Akt inhibition attenuates rasfonin-induced autophagy and apoptosis through the glycolytic pathway in renal cancer cells.
Akt inhibition attenuates rasfonin-induced autophagy and apoptosis through the glycolytic pathway in renal cancer cells.
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Akt 抑制通过糖酵解途径减弱肾癌细胞中 rasfonin 诱导的自噬和细胞凋亡
DOI：
10.1038/cddis.2015.344
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发表时间：
2015-12-03
影响因子：
9
通讯作者：
Xi Z
中科院分区：
文献类型：
--
作者：
Lu Q;Yan S;Sun H;Wang W;Li Y;Yang X;Jiang X;Che Y;Xi Z
Rasfonin是一种具有抗肿瘤作用的真菌次级代谢产物。然而，由rasfonin启动的自噬调节作用的潜在机制在很大程度上是未知的。此外，Akt积极介导诱导的自噬的功能仍然难以捉摸。在本研究中，我们观察到，rasfonin诱导自噬伴随着Akt磷酸化的上调。通过小分子抑制剂和遗传修饰抑制Akt都部分降低了rasfonin依赖的自噬通量和PARP-1裂解。myrAkts（恒定活性形式）的过表达促进了细胞类型和Akt亚型特异性方式的rasfonin诱导的细胞凋亡和自噬。采用定量PCR和免疫印迹技术，我们观察到rasfonin增加了糖酵解基因PFKFB 3的表达，并且这种增加的表达可以在Akt抑制剂的存在下被抑制。抑制PFKFB 3抑制了rasfonin激活的自噬，增强了PARP-1裂解。在葡萄糖摄取被破坏的情况下，这意味着糖酵解途径被完全阻断，rasfonin诱导的自噬和PARP-1切割被下调。总之，这些结果表明Akt主要通过影响糖酵解途径正向调节rasfonin增强的自噬和caspase依赖的凋亡。
Rasfonin is a fungal secondary metabolite with demonstrated antitumor effects. However, the underlying mechanism of the regulatory role in autophagy initiated by rasfonin is largely unknown. Moreover, the function of Akt to positively mediate the induced autophagy remains elusive. In the present study, we observed that rasfonin induced autophagy concomitant with the upregulation of Akt phosphorylation. Both the inhibition of Akt by small molecule inhibitors and genetic modification partially reduced rasfonin-dependent autophagic flux and PARP-1 cleavage. The overexpression of myrAkts (constant active form) promoted rasfonin-induced apoptosis and autophagy in a cell type- and Akt isoform-specific manner. Using quantitative PCR and immunoblotting, we observed that rasfonin increased the expression of glycolytic gene PFKFB3, and this increased expression can be suppressed in the presence of Akt inhibitor. The inhibition of PFKFB3 suppressed rasfonin-activated autophagy with enhanced PARP-1 cleavage. In the case of glucose uptake was disrupted, which mean the glycolytic pathway was fully blocked, the rasfonin-induced autophagy and PARP-1 cleavage were downregulated. Collectively, these results demonstrated that Akt positively regulated rasfonin-enhanced autophagy and caspase-dependent apoptosis primarily through affecting the glycolytic pathway.