title: Polygala tenuifolia polysaccharide (PTP) inhibits cell proliferation by repressing Bmi-1 expression and downregulating telomerase activity.
abstract: 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.
authors.affiliation: Department of Gynecology, The Third Affiliated (Tumor) Hospital, Harbin Medical University, Harbin, 150040, China.
authors.forename: Fubin
authors.initials: F
authors.lastname: Zhang
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Song
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Jingfang
authors.initials: J
authors.lastname: Wang
authors.forename: Leyuan
authors.initials: L
authors.lastname: Lin
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.forename: Hongtao
authors.initials: H
authors.lastname: Li
authors.forename: Yanju
authors.initials: Y
authors.lastname: Lv
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Jin
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Hu
authors.forename: Tao
authors.initials: T
authors.lastname: Xin
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D063150:Polycomb Repressive Complex 1 / Q000096:biosynthesis*; D031801:Polygala / Q000737:chemistry; D011134:Polysaccharides / Q000008:administration & dosage* / Q000737:chemistry; D019098:Telomerase / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C069077:BMI1 protein, human; D011134:Polysaccharides; D063150:Polycomb Repressive Complex 1; D019098:Telomerase