Involvement of proapoptotic genes in autophagic cell death induced by irradiation
Involvement of proapoptotic genes in autophagic cell death induced by irradiation
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促凋亡基因参与辐射诱导的自噬细胞死亡
DOI：
10.1038/cddiscovery.2017.68
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发表时间：
2017-12
影响因子：
7
通讯作者：
Wei Lixin
中科院分区：
文献类型：
--
作者：
Song Jianrui;Zhao Xue;Feng Yi;Xu Sheng;Zhang Yanling;Wei Lixin
放射治疗在抗癌治疗中得到了广泛的应用，但效果有限。大多数癌细胞都存在凋亡突变，很容易逃脱辐射诱导的细胞凋亡。自噬被称为II型程序性细胞死亡，可被辐射激活，特别是当细胞凋亡被阻断时，但其潜在的分子机制在很大程度上尚不清楚。我们证明了促凋亡基因PUMA和BID参与了自噬细胞死亡的调节。将野生型(WT)、bax-−/−和PUMA-−/−-−/−细胞分别照射后发现，与野生型(WT)细胞相比，bax-−/−细胞因bax缺乏而导致的细胞死亡显著减少，而PUMA-Hct116细胞的细胞死亡却显著增加，而促凋亡基因PUMA被敲除。流式细胞仪Annexin V-异硫氰酸荧光素(FITC)法分析细胞凋亡，发现bax−/−和PUMA−/−细胞的凋亡率均低于WT细胞，提示PUMA−/−细胞存在另一种类型的细胞死亡。然后，通过计数带有点状GFP-LC3的细胞的百分比，在三个细胞系中检测自噬。尽管三种细胞系在照射后都表现出明显的自噬活性，但PUMA−/−细胞的自噬活性明显高于其他两种细胞系，这表明PUMA−/−细胞可能通过自噬而死亡。当自噬被3-MA阻断时，PUMA−/−细胞中细胞死亡的减少证实了这一点。此外，我们还测试了WT和BID−/−MEF对辐射的响应。BID−/−MEF照射后死于自噬，而WT未见死亡。这些结果表明，PUMA和BID等凋亡相关基因参与了自噬细胞的死亡，这有助于确定自噬导致细胞死亡的分子机制。
Irradiation is widely used in anticancer therapy; however, the efficiency is limited. Most cancer cells have mutations in apoptosis that they can easily escape the apoptosis induced by irradiation. Autophagy has been known as type II programmed cell death that can be activated by irradiation, especially when apoptosis is blocked, but the underlying molecular mechanism is largely unknown. We demonstrated that proapoptotic genes PUMA and Bid are involved in the regulation of autophagic cell death. When wild-type (WT), Bax−/− and PUMA−/− HCT116 cells were exposed to irradiation, we found that, compared with WT, Bax−/− cells showed significantly decreased cell death because of Bax deficiency; however, surprisingly PUMA−/− cells showed significant increase in cell death although the proapoptotic gene PUMA was knocked out. By analyzing apoptosis via Annexin V-fluorescein isothiocyanate (FITC) assay with flow cytometry, both Bax−/− and PUMA−/− cells showed less apoptosis than WT, suggesting the existence of another type of cell death in PUMA−/− cells. Autophagy was then examined in three cell lines by counting the percentage of cells with punctate GFP-LC3. Although all three cell lines showed significantly increased autophagy activity after irradiation, that of PUMA−/− cells was much higher than the other two cell lines, which suggests that PUMA−/− cells may die through autophagy. This was then confirmed by the decreased cell death in PUMA−/− cells when autophagy was blocked by 3-MA. In addition, we also tested the responses of WT and Bid−/− MEFs to irradiation. Bid−/− MEFs but not WT died through autophagy after irradiation. These results imply the involvement of apoptosis-associated genes such as PUMA and Bid in autophagic cell death, which contributes to identifying the molecular mechanism by which autophagy drives cells to death.
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DOI：
10.1038/nrclinonc.2015.120
发表时间：
2015-09
期刊：
Nature reviews. Clinical oncology
影响因子：
--
作者：
Schaue D;McBride WH
通讯作者：
McBride WH
影响因子：
6.2
作者：
Delaney, G;Jacob, S;Barton, M
通讯作者：
Barton, M
影响因子：
12.4
作者：
通讯作者：
--
影响因子：
11.2
作者：
Apel, Anja;Herr, Ingrid;Mayer, Andreas
通讯作者：
Mayer, Andreas
影响因子：
16
作者：
Kroemer G;Mariño G;Levine B
通讯作者：
Levine B