Zhang Fubin, Song Xiaowei, Li Li, Wang Jingfang, Lin Leyuan, Li Cong, Li Hongtao, Lv Yanju, Jin Yinghua, Liu Ying, Hu Yu, Xin Tao
Department of Gynecology, The Third Affiliated (Tumor) Hospital, Harbin Medical University, Harbin, 150040, China.
Tumour Biol. 2015 Apr;36(4):2907-12. doi: 10.1007/s13277-014-2920-y. Epub 2014 Dec 13.
In our previous study, we isolated a homogeneous polysaccharide (PTP) with antitumor activity from the roots of Polygala tenuifolia. In view of the close correlation between Bmi-1 expression and progression of ovarian cancer, we intend to elucidate the mechanism of its activity by determining the Bmi-1 expression and the telomerase activity in human ovarian carcinoma OVCAR-3 cells following treatment with PTP at three concentrations of 0.5, 1, and 2 mg/mL for 48 h. MTT and colony-forming assays revealed that PTP had a significant inhibitory effect on the cell growth and colony formation of OVCAR-3 cells. Furthermore, Western blot and real-time PCR analysis showed that PTP inhibited Bmi-1 both in protein and transcript levels. Besides, the telomerase activity in OVCAR-3 cells was also downregulated after PTP treatment for 48 h. Taken together, the inhibitory effect of PTP on the cell growth was at least in part mediated via the downregulation of Bmi-1 expression and the telomerase activity in OVCAR-3 cells, and PTP might be a new candidate for chemotherapeutic agent against human ovarian cancer.
在我们之前的研究中，我们从远志根中分离出一种具有抗肿瘤活性的同质多糖（PTP）。鉴于Bmi-1表达与卵巢癌进展之间的密切相关性，我们打算通过测定人卵巢癌OVCAR-3细胞在用0.5、1和2 mg/mL三种浓度的PTP处理48小时后的Bmi-1表达和端粒酶活性，来阐明其活性机制。MTT和集落形成试验表明，PTP对OVCAR-3细胞的生长和集落形成具有显著抑制作用。此外，蛋白质印迹和实时PCR分析表明，PTP在蛋白质和转录水平上均抑制Bmi-1。此外，PTP处理48小时后，OVCAR-3细胞中的端粒酶活性也下调。综上所述，PTP对细胞生长的抑制作用至少部分是通过下调OVCAR-3细胞中的Bmi-1表达和端粒酶活性介导的，并且PTP可能是一种抗人卵巢癌化疗药物的新候选物。
