title: Inhibitory effects and molecular mechanisms of selenium-containing tea polysaccharides on human breast cancer MCF-7 cells.
abstract: Dietary supplementation of selenium-enriched tea is known to have an anticancer health benefit. This study was to investigate the inhibitory effect of selenium-containing tea polysaccharides (Se-GTPs) from a new variety of selenium-enriched Ziyang green tea against human MCF-7 breast cancer cells. Se-GTPs dose-dependently exhibited an effective cell growth inhibition with an IC(50) of 140.1 μg/mL by inducing MCF-7 cancer cells to undergo G2/M phase arrest and apoptosis. The blockade of cell cycle was associated with an up-regulation of p53 expression, but not CDK2. Se-GTPs clearly triggered the mitochondrial apoptotic pathway, as indicated by an increase in Bax/Bcl-2 ratio and subsequent caspase-3 and caspase-9 activation. It was also found that the generation of intracellular ROS is a critical mediator in Se-GTPs-induced cell growth inhibition. These findings suggest that Se-GTPs may serve as a potential novel dietary agent for human breast cancer chemoprevention.
authors.affiliation: Key Laboratory of Ministry of Education for Medicinal Resource and Natural Pharmaceutical Chemistry, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China.
authors.forename: Nianwu
authors.initials: N
authors.lastname: He
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Shi
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Lingmin
authors.initials: L
authors.lastname: Tian
authors.forename: Dongying
authors.initials: D
authors.lastname: Wang
authors.forename: Xingbin
authors.initials: X
authors.lastname: Yang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D005260:Female; D006801:Humans; D020128:Inhibitory Concentration 50; D061986:MCF-7 Cells; D008928:Mitochondria / Q000187:drug effects; D011134:Polysaccharides / Q000494:pharmacology*; D017382:Reactive Oxygen Species; D012643:Selenium / Q000494:pharmacology*; D015398:Signal Transduction; D013662:Tea / Q000737:chemistry*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D015854:Up-Regulation; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C494826:BAX protein, human; D011134:Polysaccharides; D017382:Reactive Oxygen Species; D013662:Tea; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D012643:Selenium