Gynaecology. Apoptosis and the expression of Bax and Bcl-2 in hyperplasia and adenocarcinoma of the uterine endometrium
Authors: Kokawa, Katsuji; Shikone, Toshihiko; Otani, Tsutomu; Nishiyama, Rika; Ishii, Yuki; Yagi, Shigetaka
Source: Human Reproduction, Volume 16, Number 10, October 2001 , pp. 2211-2218(8)
Publisher: Oxford University Press
Abstract:BACKGROUND: Apoptosis plays a crucial role in carcinogenesis in various tumours. This study was designed to investigate the occurrence of apoptosis and the expression of Bcl-2 and Bax proteins in endometrial tumours of corpus uteri. METHODS: Endometrial tissues were obtained from 20 patients with endometrioid adenocarcinoma, 16 patients with endometrial hyperplasia, and 4 patients with myoma uteri (which were used as controls). The occurrence of apoptosis was examined by using molecular biochemical techniques. The expression of Bcl-2 and Bax proteins was also investigated using immunohistochemical staining with appropriate antibodies. RESULTS: The labelling of DNA in situ indicated that apoptotic cells were sporadically seen in postmenopausal endometrium (5.2 ± 2.1, n = 4) and endometrial hyperplasia without atypia (2.6 ± 0.5, n = 9). In contrast, labelled cells were detected in atypical endometrial hyperplasia (15.9 ± 2.2, n = 7), and their numbers increased intensely in adenocarcinoma (29.3 ± 3.7, n = 20). Autoradiographic analysis revealed DNA laddering in many cases of carcinoma. Bcl-2 was highly immunopositive in hyperplasia without atypia (36.2 ± 6.5%, n = 9), but was decreased in the atypical endometrial hyperplasia (16.3 ± 4.8%, n = 7). Large fractions of the carcinoma (6.3 ± 1.8%, n = 20) and normal endometrium (2.8 ± 1.4%, n = 4) were immunonegative or slightly immunopositive to Bcl-2. In contrast, Bax immunoreactivity was more frequent and stronger in adenocarcinoma (43.6 ± 4.1%, n = 20) than that in normal endometrium (17.6 ± 6.7%, n = 4) and hyperplasia (7.2 ± 2.2%, n = 16). CONCLUSIONS: These results suggest that cells in hyperplasia expressing Bcl-2 might have prolonged survival ability. Neoplastic cells in adenocarcinoma might show apoptosis in association with a decreased expression of Bcl-2 and an increased expression of Bax. Therefore, the frequency of apoptosis and the expression of Bcl-2 and Bax might be correlated with carcinogenesis in the uterine endometrium of humans.
Document Type: Research Article
Affiliations: Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama 641-0012, Japan
Publication date: October 2001
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.