Suppressing Radiotherapy-Induced Metastasis in Aggressive Breast Cancers via 'On-Demand' siRNA Delivery from Responsive Polymer Nanoparticles

项目总结。皮肤是最容易受到辐射损伤的器官。例如，γ-辐射， 通常用于放射治疗，诱导间质细胞因子的表达，如强大的转化生长因子β 能刺激皮肤转移的化学诱导剂。不幸的是，无法治疗辐射引起的 表型变化使皮肤转移成为一种致命的现象，与 炎症性乳腺癌(IBC)和其他致命疾病的生活质量较差。我们寻求发展专题 能够穿透皮肤并使辐射触发的适应不良信号正常化的siRNA递送剂 通过在辐射时释放siRNA“解毒剂”。这些纳米载体将代表一种强大的 平台技术在广泛的皮肤辐射疾病中具有广泛的相关性。 Sirna提供了巨大的治疗潜力，但它对肝脏以外的器官的输送造成了 技术挑战。我们建议在皮肤中通过融合两种新的递送方案来解决这个问题 前沿和互补性：(I)促进纳米载体的多肽和溶液修饰 转移到真皮基质中；和(Ii)刺激反应聚合物[mpeg-P(APNBMA)]，由我们的实验室设计， 将siRNA封装到纳米载体中，具有高度可调的性质和多种化学转变， 我们之前探索过使用光。光引发P(APNBMA)中邻硝基苄基(o-Nb)部分的裂解 侧链，导致聚合物电荷逆转和刺激反应基因沉默。我们有令人信服的 新的证据表明，mEg-P(APNBMA)中的o-Nb键在弱γ辐射下也发生断裂。 在这里，我们将利用皮肤中这一令人惊讶的分裂现象，来确定局部使用mpeg- P(APNBMA)纳米载体在γ辐射后释放小干扰RNA，从而抑制iBC皮肤转移。 目标1将开发具有这两种所需特性的siRNA纳米载体的局部配方： 经皮穿透真皮，γ辐射引发皮肤成纤维细胞小干扰核糖核酸释放。它还将 提供有关siRNA纳米载体分布和辐射触发的基因沉默的定量信息 皮肤的运动学。Aim 2将评估两个关于iBC转移的主要假设：(I)辐射诱导的转化生长因子β 皮肤成纤维细胞的激活触发了淋巴管IBC栓子上皮向间充质(EMT)的转变。 (Ii)使用辐射触发的按需抑制转化生长因子β SiRNA传递，提供了一种有效且成比例的策略来消除经皮肤的IBC传播。这一目标 将提供有关辐射副作用和IBC传播的新的基本信息，它将 建立临床前siRNA剂量方案，以抑制辐射诱导的间质转移。我们的团队 结合核酸输送(Sullivan)、聚合物材料(EPPS)、转移癌等领域的协同专业知识 生物学(Van Golen)和乳腺癌治疗(临床顾问Cristofanilli)。从长远来看，我们的工作 将培育与一系列辐射引起的皮肤病相关的新的添加剂治疗平台

PROJECT SUMMARY. Skin is the most susceptible organ to radiation damage. For example, γ-radiation, commonly used in radiotherapies, induces stromal expression of cytokines such as TGFβ, a powerful chemoattractant that can stimulate skin metastasis. Unfortunately, the inability to treat radiation-induced phenotypic changes has made cutaneous metastasis a deadly phenomenon that is correlated with extremely poor quality of life in inflammatory breast cancer (IBC) and other lethal diseases. We seek to develop topical siRNA delivery agents that can penetrate skin and normalize radiation-triggered maladaptive signaling by releasing siRNA ‘antidotes’ when radiation is applied. These nanocarriers would represent a powerful platform technology with broad relevance in a wide array of skin-based radiation disorders. siRNA offers enormous potential as a therapeutic, yet its delivery to organs other than the liver poses a technological challenge. We propose to address this issue in skin by fusing two nascent delivery schemes with cutting-edge and complementary properties: (i) peptide and solution modifications that facilitate nanocarrier transit into dermal stroma; and (ii) stimulus-responsive polymers [mPEG-P(APNBMA)], designed in our labs, that encapsulate siRNA into nanocarriers with highly tunable properties and a versatile chemical transition that we previously explored using light. Light triggers cleavage of o-nitrobenzyl (o-NB) moieties in the P(APNBMA) side chains, leading to polymer charge reversal and stimulus-responsive gene silencing. We have compelling new evidence that the o-NB bonds in mPEG-P(APNBMA) also cleave in response to mild γ-radiation. Herein, we will exploit this surprising cleavage phenomenon in skin, to determine whether topical mPEG- P(APNBMA) nanocarriers release siRNA in response to γ-radiation and thereby halt IBC skin metastasis. Aim 1 will develop topical formulations of siRNA nanocarriers with both of the desired properties: transcutaneous penetration into dermis, and γ-radiation-triggered siRNA release in skin fibroblasts. It also will provide quantitative information regarding siRNA nanocarrier distribution and radiation-triggered gene silencing kinetics in skin. Aim 2 will evaluate two governing hypotheses in IBC metastasis: (i) Radiation-induced TGFβ activation in skin fibroblasts triggers the epithelial-to-mesenchymal (EMT) transition in lymphatic IBC emboli, leading to IBC invasion and growth in skin; and (ii) On-demand suppression of TGFβ, using radiation-triggered siRNA delivery, provides a potent and proportional strategy to eliminate cutaneous IBC dissemination. This aim will provide new fundamental information regarding radiation side effects and IBC dissemination, and it will establish preclinical siRNA dose regimens that will suppress radiation-induced metastasis in stroma. Our team combines synergistic expertise in nucleic acid delivery (Sullivan), polymer materials (Epps), metastatic cancer biology (van Golen), and breast cancer treatment (clinical consultant Cristofanilli). In the long-term, our work will foster new additive therapy platforms relevant to a spectrum of radiation-induced skin diseases