Mechanisms of Action for KCN1 in the Control of Uveal Melanoma Metastasis

眼部黑色素瘤是最常见的原发性眼癌。虽然原发肿瘤位于 眼睛可以控制，频繁的癌症扩散到肝脏会导致显著的死亡率。那里 目前还没有有效的治疗肝脏转移性眼部黑色素瘤的方法。在 疾病的早期/转移前阶段，低氧诱导局部表达 眼肿瘤中的趋化因子/生长因子受体，呈现单个黑色素瘤细胞 基质衍生因子(SDF)和基质衍生因子(SDF)响应各自旁分泌配体的激活 肝细胞生长因子(HGF)在肝脏中产生。在渗入血液循环后 这些细胞位于肝脏，在那里它们最初形成微转移灶，然后进展到 休眠的无血管殖民地。在疾病晚期，血管生成开关导致 形成大的肝脏大转移，导致病人死亡。我们发现 并表征了新型小分子芳基磺酰胺类化合物(AsAs)的抗肿瘤性能， 并获得了令人兴奋的初步数据，证明了我们的先导分子KCN1可以 有效地抑制原发肿瘤的生长，以及肝细胞癌的建立和发展 我们建立的小鼠原位葡萄膜黑色素瘤转移模型。我们假设 KCN1改变CXCR4/SDF和cMET/HGF介导的促肿瘤信号转导 启动转移，阻断参与肝脏早期进展的STAT3信号和血管内皮生长因子 促血管生成信号导致大转移，因为缺氧诱导因子 (HIF)可以调节这些过程，KCN1可以阻断HIF的转录。我们的目标是 建议从不同的角度定义KCN1抗肿瘤作用的机制(S 疾病发展的各个阶段。我们将确定KCN1是否抑制1)外渗 和原发葡萄膜黑色素瘤细胞进入循环并归巢到肝脏的存活 (目标1)，II)微转移灶向无血管性黑色素瘤细胞集落的进展 肝脏(目标2)，以及III)无血管黑色素瘤微转移集落进展为 通过阻断微转移诱导的血管生成在肝脏中的大转移(目标3)。我们的 初步发现支持我们的工作假设，因为我们证明了KCN1抑制cMET 细胞表面受体激活、STAT3磷酸化与血管内皮生长因子介导的肿瘤 体内血管生成。这项工作很重要，因为它将更好地定义葡萄膜的机制 黑色素瘤转移，找出治疗靶点，帮助小转移 我们确定的分子有望成为控制转移的新型治疗药物 葡萄膜黑色素瘤。

Ocular melanoma is the most common primary eye cancer. Although the primary tumor in the eye can be controlled, frequent cancer spread to the liver results in significant mortality. There are currently no effective treatments for metastastic ocular melanoma in the liver. In the early/pre-metastatic stage of the disease, hypoxia induces the focal expression of chemokine/growth factor receptors in the eye tumor, rendering single melanoma cells responsive to activation by their respective paracrine ligands, stromal derived factor (SDF) and hepatocyte growth factor (HGF) produced in the liver. After extravasation into the circulation these cells home to the liver where they initially form micrometastatic foci that progress to dormant avascular colonies. In the late disease stage, an angiogenic switch leads to the formation of large hepatic macrometastases, which cause patient demise. We have discovered and characterized the anti-tumor properties of novel small molecule arylsulfonamides (ASAs), and obtained exciting preliminary data demonstrating that KCN1, our lead molecule, can potently decrease primary tumor growth, and the establishment and progression of hepatic metastases of uveal melanoma in an orthotopic mouse model we developed. We hypothesize that KCN1 alters the pro-tumorigenic signaling mediated by CXCR4/SDF and cMet/HGF that initiates metastasis, blocks STAT3 signaling involved in early progression in the liver and VEGF pro-angiogenic signaling that leads to macrometastasis, because Hypoxia Inducible Factor (HIF) can regulate these processes and KCN1 blocks HIF transcription. The goal of our proposal is to define the mechanism(s) underlying the anti-tumor effect of KCN1 at the different stages of disease progression. We will determine whether KCN1 inhibits i) the extravasation and survival of primary uveal melanoma cells into the circulation, and their homing to the liver (Aim 1), ii) the progression of micrometastatic foci to avascular melanoma cell colonies in the liver (Aim 2), and iii) the progression of avascular melanoma micrometastatic colonies to macrometastases in the liver by blocking micrometastases-induced angiogenesis (Aim 3). Our preliminary findings support our working hypothesis, as we demonstrate that KCN1 inhibits cMet cell surface receptor activation, STAT3 phosphorylation, and VEGF-mediated tumor angiogenesis in vivo. This work is important as it will better define the mechanisms of uveal melanoma metastases, identify therapeutic targeting points, and help the translation of the small molecules we identified towards becoming novel therapeutic agents for the control of metastasis of uveal melanoma.