Tan Huixin, Gao Shiyong, Zhuang Yan, Dong Yanhong, Guan Wenhui, Zhang Kun, Xu Jian, Cui Jingru
Department of Pharmacy, The Fourth Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
The Institute of Materia Medica, The Research Center of Life Sciences and Environmental Sciences, Harbin University of Commerce, Harbin 150076, China.
Mar Drugs. 2016 Sep 12;14(9):166. doi: 10.3390/md14090166.
R-Phycoerythrin (R-PE), one of the chemical constituents of red algae, could produce singlet oxygen upon excitation with the appropriate radiation and possibly be used in photodynamic therapy (PDT) for cancer. Documents reported that R-PE could inhibit cell proliferation in HepG2 and A549 cells, which was significative for cancer therapy. This is due to the fact that R-PE could kill cancer cells directly as well as by PDT. However, little is known about the cytotoxicity of R-PE to the SGC-7901 cell. In this study, it has been found that R-PE could inhibit SGC-7901 proliferation and induce cell apoptosis, which was achieved by arresting the SGC-7901 cell at S phase. CyclinA, CDK2 and CDC25A are proteins associated with the S phase, and it was found that R-PE could increase the expression of cyclin A protein and decrease the expression of CDK2 and CDC25A proteins. Thus, it was concluded that R-PE reduced the CDK2 protein activated through decreasing the CDC25A factor, which reduced the formation of Cyclin-CDK complex. The reduction of Cyclin-CDK complex made the SGC-7901 cells arrest at the S phase. Therefore, R-PE induced apoptosis by arresting the SGC-7901 cell at S phase was successful, which was achieved by the expression of the CDC25A protein, which reduced the CDK2 protein actived and the formation of Cyclin-CDK complex.
藻红蛋白（R-PE）是红藻的化学成分之一，在受到适当辐射激发时可产生单线态氧，并可能用于癌症的光动力疗法（PDT）。文献报道，R-PE可抑制HepG2和A549细胞的增殖，这对癌症治疗具有重要意义。这是因为R-PE不仅可以直接杀死癌细胞，还可以通过光动力疗法杀死癌细胞。然而，关于R-PE对SGC-7901细胞的细胞毒性知之甚少。在本研究中，发现R-PE可抑制SGC-7901细胞增殖并诱导细胞凋亡，这是通过将SGC-7901细胞阻滞在S期来实现的。细胞周期蛋白A（CyclinA）、细胞周期蛋白依赖性激酶2（CDK2）和细胞分裂周期蛋白25A（CDC25A）是与S期相关的蛋白质，并且发现R-PE可增加Cyclin A蛋白的表达并降低CDK2和CDC25A蛋白的表达。因此，得出结论，R-PE通过降低CDC25A因子来减少活化的CDK2蛋白，从而减少细胞周期蛋白-CDK复合物的形成。细胞周期蛋白-CDK复合物的减少使SGC-7901细胞阻滞在S期。因此，R-PE通过将SGC-7901细胞阻滞在S期诱导凋亡是成功的，这是通过CDC25A蛋白的表达来实现的，该蛋白减少了活化的CDK2蛋白以及细胞周期蛋白-CDK复合物的形成。
