Liu Yuan, Chen Yan, Wen Lu, Cui Guohui
Department of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
J Huazhong Univ Sci Technolog Med Sci. 2012 Feb;32(1):1-8. doi: 10.1007/s11596-012-0001-2. Epub 2012 Jan 27.
This study explored the molecular mechanisms underlying the time-dependent autophagy and apoptosis induced by nutrient depletion in human multiple myeloma cell line RPMI8226 cells. RT-PCR and qRT-PCR were used to evaluate the transcriptional levels of Deptor, JNK1, JNK2, JNK3, Raf-1, p53, p21 and NFκB1 at 0, 6, 12, 18, 24 and 48 h after nutrient depletion in RPMI8226 cells. We found that transcriptional levels of Deptor were increased time-dependently at 0, 6, 12 and 18 h, and then decreased. Its alternation was consistent with autophagy. Transcriptional levels of Raf-1, JNK1, JNK2, p53 and p21 were increased time-dependently at 0, 6, 12, 18, 24 and 48 h accompanying with the increase of apoptosis. Transcriptional levels of NFκB1 at 6, 12, 18, 24 and 48 h were decreased as compared with 0 h. It was suggested that all the studied signaling molecules were involved in cellular response to nutrient depletion in RPMI8226 cells. Deptor contributed to autophagy in this process. Raf-1/JNK /p53/p21 pathway may be involved in apoptosis, and NFκB1 may play a possible role in inhibiting apoptosis. It remained to be studied whether Deptor was involved in both autophagy and apoptosis.
本研究探讨了人多发性骨髓瘤细胞系RPMI8226细胞中营养物质耗竭诱导的时间依赖性自噬和凋亡的分子机制。采用RT-PCR和qRT-PCR评估RPMI8226细胞营养物质耗竭后0、6、12、18、24和48小时Deptor、JNK1、JNK2、JNK3、Raf-1、p53、p21和NFκB1的转录水平。我们发现，Deptor的转录水平在0、6、12和18小时呈时间依赖性升高，然后下降。其变化与自噬一致。Raf-1、JNK1、JNK2、p53和p21的转录水平在0、6、12、18、24和48小时呈时间依赖性升高，同时凋亡增加。与0小时相比，6、12、18、24和48小时NFκB1的转录水平降低。提示所有研究的信号分子均参与RPMI8226细胞对营养物质耗竭的细胞反应。在此过程中，Deptor促进自噬。Raf-1/JNK/p53/p21通路可能参与凋亡，NFκB1可能在抑制凋亡中发挥作用。Deptor是否同时参与自噬和凋亡仍有待研究。
