Biochemical, Cellular, and In vivo Activity of Novel ATP-Competitive and Selective Inhibitors of the Mammalian Target of Rapamycin
Biochemical, Cellular, and In vivo Activity of Novel ATP-Competitive and Selective Inhibitors of the Mammalian Target of Rapamycin
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DOI：
10.1158/0008-5472.can-09-0299
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发表时间：
2009-08-01
期刊：
影响因子：
11.2
通讯作者：
Zask, Arie
中科院分区：
文献类型：
--
作者：
Yu, Ker;Toral-Barza, Lourdes;Zask, Arie
雷帕霉素的哺乳动物靶标(MTOR)主要参与细胞的生长、代谢和血管生成。虽然在一组肿瘤中显示出临床疗效，雷帕霉素和雷帕洛格是mTOR复合体I(MTORC1)的特异性和变构抑制剂，但它们不直接抑制mTOR复合体2(MTORC2)，mTORC2是癌症中的新兴参与者。在这里，我们报道了三种吡唑并嘧啶脱氧核糖核酸竞争性mTOR抑制剂Way-600、WYE-687和WYE-354(IC50，5-9nmol/L)的化学结构和生物学特性，它们的选择性显著高于磷脂酰肌醇3-激酶(PI3K)异构体(>；100倍)。与Rapalog不同的是，这些抑制剂在体外和细胞内对生长因子、氨基酸和高活性的PI3K/AKT的反应，强烈地阻断了mTORC1和mTORC2底物的磷酸化。与PI3K或双PAN PI3K/mTOR抑制剂不同，吡唑并嘧啶类化合物对P-S6K1(T389)和P-AKT(S473)的抑制作用发生在明显低于P-AKT(T308)(PI3K-PDK1读数)的抑制剂浓度下，显示出细胞内mTOR的选择性。MTOR激酶抑制剂降低了AKT下游功能，并抑制了不同癌细胞系的增殖。这些作用与雷帕霉素敏感和耐药细胞中强烈的G(1)期细胞周期停滞、选择性诱导细胞凋亡、抑制整体蛋白质合成和下调血管生成因子有关。当注射到荷瘤小鼠体内时，Wye-354抑制mTORC1和mTORC2，并在PTEN缺失的肿瘤中显示出强大的抗肿瘤活性。总之，我们的结果强调了Rapalog和mTOR激酶抑制剂在靶向肿瘤细胞生长和生存方面的机制差异，并为临床开发mTOR激酶抑制剂作为新的癌症治疗方法提供了支持。[癌症资源2009；69(15)：6232-40]
The mammalian target of rapamycin (mTOR) is centrally involved in cell growth, metabolism, and angiogenesis. While showing clinical efficacy in a subset of tumors, rapamycin and rapalogs are specific and allosteric inhibitors of mTOR complex I (mTORC1), but they do not directly inhibit mTOR complex 2 (mTORC2), an emerging player in cancer. Here, we report chemical structure and biological characterization of three pyrazolopyrimidine ATP-competitive mTOR inhibitors, WAY-600, WYE-687, and WYE-354 (IC50, 5-9 nmol/L), with significant selectivity over phosphatidylinositol 3-kinase (PI3K) isofoms (>100-fold). Unlike the rapalogs, these inhibitors acutely blocked substrate phosphorylation by mTORC1 and mTORC2 in vitro and in cells in response to growth factor, amino acids, and hyperactive PI3K/AKT. Unlike the inhibitors of PI3K or dual-pan PI3K/mTOR, cellular inhibition of P-S6K1(T389) and P-AKT(S473) by the pyrazolopyrimidines occurred at significantly lower inhibitor concentrations than those of P-AKT(T308) (PI3K-PDK1 readout), showing mTOR selectivity in cellular setting. mTOR kinase inhibitors reduced AKT downstream function and inhibited proliferation of diverse cancer cell lines. These effects correlated with a strong G(1) cell cycle arrest in both the rapamycin-sensitive and rapamycin-resistant cells, selective induction of apoptosis, repression of global protein synthesis, and down-regulation of angiogenic factors. When injected into tumor-bearing mice, WYE-354 inhibited mTORC1 and mTORC2 and displayed robust antitumor activity in PTEN-null tumors. Together, our results highlight mechanistic differentiation between rapalogs and mTOR kinase inhibitors in targeting cancer cell growth and survival and provide support for clinical development of mTOR kinase inhibitors as new cancer therapy. [Cancer Res 2009;69(15):6232-40]