Circadian Rhythms in Blood Brain Barrier Permeability and Increased Efficacy of Chemotherapy for Brain Metastases

项目摘要 乳腺癌是一种毁灭性的疾病，每年影响大量女性；据估计，每8人中就有1人患有乳腺癌。 美国女性在一生中都会被诊断出患有这种疾病。五年存活率 对于被诊断为局部或区域性乳腺癌的女性来说，这一比例超过90%。然而，在场的人 脑转移的风险使五年存活率降至不到10%。脑部的化疗治疗 转移是具有挑战性的，与外围肿瘤相比，其结果较差，可能反映了 化疗不能跨越血脑屏障和/或血肿瘤屏障 有效率。最近的研究证明了血脑屏障通透性的昼夜调节；然而，还没有研究表明 检查化疗期间的时间改变是否可以提高治疗的疗效 脑转移瘤。该项目旨在利用昼夜节律控制血脑屏障通透性，通过优化 适时化疗，提高抗肿瘤疗效，减少脑部不良反应 转移瘤。具体地说，我假设血脑屏障外流转运体表达的昼夜节律控制 BBB/BTB对化疗药物通透性的波动。两种最常见的渗透性 治疗乳腺癌的处方化疗药物阿霉素(A)和紫杉醇(P)将通过以下方式进行评估 ~(14)C标记化疗药物的荧光粉放射自显影此外，药理学 将利用抑制和遗传方法(CRISPR)来确定类型和位置(BBB或BTB) 作为渗透性改变的基础的外排转运体。携带乳腺癌脑转移的小鼠将 每两周接受一次阿霉素/环磷酰胺或紫杉醇的静脉注射 血脑屏障通透性的峰值或低谷。抗肿瘤效果将通过生物发光和 免疫组织化学。化疗的不良行为影响将通过多个行为评估 任务和睡眠评估。我预测最佳的化疗时间会增强抗肿瘤作用。 有效并将不良副作用降至最低。事实上，初步数据表明，只改变时间 可使乳腺癌脑转移灶内的化疗剂量增加约 50%。因此，时序化疗代表了一种可行的新的治疗策略。总而言之，这些研究将 提供具有很高临床相关性的基本信息，以更好地治疗乳腺癌患者。 这个职业发展培训奖将使我成为一名独立的调查员，通过允许 培训新兴技术(即CRISPR和血脑屏障/血肿瘤屏障生物学)，专业人员 开发、赠款撰写、客座实验室培训、导师培训和高度集中的研究支持。帮助 为了实现我的目标，我组建了一个多学科的指导团队，他们在 昼夜节律生物学、癌症和神经科学领域。

Project Summary Breast cancer is a devastating disease that affects large numbers of women annually; it is estimated that 1 in 8 women in the United States will be diagnosed with this disease during their lifetime. The five-year survival rate for women diagnosed with localized or regional breast cancer is greater than 90 percent. However, the presence of brain metastases reduces five-year survival rates to less than 10 percent. Chemotherapy treatment of brain metastases is challenging and has yielded inferior results compared to tumors in the periphery, likely reflecting the inability of chemotherapy to cross the blood brain barrier (BBB) and/or blood tumor barrier (BTB) at efficacious rates. Recent studies demonstrate circadian regulation of BBB permeability; however no study has examined whether temporal alterations in chemotherapy administration can improve the efficacy of treatment of brain metastases. This project aims to take advantage of circadian control of BBB permeability by optimally timing chemotherapy administration to increase anti-tumor efficacy and reduce adverse side effects of brain metastases. Specifically, I hypothesize that circadian control of efflux transporter expression at the BBB underlies the fluctuations in BBB/BTB permeability to chemotherapeutic agents. Permeability of two of the most commonly prescribed chemotherapeutic drugs for breast cancer, doxorubicin (A) and paclitaxel (P), will be assessed via phosphor autoradiography imaging by using 14C labeled chemotherapeutic drugs. Additionally, pharmacological inhibition and genetic approaches (CRISPR) will be utilized to determine both the type and location (BBB or BTB) of efflux transporters that underlie altered permeability. Mice harboring brain metastases of breast cancer will receive intravenous injections of doxorubicin/cyclophosphamide cocktail or paclitaxel every 2 weeks during either the peak or trough of BBB permeability. Anti-tumor efficacy will be assessed via bioluminescence and immunohistochemistry. Adverse behavioral effects of chemotherapy will be assessed via multiple behavioral tasks and sleep assessment. I predict that optimal timing of chemotherapy administration will increase anti-tumor efficacy and minimizes adverse side effects. Indeed, preliminary data demonstrate that altering only the timing of injection increased the amount of chemotherapy within brain metastases of breast cancer by approximately 50%. Thus, chrono-chemotherapy represents a viable and novel treatment strategy. Together, these studies will provide essential information with a high potential for clinical relevance to better treat patients with breast cancer. This career development training award will enable me to become an independent investigator by allowing training in emerging techniques (i.e., CRISPR and blood-brain barrier/blood-tumor barrier biology), professional development, grant writing, guest lab training, mentor training, and highly focused research support. To help accomplish my goals, I have assembled a multidisciplinary mentoring team that has extensive expertise in the fields of circadian biology, cancer, and neuroscience.