Graduate Program in Biological Sciences (Cell and Molecular Biology), Institute of Biosciences, UNESP, Rio Claro (SP), Brazil.
Mutat Res. 2011 Oct 1;715(1-2):7-12. doi: 10.1016/j.mrfmmm.2011.06.015. Epub 2011 Jul 7.
Intestinal cancers are correlated with diet. Thus, determining and understanding nutrient-genome interactions is important. The present work assessed the action of the oligoelement selenium on cell proliferation, cytotoxicity, and in situ apoptosis induction and on the expression CASP9, BCL-XL and APC genes in intestinal adenocarcinoma cells (HT29). HT29 cells were cultured and treated with selenium at concentrations of 5, 50 and 500ng/mL with or without the damage-inducing agent doxorubicin. These cells were then evaluated for cytotoxicity (MTT), cell proliferation and in situ apoptosis induction. To evaluate gene expression, only the cells treated with 500ng/mL of selenium were used. RNA was extracted from these cells, and the expressions of CASP9, BCL-XL and APC were analyzed by the RT-PCR method. The GAPDH gene was used as a reference gene. The MTT assay showed that selenium was not cytotoxic at any of the concentrations tested. The cell proliferation assay showed that selenium did not interfere with cell proliferation at the three concentrations tested. In contrast, when the three concentrations were combined with doxorubicin, a significant decrease in the proliferation rate was observed. The apoptosis rate was significantly increased in the selenium (500ng/mL) and doxorubicin group. CASP9 expression was increased and BCL-XL expression decreased in the selenium (500ng/mL) and doxorubicin group. APC was significantly increased in the selenium group alone. These results show that selenium increases apoptosis, especially when it is associated with a damage-inducing agent. Also, selenium has an important role in the expression of the APC gene, which is related to cell cycle regulation.
肠道癌症与饮食有关。因此，确定和了解营养-基因组相互作用非常重要。本研究评估了微量元素硒对肠腺癌细胞（HT29）增殖、细胞毒性、原位细胞凋亡诱导以及 CASP9、BCL-XL 和 APC 基因表达的作用。将 HT29 细胞进行培养并分别用浓度为 5、50 和 500ng/mL 的硒以及有或没有损伤诱导剂阿霉素处理这些细胞，然后评估细胞毒性（MTT）、细胞增殖和原位细胞凋亡诱导。为了评估基因表达，仅使用用 500ng/mL 硒处理的细胞。从这些细胞中提取 RNA，并通过 RT-PCR 方法分析 CASP9、BCL-XL 和 APC 的表达。GAPDH 基因用作参考基因。MTT 检测结果表明，在测试的任何浓度下，硒均无细胞毒性。细胞增殖检测结果表明，在测试的三个浓度下，硒均不干扰细胞增殖。相反，当三个浓度与阿霉素联合使用时，观察到增殖率显著降低。在硒（500ng/mL）和阿霉素组中，细胞凋亡率显著增加。在硒（500ng/mL）和阿霉素组中，CASP9 表达增加，BCL-XL 表达降低。单独用硒处理时，APC 显著增加。这些结果表明，硒增加细胞凋亡，特别是与损伤诱导剂联合使用时。此外，硒在 APC 基因的表达中具有重要作用，该基因与细胞周期调控有关。
