Berggren Margareta, Sittadjody Sivanandane, Song Zuohe, Samira Jean-Louis, Burd Randy, Meuillet Emmanuelle J
Department of Nutritional Sciences, College of Agriculture and Life Sciences, The University of Arizona, Tucson, Arizona 85721-0038, USA.
Nutr Cancer. 2009;61(3):322-31. doi: 10.1080/01635580802521338.
Epidemiological and clinical data suggest that selenium may prevent prostate cancer; however, the cellular effects of selenium in malignant prostate cells are not well understood. We previously reported that the activity of the tumor suppressor PTEN is modulated by thioredoxin (Trx) in a RedOx-dependent manner. In this study, we demonstrated that the activity of Trx reductase (TR) is increased by sevenfold in the human prostate cancer cell line, DU-145, after 5 days of sodium selenite (Se) treatment. The treatment of DU-145 cells with increasing concentrations of Se induced an increase in PTEN lipid phosphatase activity by twofold, which correlated with a decrease in phospho-ser(473)-Akt, and an increase in phospho-Ser(370)-PTEN levels. Se also increased casein kinase-2 (CK2) activity; and the use of apigenin, an inhibitor of CK2, revealed that the regulation of the tumor suppressor PTEN by Se may be achieved via both the Trx-TR system and the RedOx control of the kinase involved in the regulation of PTEN activity.
流行病学和临床数据表明,硒可能预防前列腺癌;然而,硒在恶性前列腺细胞中的细胞效应尚未完全明确。我们之前报道过,肿瘤抑制因子PTEN的活性受硫氧还蛋白(Trx)以氧化还原依赖的方式调节。在本研究中,我们证明,经亚硒酸钠(Se)处理5天后,人前列腺癌细胞系DU-145中的硫氧还蛋白还原酶(TR)活性增加了7倍。用浓度递增的Se处理DU-145细胞,诱导PTEN脂质磷酸酶活性增加了2倍,这与磷酸化丝氨酸(473)-Akt的减少以及磷酸化丝氨酸(370)-PTEN水平的增加相关。Se还增加了酪蛋白激酶2(CK2)的活性;使用CK2抑制剂芹菜素表明,Se对肿瘤抑制因子PTEN的调节可能通过Trx-TR系统以及参与PTEN活性调节的激酶的氧化还原控制来实现。