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

描述（由申请人提供）：据估计，在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为了改善临床结果，癌症治疗的新靶点是可取的。为此，过去几十年的研究已经发现离子通道蛋白是癌症治疗的新靶点。Hv1质子通道8,9是最新出现的离子通道之一，是癌症诊断和治疗的潜在靶点。该通道在高度转移的人类乳腺癌细胞系和肿瘤中优先表达，并且似乎对癌细胞的侵袭和转移能力至关重要该通道可能通过帮助维持大多数癌症特征的失调的pH梯度（高细胞内pH值和低细胞外pH值）来促进癌症的进展Hv1过表达引起的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，随后的细胞外空间酸化刺激酸活化蛋白酶降解细胞外基质，促进肿瘤细胞的侵袭和传播在体内和体外对Hv1电导的功能性阻断已被证明可以显著抑制癌症的进展和转移，这表明通道阻断是一种有前景的癌症治疗新途径在以往的研究中，10,13利用rna干扰技术实现了Hv1在体内和体内的功能性阻断。我们首次提出研究Hv1小分子阻滞剂作为抗肿瘤治疗药物。为了合理设计对通道具有高亲和力的小分子，我们建立了Hv1的结构模型，该模型的分子动力学模拟得到的详细的原子结构/功能数据将解决Hv1如何能够感知电压和传导质子的问题，这将有助于建立通过电压传感域离子传导的基本原理。这些问题的答案将指导高亲和力Hv1阻滞剂的设计，这些阻滞剂将通过细胞增殖和迁移试验来评估其抑制癌症进展的治疗潜力。我们假设这些计算研究和体外实验将支持Hv1阻断作为抑制乳腺癌细胞的可行机制，并允许开发新的抗肿瘤药物。

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.