title: Black raspberries inhibit N-nitrosomethylbenzylamine (NMBA)-induced angiogenesis in rat esophagus parallel to the suppression of COX-2 and iNOS.
abstract: Angiogenesis, the formation of new blood vessels, is critical to tumor growth and metastasis. Vascular endothelial growth factor (VEGF), an important angiogenic activator, is essential for angiogenesis. Our laboratory has used a rodent model of human esophageal squamous cell carcinoma (ESCC) to identify putative chemopreventive agents for this disease and determine their mechanisms of action. We reported that dietary black raspberry powder (BRB) inhibits N-nitrosomethylbenzylamine (NMBA)-induced tumor development in the rat esophagus by inhibiting the formation of DNA adducts and reducing the proliferation rate of preneoplastic cells. On a molecular level, BRB downregulates the expression of c-Jun, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). In this study we analyzed the effect of BRB on angiogenesis. VEGF expression was determined by real-time RT-PCR and immunohistochemical analysis of microvessel density (MVD). BRB significantly suppressed VEGF-C expression from a 2.38 (+/- 0.34)-fold increase in animals treated with NMBA alone to a 1.08 (+/- 0.22)-fold increase in animals treated with NMBA plus BRB (P < 0.005). The MVD of esophagus was decreased from 53.7 +/- 5.6 vessels/cm in animals treated with NMBA alone to 22.6 +/- 2.6 vessels/cm in animals treated with NMBA plus BRB (P < 0.0001). Our data also suggest that downregulation of VEGF is correlated with suppression of COX-2 (r2 = 0.86, P < 0.001) and iNOS (r2 = 0.81, P < 0.005). As high vascularity is a risk factor for metastasis and tumor recurrence, BRB may have cancer therapeutic effects in human esophageal cancer.
authors.affiliation: Cancer Chemoprevention and Support Program, Division of Hematology and Oncology, Department of Internal Medicine, College of Medicine and Public Health, The Ohio State University Columbus, OH 43210, USA. tong.chen@osumc.edu
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Miranda E
authors.initials: ME
authors.lastname: Rose
authors.forename: Hyejeong
authors.initials: H
authors.lastname: Hwang
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Nines
authors.forename: Gary D
authors.initials: GD
authors.lastname: Stoner
mesh_terms: D000818:Animals; D002273:Carcinogens; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004128:Dimethylnitrosamine / Q000031:analogs & derivatives*; D004938:Esophageal Neoplasms / Q000139:chemically induced* / Q000473:pathology; D005260:Female; D005638:Fruit; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D008833:Microcirculation; D009389:Neovascularization, Pathologic; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D010936:Plant Extracts; C014707:nitrosobenzylmethylamine; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D004128:Dimethylnitrosamine