Using methylcholanthrene-induced fibrosarcomas to study tumor immunology.

Mouse models of cancer are essential in furthering our understanding both of the mechanisms that drive tumor development and the immune response that develops in parallel, and also in providing a platform for testing novel anti-cancer therapies. The majority of solid tumor models available rely on the injection of existing cancer cell lines into naïve hosts which, while providing quick and reproducible model systems, typically lack the development of a tumor microenvironment that recapitulates those seen in human cancers. Administration of the carcinogen 3-methylcholanthrene (MCA), allows tumors to develop in situ, forming a tumor microenvironment with an established stroma and vasculature. This article provides a detailed set of protocols for the administration of MCA into mice and the subsequent monitoring of tumors. Protocols are also provided for some of the routinely used downstream applications that can be used for MCA tumors.

Interleukin-1beta induced activation of nuclear factor-kappab can be inhibited by novel pharmacological agents in osteoarthritis.

OBJECTIVES: To investigate the importance of activation of the transcription factor, nuclear factor-kappaB (NF-kappaB) by interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) in the pathogenesis of osteoarthritis (OA) and assess its suitability as a target for therapy by determining its role in the induction of the cytokine IL-6 and the degenerative enzymes, matrix metalloproteinase (MMP)-1 and MMP-3 in vitro. METHODS: Three distinct cellular models, derived from primary OA tissue, were employed, namely, fibroblast-like synoviocytes (OA-SF); co-cultures containing phenotypic macrophage-like and fibroblast-like cells (OA-COCUL); and primary OA synovial tissue explants (OA-EXP). These were treated with specific inhibitors of IL-1beta, TNF-alpha and NF-kappaB to assess their differential role in the production of pathologically relevant mediators, specifically IL-6, MMP-1, MMP-3 and the tissue inhibitor of metalloproteinases-1 (TIMP-1), which were quantified by enzyme-linked immunosorbent assay. RESULTS: Inhibition of NF-kappaB by a novel agent, RO100 at a dose of 0.1 microM, exerted significant (P < 0.05) repression of IL-6, MMP-1 and MMP-3 production in OA-SF. Notably, neither TIMP-1 production nor cell viability was significantly affected at the dose tested. These data were reproduced in OA-EXP, which might be considered as having greater physiological relevance. Interestingly, comparable efficacy was noted using IL-1beta and TNF-alpha neutralizing antibodies in OA-COCUL. CONCLUSIONS: We have demonstrated that a novel pharmacological inhibitor of NF-kappaB, RO100 inhibits pathological mediators of OA progression with equivalent efficacy as established IL-1beta and TNF-alpha neutralizing strategies. Our findings highlight a potential for developing NF-kappaB targeted therapeutics for positively regulating disease activity and improving clinical outcome in OA.