Autophagy limits the cytotoxic effects of the AKT inhibitor AZ7328 in human bladder cancer cells
Autophagy limits the cytotoxic effects of the AKT inhibitor AZ7328 in human bladder cancer cells
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DOI：
10.4161/cbt.21793
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发表时间：
2012-11-01
影响因子：
3.6
通讯作者：
McConkey, David J.
中科院分区：
文献类型：
--
作者：
Dickstein, Rian J.;Nitti, Giovanni;McConkey, David J.
背景资料：激活PI 3 K/AKT/mTOR通路的突变在尿路上皮（膀胱）癌中相对常见，但这些通路突变如何影响AKT依赖性尚不清楚。我们的特点之间的关系AKT通路的突变状态和敏感性的选择性AKT激酶抑制剂AZ 7328的影响，使用一个面板的12个良好的特点人膀胱癌细胞株。结果：AZ 7328抑制增殖和AKT底物磷酸化的浓度依赖性的方式，但对凋亡的影响很小。抑制作用与激活PIK 3CA突变的存在松散相关，并且与mTOR抑制剂雷帕霉素组合时得到加强。AZ 7328诱导的自噬在一些线和细胞暴露于AZ 7328和化学自噬抑制剂的组合apoptosis induced.Methods：Sequenome DNA测序进行鉴定突变在一组12个尿路上皮癌细胞系。药物诱导的增殖抑制和细胞凋亡采用MTT法和碘化丙啶染色与流式细胞仪分析进行定量。通过免疫印迹测量经由磷酸化的蛋白质活化。结论：AZ 7328的细胞抑制作用与PIK 3CA突变相关，并且通过使用mTOR抑制剂的双途径抑制而大大增强。此外，AZ 7328可以与自噬抑制剂相互作用，在某些细胞系中诱导凋亡。总体而言，我们的结果支持在临床前体内模型中以及最终在患有PIK 3CA突变膀胱癌的患者中进一步评估PI 3 K/AKT/mTOR通路和自噬抑制剂的组合。
Background: Mutations that activate the PI3K/AKT/mTOR pathway are relatively common in urothelial (bladder) cancers, but how these pathway mutations affect AKT dependency is not known. We characterized the relationship between AKT pathway mutational status and sensitivity to the effects of the selective AKT kinase inhibitor AZ7328 using a panel of 12 well-characterized human bladder cancer cell lines.Results: AZ7328 inhibited proliferation and AKT substrate phosphorylation in a concentration-dependent manner but had minimal effects on apoptosis. Proliferative inhibition correlated loosely with the presence of activating PIK3CA mutations and was strengthened in combination with the mTOR inhibitor rapamycin. AZ7328 induced autophagy in some of the lines and in the cells exposed to a combination of AZ7328 and chemical autophagy inhibitors apoptosis was induced.Methods: Sequenome DNA sequencing was performed to identify mutations in a panel of 12 urothelial cancer cell lines. Drug-induced proliferative inhibition and apoptosis were quantified using MTT assays and propidium iodide staining with FACS analyses. Protein activation via phosphorylation was measured by immunoblotting. Autophagy was measured by LC3 immunofluorescence and immunoblotting.Conclusions: The cytostatic effects of AZ7328 correlate with PIK3CA mutations and are greatly enhanced by dual pathway inhibition using an mTOR inhibitor. Furthermore, AZ7328 can interact with autophagy inhibitors to induce apoptosis in some cell lines. Overall, our results support the further evaluation of combinations of PI3K/AKT/mTOR pathway and autophagy inhibitors in pre-clinical in vivo models and ultimately in patients with PIK3CA mutant bladder cancers.