Down-regulation of cathepsin-D expression by antisense gene transfer inhibits tumor growth and experimental lung metastasis of human breast cancer cells.
Overexpression of cathepsin-D in primary breast cancer has been associated with rapid development of clinical metastasis. To investigate the role of this protease in breast cancer growth and progression to metastasis, we stably transfected a highly metastatic human breast cancer cell line, MDA-MB-231, with a plasmid containing either the full-length cDNA for cathepsin-D or a 535 bp antisense cathepsin-D cDNA fragment. Clones expressing antisense cathepsin-D cDNA that exhibited a 70-80% reduction in cathepsin-D protein, both intra- and extracellularly compared to controls, were selected for further experiments. These antisense-transfected cells displayed a reduced outgrowth rate when embedded in a Matrigel matrix, formed smaller colonies in soft agar and presented a significantly decreased tumor growth and experimental lung metastasis in nude mice compared with controls. However, manipulating the cathepsin-D level in the antisense cells has no effect on their in vitro invasiveness. These studies demonstrate that cathepsin-D enhances anchorage-independent cell proliferation and subsequently facilitates tumorigenesis and metastasis of breast cancer cells. Our overall results provide the first evidence on the essential role of cathepsin-D in breast cancer, and support the development of a new cathepsin-D-targeted therapy.
INSERM U540 'Endocrinologie Moléculaire et Cellulaire des Cancers', Université de Montpellier 1, 60 rue de Navacelles, 34090 Montpellier, France.
Murielle
M
Glondu
Emmanuelle
E
Liaudet-Coopman
Danielle
D
Derocq
Nadine
N
Platet
Henri
H
Rochefort
Marcel
M
Garcia
D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D002402:Cathepsin D / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D016373:DNA, Antisense / Q000235:genetics*; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000556:secondary*; D051379:Mice; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009374:Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured
D016373:DNA, Antisense; D002402:Cathepsin D