title: Overexpression of cyclin D1 and cyclin E in N-nitrosomethylbenzylamine-induced rat esophageal tumorigenesis.
abstract: Dysregulation of G1 cyclins has been implicated in several human malignancies. To further investigate the role of G1 cyclins in chemical carcinogenesis, the expression of cyclin D1 and cyclin E was analyzed by RT-PCR and immunohistochemical studies in N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal tumorigenesis. Cyclin D1 mRNA levels were increased 2.8-fold in 25 week (P < 0.05) and 6.8-fold in 45 week (P < 0.01) papillomas induced by NMBA, when compared with normal rat esophageal epithelium. Cyclin E mRNA levels were increased 6.2-fold in 25 week (P < 0.01) and 6.9-fold in 45 week (P < 0.01) papillomas. Immunohistochemical staining revealed exclusive nuclear staining of both cyclin D1 and cyclin E. Furthermore, there was a sequential increase in cyclin D1- and cyclin E-positive cells from normal epithelium, to preneoplastic lesions, to papillomas. These findings suggest that overexpression of cyclin D1 and cyclin E occur relatively early in rat esophageal tumorigenesis and participate in tumor progression in this model.
authors: Division of Environmental Health Sciences, School of Public Health, Ohio State University, Columbus, OH, USA.
authors: Q S
authors: QS
authors: Wang
authors: C L
authors: CL
authors: Sabourin
authors: H
authors: H
authors: Wang
authors: G D
authors: GD
authors: Stoner
mesh_terms: D000818:Animals; D001483:Base Sequence; D002273:Carcinogens; D019938:Cyclin D1; D016213:Cyclins / Q000235:genetics*; D017931:DNA Primers; D004128:Dimethylnitrosamine / Q000031:analogs & derivatives*; D004938:Esophageal Neoplasms / Q000139:chemically induced* / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D008969:Molecular Sequence Data; D015513:Oncogene Proteins / Q000235:genetics*; D010212:Papilloma / Q000139:chemically induced* / Q000473:pathology; D016133:Polymerase Chain Reaction; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D016213:Cyclins; D017931:DNA Primers; D015513:Oncogene Proteins; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D019938:Cyclin D1; C014707:nitrosobenzylmethylamine; D004128:Dimethylnitrosamine