title: COX-2 inhibitors and genetic background reduce mammary tumorigenesis in cyclooxygenase-2 transgenic mice.
abstract: Cyclooxygenase-2 (COX-2) overexpression is a widely recognized feature of human breast cancer and inhibitors of the enzyme have antitumor effects in a subset of tumor settings. Previously, we demonstrated that direct overexpression of COX-2 under control of the mammary-specific MMTV promoter/enhancer, was itself oncogenic and lead to the induction of mammary tumors in multiparous, outbred CD1 mice. In the present study, we provide evidence that COX-2 dependent tumor progression can also be studied in FVB/N, an inbred strain widely used for analysis of breast cancer progression. In these mice, the human COX-2 transgene was strongly induced during pregnancy/lactation and mammary tumors developed after multiple pregnancies. However, crossing the COX-2 FVB/N mice with the C57BL6 strain resulted in loss of the mammary tumorigenic phenotype despite the fact that the human COX-2 gene was induced. Treatment of the COX-2 transgenic mice in the FVB/N strain with celecoxib (1600 ppm), a COX-2 selective inhibitor, resulted significant reduction in tumor size and multiplicity when compared to transgenic mice fed with control chow. SC-560 (20 ppm), a COX-1 selective inhibitor did not have significant effect on tumorigenesis. These studies suggest that FVB/N is a susceptible mouse strain well suited to the study of COX-2 mediated tumor progression and may provide a tool for the identification of interacting genes and therapeutic treatments for this clinically important target.
authors.affiliation: Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, 06030-350, USA.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Narko
authors.forename: Ben
authors.initials: B
authors.lastname: Zweifel
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Trifan
authors.forename: Ari
authors.initials: A
authors.lastname: Ristimäki
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Lane
authors.forename: Timothy
authors.initials: T
authors.lastname: Hla
mesh_terms: D000818:Animals; D001483:Base Sequence; D000068579:Celecoxib; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D017931:DNA Primers; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009930:Organic Chemicals / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D011720:Pyrazoles / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D017931:DNA Primers; D008565:Membrane Proteins; D009930:Organic Chemicals; D011720:Pyrazoles; C404729:SC 58560; D013449:Sulfonamides; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D000068579:Celecoxib