Structure-based design of Hv1 proton channel blockers as potential anti-neoplasti

描述(申请人提供)：据估计，2011年有150万人被诊断出患有某种形式的癌症，超过50万人死于这种疾病。1为了改善临床结果，人们希望有新的癌症治疗目标。为此，过去几十年的研究发现离子通道蛋白是癌症治疗的新靶点。6，7 Hv1质子通道8，9是最新出现的作为癌症诊断和治疗潜在靶点的离子通道之一。该通道在高转移的人类乳腺癌细胞系和肿瘤中优先表达，似乎对癌细胞的侵袭和转移能力是必不可少的。10该通道可能通过帮助维持大多数癌症所特有的失调的pH梯度(高细胞内pH和低细胞外pH)而促进癌症进展。11 Hv1过度表达导致H+分泌增加，可能通过抑制酸诱导的细胞凋亡来帮助细胞存活。此外，随后细胞外间隙的酸化刺激酸激活的蛋白酶降解细胞外基质，促进肿瘤细胞的侵袭和扩散。12体内和体外Hv1电导的功能性阻断已被证明显著抑制癌症的进展和转移，突显了通道阻断是一种有前途的癌症治疗新途径。10在以前的研究中，10，13利用RNA干扰技术在体内和体外实现了对Hv1的功能阻断。我们首次提议研究Hv1的小分子阻滞剂作为抗肿瘤治疗药物。为了合理地设计具有高亲和力的小分子通道，我们为Hv1.5建立了一个结构模型，通过分子动力学模拟得到详细的原子结构/功能数据，该模型将解决Hv1如何感知电压和传导质子的问题，这将有助于建立离子通过电压敏感域传导的基本原理。对这些问题的回答将指导高亲和力Hv1阻滞剂的设计，将使用细胞增殖和迁移分析来评估其抑制癌症进展的治疗潜力。我们推测，这些计算研究和体外分析将支持Hv1阻断作为一种可行的乳腺癌细胞抑制机制，并允许开发新型抗肿瘤药物。

DESCRIPTION (provided by applicant): It is estimated that in 2011, 1.5 million people were diagnosed with some form of cancer and over 500,000 died of the disease.1 To improve clinical outcomes, new targets for cancer therapeutics are desirable. Towards this end, research studies in the past few decades have uncovered ion channel proteins as new targets for cancer therapy.6, 7 The Hv1 proton channel8,9 is one of the latest ion channels to emerge as a potential target for cancer diagnostics and treatment. The channel is preferentially expressed in highly metastatic human breast cancer cell lines and tumors, and appears to be essential for the cancer cell's ability to invade and metastasize.10 The channel likely contributes to cancer progression by helping to maintain the dysregulated pH gradient (high intracellular pH and low extracellular pH) characteristic of most cancers.11 The increased H+ secretion from Hv1 overexpression may aid cell survival by inhibiting acid-induced apoptosis. Furthermore, the subsequent acidification of the extracellular space stimulates acid-activated proteases to degrade the extracellular matrix, facilitating tumor cell invasion and dissemination.12 Functional blockade of Hv1 conductance in vivo and in vitro has been shown to significantly inhibit cancer progression and metastasis, highlighting channel blockade as a promising new avenue for cancer therapeutics.10 In previous studies,10,13 the functional blockade of Hv1 in vivo and in vito was achieved using RNA-interference technology. We propose, for the first time, to study small molecule blockers of Hv1 as antineoplastic therapeutics. To rationally design small molecules with high affinity for the channel, we develop a structural model for Hv1.5 Detailed atomistic structure/function data from molecular dynamics simulations of the model will address questions about how Hv1 is able to sense voltage and conduct protons, which will help to establish basic principles of ion conduction through voltage-sensing domains. Answers to these questions will guide the design of high affinity Hv1 blockers, which will be evaluated for their therapeutic potential to inhibit cancer progression using cell proliferation and migration assays. We hypothesize that these computational studies and in vitro assays will support Hv1 blockade as a viable mechanism for breast cancer cell inhibition and allow for the development of novel antineoplastic pharmaceuticals.