Anti-carcinogenic effects of zinc by induction of apoptosis and inhibition of DNA methylation

锌（Zn）是人类和啮齿类动物必需的金属。锌在某些情况下也具有抗癌作用。在这项研究中，我们阐明了锌是一种诱导细胞凋亡，程序性肿瘤细胞死亡。细胞内锌的浓度决定了锌诱导细胞死亡的方式。此外，锌诱导的金属硫蛋白（MT）参与MMP2的调控，与肿瘤细胞侵袭有关，并对细胞侵袭进行了研究。结果强烈提示MT通过上调MMP2促进细胞侵袭。这些结果表明，锌具有致癌和抗癌双重作用。

Zinc (Zn) is an essential metal in humans and rodents. Zn in certain instances can also be anti-carcinogenic. In this study, we clarified that Zn is an inducer of apoptosis, programed tumor cell death. The concentration of Zn in cells determines mode of Zn-induced cell death. In addition, the involvement of metallothionein (MT), is induced by Zn, in the regulation of MMP2, has been implicated in tumor cell invasion, and cell invasion was examined. The result strongly suggests that MT promotes cell invasion by up-regulating MMP2. These results proposed that Zn can have both carcinogenic and anti-carcinogenic effects.