title: Selective suppression of cathepsin L by antisense cDNA impairs human brain tumor cell invasion in vitro and promotes apoptosis.
abstract: Invasion and metastasis of certain tumors are accompanied by increased mRNA protein levels and enzymatic activity of cathepsin L. Cathepsin L has also been suggested to play a role in the proteolytic cascades associated with apoptosis. To investigate the role of cathepsin L in brain tumor invasion and apoptosis, the human glioma cell line, IPTP, was stably transfected with full-length antisense and sense cDNA of cathepsin L. Down-regulation of cathepsin L by antisense cDNA significantly impaired (up to 70%) glioma cell invasion in vitro and markedly increased glioma cell apoptosis induced by staurosporine. Compared to control and parental cell lines, antisense down-regulation of cathepsin L was associated with an earlier induction of caspase-3 activity. Up-regulation of cathepsin L activity by sense cDNA was associated with reduced apoptosis and later induction of caspase-3 activity. Moreover, down-regulation of cathepsin L lowered the expression of antiapoptotic protein Bcl-2, whereas up-regulation increased the expression of Bcl-2, indicating that cathepsin L acts upstream of caspase-3. These data show that cathepsin L is an important protein mediating the malignancy of gliomas and its inhibition may diminish their invasion and lead to increased tumor cell apoptosis by reducing apoptotic threshold.
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia.
authors.forename: Natasa
authors.initials: N
authors.lastname: Levicar
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Dewey
authors.forename: Emma
authors.initials: E
authors.lastname: Daley
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Bates
authors.forename: Derek
authors.initials: D
authors.lastname: Davies
authors.forename: Janko
authors.initials: J
authors.lastname: Kos
authors.forename: Geoffrey J
authors.initials: GJ
authors.lastname: Pilkington
authors.forename: Tamara T
authors.initials: TT
authors.lastname: Lah
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D056668:Cathepsin L; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000235:genetics*; D002448:Cell Adhesion / Q000187:drug effects / Q000235:genetics; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D003546:Cysteine Endopeptidases; D016373:DNA, Antisense / Q000235:genetics / Q000494:pharmacology*; D018076:DNA, Complementary / Q000494:pharmacology; D015316:Genetic Therapy / Q000379:methods; D005909:Glioblastoma / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D006801:Humans; D009361:Neoplasm Invasiveness; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D016373:DNA, Antisense; D018076:DNA, Complementary; D019253:Proto-Oncogene Proteins c-bcl-2; D002403:Cathepsins; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L; D019311:Staurosporine