Acoustic Droplet Initiated Radiosensitivity of Hepatocellular Carcinoma

项目摘要 肝细胞癌（HCC）是全球范围内第三大癌症死亡原因，并且是增长最快的 恶性肿瘤在美国。放射性栓塞术或体外放射治疗是常用的方法 用于HCC治疗。然而，这两种技术的治疗反应仅为25-89%。 这取决于所用的评估标准和大约13个月的无进展生存期。因此，委员会认为， 非常需要用于HCC放射增敏的其它策略。超声造影是一种很好的- 已建立的HCC成像技术，并采用超声敏感微泡更好地显示肿瘤 血管分布超声触发的微泡破坏（UTMD）和纳米泡破坏已被证明 通过诱导血管内皮细胞凋亡和增加神经酰胺， 生产我们的团队已经证明了使用UTMD进行治疗的可行性、安全性和初步疗效 在动物模型和最近的随机临床试验中，HCC对放疗敏感。但我们 我认为这些生物效应的大小受到UCA大小（直径1-8微米）的限制，这限制了它们的生物学效应。 这可以防止外渗到肿瘤组织中并限制在空化期间产生的剪切力。一个有吸引力 UCA的替代品是声学液滴，它由封装在上面的液体全氟化碳组成。 他们的沸点这些试剂的较小尺寸（< 200 nm）和相对于纳米气泡的稳定性允许 与超声敏感气泡相比，更大程度地渗透到肿瘤组织中。声学液滴可以 使用诊断超声设备局部汽化和破坏，从而产生更大的局部力 对周围组织的影响比UTMD更大。因此，本提案将研究使用 声学液滴，以提高HCC相对于UCA的放射敏感性。两种特定的液滴制剂将在 使用，优先考虑有效的临床翻译或体内液滴稳定性。在目标1中，我们将描述声学特征 通过商业批准的UCA的冷凝和通过磷脂的台式制造制成的液滴， 包被的全氟丁烷液滴，并评估其启动神经酰胺产生，细胞凋亡， 体外超声触发后相对于微米和纳米气泡的放射敏感性。目标2将评估 两种声学液滴制剂产生神经酰胺产生和血管破坏的能力相对于 在皮下HCC同基因模型中的微泡和纳米泡，以及探索对肿瘤的影响。 免疫反应最后，aim 3将评估两种声学液滴配方的潜在改进 相对于超声敏感的气泡，在人HCC的原位模型中用作放射增敏剂。在 这项工作的结论，我们将评估的机制和潜在的治疗优势， 使用声学液滴汽化用于HCC放射增敏。这些方法在临床上是可转化的， 可能最终通过改善放疗反应来提高HCC患者的生存率。

Project Summary Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide and the fastest growing malignancy in the United States. The use of radioembolization or external beam radiation are frequently used for HCC treatment. However, both these techniques demonstrate a treatment response of only 25-89% depending on the evaluation criteria used and progression free survival of roughly 13 months. Consequently, additional strategies for HCC radiosensitization are greatly needed. Contrast-enhanced ultrasound is a well- established technique for HCC imaging and employs ultrasound-sensitive microbubbles to better visualize tumor vascularity. Ultrasound-triggered microbubble destruction (UTMD) and nanobubble destruction has been shown to sensitize tumors to radiotherapy by inducing vascular endothelial cell apoptosis and increasing ceramide production. Our group has demonstrated the feasibility, safety, and preliminary efficacy of using UTMD for sensitizing HCC to radiotherapy in animal models and, more recently, in a randomized clinical trial. However, we believe the magnitude of these bioeffects is limited by the size of UCAs (1-8 µm in diameter), which restricts their extravasation into the tumor tissue and limits the shear forces generated during cavitation. One attractive alternative to UCAs is acoustic droplets, which are composed of liquid perfluorocarbons encapsulated above their boiling point. The smaller size of these agents (< 200 nm) and stability relative to nanobubbles permits greater penetration into the tumor interstitium compared to ultrasound-sensitive bubbles. Acoustic droplets can be locally vaporized and destroyed using diagnostic ultrasound equipment, thereby generating larger local forces on the surrounding tissue than can be achieved with UTMD. Consequently, this proposal will investigate the use of acoustic droplets to improve HCC radiosensitivity relative to UCA. Two specific droplet formulations will be used, prioritizing either efficient clinical translation or droplet stability in vivo. In aim 1 we will characterize acoustic droplets made via condensation of a commercially approved UCA and by benchtop fabrication of phospholipid- coated perfluorobutane droplets, and evaluate their ability to initiate ceramide production, cellular apoptosis, and radiosensitivity relative to micro- and nanobubbles following ultrasound-triggering in vitro. Aim 2 will evaluate the ability of the two acoustic droplet formulations to generate ceramide production and vascular disruption relative to micro- and nanobubbles in a subcutaneous syngeneic model of HCC as well as explore the effects on tumor immune response. Finally, aim 3 will assess the potential improvement of the two acoustic droplet formulations relative to ultrasound-sensitive gas bubbles to act as a radiosensitizer in an orthotopic model of human HCC. At the conclusion of this work, we will have evaluated the mechanisms and potential therapeutic advantages of using acoustic droplet vaporization for HCC radiosensitization. These approaches are clinically translatable and may ultimately improve HCC patient survival by improving radiotherapy response.