亚砷酸靶向CML干细胞的Hh通路治疗伊马替尼耐药的机制研究

Imatinib (IM) resistance is a crucial clinical problem to be solved in the treatment of chronic myeloid leukemia(CML).Small molecular inhibitors of Hedgehog（Hh）signaling pathway target CML stem cells(LSCs) and can overcome IM resistance, however, can not be put into clinical use so far. Arsenic trioxide (ATO) has been used in clinical cases safely for many years, and has been confirmed as a natural Hh inhibitor recent years. And the research that ATO overcoming IM resistance of CML through Hh has not been initiated yet. We have found that the use of ATO can avoid the occurrence of IM resistance, thus speculating that ATO functioned through this mechanism.We have proved ATO can reverse IM resistance of CML cell line and inhibit CML-LSCs. In this project, on the basis of its clinical effect to IM resistance of CML, we will testify the inhibitory effect of ATO to CML-LSCs and its Hh pathway using CML primary samples and mouse model. We also discuss mechanism of ATO on Hh signaling of CML through its influence on the cellular localization of Gli and the expression of this molecule and its downstream molecule. This project will be helpful to discuss the therapy of IM resistance and enlarge the application of ATO in clinical use.

伊马替尼（IM）耐药是慢性粒细胞白血病（CML）治疗中亟待解决的问题，尽管以Hedgehog（Hh）通路为靶点的小分子抑制剂可抑制CML干细胞（LSCs）而治疗IM耐药，但这些抑制剂尚无法应用于临床。亚砷酸（ATO）安全应用多年，近来被证实为该通路的天然抑制剂，但其通过Hh通路治疗CML的IM耐药的研究尚未开展。我们前期工作发现ATO可预防CML的IM耐药发生，推测可能正是通过此种机制。我们的预实验已证实ATO具逆转CML细胞耐药的作用，并能抑制CML-LSCs。在本项目中，我们将在考察ATO对IM耐药患者疗效的基础上，应用CML临床标本和鼠模型，验证ATO对CML干细胞及其Hh通路的抑制效果，并从ATO影响Gli的细胞定位和抑制该分子及其下游分子蛋白和mRNA表达的角度，探讨ATO对CML的Hh通路的作用机制。本研究对治疗CML的IM耐药和扩大ATO适应症具有重要的理论意义和应用价值。

伊马替尼（Imatinib，IM）耐药是慢性粒细胞白血病（chronic myeloid leukemia，CML）治疗中亟待解决的问题，以Hedgehog（Hh）通路为靶点的小分子抑制剂可抑制CML干细胞（leukemia stem cells,LSCs）而治疗IM耐药。该通路的天然抑制剂亚砷酸（Arsenic trioxide，ATO），安全应用于临床多年，本研究证明首次证明其可通过抑制CML- LSCs的Hh通路应用于CML的IM耐药治疗。首先，我们证明ATO 对 CML 的Hh信号转导通路相关分子的基因和蛋白表达具有抑制作用；其次，我们建立了Gli1过表达的IM耐药细胞株，证明ATO对此种机制导致的IM耐药具有抑制作用；再次，我们证明ATO对非激酶区突变的IM耐药的CML患者有一定疗效，其疗效机理与LSC的Hh通路受抑相关。最后，我们证明ATO体外应用抑制IM耐药的CML患者干细胞自我更新能力及Hh通路的关键分子。此外，我还在CML鼠模型中证明，ATO抑制IM耐药的CML-LSCs的白血病形成能力，其机制与抑制Hh通路的分子相关。我们的研究为ATO直接应用于IM耐药的CML患者的临床治疗，为扩大ATO的临床应用，提供坚实的理论和临床基础。项目资助发表核心中文论文2篇，待发表1篇。培养硕士生1名，在读。项目投入经费18万元，支出15.47万元，各项支出基本与预算相符。剩余经费2.53万元，剩余经费计划用于本项目研究后续支出。