Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
J Nutr Biochem. 2012 Sep;23(9):1086-91. doi: 10.1016/j.jnutbio.2011.06.001. Epub 2011 Dec 1.
The inhibitory effect of oral methylseleninic acid or methylselenocysteine administration on cancer cell xenograft development in nude mice is well characterized; however, less is known about the efficacy of selenate and age on selenium chemoprevention. In this study, we tested whether selenate and duration on diets would regulate prostate cancer xenograft in nude mice. Thirty-nine homozygous NU/J nude mice were fed a selenium-deficient, Torula yeast basal diet alone (Se-) or supplemented with 0.15 (Se) or 1.0 (Se+) mg selenium/kg (as Na₂SeO₄) for 6 months in Experiment 1 and for 4 weeks in Experiment 2, followed by a 47-day PC-3 prostate cancer cell xenograft on the designated diet. In Experiment 1, the Se- diet enhanced the initial tumor development on days 11-17, whereas the Se+ diet suppressed tumor growth on days 35-47 in adult nude mice. Tumors grown in Se- mice were loosely packed and showed increased necrosis and inflammation as compared to those in Se and Se+ mice. In Experiment 2, dietary selenium did not affect tumor development or histopathology throughout the time course. In both experiments, postmortem plasma selenium concentrations in Se and Se+ mice were comparable and were twofold greater than those in Se- mice. Taken together, dietary selenate at nutritional and supranutritional levels differentially inhibit tumor development in adult, but not young, nude mice engrafted with PC-3 prostate cancer cells.
口服亚甲基硒酸或甲基硒代半胱氨酸对裸鼠异种移植癌细胞生长的抑制作用已得到很好的描述；然而，对于硒酸盐和年龄对硒化学预防的效果知之甚少。在这项研究中，我们测试了饮食中的硒酸盐和时间是否会调节裸鼠前列腺癌异种移植。39 只纯合 NU/J 裸鼠在实验 1 中单独喂食缺乏硒的啤酒酵母基础饮食（Se-）或补充 0.15（Se）或 1.0（Se+）mg/kg 硒（以 Na₂SeO₄ 形式）6 个月，在实验 2 中喂食 4 周，然后在指定饮食上进行 PC-3 前列腺癌细胞异种移植 47 天。在实验 1 中，Se-饮食增强了成年裸鼠 11-17 天的初始肿瘤生长，而 Se+饮食抑制了 35-47 天的肿瘤生长。与 Se 和 Se+小鼠相比，在 Se-小鼠中生长的肿瘤细胞排列松散，且坏死和炎症增加。在实验 2 中，饮食中的硒在整个时间过程中均未影响肿瘤的生长或组织病理学。在两个实验中，Se 和 Se+小鼠的死后血浆硒浓度相似，是 Se-小鼠的两倍。总之，营养和超营养水平的饮食硒酸盐在成年但不是幼年裸鼠中，对植入 PC-3 前列腺癌细胞的异种移植瘤的生长具有不同的抑制作用。
