Center of General Education, National Taipei University of Nursing and Health Sciences, and Department of Medical Research and Educaiton, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
Oncol Rep. 2012 Feb;27(2):529-34. doi: 10.3892/or.2011.1546. Epub 2011 Nov 10.
1,6-Bis[4-(4-amino-3-hydroxyphenoxy)phenyl]diamantane (DPD) induces growth inhibition in human cancer cells. In our previous study, we discovered that DPD irreversibly inhibits the growth of Colo 205 colon cancer cells at the G0/G1 phase and induces cell differentiation. However, the detailed mechanism is still unknown. In this study, we examined the functional importance of p21 and p53 in DPD-induced anticancer effects. We used three isogenic cell lines, HCT-116, HCT-116 p53-/- and HCT-116 p21-/-, to evaluate the roles of p21 and p53 in the in vitro anticancer effects of DPD. The in vivo anti-proliferative effect of DPD was demonstrated by HCT-116 and HCT-116 p21-/- xenograft models. DPD significantly inhibited the growth as well as increased the number of HCT-116 cells in the G0/G1 phase, but not in HCT-116 p53-/- and HCT-116 p21-/- cells examined by flow cytometry. Additionally, western blot analysis showed that DPD treatment induced p21, but not p53 protein expression in HCT-116 cells. The p21-associated cell cycle regulated proteins, such as cyclin D, CDK4 and pRb were decreased after DPD treatment in HCT-116 cells. The DPD-increased G0/G1 phase and induced cell cycle regulated protein expression were not observed in HCT-116 p21-/- and HCT-116 p53-/- cells. DPD decreased cell migration in HCT-116 and HCT-116 p53-/- but not in HCT-116 p21-/- cells. p21 was required for the DPD-induced in vitro anti-colon cancer effect. The in vivo study also showed that DPD significantly inhibited tumor growth through p21 signaling. Our results clearly demonstrate that DPD-induced in vitro and in vivo anticancer effects through the activation of p21 in HCT-116 cells.
1,6-双[4-(4-氨基-3-羟苯氧基)苯]-二金刚烷（DPD）可抑制人类癌细胞生长。在我们之前的研究中，我们发现 DPD 可使 Colo 205 结肠癌细胞在 G0/G1 期不可逆地生长抑制并诱导细胞分化。然而，其详细的机制仍不清楚。在这项研究中，我们研究了 p21 和 p53 在 DPD 诱导的抗癌作用中的功能重要性。我们使用三种同基因细胞系，HCT-116、HCT-116 p53-/-和 HCT-116 p21-/-，来评估 p21 和 p53 在 DPD 的体外抗癌作用中的作用。DPD 的体内抗增殖作用通过 HCT-116 和 HCT-116 p21-/-异种移植模型来证明。DPD 显著抑制 HCT-116 细胞的生长并增加其 G0/G1 期的细胞数量，但在 HCT-116 p53-/-和 HCT-116 p21-/-细胞中未观察到。此外，western blot 分析显示 DPD 处理诱导 HCT-116 细胞中 p21，但不诱导 p53 蛋白表达。在 HCT-116 细胞中，DPD 处理后 p21 相关的细胞周期调节蛋白，如周期蛋白 D、CDK4 和 pRb 减少。在 HCT-116 p21-/-和 HCT-116 p53-/-细胞中未观察到 DPD 增加的 G0/G1 期和诱导的细胞周期调节蛋白表达。DPD 降低 HCT-116 和 HCT-116 p53-/-细胞的迁移，但不降低 HCT-116 p21-/-细胞的迁移。p21 是 DPD 诱导的体外抗结肠癌作用所必需的。体内研究也表明，DPD 通过 p21 信号显著抑制肿瘤生长。我们的结果清楚地表明，DPD 通过激活 HCT-116 细胞中的 p21 诱导体外和体内抗癌作用。
