Selective suppression of cathepsin L by antisense cDNA impairs human brain tumor cell invasion in vitro and promotes apoptosis.
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.
Levicar
Natasa
N
Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia.
Dewey
Ricardo A
RA
Daley
Emma
E
Bates
Timothy E
TE
Davies
Derek
D
Kos
Janko
J
Pilkington
Geoffrey J
GJ
Lah
Tamara T
TT
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
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