title: p53 alteration, proliferating cell nuclear antigen, and nucleolar organizer regions in thymic epithelial tumors.
abstract: We examined p53 protein expression, p53 gene mutation, proliferating cell nuclear antigen (PCNA), and argyrophilic nuclear organizer regions (AgNOR), in 30 patients with surgically-treated thymic tumors (26 thymoma and 4 thymic carcinoma cases). p53 expression ratio with DO-1 was divided as p53 negative (0% positivity), low expressor (<10% positivity), high expressor (>10% positivity). The incidence of p53 low and high expressor in thymoma were 19% (5/26) and 8% (2/26), respectively. p53 immunopositivity in thymoma was significantly correlated with PCNA labeling index (LI). p53 expression ratio in invasive thymoma (33%) tended to be higher than that in non-invasive thymoma (18%). p53 expression was detected in one of the thymic carcinoma. There were no p53 gene mutations in 15 invasive thymoma, although one of four (25%) thymic carcinomas showed two point mutations. p53 gene alterations seem to be associated with malignant activity of tumor cells, and therefore detection of p53 gene mutations is useful as a diagnostic factor.
authors.affiliation: VCC, 649 Medical Research Building II, Carbone LAB (648), Nashville, TN 37232-6838, USA.
authors.forename: T
authors.initials: T
authors.lastname: Oyama
authors.forename: T
authors.initials: T
authors.lastname: Osaki
authors.forename: T
authors.initials: T
authors.lastname: Mitsudomi
authors.forename: R
authors.initials: R
authors.lastname: Ogawa
authors.forename: R
authors.initials: R
authors.lastname: Nakanishi
authors.forename: K
authors.initials: K
authors.lastname: Sugio
authors.forename: K
authors.initials: K
authors.lastname: Yasumoto
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009697:Nucleolus Organizer Region / Q000473:pathology*; D017354:Point Mutation; D011237:Predictive Value of Tests; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*; D013945:Thymoma / Q000737:chemistry / Q000473:pathology*; D013953:Thymus Neoplasms / Q000737:chemistry / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53