Amin Amr, Bajbouj Khuloud, Koch Adrian, Gandesiri Muktheshwar, Schneider-Stock Regine
Department of Biology, College of Science, United Arab Emirates University, Al-Ain 15551, United Arab Emirates.
Experimental Tumor Pathology, Institute of Pathology, University of Erlangen, Erlangen 91054, Germany.
Int J Mol Sci. 2015 Jan 9;16(1):1544-61. doi: 10.3390/ijms16011544.
Crocin, a bioactive molecule of saffron, inhibited proliferation of both HCT116 wild-type and HCT116 p53(-/-) cell lines at a concentration of 10 mM. Flow cytometric analysis of cell cycle distribution revealed that there was an accumulation of HCT116 wild-type cells in G1 (55.9%, 56.1%) compared to the control (30.4%) after 24 and 48 h of crocin treatment, respectively. However, crocin induced only mild G2 arrest in HCT116 p53(-/-) after 24 h. Crocin induced inefficient autophagy in HCT116 p53(-/-) cells, where crocin induced the formation of LC3-II, which was combined with a decrease in the protein levels of Beclin 1 and Atg7 and no clear p62 degradation. Autophagosome formation was not detected in HCT116 p53(-/-) after crocin treatment predicting a nonfunctional autophagosome formation. There was a significant increase of p62 after treating the cells with Bafilomycin A1 (Baf) and crocin compared to crocin exposure alone. Annexin V staining showed that Baf-pretreatment enhanced the induction of apoptosis in HCT116 wild-type cells. Baf-exposed HCT116 p53(-/-) cells did not, however, show any enhancement of apoptosis induction despite an increase in the DNA damage-sensor accumulation, γH2AX indicating that crocin induced an autophagy-independent classical programmed cell death.
藏红花素是藏红花的一种生物活性分子，在浓度为10 mM时可抑制HCT116野生型和HCT116 p53(-/-)细胞系的增殖。细胞周期分布的流式细胞术分析显示，在藏红花素处理24小时和48小时后，与对照组（30.4%）相比，HCT116野生型细胞在G1期出现积累（分别为55.9%和56.1%）。然而，藏红花素在处理24小时后仅在HCT116 p53(-/-)细胞中诱导了轻微的G2期阻滞。藏红花素在HCT116 p53(-/-)细胞中诱导了低效的自噬，其中藏红花素诱导了LC3-II的形成，这与Beclin 1和Atg7蛋白水平的降低以及p62没有明显降解相关。藏红花素处理后，在HCT116 p53(-/-)细胞中未检测到自噬体形成，预示着形成了无功能的自噬体。与单独暴露于藏红花素相比，用巴弗洛霉素A1（Baf）和藏红花素处理细胞后，p62显著增加。膜联蛋白V染色显示，Baf预处理增强了HCT116野生型细胞的凋亡诱导。然而，尽管DNA损伤传感器γH2AX的积累增加，但暴露于Baf的HCT116 p53(-/-)细胞并未显示出凋亡诱导的任何增强，这表明藏红花素诱导了一种不依赖自噬的经典程序性细胞死亡。
