Chen Y C, Kuo T C, Lin-Shiau S Y, Lin J K
Institute of Biochemistry, College of Medicine, National Taiwan University, Taipei, Republic of China.
Mol Carcinog. 1996 Dec;17(4):224-34. doi: 10.1002/(SICI)1098-2744(199612)17:4<224::AID-MC6>3.0.CO;2-D.
Curcumin (diferuloyl methane) is the major active yellow pigment of turmeric and curry. Studies in recent years have indicated that curcumin is a potent inhibitor of the initiation and promotion of chemical carcinogen-induced skin carcinogenesis in mice. When COLO205 colorectal carcinoma cells were treated with curcumin (60 microM), the appearance of apoptotic DNA ladders was delayed about 5 h, and G1 arrest was detected. Further analysis of the endonuclease activities in these cells revealed that the activity of Ca(+2)-dependent endonuclease in COLO205 cells was profoundly inhibited and that the extent of inhibition depended on the degree of calcium depletion. The reduction of p53 gene expression was accompanied by the induction of HSP70 gene expression in the curcumin-treated cells. These findings suggest that curcumin may induce the expression of the HSP70 gene through the initial depletion of intracellular Ca(+2), followed by the suppression of p53 gene function in the target cells.
姜黄素（二阿魏酰甲烷）是姜黄和咖喱中的主要活性黄色色素。近年来的研究表明，姜黄素是小鼠化学致癌物诱导的皮肤癌发生起始和促进阶段的有效抑制剂。用姜黄素（60微摩尔）处理COLO205结肠癌细胞时，凋亡DNA梯带的出现延迟约5小时，并检测到G1期阻滞。对这些细胞内切核酸酶活性的进一步分析表明，COLO205细胞中钙依赖性内切核酸酶的活性受到显著抑制，且抑制程度取决于钙耗竭的程度。在姜黄素处理的细胞中，p53基因表达的降低伴随着HSP70基因表达的诱导。这些发现表明，姜黄素可能通过最初使细胞内Ca(+2)耗竭，随后抑制靶细胞中p53基因功能来诱导HSP70基因的表达。
