title: The participation of myofibroblasts in the capsular formation of human conventional and chromophobe renal cell carcinomas.
abstract: The presence of myofibroblasts has been elucidated in neoplastic capsules of various organs. In the present article, we examine the presence of myofibroblasts in the capsule of renal cell carcinoma (RCC) and discuss the origin of the myofibroblasts. Nineteen renal tumors (conventional RCC, n=17; chromophobe RCC, n=2) with evident and totally surrounded fibrous capsule were selected. Abundant myofibroblasts were immunohistochemically observed in the capsule of the RCCs. These findings were confirmed by electron and immunoelectron microscopic studies of three conventional RCCs. Type III and I collagens were predominant in the outer and inner layers of the RCC capsule, respectively. The cytoplasm of the tubular epithelial cells in the tissue surrounding the neoplastic capsule stained positively for transforming growth factor (TGF)-beta 1. In situ hybridization detected type I collagen mRNA in myofibroblasts of the capsule. Myofibroblasts may participate in the capsular formation of conventional and chromophobe RCCs through the collagen production.
authors.affiliation: Department of Urology, Program of Tumor Biology and Regulation, Kochi Medical School, Kochi University, Kochi 783-8505, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shimasaki
authors.forename: N
authors.initials: N
authors.lastname: Kuroda
authors.forename: L
authors.initials: L
authors.lastname: Guo
authors.forename: Y
authors.initials: Y
authors.lastname: Jin
authors.forename: E
authors.initials: E
authors.lastname: Miyazaki
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
authors.forename: M
authors.initials: M
authors.lastname: Toi
authors.forename: M
authors.initials: M
authors.lastname: Hiroi
authors.forename: H
authors.initials: H
authors.lastname: Enzan
authors.forename: T
authors.initials: T
authors.lastname: Shuin
mesh_terms: D002292:Carcinoma, Renal Cell / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D003094:Collagen / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D006801:Humans; D016253:Microscopy, Immunoelectron
chemical_list: D003094:Collagen