PDAC-on-a-Chip for Selection of Aggressive, Therapy-Resistant Tumor Cells

描述(申请人提供)：手术切除是胰腺导管腺癌(PDAC)的唯一治疗方法，但对于已经转移的患者是禁忌。提高治愈率的选择包括更早地发现和/或有效地针对转移细胞群进行治疗。根据定义，所有转移性癌症必须能够逃离原发肿瘤部位，在循环系统内存活，并在次要部位种植和增殖。目前，体外系统不能充分模拟迁移细胞从肿瘤通过循环系统时所经历的微环境变化。该项目是一名癌症生物化学家和一名生物医学工程师的合作项目，目的是开发一种“PDAC-on-a-Chip”，重建肿瘤和循环环境中的氧气环境。因此，这种设备能够分离出需要作为治疗靶点的部分侵袭性肿瘤细胞。“肿瘤隔间”中的细胞将暴露在类似体内的慢性或间歇性低氧中，从而触发细胞的运动。可移动的细胞可以穿透凝胶屏障，进入血管内。 进入模拟肿瘤血管或淋巴系统的富含氧气的次级“循环室”。侵袭细胞所经历的氧气休克进一步选择了循环存活的细胞，很可能等同于体内观察到的循环中的肿瘤细胞。在转移性癌症中，这种循环细胞群也必须至少含有一种癌症干细胞。由于间歇性缺氧被认为是触发上皮-间充质转化的关键因素，而上皮-间充质转化与干细胞的产生/选择和治疗耐药有关，因此PDAC-on-a-Chip为分离干细胞丰富的群体提供了一种新的方法。据我们所知，这是唯一一个通过调节培养条件来选择/生成和收集相当于在实验中观察到的循环癌细胞群体的细胞的体外设备 活着。该设备将用于收集细胞，以无偏见地识别转移癌和胰腺癌干细胞的标志物。这些标志物的鉴定可用于筛选患者样本中的侵袭性PDAC，并最终为治疗开发提供靶点。在多重格式中，该设备还可用于筛选抗肿瘤和/或抗癌干细胞疗法。 公共卫生相关性：胰腺肿瘤中缺氧的存在与患者预后不良相关。该项目的重点是开发更好的肿瘤缺氧和转移的体外模型。这项新技术将改进细胞毒性和抗转移药物的筛选，帮助寻找新的治疗靶点，并有助于识别侵袭性癌症的相关生物标记物。总体目标是改善胰腺癌患者的治疗结果。

DESCRIPTION (provided by applicant): Surgical resection is the only curative therapy for pancreatic ductal adenocarcinoma (PDAC) but is contraindicated in patients in which the disease has metastasized. Options to improve curative rates include earlier detection and/or effective therapeutic targeting of the metastatic cell population. By definition, all metastatic cancers must be able to escape the primary tumor site, survive within the circulatory system and implant and proliferate in a secondary site. Currently, in vitro systems cannot adequately mimic the changing microenvironments a migrating cell experiences as it travels from the tumor and through the circulatory system. This project is a collaborative venture between a cancer biochemist and a biomedical engineer to develop a 'PDAC-on-a-chip' that recreates the oxygen environments found both in the tumor and circulatory environment. This device, therefore, is capable of isolating the fraction of aggressive tumor cells that needs to be targeted for therapy. Cells in the 'tumor compartment' will be exposed to in vivo-like chronic or intermittent, cycling hypoxia that triggers cell motility. The motile cells can penetrate a gel barrier and 'intravasate' into a secondary oxygen-rich 'circulatory compartment' that mimics the tumor blood vessel or lymphatic system. The oxygen shock experienced by invasive cells further selects for circulation-viable cells likely equivalent to the circulating tumor cells observed in vivo. In metastatic cancers, this circulating cell population must also contain at least one cancer stem cell. Since intermittent hypoxia has been proposed as a key player in triggering the epithelial-mesenchymal-transition that is involved with stem cell generation/selection and therapy resistance, the PDAC-on-a-chip offers a new way to isolate stem cell-enriched populations. As far as we are aware, this is the only in vitro device that modulates culture conditions to select/generate and collect cells equivalent to the circulating cancer cell populations observed in vivo. This device will be used to collect cells for the unbiased identification of markers of metastatic cancer and pancreatic cancer stem cells. Identification of these markers could be used to screen patient samples for aggressive PDAC and ultimately provide targets for therapy development. In multiplexed format, this device could also be used to screen for anti-metastic and/or anti-cancer stem cell therapies. PUBLIC HEALTH RELEVANCE: The presence of hypoxia in pancreatic tumors is correlated with poor patient outcome. The proposed project focuses on the development of better in vitro models of tumor hypoxia and metastasis. This new technology will improve the screening of cytotoxic and antimetastatic agents, help find new targets for therapy and aid in the identificatio of relevant biomarkers for aggressive cancer. The overall objective is to improve treatment outcome in pancreatic cancer patients.