title: The expression of bcl-2 and bcl-6 protein in normal and malignant transitional epithelium.
abstract: The bcl-2 proto-oncogene plays a key role in cell longevity by preventing apoptosis. Bcl-2 is important in developing and maintaining the normal function of lymphoid and epithelial tissues. The bcl-6 protein is a 96 kDa nuclear protein selectively expressed in mature B cells within normal germinal centers as well as in their transformed counterparts in diffuse large B cell lymphoma. Recently, the bcl-6 protein has also been reported to be expressed in normal skin and epidermal neoplasms. In this study, 47 cases of transitional cell carcinomas (TCCs) were immunohistochemically studied for bcl-2 and bcl-6 protein expression. The results showed that bcl-2 was expressed only on basal layer cells, whereas bcl-6 expression was restricted to the superficial layers in the normal transitional epithelium. Von Brunn's nests showed strong immunostaining to bcl-2, but were negative to bcl-6. Among 47 TCCs, 15 (32.6%) and 29 (61.7%) cases were positive for bcl-2 and bcl-6, respectively. Compared with the normal transitional epithelium, the expression of bcl-2 was significantly decreased, whereas bcl-6 expression was significantly increased in TCCs. Additionally, the strong expression of bcl-6 had a positive correlation with the histopathologic grade of TCC. In conclusion, bcl-2 and bcl-6 proteins may play a role in the pathogenesis of TCCs, and bcl-6 expression reflects histopathologic grade.
authors.affiliation: Department of Pathology and Urology, Korea University Medicine College, 126-1, 5 Ga, Anam Dong, Sungbuk Gu, Seoul, Korea.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Lin
authors.forename: Hankyeom
authors.initials: H
authors.lastname: Kim
authors.forename: Hongseok
authors.initials: H
authors.lastname: Park
authors.forename: Youngsik
authors.initials: Y
authors.lastname: Kim
authors.forename: Jun
authors.initials: J
authors.lastname: Cheon
authors.forename: Insun
authors.initials: I
authors.lastname: Kim
mesh_terms: D002295:Carcinoma, Transitional Cell / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors / Q000378:metabolism*; D001743:Urinary Bladder / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000209:etiology / Q000378:metabolism* / Q000473:pathology
chemical_list: D004268:DNA-Binding Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors