Inhibition of metastasis-initiating cells by chimeric polypeptide nanoparticles

摘要 只有不到10%的转移性肿瘤可以通过目前的治疗方法治愈，这一事实证明需要更多的治疗方法 治疗这些肿瘤的有效策略。这个项目的总体目标是开发一种纳米级的药物载体 改善癌症转移治疗的系统。这份K99/R00建议书的申请人最近设计了一个 新型多肽药物载体嵌合多肽(CP)在药物表面自组装成纳米粒子 结合，并表现出较长的循环半衰期和良好的肿瘤蓄积，与 免费的药品。候选人假设转移起始细胞(MICs)的侵袭行为可能是 利用负载抗MIC药物盐霉素(Sali)碱的CP基纳米粒给药 关于以下观察：(A)纳米级药物载体在肿瘤的血管周围区域积聚；(B) 作为转移的第一步，MICs通过血管周围空间迁移并侵入血管，并且 (C)MICs依赖局部细胞外基质(ECM)中强大的多肽酶活性来降解ECM 他们的迁徙。我们将利用这三个事实来设计一种纳米级的输送系统， 通过负载Sali的CP纳米颗粒靶向MICs。这项提议的总体假设是 通过以下三个目标进行测试：(1)Sali将与一系列不同组成的CP偶联， CP-Sali的理化性质和相对分子质量对其体内稳定性的系统影响 共轭；(2)连接触发的Cp-Sali共轭化合物自组装成直径小于100 nm 颗粒及其体内稳定性将被量化；(3)一种与侵袭相关的多肽底物 蛋白水解酶，基质金属蛋白酶2(MMP2)，将被整合到初级氨基酸序列中。 CP和由此产生的MMP2依赖的切割、细胞摄取、细胞毒性和转移- 将研究CP(MMP2)-SALi偶联物的抑制活性。拟议的药物载体系统将是 第一次利用MICs的移动性进行药物传递，这项研究可能会导致一种治疗癌症的新方法 转移瘤。候选人的总体职业目标是成为一名独立调查员，为 纳米技术与癌症治疗的接口。这一目标得到了应聘者出色的先前培训的支持 和研究效率。通过这一职业发展奖，候选人将：(1)获得额外的 在著名的阿舒托什·奇尔科蒂博士和马克·W·德惠斯特博士的指导下进行培训 分别在纳米技术和癌症治疗方面的研究人员；(2)与他的职业咨询密切互动 委员会，并在委员会的指导下完成职业转型；(3)开展研究 结果，这不仅是他申请未来癌症联邦资金的基础 纳米技术。这项研究与公共健康相关，因为它将导致一种创新的治疗方法 癌症转移的治疗策略。

Abstract Less than 10% of metastatic tumors are curable by current therapies, a fact that warrants the need for more effective strategies to treat these tumors. The overall goal of this project is to develop a nanoscale drug carrier system to improve therapy of cancer metastases. The applicant of this K99/R00 proposal recently designed a novel polypeptide drug carrier, chimeric polypeptides (CP), which self-assembles into nanoparticles upon drug conjugation, and which displays a long circulation half-life and good accumulation in tumors, as compared to free drug. The candidate hypothesizes that the invasive behaviors of metastasis-initiating cells (MICs) can be utilized for drug delivery using CP-based nanoparticles loaded with an anti-MIC drug, salinomycin (Sali) base on the following observations: (a) nanoscale drug carriers accumulate in the perivasuclar region of tumors; (b) MICs migrate through the perivascular space and invade a blood vessel as their first step in metastasis, and (c) MICs rely on potent peptidase activities in the local extracellular matrix (ECM) to degrade the ECM facilitate their migration. We will leverage these three facts to design a nanoscale delivery system that specifically targets MICs via a CP nanoparticle that is loaded with Sali. The overall hypothesis of this proposal will be tested by the following three aims: (1) Sali will be conjugated with a range of CPs with varied composition, physico-chemical properties and molecular weights to systematically vary the in vivo stability of the CP-Sali conjugate; (2) the attachment triggered self-assembly of the CP-Sali conjugates into sub-100 nm diameter particles and their in vivo stability will be quantified; (3) a peptide substrate of an invasion-associated proteinase, matrix metalloproteinase 2 (MMP2), will be incorporated into the primary amino acid sequence of the CP, and the resulting MMP2-dependent cleavage, cellular uptake, cytotoxicity, and the metastasis- inhibitory activity of CP(MMP2)-sali conjugates will be studied. The proposed drug carrier system will be the first to exploit the mobility of MICs for drug delivery, and the study may lead to a novel therapy for cancer metastases. The overall career goal of the candidate is to become an independent investigator contributing at the interface of nanotechnology and cancer therapy. This goal is backed by candidate's excellent prior training and research productivity. Through this career development award, the candidate will: (1) acquire additional training under the mentorship of Dr. Ashutosh Chilkoti and Dr. Mark W. Dewhirst, who are well-known investigators in nanotechnology and cancer therapy, respectively; (2) closely interact with his career advisory committee and accomplish career transition under the guidance of the committee; (3) produce research results, which serve not only as a foundation for him to apply for future federal funding on cancer nanotechnology. This research is relevant to public health because it will lead to an innovative therapeutic strategy for the treatment of cancer metastasis.