain reaction (RT-PCR) and western blotting. In vitro invasion of OS cell lines             (Saos-2, MG-63) were investigated by the Matrigel invasion assay. Mean MMP-9 protein             and mRNA expression was significantly suppressed; in addition, mean TIMP-1 protein             mRNA expression were upregulated by increasing GA concentrations. GA reduced the             invasiveness of OS cell lines dose-dependently. Furthermore, specific inhibition             of TIMP-1 secretion with siRNA against TIMP-1 significantly reduced the effect             of GA on OS cell lines. Overall, our findings suggest that GA reduces the invasive             potential of OS cells via attenuation of MMP-9 and upregulation of TIMP-1. Moreover,             TIMP-1 played an important role in the reduction of invasive potential of the             OS cells which were treated by GA.
authors.affiliation: Department of Orthopedic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, PR China.
authors.forename: Zeng-Feng
authors.initials: ZF
authors.lastname: Xin
authors.forename: Cheng-Chun
authors.initials: CC
authors.lastname: Shen
authors.forename: Li-Jiang
authors.initials: LJ
authors.lastname: Tao
authors.forename: Shi-Gui
authors.initials: SG
authors.lastname: Yan
authors.forename: Hao-Bo
authors.initials: HB
authors.lastname: Wu
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D055785:Gene Knockdown Techniques; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D012516:Osteosarcoma / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D044004:Xanthones / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D044004:Xanthones; C052659:gambogic acid; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9