Bax and Bcl-2 protein expression following radiation therapy versus radiation plus thermoradiotherapy in stage IIIB cervical carcinoma

✍ Scribed by Yoko Harima; Kenji Nagata; Keizo Harima; Atsutoshi Oka; Valentina V. Ostapenko; Nobuaki Shikata; Takeo Ohnishi; Yoshimasa Tanaka

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 312 KB
• Volume: 88
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/(sici)1097-0142(20000101)88:1<132::aid-cncr18>3.0.co;2-h

✦ Synopsis

BACKGROUND.

The relative amounts of Bcl-2 and Bax proteins determine cell survival or death following an apoptotic stimulus. To clarify the molecular mechanism of cell death after radiotherapy or thermoradiotherapy and its relation to the response of AJCC/UICC Stage IIIB cervical carcinomas, the expression of Bax and Bcl-2 proteins was investigated both before and in the course of treatment given during this study.

METHODS. Thirty-seven patients with Stage IIIB carcinoma of the uterine cervix

were treated with external beam irradiation to the pelvis combined with iridium-192 high-dose-rate intracavitary brachytherapy. All patients were randomized to one of the following two groups: the radiotherapy (RT) group of 19 patients who were given radiotherapy alone, and the thermoradiotherapy (TRT) group of 18 patients who were given 3 sessions of hyperthermia in addition to RT. Specimens of the cervical tumors were obtained by punch biopsy both before and in the course of the treatment (after a total dose of 10.8 grays [Gy] for the RT group or after 10.8 Gy plus 1 session of hyperthermia for the TRT group). The tumor sections were stained with anti-Bax and anti-Bcl-2 monoclonal antibody. On the basis of the percentage of immunopositive cells, both pretreatment and posttreatment samples were scored. Furthermore, relative changes in protein expression were determined by comparing the pretreatment scores with those in the course of treatment. In addition, treatment response was evaluated.