Dual mTORC2/mTORC1 targeting results in potent suppressive effects on acute myeloid leukemia (AML) progenitors.
Dual mTORC2/mTORC1 targeting results in potent suppressive effects on acute myeloid leukemia (AML) progenitors.
复制标题
DOI：
10.1158/1078-0432.ccr-10-2285
复制
发表时间：
2011-07-01
期刊：
影响因子：
--
通讯作者：
Platanias LC
中科院分区：
文献类型：
--
作者：
Altman JK;Sassano A;Kaur S;Glaser H;Kroczynska B;Redig AJ;Russo S;Barr S;Platanias LC
确定mTORC2和RI-mTORC1复合物是否存在于AML细胞中，并检查mTORC2/mTORC1双重抑制对原始AML白血病祖细胞的影响。使用了不同实验方法的组合，包括免疫印迹法检测白血病细胞系和原发性AML母细胞中mTOR通路磷酸化/活化形式的元件；细胞增殖试验；直接评估白血病细胞多体部分mRNA的翻译；甲基纤维素的克隆性测定评价白血病祖细胞集落形成。mTORC2复合物在AML细胞中活跃，并在白血病发生中发挥关键作用。在AML细胞中，雷帕霉素不敏感（RI） mTORC1复合物也形成并调节翻译抑制因子4E-BP1的活性。OSI-027阻断mTORC1和mTORC2活性，抑制细胞周期蛋白D1和其他介导AML细胞增殖反应的基因的mRNA翻译。此外，OSI-027作为AML患者原始白血病前体的有效抑制因子，在体外诱导抗白血病作用方面比雷帕霉素更有效。mTORC2和mTORC1的双重靶向对AML患者的原始白血病祖细胞有有效的抑制作用。用osio -027抑制mTOR催化位点导致mTORC2和RI-mTORC1复合物的抑制，并引起比用雷帕霉素选择性靶向mTORC1更有效的抗白血病反应。
To determine whether mTORC2 and RI-mTORC1 complexes are present in AML cells and to examine the effects of dual mTORC2/mTORC1 inhibition on primitive AML leukemic progenitors. Combinations of different experimental approaches were used, including immunoblotting to detect phosphorylated/activated forms of elements of the mTOR pathway in leukemic cell lines and primary AML blasts; cell proliferation assays; direct assessment of mRNA translation in polysomal fractions of leukemic cells; and clonogenic assays in methylcellulose to evaluate leukemic progenitor colony formation. mTORC2 complexes are active in AML cells and play critical roles in leukemogenesis. Rapamycin insensitive (RI) mTORC1 complexes are also formed and regulate the activity of the translational repressor 4E-BP1 in AML cells. OSI-027, blocks mTORC1 and mTORC2 activities and suppresses mRNA translation of cyclin D1 and other genes that mediate proliferative responses in AML cells. Moreover, OSI-027 acts as a potent suppressor of primitive leukemic precursors from AML patients and is much more effective than rapamycin in eliciting antileukemic effects in vitro. Dual targeting of mTORC2 and mTORC1 results in potent suppressive effects on primitive leukemic progenitors from AML patients. Inhibition of the mTOR catalytic site with OSI-027 results in suppression of both mTORC2 and RI-mTORC1 complexes and elicits much more potent antileukemic responses than selective mTORC1 targeting with rapamycin.