Identification of Gene Function and Functional Pathways by Systemic Plasmid-Based Ribozyme Targeting in Adult Mice

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 99; no. 6; pp. 3878 - 3883
• Main Authors: Kashani-Sabet, Mohammed, Liu, Yong, Fong, Sylvia, Desprez, Pierre-Yves, Liu, Shuqing, Tu, Guanghuan, Nosrati, Mehdi, Handumrongkul, Chakkrapong, Liggitt, Denny, Thor, Ann D., Debs, Robert J.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19.03.2002; National Acad Sciences; The National Academy of Sciences
• Subjects: Aging; Animals; Antigens, CD - genetics; Biological Sciences; Cell lines; Cytokines; Endothelial cells; Female; Gene Expression Regulation, Neoplastic; Gene Targeting; Genes; Integrin beta3; Lung Neoplasms - genetics; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Lungs; Melanoma; Melanoma - genetics; Melanoma - metabolism; Melanoma - pathology; Metastasis; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness - genetics; Neoplasm Invasiveness - pathology; Neoplasm Metastasis - genetics; Neoplasm Metastasis - pathology; NF-kappa B - antagonists & inhibitors; NF-kappa B - deficiency; NF-kappa B - genetics; NF-kappa B - metabolism; Phenotypes; Plasmids; Plasmids - genetics; Platelet Endothelial Cell Adhesion Molecule-1 - genetics; Platelet Membrane Glycoproteins - genetics; RNA, Catalytic - genetics; RNA, Catalytic - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Rodents; Substrate Specificity; Tumor cell line; Tumors
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.002025599

To date, functional genomic studies have been confined to either cell-based assays or germline mutations, using transgenic or knockout animals. However, these approaches are often unable either to recapitulate complex biologic phenotypes, such as tumor metastasis, or to identify the specific genes and functional pathways that produce serious diseases in adult animals. Although the transcription factor NF-κB transactivates many metastasis-related genes in cells, the precise genes and functional-pathways through which NF-κB regulates metastasis in tumor-bearing hosts are poorly understood. Here, we show that the systemic delivery of plasmid-based ribozymes targeting NF-κB in adult, tumor-bearing mice suppressed NF-κB expression in metastatic melanoma cells, as well as in normal cell types, and significantly reduced metastatic spread. Plasmid-based ribozymes suppressed target-gene expression with sequence specificity not achievable by using synthetic oligonucleotide-based approaches. NF-κB seemed to regulate tumor metastasis through invasion-related, rather than angiogenesis-, cell-cycle- or apoptosis-related pathways in tumor-bearing mice. Furthermore, ribozymes targeting either of the NF-κB-regulated genes, integrin β3or PECAM-1 (a ligand-receptor pair linked to cell adhesion), reduced tumor metastasis at a level comparable to NF-κB. These studies demonstrate the utility of gene targeting by means of systemic, plasmid-based ribozymes to dissect out the functional genomics of complex biologic phenotypes, including tumor metastasis.