title: Target validation using RNA interference in solid tumors.
abstract: Reverse genetics is one strategy that is currently used to establish a link between a target gene and a disease phenotype. In this process, the function of a gene is inhibited and the consequence of its loss on a desired biological function, such as tumor growth and metastasis, is monitored. RNA interference (RNAi) has been found to be the most effective method to specifically inhibit gene expression. Notably, interactions between cancer cells, stromal cells, and the extracellular matrix (ECM) are crucial to angiogenesis and tumorigenesis. Tumor cells and the surrounding stroma are the principle source of growth factors and cytokines, which induce remodeling of the ECM mediated by metalloproteases (MMPs) secreted by macrophages. The production of macrophages is regulated by colony-stimulating factor (CSF)-1, which is overexpressed in several tumors. When short-interfering RNAs (siRNAs) targeting either the CSF-1 or its receptors were delivered into colon and breast cancer xenografts in mice, tumor growth was inhibited. Associated with this suppression, we observed decreased tumor vascularity, reduced expression of angiogenic factors and MMPs, and decreased macrophage recruitment to the tumors. The suppression of CSF-1 by RNA interference is therefore a powerful tool to block gene function and influence tumor-stroma interactions in solid tumor development.
authors.affiliation: Laboratory for Cardiovascular Research, Center for Anatomy and Cell Biology, Vienna Medical University, Vienna, Austria.
authors.forename: Seyedhossein
authors.initials: S
authors.lastname: Aharinejad
authors.forename: Mouldy
authors.initials: M
authors.lastname: Sioud
authors.forename: Trevor
authors.initials: T
authors.lastname: Lucas
authors.forename: Dietmar
authors.initials: D
authors.lastname: Abraham
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D002450:Cell Communication / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000235:genetics; D018390:Gene Targeting / Q000379:methods; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D008264:Macrophages / Q000378:metabolism / Q000473:pathology; D053505:Matrix Metalloproteinases, Secreted / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D034622:RNA Interference / Q000187:drug effects*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D014183:Transplantation, Heterologous
chemical_list: D000970:Antineoplastic Agents; D034741:RNA, Small Interfering; D016173:Macrophage Colony-Stimulating Factor; D053505:Matrix Metalloproteinases, Secreted