ASC Induces Apoptosis via Activation of Caspase-9 by Enhancing Gap Junction-Mediated Intercellular Communication.
ASC Induces Apoptosis via Activation of Caspase-9 by Enhancing Gap Junction-Mediated Intercellular Communication.
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DOI：
10.1371/journal.pone.0169340
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Miyagawa SI
中科院分区：
文献类型：
--
作者：
Kitazawa M;Hida S;Fujii C;Taniguchi S;Ito K;Matsumura T;Okada N;Sakaizawa T;Kobayashi A;Takeoka M;Miyagawa SI
ASC（包含CARD的凋亡相关斑点样蛋白）是炎性小体的关键衔接分子，其介导炎症和凋亡信号。异常甲基化诱导的ASC沉默已在多种癌细胞中观察到，从而暗示ASC在肿瘤抑制中，尽管这种作用仍然不完全确定，特别是在紧密相邻的细胞增殖的背景下。由于已证实ASC也在HT 1080纤维肉瘤细胞中被异常甲基化沉默，因此研究了该细胞系以表征ASC在肿瘤进展中的确切作用和机制。基于低和高细胞密度条件之间的比较以及异种移植鼠模型，使用体外细胞培养物检查ASC的作用。通过将ASC基因插入到pcDNA 3和pMX-IRES-GFP载体中建立ASC过表达，将后者包装到逆转录病毒中，并使用亲本细胞作为内部对照进行可重复的竞争性测定，以评价细胞活力。使用shRNA沉默p21和p53。在体外培养和集落形成试验以及体内异位肿瘤形成试验中，与高细胞密度条件下的对照细胞相比，表达ASC的转染子中的细胞活力受到抑制。在低细胞密度条件下未检测到这种抑制。此外，在高细胞密度下，在ASC引入的细胞中观察到凋亡的显著进展，但在低细胞密度下则没有。ASC依赖性细胞凋亡不是由p21、p53或caspase-1介导的，而是由caspase-9的切割以及NF-κ B相关的X连锁凋亡相关蛋白的抑制介导的。观察到胱天蛋白酶-9裂解依赖于间隙连接形成。本研究揭示的ASC通过caspase-9和缝隙连接诱导细胞凋亡的显著作用可能导致有希望的抗癌治疗的新方法。
ASC (apoptosis-associated speck-like protein containing a CARD) is a key adaptor molecule of inflammasomes that mediates inflammatory and apoptotic signals. Aberrant methylation-induced silencing of ASC has been observed in a variety of cancer cells, thus implicating ASC in tumor suppression, although this role remains incompletely defined especially in the context of closely neighboring cell proliferation. As ASC has been confirmed to be silenced by abnormal methylation in HT1080 fibrosarcoma cells as well, this cell line was investigated to characterize the precise role and mechanism of ASC in tumor progression. The effects of ASC were examined using in vitro cell cultures based on comparisons between low and high cell density conditions as well as in a xenograft murine model. ASC overexpression was established by insertion of the ASC gene into pcDNA3 and pMX-IRES-GFP vectors, the latter being packed into a retrovirus and subjected to reproducible competitive assays using parental cells as an internal control, for evaluation of cell viability. p21 and p53 were silenced using shRNA. Cell viability was suppressed in ASC-expressing transfectants as compared with control cells at high cell density conditions in in vitro culture and colony formation assays and in in vivo ectopic tumor formation trials. This suppression was not detected in low cell density conditions. Furthermore, remarkable progression of apoptosis was observed in ASC-introduced cells at a high cell density, but not at a low one. ASC-dependent apoptosis was mediated not by p21, p53, or caspase-1, but rather by cleavage of caspase-9 as well as by suppression of the NF-κB-related X-linked inhibitor-of-apoptosis protein. Caspase-9 cleavage was observed to be dependent on gap junction formation. The remarkable effect of ASC on the induction of apoptosis through caspase-9 and gap junctions revealed in this study may lead to promising new approaches in anticancer therapy.
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影响因子：
16
作者：
Martinon, F;Burns, K;Tschopp, J
通讯作者：
Tschopp, J
DOI：
10.1073/pnas.1016814108
发表时间：
2010-12-14
影响因子：
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作者：
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影响因子：
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影响因子：
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影响因子：
3.7
作者：
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