Isolating circulating tumor cells using a centrifuge on a chip

描述(申请人提供)：下一代个性化抗癌治疗将越来越需要配套的诊断测试，以确定特定基因突变的存在，药物靶标是可用的。循环或其他体液中的癌症组织或播散性癌细胞将被要求进行这些检测。直接取自肿瘤的组织是理想的，因为它高度纯净，可以产生敏感的突变分析，但在某些情况下不能这样做，因为原发肿瘤可能已经切除，微转移灶太小而无法活检，或者肿瘤位于敏感的解剖位置附近，从而阻碍了安全的手术途径。在这种情况下，血液中存在的播散性肿瘤细胞可能非常有用，因为这是一个很容易获得的来源。在伴随诊断中使用血液细胞的一个主要问题是，在未经处理的样本中存在大量的白细胞背景；这些细胞阻止了计数，并压倒了罕见癌细胞的分子信号，因此必须去除才能进行准确的诊断。我们正在开发“芯片上的离心机”技术，以应对这一挑战，并从血液样本中浓缩稀有的循环癌细胞，使其达到高纯度。该设备创新性地利用高流体流速下的惯性流体物理来产生微尺度涡流，这些涡流选择性地、被动地分离较大的细胞，并将它们释放到芯片外的小体积流体中。我们已经用这个设备进行了一项初步研究，我们从晚期前列腺癌和膀胱癌患者中分离出可能的肿瘤细胞，这些细胞可以用于下游的分子分析。这项技术易于使用，比目前的微流控细胞分离技术快一个数量级。我们的目标是验证离心机芯片技术作为癌症分期的函数来计数循环中的肿瘤细胞，并评估用这种方法纯化的细胞是否产生更高质量的遗传和突变分析。最终，这样的设备可能会提供具有成本效益和快速的“液体活组织检查”样本，可用于下游的基因分析，以便更有效地个性化抗癌治疗。

DESCRIPTION (provided by applicant): The coming generation of personalized anti-cancer treatments will increasingly require companion diagnostic tests to ascertain the presence of specific genetic mutations for which drug targets are available. Cancer tissue or disseminated cancer cells in the circulation or other bodily fluids will be required to carry out these assays. Tissue directly from the tumor is ideal because it is highly pure and can yield sensitive mutational analyses, but this is not available in certain cases as the primary tumor may have already been resected, micrometastases are too small to biopsy, or tumor is present near sensitive anatomical sites thus preventing safe surgical access. In such cases, disseminated tumor cells present in the blood can be highly useful as this is an easily accessible source. A major problem with using cells from blood in companion diagnostics is the presence of a large background of white blood cells within unprocessed samples; these cells prevent the counting and overpower the molecular signal from rare cancer cells and must therefore be removed for accurate diagnosis. We are developing the "Centrifuge on a Chip" technology to address this challenge and enrich rare circulating cancer cells from blood samples to high purity. This device innovatively utilizes inertial fluid physics at high fluid flow rates to generate microscale vortics which size-selectively and passively isolate larger cells and releases them into a small volume of fluid off chip. We have conducted a pilot study with this device in which we have isolated putative tumor cells from patients with advanced malignancies of the prostate and bladder and these cells can be processed for downstream molecular assays. This technology is easy to use and an order of magnitude faster than current microfluidic cell separation technologies. We aim to validate the Centrifuge Chip technology to enumerate circulating tumor cells as a function of cancer stage and to evaluate whether cells purified with this approach yield higher quality genetic and mutational analyses. Ultimately, such a device may provide a cost-effective and rapid 'liquid biopsy' sample which can be utilized for downstream genetic analyses in order to more effectively personalize anti-cancer therapy.