title: Depletion of procathepsin D gene expression by RNA interference: a potential therapeutic target for breast cancer.
abstract: Elevated level of procathepsin D (pCD), a zymogen of lysosomal aspartic proteinase cathepsin D, is associated with highly invasive neoplasms that include breast cancer. Independent studies have established that secreted pCD functions as a growth factor acting both in an autocrine and paracrine manner. Therefore, to explore whether pCD can be employed as a therapeutic target, the present study evaluates the impact of pCD knockdown using RNA interference technology. Of the three siRNA oligos tested, siRNA-3 exhibited a 90% inhibitory effect on pCD gene expression. Stable attenuation of pCD in breast cancer cells MDA-MB-231 was achieved by using a plasmid vector-based shRNA system. Pronounced suppression of pCD expression was accompanied by a significant reduction in invasion and proliferation of MDA-MB-231 cells stably transfected with functional shRNA. Importantly, in the athymic nude mice model, downregulation of pCD in breast cancer cells significantly reduced their metastatic potential. In addition, we observed a reduction in Cdc42 and NFkappaB2 expression in MDA-MB-231 cells with decreased pCD expression. When combined, our in vitro and in vivo experiments demonstrate that targeting pCD through RNAi technology represents a potential therapeutic tool for developing a therapy against breast cancer.
authors.affiliation: Department of Pothology, University of Louisville, Louisville, Kentucky 40202, USA.
authors.forename: Sujata Saraswat
authors.initials: SS
authors.lastname: Ohri
authors.forename: Aruna
authors.initials: A
authors.lastname: Vashishta
authors.forename: Mary
authors.initials: M
authors.lastname: Proctor
authors.forename: Martin
authors.initials: M
authors.lastname: Fusek
authors.forename: Vaclav
authors.initials: V
authors.lastname: Vetvicka
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy*; D002402:Cathepsin D / Q000037:antagonists & inhibitors* / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors* / Q000235:genetics*; D005260:Female; D006801:Humans; D051379:Mice; D052002:NF-kappa B p50 Subunit / Q000037:antagonists & inhibitors; D009361:Neoplasm Invasiveness; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D020764:cdc42 GTP-Binding Protein / Q000037:antagonists & inhibitors
chemical_list: D004792:Enzyme Precursors; D052002:NF-kappa B p50 Subunit; C489548:NFKB1 protein, human; D034741:RNA, Small Interfering; C058345:procathepsin D; D002402:Cathepsin D; D020764:cdc42 GTP-Binding Protein