title: Localization of thymidine phosphorylase in breast cancer tissue.
abstract: Thymidine phosphorylase levels are higher in some human cancer tissues than in adjacent normal tissue. However, the ultrastructural localization of thymidine phosphorylase in cancer tissue has been demonstrated only in advanced gastric and colorectal cancer. We investigated the localization of thymidine phosphorylase in breast cancer tissue by immunohistochemistry and its ultrastructural localization by immunoelectron microscopy. Surgically resected specimens from 30 cases of breast cancer were analyzed. Immunohistochemical analysis revealed that cancer cells were positive in 13 cases. However, there were 21 cases that showed thymidine phosphorylase-positive inflammatory cells in cancer tissue. Thymidine phosphorylase-positive staining was detected among both cancer cells and inflammatory cells in 11 cases. Thymidine phosphorylase was diffusely positive in the cytoplasm of cancer cells and specifically positive in mitochondria of neutrophils and specific cytoplasmic granules of macrophages in cancer tissue by immunoelectron microscopy. These findings suggest that thymidine phosphorylase is produced by macrophages and is present in mitochondria of neutrophils and cytoplasmic granules of cancer cells.
authors.affiliation: Department of Tumor Surgery, Kochi Medical School, Oko-cho, Kohasu, Nankoku, 783-8505, Japan. kobayasm@med.kochi-ms.ac.jp
authors.forename: Michiya
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Takeki
authors.initials: T
authors.lastname: Sugimoto
authors.forename: Takehiro
authors.initials: T
authors.lastname: Okabayashi
authors.forename: Ken
authors.initials: K
authors.lastname: Okamoto
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Namikawa
authors.forename: Naoshige
authors.initials: N
authors.lastname: Tochika
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Moriki
authors.forename: Keijiro
authors.initials: K
authors.lastname: Araki
mesh_terms: D015720:5'-Nucleotidase / Q000032:analysis*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000648:ultrastructure; D000069287:Capecitabine; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000378:metabolism; D005260:Female; D005472:Fluorouracil / Q000031:analogs & derivatives; D006801:Humans; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron
chemical_list: D003841:Deoxycytidine; D000069287:Capecitabine; D015720:5'-Nucleotidase; D005472:Fluorouracil