OBJECTIVE: To investigate the clinical significance of Bmi-1 expression as a prognostic marker for cervical cancer. Design. Retrospectively collected data from a population-based cohort. SETTING: Jiangsu Province Hospital. Population. Eighty-eight women diagnosed with cervical carcinoma between 2000 and 2003. METHODS: RT-PCR assay was performed to determine Bmi-1 mRNA expression in 18 cervical cancer and noncancerous tissue samples and immunohistochemistry to detect Bmi-1 protein expression in 88 cervical cancer samples. The correlation between Bmi-1 expression and clinicopathological factors was analyzed. Additionally, statistical analyses were applied to test for prognostic associations. RNA interference was used to downregulate Bmi-1 expression in a cervical cancer cell line (HeLa). In vitro cytotoxicity was measured by the methylthiazoletetrazolium and colony formation assays. Effects of Bmi-1 inhibition on in vivo growth of cancer cells was detected by the tumorigenicity assay. Cell cycle distribution and cell apoptosis were measured by flow cytometry. MAIN OUTCOME MEASURES: The levels of Bmi-1 mRNA and protein expression in tissues were evaluated by RT-PCR and Western Blot assays. RESULTS: The level of Bmi-1 mRNA expression in cervical cancer tissues was significantly higher than that in corresponding noncancerous tissues. High Bmi-1 expression was significantly correlated with poor tumor differentiation, advanced International Federation of Gynecology and Obstetrics stage and positive lymph node metastasis. Patients with high Bmi-1 expression showed shorter overall survival than those with low expression. Univariate and multivariate analyses showed that high Bmi-1 expression was an independent prognostic factor. CONCLUSIONS: RNA interference-mediated Bmi-1 inhibition could inhibit in vitro and in vivo growth, enhance apoptosis and induce cell cycle arrest of cervical cancer cells. Bmi-1 might be an independent prognostic marker for cervical cancer patients.
OBJECTIVE: To investigate the clinical significance of Bmi-1 expression as a prognostic marker for cervical cancer. Design. Retrospectively collected data from a population-based cohort. SETTING: Jiangsu Province Hospital. Population. Eighty-eight women diagnosed with cervical carcinoma between 2000 and 2003. METHODS: RT-PCR assay was performed to determine Bmi-1 mRNA expression in 18 cervical cancer and noncancerous tissue samples and immunohistochemistry to detect Bmi-1 protein expression in 88 cervical cancer samples. The correlation between Bmi-1 expression and clinicopathological factors was analyzed. Additionally, statistical analyses were applied to test for prognostic associations. RNA interference was used to downregulate Bmi-1 expression in a cervical cancer cell line (HeLa). In vitro cytotoxicity was measured by the methylthiazoletetrazolium and colony formation assays. Effects of Bmi-1 inhibition on in vivo growth of cancer cells was detected by the tumorigenicity assay. Cell cycle distribution and cell apoptosis were measured by flow cytometry. MAIN OUTCOME MEASURES: The levels of Bmi-1 mRNA and protein expression in tissues were evaluated by RT-PCR and Western Blot assays. RESULTS: The level of Bmi-1 mRNA expression in cervical cancer tissues was significantly higher than that in corresponding noncancerous tissues. High Bmi-1 expression was significantly correlated with poor tumor differentiation, advanced International Federation of Gynecology and Obstetrics stage and positive lymph node metastasis. Patients with high Bmi-1 expression showed shorter overall survival than those with low expression. Univariate and multivariate analyses showed that high Bmi-1 expression was an independent prognostic factor. CONCLUSIONS: RNA interference-mediated Bmi-1 inhibition could inhibit in vitro and in vivo growth, enhance apoptosis and induce cell cycle arrest of cervical cancer cells. Bmi-1 might be an independent prognostic marker for cervical cancerpatients.
Authors: Lan Wang; Jun-Ling Liu; Liang Yu; Xiang-Xia Liu; Hong-Mei Wu; Fang-Yong Lei; Shu Wu; Xi Wang Journal: Medicine (Baltimore) Date: 2015-05 Impact factor: 1.889