Cancer Stem Cell Mechanotransduction in Engineered Matrix

PI: Jabbari， Esmaiel提案号：1403545机构：University of South Carolina at columbia标题：Cancer Stem Cell Mechanotransduction in Engineered matrix在不同的癌症中，乳腺癌是最常见的类型。癌症患者死亡的一个主要因素是化疗后癌症复发。30%的乳腺癌患者会复发。最近的观察表明，癌症复发可能与肿瘤中不受化疗影响的少量生长缓慢的癌症干细胞（CSCs）有关。化疗后，肿瘤的大部分缩小到小于初始大小的百分之几，从而使肿瘤中充满了对常规治疗没有反应的CSCs。富集的CSCs分裂、生长、再生肿瘤体积，导致肿瘤复发或复发。与这一观点相一致的是，三阴性癌（TNBC）是最具侵袭性的乳腺癌类型，在不同类型的乳腺癌中，CSCs的亚群最高，存活率为77%，而其他类型的存活率为93%。该项目更广泛的意义在于了解肿瘤环境中这些因素对CSCs存活的影响。其中一个起中心作用的因素是肿瘤组织的硬度。例如，乳房中的肿块感觉比其他组织更硬，这可能是乳腺癌的征兆，应该进行检查。该项目的目的是确定组织刚度在组织样三维基质中对CSC存活和生长的作用。这个项目的重要性在于确定新的靶向组织硬度的药物来破坏CSCs，并开发一种试剂盒来测试针对癌症干细胞的药物。PI将使用几个项目来招募代表性不足的学生，他将与南卡罗来纳儿童博物馆合作，为孩子们开发一个名为“水凝胶”的互动展览。本提案由化学、生物工程、环境和运输系统部门的生物医学工程项目和材料研究部门的生物材料项目共同资助。癌症复发与一小部分生长缓慢的癌症干细胞（CSCs）有关，这些干细胞对传统疗法没有反应。自然衍生的基质被广泛用作研究CSC存活的基质，但由于许多配体-受体相互作用，机械转导对维持CSC的CSC信号通路的影响无法研究。这项工作的目的是设计一种具有特定特性的基质，作为筛选和富集CSCs的筛子，并研究基质刚度对维持CSCs的细胞内通路的影响。总体假设是，在没有受体-配体相互作用的情况下，基质刚度是通过GPCR/脂筏/Rho/ROCK信号通路激活YAP/TAZ的细胞外激活因子，导致CSC存活。进一步假设，在整合素结合配体存在的情况下，局灶黏附是Hippo的细胞外激活因子，通过FAK/Rac信号通路和细胞外周应激纤维的形成，导致LATS1/2激酶的表达，YAP/TAZ转录因子的抑制和CSC维持的丧失。下面的方法被用来检验假设。在Aim 1中，癌细胞将被封装在新型乳酸链延伸聚乙二醇（SPELA）水凝胶中，并在补充了阿霉素（Dox）和/或盐碱霉素（Sal）的培养基中培养，以在生长中的CSC菌落中选择和富集最具侵袭性的CSC表型。在Aim 2中，基质刚度对通过GPCR/脂筏/Rho/ROCK信号通路激活YAP/TAZ转录因子的影响将通过SPELA水凝胶封装富集的CSC菌落进行研究。在Aim 3中，我们将研究共轭整合素结合配体对CSC Hippo信号通路激活的影响，并将富集的CSC菌落包封在具有最佳刚度的SPELA水凝胶中。这项工作的智力价值是一个模型工程培养系统筛选最有效的药物和靶向配体对抗最具侵袭性的CSC菌落。这项工作的更广泛的影响在于在基础研究、药物发现和个性化医疗中产生癌症干细胞芯片，作为更相关的体外肿瘤模型。

PI: Jabbari, Esmaiel Proposal Number: 1403545Institution: University of South Carolina at ColumbiaTitle: Cancer Stem Cell Mechanotransduction in Engineered MatrixAmong different cancers, breast cancer is the most common type. A major contributing factor to mortality in cancer patients is the return of the cancer after chemotherapy. Cancer relapse affects 30% of breast cancer patients. Recent observations indicate that cancer relapse may be related to a very small population of slow-growing cancer stem cells (CSCs) in the tumor that are unaffected by chemotherapy. After chemotherapy, the bulk of the tumor shrinks to less than a few percent of the initial size, thus enriching the tumor with CSCs that do not respond to conventional therapies. The enriched CSCs divide, grow and regenerate the tumor volume, leading to cancer relapse or recurrence. Consistent with that notion, the triple negative cancer (TNBC), which is the most aggressive type of breast cancer, has the highest sub-population of CSCs among different breast cancer types with 77% survival rate, compared to 93% for other types, The broader significance of this project is understanding the role of those factors in the tumor environment that contribute the survival of CSCs. One of the factors that play a central role is the tumor tissue stiffness. For example, lumps in the breast that feel stiffer than the rest of the tissue are a sign of possible breast cancer that should be checked. The objective of this project was to determine the role of tissue stiffness on CSC survival and growth in a tissue-like three-dimensional matrix. The importance of this project lies in identifying new agents that target tissue stiffness to destroy CSCs and the development of a kit to test drugs against cancer stem cells. The PI will use several programs to recruit under-represented students and he will work with the South Carolina Children's museum to develop an interactive exhibit titled "hydrogels" for kids. This proposal is co-funded by the Biomedical Engineering Program in the Chemical, Bioengineering, Environmental and Transport Systems Division, and by the Biomaterials Program in the Division of Materials Research.Cancer relapse is related to a very small population of slow-growing cancer stem cells (CSCs) that do not respond to conventional therapies. Naturally derived matrices are widely used as a matrix to study CSC survival but due to many ligand-receptor interactions, the effect of mechanotransduction on CSC signaling pathways that maintain CSC cannot be investigated. The objective of this work is to engineer a matrix with defined properties to serve as a sieve for selection and enrichment of CSCs and to investigate the effect of matrix stiffness on intracellular pathways that maintain CSCs. The overall hypothesis is that in the absence of receptor-ligand interaction, matrix stiffness is the extracellular activator of YAP/TAZ through GPCR/lipid rafts/Rho/ROCK signaling pathway, leading to CSC survival. It is further hypothesized that in the presence of integrin-binding ligands, focal adhesion is the extracellular activator of Hippo through the FAK/Rac signaling pathway and stress fiber formation in the cell periphery, leading to the expression of LATS1/2 kinases, inhibition of YAP/TAZ transcription factors and loss of CSC maintenance. The following approach is used to test the hypothesis. In Aim 1, cancer cells will be encapsulated in the novel lactide-chain-extended polyethylene glycol (SPELA) hydrogel and cultured in a medium supplemented with Doxorubicin (Dox) and/or Salinomycin (Sal) to select and enrich for the most invasive CSC phenotype in the growing CSC colonies. In Aim 2, the effect of matrix stiffness on the activation of YAP/TAZ transcription factors through GPCR/lipid rafts/Rho/ROCK signaling pathway of CSC will be investigated with the enriched CSC colonies encapsulated in the SPELA hydrogel. And in Aim 3, the effect of conjugated integrin-binding ligands on the activation of Hippo signaling pathway of CSC will be investigated with the enriched CSC colonies encapsulated in the SPELA hydrogel with optimum stiffness. The intellectual merit of this work is a model engineered culture system to screen for the most effective drugs and targeting ligands against the most invasive CSC colonies. The broader impact of this work lies in generating a cancer stem cell-on-a-chip as a more relevant in vitro tumor model in basic research, drug discovery and personalized medicine.