Institute of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan, ROC.
Int J Mol Med. 2010 Nov;26(5):673-8. doi: 10.3892/ijmm_00000513.
Curcumin (diferuloylmethane), which is obtained from turmeric, the rhizome of Curcuma longa (L.), inhibits many human cancer cells. However, the molecular mechanisms responsible for curcumin-induced endoplasmic reticulum stress in human hepatic cellular carcinoma J5 cells, are not yet clearly understood. J5 cells were treated with various concentrations of curcumin for different durations. The cell viability was detected by MTT assay. The protein expressions of caspase-12, ATF6, GADD153, Calnexin, Calreticulin, PDI and Ero1-Lα, which are associated with endoplasmic reticulum stress and the unfolding protein response pathway, were examined by Western blot analysis. The cell cycle was analyzed by flow cytometry. The protein expressions of TCTP, Mcl-1, Bcl-2 and Bax, which are related to mitochondrial dysfunction, were detected by Western blot analysis. We also detected the ATF6 protein location by immunocytochemistry. The results showed that curcumin inhibits the proliferation of J5 cells in a time- and dose-dependent manner. Curcumin induced the unfolding protein response by down-regulating the protein expressions of Calnexin, PDI and Ero1-Lα and up-regulating the Calreticulin expression. Curcumin induces the GADD153 expression by cleaving caspase-12 and ATF6, and then by translocating ATF6 to the nucleus. Curcumin also down-regulates the protein expressions of TCTP, Mcl-1 and Bcl-2, in order to induce mitochondrial dysfunction. Curcumin induced cell cycle arrest at the G2/M phase by decreasing the Cdc2 expression. In conclusion, the present study showed that curcumin inhibits the proliferation of J5 cells by inducing endoplasmic reticulum stress and mitochondrial dysfunction.
姜黄素（二芳基甲烷），来源于姜黄，是姜黄属（Curcuma longa（L.））的根茎，能抑制多种人类癌细胞。然而，姜黄素诱导人肝癌 J5 细胞内质网应激的分子机制尚不清楚。用不同浓度的姜黄素处理 J5 细胞不同时间。MTT 法检测细胞活力。用 Western blot 分析检测与内质网应激和未折叠蛋白反应途径相关的 caspase-12、ATF6、GADD153、Calnexin、Calreticulin、PDI 和 Ero1-Lα 的蛋白表达。用流式细胞术分析细胞周期。用 Western blot 分析检测与线粒体功能障碍相关的 TCTP、Mcl-1、Bcl-2 和 Bax 的蛋白表达。我们还用免疫细胞化学检测 ATF6 蛋白定位。结果表明，姜黄素呈时间和剂量依赖性抑制 J5 细胞增殖。姜黄素通过下调 Calnexin、PDI 和 Ero1-Lα 的蛋白表达和上调 Calreticulin 的表达诱导未折叠蛋白反应。姜黄素通过切割 caspase-12 和 ATF6 诱导 GADD153 表达，然后将 ATF6 易位到核内。姜黄素还下调 TCTP、Mcl-1 和 Bcl-2 的蛋白表达，以诱导线粒体功能障碍。姜黄素通过降低 Cdc2 的表达诱导细胞周期停滞在 G2/M 期。总之，本研究表明姜黄素通过诱导内质网应激和线粒体功能障碍抑制 J5 细胞增殖。
