Cancer Stem Cell Mechanotransduction in Engineered Matrix

PI：Jabbari，Esmaiel提案编号：1403545机构：南卡罗来纳大学哥伦比亚分校题目：工程基质中的癌症干细胞机械转导在不同的癌症中，乳腺癌是最常见的类型。癌症患者死亡率的一个主要因素是化疗后癌症复发。癌症复发影响30%的乳腺癌患者。最近的观察表明，癌症复发可能与肿瘤中生长缓慢的癌症干细胞(CSCs)数量非常少有关，这些细胞不受化疗的影响。化疗后，肿瘤的体积缩小到不到初始大小的几分之一，从而使肿瘤中充满了对传统疗法无效的肿瘤干细胞。浓缩的CSCs分裂、生长和再生肿瘤体积，导致癌症复发或复发。与这一概念一致的是，三重阴性乳腺癌(TNBC)是最具侵袭性的乳腺癌类型，其CSC亚群在不同类型的乳腺癌中最高，存活率为77%，而其他类型的存活率为93%。本项目更广泛的意义在于了解肿瘤环境中那些影响CSCs生存的因素的作用。发挥核心作用的因素之一是肿瘤组织的硬度。例如，乳房中感觉比其他组织更僵硬的肿块是可能患有乳腺癌的迹象，应该进行检查。该项目的目的是确定组织硬度对CSC在组织样三维基质中存活和生长的作用。该项目的重要性在于确定以组织僵硬为目标的新试剂以摧毁CSCs，并开发一种试剂盒来测试对抗癌症干细胞的药物。PI将利用几个项目来招收代表不足的学生，他将与南卡罗来纳州儿童博物馆合作，为儿童开发一个名为“水凝胶”的互动展览。这项建议由化学、生物工程、环境和运输系统部门的生物医学工程计划和材料研究部门的生物材料计划共同资助。癌症复发与极少数生长缓慢的癌症干细胞(CSC)有关，这些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-受体的相互作用，机械转导对维持CSC的CSC信号通路的影响尚不能被研究。这项工作的目的是设计一种具有特定性质的基质作为筛选和丰富CSCs的筛子，并研究基质硬度对维持CSCs的细胞内通路的影响。总的假设是，在没有受体-配体相互作用的情况下，基质刚性是YAP/TAZ的细胞外激活剂，通过GPCR/脂质筏/Rho/ROCK信号通路，导致CSC存活。进一步假设，在整合素结合配体存在的情况下，焦点黏附通过FAK/RAC信号通路和细胞外周应激纤维的形成而激活HIPPO，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。以下方法被用来检验这一假设。在目标1中，癌细胞将被包裹在新型丙交酯扩链聚乙二醇(SPELA)水凝胶中，并在添加多柔比星(Dox)和/或盐霉素(SAL)的培养基中培养，以在不断生长的CSC克隆中选择和丰富最具侵袭性的CSC表型。在目标2中，将丰富的CSC克隆包裹在SPELA水凝胶中，研究基质硬度对CSC通过GPCR/Lipoid Rofts/Rho/ROCK信号通路激活YAP/TAZ转录因子的影响。在目标3中，通过将丰富的CSC克隆包裹在具有最佳硬度的SPELA水凝胶中，研究共轭整合素结合配体对CSC激活Hippo信号通路的影响。这项工作的智力价值是一个模型工程培养系统，以筛选最有效的药物和针对最具侵袭性的CSC克隆的靶向配体。这项工作的更广泛的影响在于产生一种芯片上的癌症干细胞，作为一种在基础研究、药物发现和个性化医学中更具相关性的体外肿瘤模型。

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.