title: MMP-9 short interfering RNA induced senescence resulting in inhibition of medulloblastoma growth via p16(INK4a) and mitogen-activated protein kinase pathway.
abstract: The involvement of matrix metalloproteinases (MMP) has been suggested in cellular mechanisms leading to medulloblastoma, the most common malignant brain tumor in children. A significant association of the expression levels of MMP-9 with survival and M stage suggests that patients with medulloblastoma metastatic disease at diagnosis may benefit from the anti-MMP therapy. Here, we have evaluated the tumorigenicity of medulloblastoma cells after infection with an adenovirus containing a 21-bp short interfering RNA sequence of the human MMP-9 gene (Ad-MMP-9). Infection of Daoy medulloblastoma cells with Ad-MMP-9 reduced MMP-9 activity and protein levels compared with parental and Ad-SV controls. Ad-MMP-9 decreased the number of viable Daoy cells in a concentration-dependent manner. Fluorescence-activated cell sorting analysis indicated that Ad-MMP-9 infection caused a dose-dependent cell cycle arrest in the G(0)-G(1) phase. Ad-MMP-9-induced cell cycle arrest seems to be mediated by the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway and the cell cycle inhibitor p16(INK4a) and is phenotypically indistinguishable from senescence. Ad-MMP-9 treatment inhibited medulloblastoma tumor growth in an intracranial model and was mediated by up-regulation of p16 expression. These studies validate the usefulness of targeting MMP-9 and provide a novel perspective in the treatment of medulloblastoma.
authors.affiliation: Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605, USA.
authors.forename: Jasti S
authors.initials: JS
authors.lastname: Rao
authors.forename: Praveen
authors.initials: P
authors.lastname: Bhoopathi
authors.forename: Chandramu
authors.initials: C
authors.lastname: Chetty
authors.forename: Meena
authors.initials: M
authors.lastname: Gujrati
authors.forename: Sajani S
authors.initials: SS
authors.lastname: Lakka
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002453:Cell Cycle / Q000235:genetics; D048708:Cell Growth Processes / Q000235:genetics; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D015536:Down-Regulation; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D008527:Medulloblastoma / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D050130:Oncolytic Virotherapy / Q000379:methods; D034741:RNA, Small Interfering / Q000235:genetics*; D023041:Xenograft Model Antitumor Assays
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D034741:RNA, Small Interfering; D020780:Matrix Metalloproteinase 9